Time to fit new brakes soon some help pls :-)
Discussion
Hello all I have searched most of the old threads regarding what disks, calipers etc to use as upgrades but most of you guys who have done the work have larger wheels, hence bigger new kits where fitted. So thought I better check here first.
I am wanting to replace both fronts and rears but know that I am limited to what I can fit with only 15's on the front and 16's rear. Am I best to wait and get bigger wheels before an upgrade? or have any of you guys done a make over that you are happy with and can do the odd track day without too much fade.
If I can do an upgrade do any of you have the complete parts list I would have to buy, just so I can get some local prices and start spending. That would help me alot.
Many thanks
Kylie 89Esp Turbo
I am wanting to replace both fronts and rears but know that I am limited to what I can fit with only 15's on the front and 16's rear. Am I best to wait and get bigger wheels before an upgrade? or have any of you guys done a make over that you are happy with and can do the odd track day without too much fade.
If I can do an upgrade do any of you have the complete parts list I would have to buy, just so I can get some local prices and start spending. That would help me alot.
Many thanks
Kylie 89Esp Turbo
Kylie - I was going to do a complete brake upgrade to the AP's on my '98 but was advised by L. Marcella on the TurboEsprit list (Larry's an SCCA racer) to just try different pads. I purchased and installed (actually Karl installed them for me - thanks!) the Porterfield R4s pads and it accomplished what I was looking for - better "bite".
Just thought that you might want to try that before spending a lot of money...
ErnestM
Just thought that you might want to try that before spending a lot of money...
ErnestM
Kylie -try posting on the uk yahoo group. I know several of the guys with the toyota setup (which i think yours has?) who have tried different things with varying degrees of success. There are disc/pad upgrades (EBC i think was one name mentioned).
I found my brembo v8 was better with porterfields compared to the stock pad, but even better still with pagids. Only downside with pagids is the increased noise (squeal) but you can minimise this with the use of copious quantities of copperslip apparently.
As has been said - always try some pad options first before spending significant money.
I've just bought a full sport 350 brake setup which is going on my car in the next few weeks - big AP calipers and bigger/thicker discs all round - as a result my brembo calipers will be available... might be expensive to ship to you though
I found my brembo v8 was better with porterfields compared to the stock pad, but even better still with pagids. Only downside with pagids is the increased noise (squeal) but you can minimise this with the use of copious quantities of copperslip apparently.
As has been said - always try some pad options first before spending significant money.
I've just bought a full sport 350 brake setup which is going on my car in the next few weeks - big AP calipers and bigger/thicker discs all round - as a result my brembo calipers will be available... might be expensive to ship to you though
Kylie try this link
www.pnmengineering.com or +44 151 630 6101 and ask for Pete.
His kit is based around a standard wheel. Uses Hi-Spec 4 pot Calipers (in gold or black), slotted 285mm discs, stainless steel braided hoses, brackets and fixings for £590 Inc VAT. I don't know what the exchange rate is in New Zealand but Us dollars is about $975 Us dollars.
If you do speak to Pete then give me a mention as Iam always in there every other day!!
I have another one or two cheaper options using a used 4 pots caliper but need to do some work on it.
Iam not sure that putting EBC Green stuff will help with our single pot calipers. I think they will cause brake judder. You may have to go to Red/Black stuff, I forget which one but they recommend them for BMW's with single pot calipers.
Hope this helps,
Dave Walters
www.pnmengineering.com or +44 151 630 6101 and ask for Pete.
His kit is based around a standard wheel. Uses Hi-Spec 4 pot Calipers (in gold or black), slotted 285mm discs, stainless steel braided hoses, brackets and fixings for £590 Inc VAT. I don't know what the exchange rate is in New Zealand but Us dollars is about $975 Us dollars.
If you do speak to Pete then give me a mention as Iam always in there every other day!!
I have another one or two cheaper options using a used 4 pots caliper but need to do some work on it.
Iam not sure that putting EBC Green stuff will help with our single pot calipers. I think they will cause brake judder. You may have to go to Red/Black stuff, I forget which one but they recommend them for BMW's with single pot calipers.
Hope this helps,
Dave Walters
Kylie,
As previously mentioned, there is little benefit to be derived from upgrading the brake hardware. Exotic rotors and multi-pot calipers will not eleviate the fundamental problem inherent in these cars' braking systems, namely lack of proper cooling due to poor airflow to the brakes.
It all boils down to physics really. Stored Chemical energy (fuel) is converted to mechanical energy (Engine) which is converted to Kinetic energy (Mass of the car/momentum), braking requires this energy to be dissapated. The Brakes convert this Kinetic energy to Infra-Red energy (heat) to allow this energy to leave the system (from the car to the atmosphere). Once the energy level has dropped below that which is acting against the car (Friction and Drag), the car slows and stops. The problem with adding exotic rotors and multi-pot calipers is that they do little to enhance this energy transfer. The energy remains in the system due to lack of cooling airflow. The first thing any serious Esprit racer does is to fabricate and install brake cooling ducts.
Since these brakes operate in a less than ideal temperature environment, much more benefit is to be had by simply switching to higher temp compounds in the pads which is both cost and benefit efficient. It's doubtful that you'll appreciably decrease your stopping distance, but the higher heat compounds in the pads allow you to stay in the game longer before they succumb to the heat giving you greater confidence and longer braking efficiency.
One positive benefit can be rebuilding your calipers and master cylinder as well as adding SS Brakelines to insure the system you do have is operating in top form. Be aware that the SS brakelines can lead to slightly easier lockup as they transfer the pedal pressure to the calipers in a much more positive way, but this merely takes acclimation on your part. Personally, I like the more positive feel. Also, annual Brake Bleeding (or at least prior to any Track events)will reduce the potential for fluid boil and extend the life of the hardware itself by regularly expelling the moisture from the system. Hope this helps. Happy Motoring!...Jim'85TE
As previously mentioned, there is little benefit to be derived from upgrading the brake hardware. Exotic rotors and multi-pot calipers will not eleviate the fundamental problem inherent in these cars' braking systems, namely lack of proper cooling due to poor airflow to the brakes.
It all boils down to physics really. Stored Chemical energy (fuel) is converted to mechanical energy (Engine) which is converted to Kinetic energy (Mass of the car/momentum), braking requires this energy to be dissapated. The Brakes convert this Kinetic energy to Infra-Red energy (heat) to allow this energy to leave the system (from the car to the atmosphere). Once the energy level has dropped below that which is acting against the car (Friction and Drag), the car slows and stops. The problem with adding exotic rotors and multi-pot calipers is that they do little to enhance this energy transfer. The energy remains in the system due to lack of cooling airflow. The first thing any serious Esprit racer does is to fabricate and install brake cooling ducts.
