500+bhp Mk3 Fiesta Project
Discussion
Nice project!
I have a question about underbody protection used on fiesta, as I noticed it is 3M seam sealer and I wonder how it feels like when sealer is dry? is it rubbery like feeling, or is it solid hard, can you stratch it down easily or no?
I already bought underbody protection from teroson(terotex 2000 hs), but if this thing is better, a would rather use 3m seam selaer
please can you give some more info about product used on fiesta
Thanks
I have a question about underbody protection used on fiesta, as I noticed it is 3M seam sealer and I wonder how it feels like when sealer is dry? is it rubbery like feeling, or is it solid hard, can you stratch it down easily or no?
I already bought underbody protection from teroson(terotex 2000 hs), but if this thing is better, a would rather use 3m seam selaer
please can you give some more info about product used on fiesta
Thanks
alfista145 said:
Nice project!
I have a question about underbody protection used on fiesta, as I noticed it is 3M seam sealer and I wonder how it feels like when sealer is dry? is it rubbery like feeling, or is it solid hard, can you stratch it down easily or no?
I already bought underbody protection from teroson(terotex 2000 hs), but if this thing is better, a would rather use 3m seam selaer
please can you give some more info about product used on fiesta
Thanks
I do not like you... :-/ you bumping b'stardI have a question about underbody protection used on fiesta, as I noticed it is 3M seam sealer and I wonder how it feels like when sealer is dry? is it rubbery like feeling, or is it solid hard, can you stratch it down easily or no?
I already bought underbody protection from teroson(terotex 2000 hs), but if this thing is better, a would rather use 3m seam selaer
please can you give some more info about product used on fiesta
Thanks
Wow. Long term Fiesta fan having had a Mk2, Mk3 and Mk3.5 Si myself, but got hacked off with cost and PITA of trying to modify cars with limited space and having it as my daily as well. That's why I turned to bikes. Was a regular reader over on fiestaturbo.com prior to getting on 2 wheels and saw some great projects there, but not quite anything like this.
A very well done though, and here's hoping for another update soon.
A very well done though, and here's hoping for another update soon.
alfista145 said:
Nice project!
I have a question about underbody protection used on fiesta, as I noticed it is 3M seam sealer and I wonder how it feels like when sealer is dry? is it rubbery like feeling, or is it solid hard, can you stratch it down easily or no?
I already bought underbody protection from teroson(terotex 2000 hs), but if this thing is better, a would rather use 3m seam selaer
please can you give some more info about product used on fiesta
Thanks
Hello, The sealer is flexible enough to withstand stone chips but still hard firm to prevent it being removed easily; as you probably know some sealers can be pulled/torn away from the car, but the 3M cannot be. It is very much like OEM sealer.I have a question about underbody protection used on fiesta, as I noticed it is 3M seam sealer and I wonder how it feels like when sealer is dry? is it rubbery like feeling, or is it solid hard, can you stratch it down easily or no?
I already bought underbody protection from teroson(terotex 2000 hs), but if this thing is better, a would rather use 3m seam selaer
please can you give some more info about product used on fiesta
Thanks
Kozy said:
I know it was a while back now, but did you do any kind of check on the heat distribution within the braking system with those rear brakes?
Other than calculate bias, no I didn't. I can't say it's something I have ever done for past brake conversions. I would expect AP have modelled the discs themselves, so all I'll do is check operational temps with thermo paint.mwstewart said:
Other than calculate bias, no I didn't. I can't say it's something I have ever done for past brake conversions.
Would you mind sharing the specs so that I might have a look at it? I can geek out massively on brake system design and wouldn't mind checking yours out as it's such a unorthodox build! 
Kozy said:
Would you mind sharing the specs so that I might have a look at it? I can geek out massively on brake system design and wouldn't mind checking yours out as it's such a unorthodox build!
No problem!The rear calipers are: http://www.apracing.com/ProductDetail.aspx?Product...
The rear pads are only available friction material APF401, so that is what I have for now. They will be remade in APF405 when I get chance.
The rear discs are 278 x 16mm floating http://www.apracing.com/product_details/race_car/b...
You should be able to pull the bell specs from above. Bell material is 7075 and so is the wheel hub. Caliper mounting brackets are also 7075.
mwstewart said:
No problem!
The rear calipers are: http://www.apracing.com/ProductDetail.aspx?Product...
The rear pads are only available friction material APF401, so that is what I have for now. They will be remade in APF405 when I get chance.
The rear discs are 278 x 16mm floating http://www.apracing.com/product_details/race_car/b...
