Track day advice
Discussion
Took my 996 out on track the other day and had a major brown trouser moment. Towards the end of a 15min stint my brakes totally failed (no obvious prior warning), the pedal just simple hit the floor. Luckily I saw a red flag ahead so had just eased off the throttle (if it wasn't for this flag, I would have been really in trouble). Left the brakes to cool down for 45mins and had around 80% brake performance return. Obviously I had boiled the fluid. If I replace the fluid with ATE Super Blue racing DOT 4 would this prevent the problem from re-occurring or is a more serious brake upgrade required.
Just surprised after only a 15min session to have such an issue.
NOTE: For info car is a lightly modified 996.1 C2. Brakes have never been a problem before on fast road/Alpine pass type scenarios. In-fact I always thought the brakes were one of the strong points.
Maybe just a case of old fluid (not replaced for about 3 years as it has only done about 10,000miles in that time.
Just surprised after only a 15min session to have such an issue.
NOTE: For info car is a lightly modified 996.1 C2. Brakes have never been a problem before on fast road/Alpine pass type scenarios. In-fact I always thought the brakes were one of the strong points.
Maybe just a case of old fluid (not replaced for about 3 years as it has only done about 10,000miles in that time.
Had this happen in my own car when I first start track driving and also when riding shotgun in a friends car (I calmly told him to use the grass when we ran out of tarmac 
). In both cases it was caused by old fluid and worn down pads (more than 50%). Standard Porsche brakes will take a lot of abuse as long as the pads and fluid are fresh. Of course, you can improve their performance and make them run cooler but that's a whole different ball game.
). In both cases it was caused by old fluid and worn down pads (more than 50%). Standard Porsche brakes will take a lot of abuse as long as the pads and fluid are fresh. Of course, you can improve their performance and make them run cooler but that's a whole different ball game.mm450exc said:
Here is the sequence of things you might need....
1) Castrol SRF
That should be it if you got ok brakes.
2) Brakes - Alcon if you brakes bend out of shape/RS29 pads
3) ATEC Brake lines
4) GT3 Brake Master Cylinder
This is exactly what I would recommend too. Did this on my 997 Turbo and never had an issue on any track days.1) Castrol SRF
That should be it if you got ok brakes.
2) Brakes - Alcon if you brakes bend out of shape/RS29 pads
3) ATEC Brake lines
4) GT3 Brake Master Cylinder
mm450exc said:
Here is the sequence of things you might need....
1) Castrol SRF
That should be it if you got ok brakes.
2) Brakes - Alcon if you brakes bend out of shape/RS29 pads
3) ATEC Brake lines
4) GT3 Brake Master Cylinder
This is exactly what I would recommend too. Did this on my 997 Turbo and never had an issue on any track days.1) Castrol SRF
That should be it if you got ok brakes.
2) Brakes - Alcon if you brakes bend out of shape/RS29 pads
3) ATEC Brake lines
4) GT3 Brake Master Cylinder
Hmm, it depends on the circuit and your ability. My slightly tweeked 996 will do 2-3 fast laps max round Oulton before the brakes fade. Just the same with a standard BMW M3, Audi TT, Honda Civic Type R, etc...pretty much any sporty car with decent grip. I very much doubt it would be the same at Silverstone though.
The brakes' job is to turn motion into heat and the amount of heat they can absorb is dependent on the volume of friction material. So, on track the repeated hard use can reach the limit of the absorption capacity of the pads, at which point you'll keep pushing the pedal, the pads are definitely in contact with the discs, but they aren't slowing the car down (or nothing like as much as you need). So, whilst 60-70-80% warn pads will be fine in general road use (as the heat they absorb has time to dissipate between applications), potentially for thousands more miles, on track you may get fade/failure very quickly. Once they overheat you can run into further problems like the pads starting to melt, increasing wear considerably and creating "pick up" on the disc and also heat is transferred upstream to the fluid etc.
I borrowed a very fun to drive Civic once and kept driving it when the brakes started to fade - the result was it needed new calipers, new discs and new pads. I have what's left of one of the pad backing plates as a souvenir - it's rather warped and has a hole in caused by the piston cutting through it like a cookie cutter.
Carrying on with fading brakes was an expensive mistake, I've not done it since.
The brakes' job is to turn motion into heat and the amount of heat they can absorb is dependent on the volume of friction material. So, on track the repeated hard use can reach the limit of the absorption capacity of the pads, at which point you'll keep pushing the pedal, the pads are definitely in contact with the discs, but they aren't slowing the car down (or nothing like as much as you need). So, whilst 60-70-80% warn pads will be fine in general road use (as the heat they absorb has time to dissipate between applications), potentially for thousands more miles, on track you may get fade/failure very quickly. Once they overheat you can run into further problems like the pads starting to melt, increasing wear considerably and creating "pick up" on the disc and also heat is transferred upstream to the fluid etc.
I borrowed a very fun to drive Civic once and kept driving it when the brakes started to fade - the result was it needed new calipers, new discs and new pads. I have what's left of one of the pad backing plates as a souvenir - it's rather warped and has a hole in caused by the piston cutting through it like a cookie cutter.
Carrying on with fading brakes was an expensive mistake, I've not done it since.Jim1556 said:
+ 1 for the fluid: Motul RBF600, RS29 pads, should be all you need...