Since these brakes operate in a less than ideal temperature environment, much more benefit is to be had by simply switching to higher temp compounds in the pads which is both cost and benefit efficient. It's doubtful that you'll appreciably decrease your stopping distance, but the higher heat compounds in the pads allow you to stay in the game longer before they succumb to the heat giving you greater confidence and longer braking efficiency.
One positive benefit can be rebuilding your calipers and master cylinder as well as adding SS Brakelines to insure the system you do have is operating in top form. Be aware that the SS brakelines can lead to slightly easier lockup as they transfer the pedal pressure to the calipers in a much more positive way, but this merely takes acclimation on your part. Personally, I like the more positive feel. Also, annual Brake Bleeding (or at least prior to any Track events)will reduce the potential for fluid boil and extend the life of the hardware itself by regularly expelling the moisture from the system. Hope this helps. Happy Motoring!...Jim'85TE
Jim,
Your points are all very true. I think stopping power though is increased with a larger disc. Also I think why these brake upgrades are popular is because there are more pad options and the pads are generally bigger than our stock pads.
If you try to stop something towards it's hub, it's harder to do so than further away toward the rim isn't it?
How do single piston calipers cope when they have to rely on pushing upto a back plate. Surely a twin or 4 piston caliper with piston pushing from both sides would be better?
BTW these are genuine questions and Iam not trying to undermine your expertise in these matters.
Iam trying to understand myself and Iam learning every day. Braking improvement is on my agenda and need to fully understand before wasting my money.
Your points are all very true. I think stopping power though is increased with a larger disc. Also I think why these brake upgrades are popular is because there are more pad options and the pads are generally bigger than our stock pads.
If you try to stop something towards it's hub, it's harder to do so than further away toward the rim isn't it?
How do single piston calipers cope when they have to rely on pushing upto a back plate. Surely a twin or 4 piston caliper with piston pushing from both sides would be better?
BTW these are genuine questions and Iam not trying to undermine your expertise in these matters.
Iam trying to understand myself and Iam learning every day. Braking improvement is on my agenda and need to fully understand before wasting my money.
Here's Larry's page on brake pads and such in case anyone is interested:
http://home.earthlink.net/~lmarsala/Products.htm
ErnestM
http://home.earthlink.net/~lmarsala/Products.htm
ErnestM
ErnestM said:
Kylie - I was going to do a complete brake upgrade to the AP's on my '98 but was advised by L. Marcella on the TurboEsprit list (Larry's an SCCA racer) to just try different pads. I purchased and installed (actually Karl installed them for me - thanks!) the Porterfield R4s pads and it accomplished what I was looking for - better "bite".
Just thought that you might want to try that before spending a lot of money...
ErnestM
Thanks Ernest, I guess your a bit better off than myself with your car already having excellent brakes to tinker with, like Dave said we just have small single piston calipers. I was however advised to buy green EBC pads which we put in over a month ago but with very little improvements. I am taking the car in over the weekend to get the garage have a closer look and make sure its not a leaky pump or bad fluids etc.
rob.e said:Thanks Rob I will drop a post there too, shipping no worries, the other half buys in over 20 containers worth of goods for his business from all over the world so am sure I could sort something
Kylie -try posting on the uk yahoo group. I know several of the guys with the toyota setup (which i think yours has?) who have tried different things with varying degrees of success. There are disc/pad upgrades (EBC i think was one name mentioned).
I found my brembo v8 was better with porterfields compared to the stock pad, but even better still with pagids. Only downside with pagids is the increased noise (squeal) but you can minimise this with the use of copious quantities of copperslip apparently.
As has been said - always try some pad options first before spending significant money.
I've just bought a full sport 350 brake setup which is going on my car in the next few weeks - big AP calipers and bigger/thicker discs all round - as a result my brembo calipers will be available... might be expensive to ship to you though
Will send you an email too.
I've just bought a S300 front bumper with loose side spats. I won't be putting fogs in as I want to make mine look like a S300. Will do the same as you Mark with the ducting.
I have left the side spats off for the time being until I decided to put wheel arch extensions on.
BTW, Mark, have you got a new car now, did you get the insurance sorted?
cheers,
Dave Walters
I have left the side spats off for the time being until I decided to put wheel arch extensions on.
BTW, Mark, have you got a new car now, did you get the insurance sorted?
cheers,
Dave Walters
Hi an update, took my car in to the shop to ensure that the brakes were working well, it seems the disks are slightly glazed and the one of the rears needs replacing soon. It was recommended some nice Wilwood 4 pistons calipers as an upgrade, my standard disks will be fine. So hopefully I will get this sorted over the next month.
Cheers
Kylie
Cheers
Kylie
Hey Kylie,
There is no question that the Wilwoods are far superior setup than the factory. I purchased a kit that included calipars, discs, hats, mounting brackets, and ss lines from Claudius at Lotus PBC in Ceritos California. The rotors are 11.8 inches and fit inside the factory 15 wheel. You can see them at lotusespritworld.com on the owners page under John C. Anderson. I've had them on the car for over a year now and they have provided very consistant braking from the track to daily driving. On the track, fade is very minimal and left/right bias seems non-exhistant. I'm surprised no one has stated it yet but the factory calipars and rotors are not designed for track use. There designed for street applications. They are a very stout setup, no question, and work well with quality rotors and pads but they are not designed for track use. If you are conservative on the track then the factory brakes will probably give you what you need. If you like to push yourself and the car or are considering entering a few races then upgrading these components is the way to go.
John
There is no question that the Wilwoods are far superior setup than the factory. I purchased a kit that included calipars, discs, hats, mounting brackets, and ss lines from Claudius at Lotus PBC in Ceritos California. The rotors are 11.8 inches and fit inside the factory 15 wheel. You can see them at lotusespritworld.com on the owners page under John C. Anderson. I've had them on the car for over a year now and they have provided very consistant braking from the track to daily driving. On the track, fade is very minimal and left/right bias seems non-exhistant. I'm surprised no one has stated it yet but the factory calipars and rotors are not designed for track use. There designed for street applications. They are a very stout setup, no question, and work well with quality rotors and pads but they are not designed for track use. If you are conservative on the track then the factory brakes will probably give you what you need. If you like to push yourself and the car or are considering entering a few races then upgrading these components is the way to go.
John
Hi John, I had a peep at your site just the other day and I got to say its sparking!! I can't can't beleive how much time and energy you had to restore all those parts, they look great. I gone in to have another look at your brakes and and they do look sharp. The disks you purchased are slightly larger I take it?
Theres some pragmatic info on brake upgrades here
www.0800brakes.co.nz/pg8.htm
For road use I suspect higher spec fluids, pads and a complete overhaul is probably all thats required - track use is something completely different. Getting a good pad/disc combo is probably the key.