You should be able to pull the bell specs from above. Bell material is 7075 and so is the wheel hub. Caliper mounting brackets are also 7075.
Excellent stuff thankyou! Need the front brakes too, as it's a Front/rear temperature bias I'm looking at.The rear calipers are: http://www.apracing.com/ProductDetail.aspx?Product...
The rear pads are only available friction material APF401, so that is what I have for now. They will be remade in APF405 when I get chance.
The rear discs are 278 x 16mm floating http://www.apracing.com/product_details/race_car/b...
You should be able to pull the bell specs from above. Bell material is 7075 and so is the wheel hub. Caliper mounting brackets are also 7075.
Out of interest, how did you calculate bias?
Kozy said:
Excellent stuff thankyou! Need the front brakes too, as it's a Front/rear temperature bias I'm looking at.
Out of interest, how did you calculate bias?
Front discs: http://www.apracing.com/product_details/race_car/b...Out of interest, how did you calculate bias?
Front Calipers: http://www.apracing.com/product_details/road_car_u...
A guy on the M3 forum I use helped with the bias calcs and later wrote a good post which explained: http://www.m3forum.net/m3forum/showthread.php?t=41...
I will dig out the Excel sheet
Only read the first page of the M3 thread but it seems that method of bias calculation is highly misleading! That F/R ratio is utterly irrelevant when it takes no account of the vehicles dimensions, the grip available, load transfer and so on. At best you're taking a complete guess as to the ratio of front and rear force you require.
Mine takes into account the load transfer and tyre grip, with the latter being critical to the calculation, the same as it is in reality. It works such that if you make a change to the system, say tyre grip, and it increases the deployable brake force, the threshold acceleration changes, as does the load transfer, the tyre loads and which affects the bias when the F/R ratio would be unchanged.
It does this by employing a calculus algorithm I developed to determine the point at which the front tyres brake force would overcome the grip. Nasty piece of work, however it seems to give reliable results.
Anyway, I ran your specs though the calculator. The results are frankly terrifying.
The rear brake PTR (Pressure Torque Ratio - amount of brake torque per psi line pressure) with a pad mu of .5 is 0.773. That is utterly utterly mental. Most FWD cars are knocking around between .1 and .2.
The bias metric I use is the rear tyre saturation, i.e how much of the available tractive force available is remaining. Safe figures are 30-50%, well biased systems are maybe 10%. 'Perfect bias is 0%, i.e front and rear lock at the same time.
Now it's down to the mercy of the prop valve but taking a typical knee point of 425psi and pressure reduction of 65%, the bias is coming in at a staggering -338%!
I expected it to be a bit rear biased but that is something else. The temperature distribution is OK if a little front biased so it's really those calipers which are the problem, they are far, far too powerful for the application. Looking at the specs, I'd assume they were designed with the front axle of a kit car in mind. You'd need to lock out the rear pressure at a maximum of 200psi for them to work safely and I'm not sure you'll find a prop valve that will do that.
Not criticising at all but I would advise you to seriously reconsider those rear brakes on safety grounds.
If you would like a copy of my spreadsheet to review, email me and I will send you a copy.
Mine takes into account the load transfer and tyre grip, with the latter being critical to the calculation, the same as it is in reality. It works such that if you make a change to the system, say tyre grip, and it increases the deployable brake force, the threshold acceleration changes, as does the load transfer, the tyre loads and which affects the bias when the F/R ratio would be unchanged.
It does this by employing a calculus algorithm I developed to determine the point at which the front tyres brake force would overcome the grip. Nasty piece of work, however it seems to give reliable results.
Anyway, I ran your specs though the calculator. The results are frankly terrifying.
The rear brake PTR (Pressure Torque Ratio - amount of brake torque per psi line pressure) with a pad mu of .5 is 0.773. That is utterly utterly mental. Most FWD cars are knocking around between .1 and .2.
The bias metric I use is the rear tyre saturation, i.e how much of the available tractive force available is remaining. Safe figures are 30-50%, well biased systems are maybe 10%. 'Perfect bias is 0%, i.e front and rear lock at the same time.
Now it's down to the mercy of the prop valve but taking a typical knee point of 425psi and pressure reduction of 65%, the bias is coming in at a staggering -338%!
I expected it to be a bit rear biased but that is something else. The temperature distribution is OK if a little front biased so it's really those calipers which are the problem, they are far, far too powerful for the application. Looking at the specs, I'd assume they were designed with the front axle of a kit car in mind. You'd need to lock out the rear pressure at a maximum of 200psi for them to work safely and I'm not sure you'll find a prop valve that will do that.