Why weren't you lapping the RS, Richie?
Many thanks for the advice guys Why weren't you lapping the RS, Richie?
Which upgraded pads work best with stock Discs/calipers (also bearing in mind road compliance)?It was a bit lastminute.com Jim regarding the evening session at the Ring last Wednesday. My mate just popped around and with his beast and off we went. I did however manage to do a few laps in an RS with another owner who was kind enough to take me out with him whilst my brakes were cooling down.
Here's a few pics from the other day:
And so that you don't go calling the ghey police; on the 30th I'll give the white one a go (hopefully it has a proper set of brakes
) and he'll be taking his 964RS 
Do you fancy making the trip down for my RS's first outing of the year?
3 years is bad for brake fluid. It's time critical not miles critical. So for road use, I'd not go past the 2 years.
For trackday use, I'd use a modest race fluid like Motul 600, change it one or twice a year and not let the disks or pads get too worn before renewing them. For race use then I would have a much more stringent regime. Mind you I'm a bit of a granny driver at track days!
Bert
For trackday use, I'd use a modest race fluid like Motul 600, change it one or twice a year and not let the disks or pads get too worn before renewing them. For race use then I would have a much more stringent regime. Mind you I'm a bit of a granny driver at track days!
Bert
BertBert said:
3 years is bad for brake fluid. It's time critical not miles critical. So for road use, I'd not go past the 2 years.
For trackday use, I'd use a modest race fluid like Motul 600, change it one or twice a year and not let the disks or pads get too worn before renewing them. For race use then I would have a much more stringent regime. Mind you I'm a bit of a granny driver at track days!
Bert
2 years is quite a new thing for fluid change, in the past I have had cars with 5 year old stuff it works fine for road use, (talking teen days)For trackday use, I'd use a modest race fluid like Motul 600, change it one or twice a year and not let the disks or pads get too worn before renewing them. For race use then I would have a much more stringent regime. Mind you I'm a bit of a granny driver at track days!
Bert
and the UK is not a humidity high country.
I missed off my fluid change last service as the car was not being used and OPC is a rip off for that change, it's 4 years old and just works as normal. saying that I am just about to change it to motul 660 now just to keep things in line and I want to do a few track days this year and use the car more, but last year at Spa no issue with 3 year old stuff.
I do change my pads 1/2 worn though (RS29 most of the time) and heat manage my brakes.
I have never had Fluid go off in 50 cars, and 30 years of driving.
Statements made by the "Big 3" domestic OEM manufacturers that the brake fluid in their vehicles lasts the life of the vehicle ..
...One of the task force members involved with the OEMs found out one of the OEMs did a study using test fleets comprised of thousands of vehicles from various locations that were approximately 8 years old. They tested the brake fluid for moisture and discovered an average of less than one percent over the entire fleet. .. ... "
A number of import car makers do recommend brake fluid changes for preventive maintenance at specific time/mileage intervals:
Acura: 36 months
Audi: 24 months
BMW: 24 months, or when indicated by Service Inspection Indicator
Honda: 36 months
Jaguar: 24 months all models except 2009 XF (36 months)
Land Rover: 36 months
Lexus: 36 months or 30,000 miles, which ever comes first
Mercedes-Benz: 24 months
MINI 24 months
Saab: 48 months (all models except 9-7X)
Smart: 24 months or 20,000 miles, which ever comes first
Subaru: 30 months or 30,000 miles (normal service) or 15 months/15,000 miles (severe service)
Suzuki: 24 months or 30,000 miles, which ever comes first (Forenza & Reno), 60 months or 60,000 miles (Grand Vitara and SX4)
Volkswagen: 24 months (New Beetle, City Gold, City Jetta), 36 months (all other models except Routan)
Volvo: 24 months or 37,000 miles
more an issue is Air filter changes is 60k miles or 6 years with Porsche !!! mine are dusty after 12 months again showing UK is NOT a humidity high country.
I would say change your air filter every 12 months, not every 6 years !
And yes while best to change fluid every 2 years it's seems that's a non over hyped issue.
If I did track days then yes change every 6 track days to be on the correct side of preventive maintenance.
Edited by PorscheGT4 on Friday 8th May 12:51
keep it lit said:
Hey Rich,
I presume that is your WILD 996... if so I've seen that car many times, just trying to work out if I've seen it at the ring a few times, or over here in the UK... help me out mate
Hi Ade, it's been up at the Ring many times so maybe there, or maybe pics of it over on 911uk.com I presume that is your WILD 996... if so I've seen that car many times, just trying to work out if I've seen it at the ring a few times, or over here in the UK... help me out mate
Do you fancy bring your weapon over to the Ring GP circuit on the 30th May? There is an all day open circuit priced at €27 per 15min session; I'll be going in mine
I'd also look at Performance Friction. When I raced the 964 I tried these as the 968 racers were using them and they were about 1/3rd the cost (£76 rather than £228 I think). Despite being exactly the same pad as a 968 I found they didn't work for me as they faded on my car, but the only compound available for those cars was PF97 (which I think means developed in 1997). They've developed newer compounds which should be available for later cars, I'd definitely check prices. NineX can supply them or otherwise try Questmead.
Gassing Station | 911/Carrera GT | Top of Page | What's New | My Stuff