Keep in mind you may need a COF for a new brake system in NZ - might need to be careful who does the WOF.
www.0800brakes.co.nz/pg8.htm
For road use I suspect higher spec fluids, pads and a complete overhaul is probably all thats required - track use is something completely different. Getting a good pad/disc combo is probably the key.
Keep in mind you may need a COF for a new brake system in NZ - might need to be careful who does the WOF.
Hi those of you who have Wilwood calipers without dust seals is that too much of a problem? Some reading material says that you need to replace them every two years, but that must be for high miler cars? Just that I can get some American Wilwood superlite calipers locally for $288.00 NZD + gst each and thought that was a good price.
Hey there, I've remember someone else mentioning this as a potential problem but I have yet to have any problems with it. Nor have I spoken to anyone who has experienced it. Try giving Wilwood a call, their tech support is very good with issues like this. I'm sure that they would have addressed the issue if it were a serious problem.
John
John
Hi guys, arrrrh now totally confused 
I went to see a guy yesterday who pretty much knows his stuff about brake set-ups esp for what I am trying to acheive. I asked him about his Wilwoods set-up and he showed me the size of wilwoods pad v's the size of the toyota one that I have. Well to me the Toyota shape looked ever so slightly larger. He said my green EBC pads were just marketing hipe and no wonder I am having trouble, a much more meaty pad will have the same braking power as the wilwoods, but depends on how long I want my rotors to last. In my case should last ages due to low miles. He just said upgrade your fluids and put a meaty pad in there and you will be sorted. I said well I must have new slotted rotors then?, he only if you want to improve your braking by a one tenths of a second as thats the time to rid of any gases. So I said but glazing up of pads? He said yeah if that concerns you then slotted rotors will do the trick. So many options out there.
Here is some refresher reading that you guys might be interested in, sorry its a lot, might be best to copy and paste into word to read it better.
BRAKE UPGRADE INFORMATION & PRICE LIST
Thankfully most of us these days realize that there is a lot more to preparing a competitive car than providing it with endless reserves of horsepower and torque. What a lot of people don’t realize are the performance and safety gains that can be made to the vehicle by inexpensively speccing up their existing road brake system with proper race compounds and fluids. This does not mean using road oriented metallic or kevlar pads or “DOT 5” fluid. Although these will be better than a set of standard cardboard pads, they really should not be let anywhere near a race car or track
.
RACEBRAKES 0800BRAKES, as well as supplying race calipers and race rotors, also specialize in setting up race brake systems for competitors on a budget or where the rules of a race control class prohibit the use of anything other than the standard original equipment foundation brake system. The GT and Production Muscle Car class (500+hp, 16-1700kg, 270kph) and the HQ’s being examples of these.
Most standard brake systems, once equipped to handle the heat generated under racing conditions, are more than adequate for events like the Dunlop Targa and other club racing duties.
If we think of the brake system as a chain that is only as strong as its weakest link, and heat as its enemy, we find that the weakest link in a road brake system is the friction materials. A good quality standard road compound will have a maximum c.w.t (continuous working temperature) of around 300 degrees C. An Aussie V8 Supercar generates around 650 degrees C at the end of Conrod. What we need to do is put proper race compounds into our road calipers, as the smaller road brake system is not as good at dissipating heat as the larger brake systems and can generate temperatures equivalent to larger race cars.
The problem you may come across when looking for proper race compounds for your road calipers is that the manufacturers of the race compounds will generally only manufacture pads for recognized race calipers 6--=\gh that someone (like Ken Williams) wants to take one racing.
RACEBRAKES 0800BRAKES are able to supply or manufacture race pads for any type of caliper with race compounds that will handle temperatures of at least 700 degrees C. Some compounds will handle much more. These compounds perform from dead cold and make a blindingly good street pad regardless of their racing abilities. Don’t panic if your vehicle is equipped with drum brakes as we carry a German Pagid drum brake compound for these applications. We even have the old Ferodo DS11 compound available if you wanted to spec up your GT Falcon, Monaro, Charger or Torana for authenticity’s sake to the Bathurst compounds of the sixties and seventies. This material, for you aficionados out there, “was introduced in the late fifties and was almost universally used in Formula One right up until cast iron discs were superseded by carbonfibre reinforced carbon (carbon-carbon) discs and pads in the eighties. According to Federal-Mogul’s records (Ferodo Racing’s parent company), between 1961 and 1981, 265 of 267 Grand Prix victories were scored using DS11 pads”. (Article entitled From DS11 to DS3000 by Ian Bamsey, Racetech magazine) Two decades of dominance. Let’s see if Ferrari or HRT can match that.
Interestingly enough, speaking of dominance, Ferodo’s replacement for the DS11 compound called DS3000 was used by every manufacturer except Mitsubishi (who we believe used Raybestos) in the 2002 World Rally Championship (and no, it is not a control pad). DS3000, of course, was used by Peugeot to win Rally of New Zealand 2003. Mark Skaife and HRT used it for their 2001 & 2002 Australian V8 Supercar titles and other recent local success by DS3000 includes 1st Superpole, Yellow Pages 500, October 2002, 1st overall Dunlop Targa 2002 and 1st overall NZ V8 Tourer Championship 2003.
For the record, Ferodo’s DS11 compound had a coefficient of friction (which denotes how “grabby” a disc pad is) or mu rating of .31. Low by today’s standards compared with DS3000 Plus at .68. A metallic road pad, (not to be confused with carbon metallics), which most of you have used before, also has a low coefficient of friction rating, again of around .3. This lack of power in a road metallic pad and DS11’s poor cold performance do NOT make them desirable as modern race compounds.
DS11 did however have a “recommended maximum temperature of 750 degrees C but is commonly used at temperatures in excess of 1000 degrees C” (Ferodo International Technical News F16, July 1980). Impressive numbers sure, (a Bendix Metal King Plus has a maximum c.w.t of 400 degrees C) but if your brake assembly is being asked to cope with those sorts of temperatures, you are going to be having extra problems over and above brake fade.
Compare Mintex’s new M1177 material at .61 (dropping off a little after 500 degrees C but still holding a massive .55 c.o.f at 700 degrees C), Mintex M1166 sprint compound at .47, Mintex M1155 targa/endurance compound at .43 and Mintex M1144 (Formula Ford compound) at .45. EBC, on the other hand, doesn’t seem to know where they are as they claim up to three different friction levels for some of its compounds, Red Stuff .33, .4, and .45, Yellow Stuff .34, .4, and .42, and Blue Stuff .38, and .4 depending on which brochure you pick up or which web site you visit. This proves the importance of obtaining an industry standard C.O.F/temperature graph, which should be available from any reputable supplier of friction materials, to determine how a disc pad material performs at any given temperature. The claim made for Green Stuff is .46 but as it is only recommended for road use or 4X4’s and since even Mintex’s baby compound (M1144) outperforms it in both road and race applications we struggle to take it too seriously. To obtain graphs on above mentioned products plus Pagid, Wilwood Polymatrix, SBS, but excluding EBC, please contact us at RACEBRAKES 0800 BRAKES. We can, however, provide the brochures of the conflicting claims made by EBC.