Not criticising at all but I would advise you to seriously reconsider those rear brakes on safety grounds.
If you would like a copy of my spreadsheet to review, email me and I will send you a copy.
Edited by Kozy on Thursday 25th July 14:59
You have taken the calculation and its purpose out of context. I do not believe it is misleading: it is intended to provide data to make a comparison of modified braking components with stock, on the same car. Load transfer, grip etc can be taken as constant (within reason!) when comparing systems on the same car - the goal is to either tailor bias to suit the driver, or in the case of the M3 keep bias within the realms operable by the standard ABS programming.
The equations you speak of would be useful for creating a system for a scratch-built car, but less so in my opinion when upgrading an established platform. Also, to arrive at your figure you would be required to estimated a few variables for my car, for example the weight distribution, and intended tyre size and compound, all of which I have not revealed.
Let's take things back to basics. All I am interested in at this point is a comparison of the modified system bias to standard, so to make sure I'm not going completely insane I quickly ratified using http://www.tceperformanceproducts.com/bias-calcula...
As you can see my static bias comes out at 59.5% to the front. Factor in the (dynamic) 60% front bias from the valve, and I am more than happy.
FYI the calipers are from the rear of an F3 car.
The equations you speak of would be useful for creating a system for a scratch-built car, but less so in my opinion when upgrading an established platform. Also, to arrive at your figure you would be required to estimated a few variables for my car, for example the weight distribution, and intended tyre size and compound, all of which I have not revealed.
Let's take things back to basics. All I am interested in at this point is a comparison of the modified system bias to standard, so to make sure I'm not going completely insane I quickly ratified using http://www.tceperformanceproducts.com/bias-calcula...
As you can see my static bias comes out at 59.5% to the front. Factor in the (dynamic) 60% front bias from the valve, and I am more than happy.
FYI the calipers are from the rear of an F3 car.
Do you know how the stock system comes out though?
The brake force needs to match the dynamic weight distribution, plus a degree more front bias for safety. I'd wager the weight distribution was more than 60% sitting still, add say, 15-20% load transfer under heavy braking on average road tyres to give you 75-80%, and then think which axle is going to saturate and lock up first.
Again, I would advise you to reconsider it if you intend on driving the thing hard.
If you're happy with it though, carry on. Just take care the first time you hit the brakes...
The brake force needs to match the dynamic weight distribution, plus a degree more front bias for safety. I'd wager the weight distribution was more than 60% sitting still, add say, 15-20% load transfer under heavy braking on average road tyres to give you 75-80%, and then think which axle is going to saturate and lock up first.
Again, I would advise you to reconsider it if you intend on driving the thing hard.
If you're happy with it though, carry on. Just take care the first time you hit the brakes...
Kozy said:
Do you know how the stock system comes out though?
The brake force needs to match the dynamic weight distribution, plus a degree more front bias for safety. I'd wager the weight distribution was more than 60% sitting still, add say, 15-20% load transfer under heavy braking on average road tyres to give you 75-80%, and then think which axle is going to saturate and lock up first.
Again, I would advise you to reconsider it if you intend on driving the thing hard.
If you're happy with it though, carry on. Just take care the first time you hit the brakes...
Yes sure, stock is 64% static. I'm happy to admit I'm no expert when it comes to braking, but I want to get the car finished and corner weighted before I start tuning it further.The brake force needs to match the dynamic weight distribution, plus a degree more front bias for safety. I'd wager the weight distribution was more than 60% sitting still, add say, 15-20% load transfer under heavy braking on average road tyres to give you 75-80%, and then think which axle is going to saturate and lock up first.
Again, I would advise you to reconsider it if you intend on driving the thing hard.
If you're happy with it though, carry on. Just take care the first time you hit the brakes...
Cheers.
No problem.
If at some point during your break from the project you want to go through the calculations and double check that you've got a well balanced system for this particular car, then feel free to drop me an email and I will be more than happy to talk you through it all. Even if we do eventually come to the conclusion that the current system is OK, with something as safety critical as brakes it can never hurt to be too thorough.
Don't worry, I don't charge anything!
If at some point during your break from the project you want to go through the calculations and double check that you've got a well balanced system for this particular car, then feel free to drop me an email and I will be more than happy to talk you through it all. Even if we do eventually come to the conclusion that the current system is OK, with something as safety critical as brakes it can never hurt to be too thorough.
Don't worry, I don't charge anything!
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