Which brings us to the next weakest link in the chain. The Brake Fluid.
There is no point having materials sitting in the wheels able to handle 700+ degrees C if your brake fluid is going to boil as soon as you put them to the test. First let us dispel a few common misconceptions. You do NOT want to use a DOT 5 brake fluid. DOT 5 is the rating given to silicone brake fluid (more correctly called Silicone Basal Brake Fluids or SBBF’s) We must also not confuse “silicone” fluids with “synthetic” fluids. Silicone fluids are not miscible (mixable) with conventional fluids however synthetic race fluids can be mixed with conventional road fluids. Very handy if you have rolled the car in the back of beyond, tipped all your race fluid out of the reservoir, but the car will still be driveable if only you can top up your master cylinder. Remember, mixing standard brake fluid with your race fluid will proportionally dilute the properties of your race fluid.
Now back to the DOT rating. All brake fluid, apart from silicone fluids, are hydroscopic which means that they will absorb moisture. The higher the DOT rating, the less hydroscopic they are. In other words, the less moisture they will absorb over a given period. Over time this will contribute to a brake fluids “wet boiling point”. Using a high DOT rating in a road car theoretically means that you will not have to change your fluid as often as you would if you were using a lower DOT rated fluid. This however does not apply to a race car as a race cars brake system produces so much moisture and debris that the laws of longevity are not really relevant.
Silicone fluids are NOT hydroscopic, meaning that they will not absorb moisture. This however is their downfall. All brake systems produce moisture. Particularly race brake systems as it is the extreme temperature changes that cause excessive moisture build up. As the brake system produces moisture, a conventional brake fluid will absorb it but a silicone fluid won’t. The moisture is still in the system but instead of absorbing into the brake fluid (admittedly reducing its boiling point), it just sits there in little water pockets waiting for the brake system to get hot so that it can vaporise. Even a well soaked brake fluid will have a higher boiling point than water.
RACEBRAKES 0800BRAKES handy hint: Avoid the risk of vaporizing your brake fluid at all costs. The results of a brake pedal going to the floor can be extremely hazardous to your health. Replace your silicone fluid with a proper race fluid. We have found ELF’s XT3167 to be very good value for money. We know that silicone fluid is kind to your paintwork if you spill it, but what are your priorities?
Keeping in mind that a DOT 5 is a silicone fluid, the highest DOT rating generally available for a conventional or synthetic fluid is a DOT 5.1 (notice the point one and we also note that there are DOT 6 fluids out there) So while a DOT rating has its place, what we are really looking for in a race fluid is a high dry boiling point. Interestingly, two of the best race fluids on the planet today, Brembo’s LCF600 Plus (this is the stuff that they tip into the Ferrari F1 cars and is available from RACEBRAKES 0800BRAKES in 500ml bottles) and Castrol’s SRF are both rated as DOT4+.
Incidentally, the minimum dry boiling point requirements of a DOT 4 fluid is 230 degrees C, DOT 5 (silicone) is 250 degrees C and DOT 5.1 has a minimum dry boiling point requirement of 260 degrees C. Admittedly, most off the shelf DOT4 road fluids will exceed the minimum requirements. In comparison, Brembo’s LCF600 Plus has a dry boiling point of 316 degrees C and Castrol’s SRF has a dry boiling point of 310 degrees C.
The other (and some would argue most important) advantage of a proper race fluid is that it is a lot less compressible than standard road fluids. In other words, they are less squashy. The less compressible race fluids help eliminate a lot of your spongy pedal and long pedal travel problems. It really is a shame when people spend hundreds of dollars outfitting their vehicles with braided hoses to firm up the pedal, then go and put a road fluid (or even worse, a silicone fluid which is highly compressible) into their car to save themselves a few dollars??
Now that we have our fluids sussed, the third weak link in the chain now becomes the rotors.
RACEBRAKES 0800BRAKES can of course supply 2 piece race rotors. However, once the price of manufacturing hats to make them fit your vehicle is taken into account, it seems almost churlish to wrap your standard road calipers back around them so we go shopping for a pretty set of four pots and there goes the budget.
As this discussion is centered around a “bang fer yer buck” makeover of a standard road brake system, we will be concentrating on what to do with your standard road rotors.
Firstly, RACEBRAKES 0800BRAKES and the manufacturers of road rotors do NOT officially recommend the use of non race rotors for motorsport use. However, RACEBRAKES 0800BRAKES are more than happy to supply quality road rotors for these purposes if it suits the clients budget or is mandatory because of control class rulings. The reality is that a lot of people go racing very successfully on road rotors.
The minimum requirement for racing on road rotors is… Make sure they are above the minimum thickness as specified by the rotor or vehicle manufacturer. The thinner a rotor gets, the less its ability to dissipate heat, which will increase the risk of it warping or cracking.
RACEBRAKES 0800BRAKES handy hint: Proper race pads are of course designed to dissipate heat efficiently. If we had a dollar for every client that suffered continual warping problems while racing on road oriented “performance pads” who then found that their warping problems were eliminated by using a proper racing friction material…..
Cross drilled and Slotted Rotors.
As a general rule of thumb, we at RACEBRAKES 0800BRAKES will try to steer you away from cross drilled rotors. The main advantage of cross drilled rotors is unsprung weight which is of course extremely critical on very light weight cars. However, having all those holes drilled through them makes them a bit of a “grenade” rotor, prone to warping and cracking when used on heavier vehicles that generate a lot of heat under braking. A very light weight car will, of course, not generate as much heat under braking therefore cross drilled rotors may not be such an issue.
The other advantage of cross drilled rotors is their ability to de-gas and continually de-glaze the disc pads.
These processes, without the disadvantages of cross drilling, are to be found in “slotted only” disc rotors.
No point in having the flash, powerful race pads in the car if they glaze up and lose their efficiency.
However, slotted rotor upgrades are NOT an absolute necessity if you are running modern, high coefficient race materials that perform from dead cold in your road calipers.
RACEBRAKES 0800BRAKES will surprise you with their range of “slotted only” rotors. If, like the Mercedes 280E rotors, they are not available off the shelf, we can source them in about a week.
Summary.
For around the five hundred dollar mark, RACEBRAKES 0800BRAKES can set up your existing brake system to a point where we can guarantee that you will not outdrive your brakes on the road or on the track. This is what we call a Package 4 upgrade and consists of a front and rear friction and fluid upgrade. We are more than happy to offer a special price to Targa competitors and can fax you an approximate brake upgrade price list on request. A full front and rear upgrade of your existing componentry including braided hoses and slotted rotors will set you back approximately $1800.
While we cannot guarantee mileage on friction materials and always recommend taking a spare set of pads (even if these are just road pads as hole fillers if necessary), most of our clients get through prologue and the Dunlop Targa on one set of endurance pads.
If because of excessive weight, horsepower or speed you are able to outdrive 700+ degree materials, we would advise spending a couple of hundred dollars on brake ducting to cool everything down.
At the end of the day, we must remember that a brake system is only as good as the vehicles tyres and that a properly set up big race brake system will always beat a properly set up smaller road brake system. But that is a different story for different budgets.
For further information, specification sheets, or an accurate quote for your vehicle, please feel free to phone Steve or John at RACEBRAKES 0800BRAKES (0800 272537) or visit our web site at www.0800brakes.co.nz . Our e-mail address is sales@0800brakes.co.nz. and we are situated at 351 New North Road, Eden Terrace, Auckland, New Zealand.
RACEBRAKES 0800BRAKES
APPROXIMATE BRAKE UPGRADE PRICE LIST
Package 1 Front friction upgrade $250 - $300
Package 2 Front friction and fluid upgrade $300 - $350
Package 3 Front and rear friction upgrade $400 - $450
Package 4 Front and rear friction and fluid upgrade $450 - $500
Package 5 Front rotor and front friction upgrade $650 - $700
Package 6 Front rotor, front friction and fluid upgrade $700 - $750
Package 7 Front rotor and front and rear friction upgrade $800 - $850
Package 8 Front rotor, front and rear friction and fluid upgrade $850 - $900
Package 9 Front and rear rotor and front and rear friction upgrade $1200 - $1250
Package 10 Front and rear rotor, front and rear friction and fluid upgrade $1250 - $1300
Braided hose upgrades can be added on top of these packages at an average cost of $80 per hose.
These prices are based around cars with medium sized brakes such as 323 DOHC Turbo or Lancer GSR using the Mintex M1166 friction compounds and the ELF XT3167 race fluid.
For larger brake systems such as those fitted to EVO’s, Skylines, Aussies etc add approximately 10%.
Keep in mind that an EVO 1 or a V-tec Prelude have much larger front disc pads than the VS HSV clubbies that didn’t opt for the big brake kit.
For vehicles with smaller brake systems such as Starlets and older Civics etc deduct approximately 10%.
For an accurate quote please phone 0800BRAKES (0800 272537).
As long as the vehicle weighs under 1800kg and is not an 800hp monster the following rule of thumb applies…..
Package 1 will not be outdriven on the road and we will guarantee that with Package 2 or Package 4.
For club racing or track days, Package 2 is the minimum but you will really appreciate Package 4 which we can then guarantee will not be outdriven on the road or the track.
You will need a really good reason not to do the fluid upgrade, and if that is your choice we recommend at least putting fresh road fluid in. Caliper upgrades are not usually necessary (or allowed in a lot of race classes) but if you are after the look of a big red Brembo you will need to budget around $1000 per caliper.
Update: One of the most commonly asked questions is…. “How long are my race pads going to last under road conditions?”
Our best attempt at answering that question goes like this…….. While we cannot guarantee mileage on a set of race pads, we can give you some indication as to what to expect. As a general rule, 500 race k’s is considered good mileage out of a set of race pads. However this is where we should be pointing out that we need to be comparing apples with apples. If you were only going to get 500 road k’s out of your $200 race pads, this would not be considered a good investment in terms of dollars per kilometre as most people would be going through a set of pads every 1-2 weeks. If we use 40,000km as an average mileage (some people get more, some people get less, but everybody is happy with this as an average) for a set of road pads under normal road conditions and we fit our race pads and drive the car exactly the same way as we did on the road pads, we would expect to get higher mileage from them as they are of a denser material composition. What we find in reality however, is this. The race pads are fitted and the car is now driven in an entirely different manner than it was before. The braking points become later, the pedal pressure is applied more vigorously, and the car is taken to track days etc. Why, because you can. (heat, therefore track work, is one of the big killers of pad life). This usually results in the vehicle getting less mileage (say 20-30,000km) on the race pads than the road pads because it is now being driven in a totally different way.
For people who are only doing 5000km a year in their cars, 20-30,000km will equate to 4-6 years motoring.
To prove the theory that race pads will last longer than road pads when driven in exactly the same way as each other, ask yourself this question….. If 500 race kilometres is considered good mileage out of a set of race pads, on a V8 Tourer for example, how many race kilometres would a V8 Tourer get out of a set of standard road pads?
De-gassing. What is it and how will it benefit me? (By Steve Borg, Disc Brakes Australia DBA)
As we know normal brake discs have a smooth, flat surface. Holes and slots in the face of the disc have a number of purposes. Firstly, removing gasses from the face of the disc, these gasses greatly reduce the coefficient of friction. Disc pads, when hot, expel gasses. These gasses form a cushion between the face of the disc and the pad.
It takes a tenth of a second to squeeze these gasses out on normal rotors. Now this does not sound like a very long time, but consider this. When a vehicle is travelling at 100km/h, it is moving at a rate of 30 metres per second, therefore a tenth of a second is three metres. So in essence, when the brakes are applied, the vehicle travels for three metres squeezing out gasses and not creating friction to slow the vehicle. (Race Brakes 0800 Brakes comment: This is probably not a big issue at city speeds but consider the lap time savings of a 300 km/h race car with 6 braking points per lap. This could add up to a saving of half a second per lap which could mean the difference between 1st or 14th in an Aussie V8 Supercar grid.)
Another problem that occurs (which we touched on briefly earlier in this article) when the build up of gasses is not released, is that the pad material becomes hardened and glazed, greatly reducing the grip between the pad and disc. Cross drilling (see earlier comments) and slotting allow these gasses to be removed immediately, also helps to deglaze the pads, increasing the grip between the pad and disc, hence shortening the braking distance. Cross drilling and slotting makes the disc surface uneven so water and dust cannot develop into a thin layer that becomes a smooth, glass like surface and can greatly reduce the coefficient of friction. (Race Brakes 0800 Brakes comment: This ability to keep the disc pads continually deglazed is their main justification for using them as road rotors)
Cross drilling and slotting work effectively to reduce the main problems that occur in brake systems.
But there are some trade offs, such as a shorter pad life of approximately 10% so if you’re getting 40,000km from a set of pads (NB: He uses this figure too) this can be reduced to 36,000km, a small price to pay for better braking performance. Also, the cross drilled rotors are more prone to cracking under extreme conditions, such as racing.
Both the cross drilled and slotted and just slotted discs have the same performance qualities.
So the question is, do I fit cross drilled and slotted or just slotted discs?
This question has to be asked of the driver, what is the main use of the vehicle?
Is the vehicle used for racing, or driven extremely hard?
Does the vehicle go off road? (circuit or strip work I presume)
If the answer is yes to either of these questions, slotted only discs should be recommended.
I went to see a guy yesterday who pretty much knows his stuff about brake set-ups esp for what I am trying to acheive. I asked him about his Wilwoods set-up and he showed me the size of wilwoods pad v's the size of the toyota one that I have. Well to me the Toyota shape looked ever so slightly larger. He said my green EBC pads were just marketing hipe and no wonder I am having trouble, a much more meaty pad will have the same braking power as the wilwoods, but depends on how long I want my rotors to last. In my case should last ages due to low miles. He just said upgrade your fluids and put a meaty pad in there and you will be sorted. I said well I must have new slotted rotors then?, he only if you want to improve your braking by a one tenths of a second as thats the time to rid of any gases. So I said but glazing up of pads? He said yeah if that concerns you then slotted rotors will do the trick. So many options out there. Here is some refresher reading that you guys might be interested in, sorry its a lot, might be best to copy and paste into word to read it better.
BRAKE UPGRADE INFORMATION & PRICE LIST
Thankfully most of us these days realize that there is a lot more to preparing a competitive car than providing it with endless reserves of horsepower and torque. What a lot of people don’t realize are the performance and safety gains that can be made to the vehicle by inexpensively speccing up their existing road brake system with proper race compounds and fluids. This does not mean using road oriented metallic or kevlar pads or “DOT 5” fluid. Although these will be better than a set of standard cardboard pads, they really should not be let anywhere near a race car or track
.
RACEBRAKES 0800BRAKES, as well as supplying race calipers and race rotors, also specialize in setting up race brake systems for competitors on a budget or where the rules of a race control class prohibit the use of anything other than the standard original equipment foundation brake system. The GT and Production Muscle Car class (500+hp, 16-1700kg, 270kph) and the HQ’s being examples of these.
Most standard brake systems, once equipped to handle the heat generated under racing conditions, are more than adequate for events like the Dunlop Targa and other club racing duties.
If we think of the brake system as a chain that is only as strong as its weakest link, and heat as its enemy, we find that the weakest link in a road brake system is the friction materials. A good quality standard road compound will have a maximum c.w.t (continuous working temperature) of around 300 degrees C. An Aussie V8 Supercar generates around 650 degrees C at the end of Conrod. What we need to do is put proper race compounds into our road calipers, as the smaller road brake system is not as good at dissipating heat as the larger brake systems and can generate temperatures equivalent to larger race cars.
The problem you may come across when looking for proper race compounds for your road calipers is that the manufacturers of the race compounds will generally only manufacture pads for recognized race calipers 6--=\gh that someone (like Ken Williams) wants to take one racing.
RACEBRAKES 0800BRAKES are able to supply or manufacture race pads for any type of caliper with race compounds that will handle temperatures of at least 700 degrees C. Some compounds will handle much more. These compounds perform from dead cold and make a blindingly good street pad regardless of their racing abilities. Don’t panic if your vehicle is equipped with drum brakes as we carry a German Pagid drum brake compound for these applications. We even have the old Ferodo DS11 compound available if you wanted to spec up your GT Falcon, Monaro, Charger or Torana for authenticity’s sake to the Bathurst compounds of the sixties and seventies. This material, for you aficionados out there, “was introduced in the late fifties and was almost universally used in Formula One right up until cast iron discs were superseded by carbonfibre reinforced carbon (carbon-carbon) discs and pads in the eighties. According to Federal-Mogul’s records (Ferodo Racing’s parent company), between 1961 and 1981, 265 of 267 Grand Prix victories were scored using DS11 pads”. (Article entitled From DS11 to DS3000 by Ian Bamsey, Racetech magazine) Two decades of dominance. Let’s see if Ferrari or HRT can match that.
Interestingly enough, speaking of dominance, Ferodo’s replacement for the DS11 compound called DS3000 was used by every manufacturer except Mitsubishi (who we believe used Raybestos) in the 2002 World Rally Championship (and no, it is not a control pad). DS3000, of course, was used by Peugeot to win Rally of New Zealand 2003. Mark Skaife and HRT used it for their 2001 & 2002 Australian V8 Supercar titles and other recent local success by DS3000 includes 1st Superpole, Yellow Pages 500, October 2002, 1st overall Dunlop Targa 2002 and 1st overall NZ V8 Tourer Championship 2003.
For the record, Ferodo’s DS11 compound had a coefficient of friction (which denotes how “grabby” a disc pad is) or mu rating of .31. Low by today’s standards compared with DS3000 Plus at .68. A metallic road pad, (not to be confused with carbon metallics), which most of you have used before, also has a low coefficient of friction rating, again of around .3. This lack of power in a road metallic pad and DS11’s poor cold performance do NOT make them desirable as modern race compounds.
DS11 did however have a “recommended maximum temperature of 750 degrees C but is commonly used at temperatures in excess of 1000 degrees C” (Ferodo International Technical News F16, July 1980). Impressive numbers sure, (a Bendix Metal King Plus has a maximum c.w.t of 400 degrees C) but if your brake assembly is being asked to cope with those sorts of temperatures, you are going to be having extra problems over and above brake fade.
Compare Mintex’s new M1177 material at .61 (dropping off a little after 500 degrees C but still holding a massive .55 c.o.f at 700 degrees C), Mintex M1166 sprint compound at .47, Mintex M1155 targa/endurance compound at .43 and Mintex M1144 (Formula Ford compound) at .45. EBC, on the other hand, doesn’t seem to know where they are as they claim up to three different friction levels for some of its compounds, Red Stuff .33, .4, and .45, Yellow Stuff .34, .4, and .42, and Blue Stuff .38, and .4 depending on which brochure you pick up or which web site you visit. This proves the importance of obtaining an industry standard C.O.F/temperature graph, which should be available from any reputable supplier of friction materials, to determine how a disc pad material performs at any given temperature. The claim made for Green Stuff is .46 but as it is only recommended for road use or 4X4’s and since even Mintex’s baby compound (M1144) outperforms it in both road and race applications we struggle to take it too seriously. To obtain graphs on above mentioned products plus Pagid, Wilwood Polymatrix, SBS, but excluding EBC, please contact us at RACEBRAKES 0800 BRAKES. We can, however, provide the brochures of the conflicting claims made by EBC.
Which brings us to the next weakest link in the chain. The Brake Fluid.
There is no point having materials sitting in the wheels able to handle 700+ degrees C if your brake fluid is going to boil as soon as you put them to the test. First let us dispel a few common misconceptions. You do NOT want to use a DOT 5 brake fluid. DOT 5 is the rating given to silicone brake fluid (more correctly called Silicone Basal Brake Fluids or SBBF’s) We must also not confuse “silicone” fluids with “synthetic” fluids. Silicone fluids are not miscible (mixable) with conventional fluids however synthetic race fluids can be mixed with conventional road fluids. Very handy if you have rolled the car in the back of beyond, tipped all your race fluid out of the reservoir, but the car will still be driveable if only you can top up your master cylinder. Remember, mixing standard brake fluid with your race fluid will proportionally dilute the properties of your race fluid.
Now back to the DOT rating. All brake fluid, apart from silicone fluids, are hydroscopic which means that they will absorb moisture. The higher the DOT rating, the less hydroscopic they are. In other words, the less moisture they will absorb over a given period. Over time this will contribute to a brake fluids “wet boiling point”. Using a high DOT rating in a road car theoretically means that you will not have to change your fluid as often as you would if you were using a lower DOT rated fluid. This however does not apply to a race car as a race cars brake system produces so much moisture and debris that the laws of longevity are not really relevant.
Silicone fluids are NOT hydroscopic, meaning that they will not absorb moisture. This however is their downfall. All brake systems produce moisture. Particularly race brake systems as it is the extreme temperature changes that cause excessive moisture build up. As the brake system produces moisture, a conventional brake fluid will absorb it but a silicone fluid won’t. The moisture is still in the system but instead of absorbing into the brake fluid (admittedly reducing its boiling point), it just sits there in little water pockets waiting for the brake system to get hot so that it can vaporise. Even a well soaked brake fluid will have a higher boiling point than water.
RACEBRAKES 0800BRAKES handy hint: Avoid the risk of vaporizing your brake fluid at all costs. The results of a brake pedal going to the floor can be extremely hazardous to your health. Replace your silicone fluid with a proper race fluid. We have found ELF’s XT3167 to be very good value for money. We know that silicone fluid is kind to your paintwork if you spill it, but what are your priorities?
Keeping in mind that a DOT 5 is a silicone fluid, the highest DOT rating generally available for a conventional or synthetic fluid is a DOT 5.1 (notice the point one and we also note that there are DOT 6 fluids out there) So while a DOT rating has its place, what we are really looking for in a race fluid is a high dry boiling point. Interestingly, two of the best race fluids on the planet today, Brembo’s LCF600 Plus (this is the stuff that they tip into the Ferrari F1 cars and is available from RACEBRAKES 0800BRAKES in 500ml bottles) and Castrol’s SRF are both rated as DOT4+.
Incidentally, the minimum dry boiling point requirements of a DOT 4 fluid is 230 degrees C, DOT 5 (silicone) is 250 degrees C and DOT 5.1 has a minimum dry boiling point requirement of 260 degrees C. Admittedly, most off the shelf DOT4 road fluids will exceed the minimum requirements. In comparison, Brembo’s LCF600 Plus has a dry boiling point of 316 degrees C and Castrol’s SRF has a dry boiling point of 310 degrees C.
The other (and some would argue most important) advantage of a proper race fluid is that it is a lot less compressible than standard road fluids. In other words, they are less squashy. The less compressible race fluids help eliminate a lot of your spongy pedal and long pedal travel problems. It really is a shame when people spend hundreds of dollars outfitting their vehicles with braided hoses to firm up the pedal, then go and put a road fluid (or even worse, a silicone fluid which is highly compressible) into their car to save themselves a few dollars??
Now that we have our fluids sussed, the third weak link in the chain now becomes the rotors.
RACEBRAKES 0800BRAKES can of course supply 2 piece race rotors. However, once the price of manufacturing hats to make them fit your vehicle is taken into account, it seems almost churlish to wrap your standard road calipers back around them so we go shopping for a pretty set of four pots and there goes the budget.
As this discussion is centered around a “bang fer yer buck” makeover of a standard road brake system, we will be concentrating on what to do with your standard road rotors.
Firstly, RACEBRAKES 0800BRAKES and the manufacturers of road rotors do NOT officially recommend the use of non race rotors for motorsport use. However, RACEBRAKES 0800BRAKES are more than happy to supply quality road rotors for these purposes if it suits the clients budget or is mandatory because of control class rulings. The reality is that a lot of people go racing very successfully on road rotors.
The minimum requirement for racing on road rotors is… Make sure they are above the minimum thickness as specified by the rotor or vehicle manufacturer. The thinner a rotor gets, the less its ability to dissipate heat, which will increase the risk of it warping or cracking.
RACEBRAKES 0800BRAKES handy hint: Proper race pads are of course designed to dissipate heat efficiently. If we had a dollar for every client that suffered continual warping problems while racing on road oriented “performance pads” who then found that their warping problems were eliminated by using a proper racing friction material…..
Cross drilled and Slotted Rotors.
As a general rule of thumb, we at RACEBRAKES 0800BRAKES will try to steer you away from cross drilled rotors. The main advantage of cross drilled rotors is unsprung weight which is of course extremely critical on very light weight cars. However, having all those holes drilled through them makes them a bit of a “grenade” rotor, prone to warping and cracking when used on heavier vehicles that generate a lot of heat under braking. A very light weight car will, of course, not generate as much heat under braking therefore cross drilled rotors may not be such an issue.
The other advantage of cross drilled rotors is their ability to de-gas and continually de-glaze the disc pads.
These processes, without the disadvantages of cross drilling, are to be found in “slotted only” disc rotors.
No point in having the flash, powerful race pads in the car if they glaze up and lose their efficiency.
However, slotted rotor upgrades are NOT an absolute necessity if you are running modern, high coefficient race materials that perform from dead cold in your road calipers.
RACEBRAKES 0800BRAKES will surprise you with their range of “slotted only” rotors. If, like the Mercedes 280E rotors, they are not available off the shelf, we can source them in about a week.
Summary.
For around the five hundred dollar mark, RACEBRAKES 0800BRAKES can set up your existing brake system to a point where we can guarantee that you will not outdrive your brakes on the road or on the track. This is what we call a Package 4 upgrade and consists of a front and rear friction and fluid upgrade. We are more than happy to offer a special price to Targa competitors and can fax you an approximate brake upgrade price list on request. A full front and rear upgrade of your existing componentry including braided hoses and slotted rotors will set you back approximately $1800.
While we cannot guarantee mileage on friction materials and always recommend taking a spare set of pads (even if these are just road pads as hole fillers if necessary), most of our clients get through prologue and the Dunlop Targa on one set of endurance pads.
If because of excessive weight, horsepower or speed you are able to outdrive 700+ degree materials, we would advise spending a couple of hundred dollars on brake ducting to cool everything down.
At the end of the day, we must remember that a brake system is only as good as the vehicles tyres and that a properly set up big race brake system will always beat a properly set up smaller road brake system. But that is a different story for different budgets.
For further information, specification sheets, or an accurate quote for your vehicle, please feel free to phone Steve or John at RACEBRAKES 0800BRAKES (0800 272537) or visit our web site at www.0800brakes.co.nz . Our e-mail address is sales@0800brakes.co.nz. and we are situated at 351 New North Road, Eden Terrace, Auckland, New Zealand.
RACEBRAKES 0800BRAKES
APPROXIMATE BRAKE UPGRADE PRICE LIST
Package 1 Front friction upgrade $250 - $300
Package 2 Front friction and fluid upgrade $300 - $350
Package 3 Front and rear friction upgrade $400 - $450
Package 4 Front and rear friction and fluid upgrade $450 - $500
Package 5 Front rotor and front friction upgrade $650 - $700
Package 6 Front rotor, front friction and fluid upgrade $700 - $750
Package 7 Front rotor and front and rear friction upgrade $800 - $850
Package 8 Front rotor, front and rear friction and fluid upgrade $850 - $900
Package 9 Front and rear rotor and front and rear friction upgrade $1200 - $1250
Package 10 Front and rear rotor, front and rear friction and fluid upgrade $1250 - $1300
Braided hose upgrades can be added on top of these packages at an average cost of $80 per hose.
These prices are based around cars with medium sized brakes such as 323 DOHC Turbo or Lancer GSR using the Mintex M1166 friction compounds and the ELF XT3167 race fluid.
For larger brake systems such as those fitted to EVO’s, Skylines, Aussies etc add approximately 10%.
Keep in mind that an EVO 1 or a V-tec Prelude have much larger front disc pads than the VS HSV clubbies that didn’t opt for the big brake kit.
For vehicles with smaller brake systems such as Starlets and older Civics etc deduct approximately 10%.
For an accurate quote please phone 0800BRAKES (0800 272537).
As long as the vehicle weighs under 1800kg and is not an 800hp monster the following rule of thumb applies…..
Package 1 will not be outdriven on the road and we will guarantee that with Package 2 or Package 4.
For club racing or track days, Package 2 is the minimum but you will really appreciate Package 4 which we can then guarantee will not be outdriven on the road or the track.
You will need a really good reason not to do the fluid upgrade, and if that is your choice we recommend at least putting fresh road fluid in. Caliper upgrades are not usually necessary (or allowed in a lot of race classes) but if you are after the look of a big red Brembo you will need to budget around $1000 per caliper.
Update: One of the most commonly asked questions is…. “How long are my race pads going to last under road conditions?”
Our best attempt at answering that question goes like this…….. While we cannot guarantee mileage on a set of race pads, we can give you some indication as to what to expect. As a general rule, 500 race k’s is considered good mileage out of a set of race pads. However this is where we should be pointing out that we need to be comparing apples with apples. If you were only going to get 500 road k’s out of your $200 race pads, this would not be considered a good investment in terms of dollars per kilometre as most people would be going through a set of pads every 1-2 weeks. If we use 40,000km as an average mileage (some people get more, some people get less, but everybody is happy with this as an average) for a set of road pads under normal road conditions and we fit our race pads and drive the car exactly the same way as we did on the road pads, we would expect to get higher mileage from them as they are of a denser material composition. What we find in reality however, is this. The race pads are fitted and the car is now driven in an entirely different manner than it was before. The braking points become later, the pedal pressure is applied more vigorously, and the car is taken to track days etc. Why, because you can. (heat, therefore track work, is one of the big killers of pad life). This usually results in the vehicle getting less mileage (say 20-30,000km) on the race pads than the road pads because it is now being driven in a totally different way.
For people who are only doing 5000km a year in their cars, 20-30,000km will equate to 4-6 years motoring.
To prove the theory that race pads will last longer than road pads when driven in exactly the same way as each other, ask yourself this question….. If 500 race kilometres is considered good mileage out of a set of race pads, on a V8 Tourer for example, how many race kilometres would a V8 Tourer get out of a set of standard road pads?
De-gassing. What is it and how will it benefit me? (By Steve Borg, Disc Brakes Australia DBA)
As we know normal brake discs have a smooth, flat surface. Holes and slots in the face of the disc have a number of purposes. Firstly, removing gasses from the face of the disc, these gasses greatly reduce the coefficient of friction. Disc pads, when hot, expel gasses. These gasses form a cushion between the face of the disc and the pad.
It takes a tenth of a second to squeeze these gasses out on normal rotors. Now this does not sound like a very long time, but consider this. When a vehicle is travelling at 100km/h, it is moving at a rate of 30 metres per second, therefore a tenth of a second is three metres. So in essence, when the brakes are applied, the vehicle travels for three metres squeezing out gasses and not creating friction to slow the vehicle. (Race Brakes 0800 Brakes comment: This is probably not a big issue at city speeds but consider the lap time savings of a 300 km/h race car with 6 braking points per lap. This could add up to a saving of half a second per lap which could mean the difference between 1st or 14th in an Aussie V8 Supercar grid.)
Another problem that occurs (which we touched on briefly earlier in this article) when the build up of gasses is not released, is that the pad material becomes hardened and glazed, greatly reducing the grip between the pad and disc. Cross drilling (see earlier comments) and slotting allow these gasses to be removed immediately, also helps to deglaze the pads, increasing the grip between the pad and disc, hence shortening the braking distance. Cross drilling and slotting makes the disc surface uneven so water and dust cannot develop into a thin layer that becomes a smooth, glass like surface and can greatly reduce the coefficient of friction. (Race Brakes 0800 Brakes comment: This ability to keep the disc pads continually deglazed is their main justification for using them as road rotors)
Cross drilling and slotting work effectively to reduce the main problems that occur in brake systems.
But there are some trade offs, such as a shorter pad life of approximately 10% so if you’re getting 40,000km from a set of pads (NB: He uses this figure too) this can be reduced to 36,000km, a small price to pay for better braking performance. Also, the cross drilled rotors are more prone to cracking under extreme conditions, such as racing.
Both the cross drilled and slotted and just slotted discs have the same performance qualities.
So the question is, do I fit cross drilled and slotted or just slotted discs?
This question has to be asked of the driver, what is the main use of the vehicle?
Is the vehicle used for racing, or driven extremely hard?
Does the vehicle go off road? (circuit or strip work I presume)
If the answer is yes to either of these questions, slotted only discs should be recommended.
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