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Old 06-02-2022, 06:55 PM   #1
Nickagriffin
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Default Budget track car brake fade issues

Hey all, I recently took my turbobrick out for my first track session a few weekends back. Before the event, I put new EBC Yellowstuff pads in the front and Bosch metallic pads in the rear. I also did a full flush with DOT4 fluid.

The brick did really well other than some scary brake fade moments. It seemed like the hotter it got, the squishyer the pedal got. I talked to some brake guys and they all had different ideas. Another factor to keep in mind is that the brake bleeder nipples broke off of BOTH front calipers. I figure I can go at this two ways:

Option 1 (expensive)
- R calipers in the front (potentially also in the rear down the line)
- Race compound pads all around
- Stainless brake lines
- RBF 600 fluid

Option 2 (cheap)
- Replace front calipers with set I have on a parts car
- Race compound pads all around
- Stainless brake lines
- RBF 600 fluid
- Air ducting for cooling ?

I really don't want to go back on the track with a good chance of experiencing fade, especially as I start going faster. Is the OEM stuff really good enough?

More car specs:
- 1992 sedan (factory ABS)
- b230+t around 200hp
- 255s on 17x9s
- Brand new master cylinder
- Around 2700lbs without driver
- Top speed on the straight was around 110mph
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Old 06-02-2022, 06:59 PM   #2
mikep
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If there is still old fluid in the calipers, start there. Ducting can?t hurt.
As for the pads, i have no experience with ebc.
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Old 06-02-2022, 07:19 PM   #3
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Originally Posted by mikep View Post
If there is still old fluid in the calipers, start there. Ducting can?t hurt.
As for the pads, i have no experience with ebc.
I forgot to mention, I talked to a tech at the track and he told me to take the caliper off and bleed it through the line connection. The way I did it was by flipping the caliper over so the line was at the top and I had a friend pump and hold the brakes the normal way. Seems like that should have gotten -most- of the air and old fluid out of the fronts... right?
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Old 06-02-2022, 07:49 PM   #4
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Stock calipers offer plenty of power for track use, they just can’t handle the heat as you found.
I’ve melted the boots off a set of front calipers on the turbo 242 while at a track day.

Ducting and race pads are your cheapest option, or a well balanced brake kit with appropriate sized aluminum calipers and rotors.

STS offers two wilwood brake kits, BNE has a brembo kit. Both options would be a big step up in brakes. The R kits work, but they require a MC change and result in an unbalanced brake setup.
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Old 06-02-2022, 07:52 PM   #5
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Try pads and fluid first.

I run stock Girlings on my 740 endurance racecar. Stock calipers are more than enough to stop the car and out break many other cars. I suspect it is similar for 240s, but others can chime in.

I run custom ordered Raybestos ST-43 race pads. They last 6 or more endurance races, never fade, and don't eat rotors too bad. They are super noisy and squeal a lot. $260 a set for fronts/$160 for rears. There are probably better options for street/track use, but for endurance racing the ST-43 is king IMHO.

Motul 600/660 is great stuff, ATE TYP 200 is also great and less expensive. I have been running it for years and have never had it boil.

I use cheap blank vented rotors. No drilled holes to crack. Slotted are probably fine, but never felt the need to spend more $$. I have seen people with exploded drilled rotors from track use.

I run rubber lines, others feel stainless help.

I had inconsistent braking until I got a Motive power bleeder.

I hear ducting helps, but I have not ducted yet.

At some point I want to move to Wilwood calipers in front, but it is mostly to be able to get off the shelf ST-43 pads at about $100 less and be able to change the pads without disassembling the caliper.

Are you endurance racing?
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Old 06-03-2022, 01:13 AM   #6
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One problem we encountered when converting a street car to track use was there was contamination baked on to the inside of 30 year the old callipers, which when subjected to the heat of track braking dislodged and contaminated the break fluid, resulting in boiling fluid and brakes going away. A simple solution was to buy a remanufactured caliber (nice and clean) and using a high temp brake fluid such as Red Line RL - 600 ( don't settle for any non racing fluid).
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Old 06-03-2022, 09:04 AM   #7
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Quote:
Originally Posted by culberro View Post
The R kits work, but they require a MC change and result in an unbalanced brake setup.
For fronts R calipers only, there is no requirement or need for a MC change. Usually just larger wheels.
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Old 06-03-2022, 09:42 AM   #8
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All good advice. I think I'll try keeping the stock calipers w/ ducting for now until I have the funds for the nice Willwood/Brembo stuff.

Say for the sake of the argument, I only could afford one set of race pads at a time. Would it be dumb to run race pads in the rear and keep the EBC yellowstuff (street/track) in the front? Or would that cause a dangerous imbalance in braking force?

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Are you endurance racing?
No, I'm currently doing HPDE sessions which are typically 35 minutes.

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Originally Posted by dkrause View Post
One problem we encountered when converting a street car to track use was there was contamination baked on to the inside of 30 year the old callipers, which when subjected to the heat of track braking dislodged and contaminated the break fluid, resulting in boiling fluid and brakes going away.
That's an interesting point. Would it be worth trying to clean the calipers I have before trying ordering new ones or is it a lost cause?
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Old 06-03-2022, 09:44 AM   #9
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Originally Posted by dbarton View Post
For fronts R calipers only, there is no requirement or need for a MC change. Usually just larger wheels.
Dave B
Dave, I'm sure you've tried every brake setup under the sun. If only doing fronts, would you recommend R brakes or Willwood/brembo? I'd like to stick with 17" wheels
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Old 06-03-2022, 09:48 AM   #10
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Wheel fans.
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Old 06-03-2022, 10:05 AM   #11
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Originally Posted by Nickagriffin View Post
Say for the sake of the argument, I only could afford one set of race pads at a time. Would it be dumb to run race pads in the rear and keep the EBC yellowstuff (street/track) in the front? Or would that cause a dangerous imbalance in braking force?
I would do the fronts first. You don't want better braking in the rear. Rears last a lot longer than fronts. Are you locking up the rears?

For HPDE there might be more affordable pad options, but I don't have the experience to advise.

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Originally Posted by Nickagriffin View Post
Dave, I'm sure you've tried every brake setup under the sun. If only doing fronts, would you recommend R brakes or Willwood/brembo? I'd like to stick with 17" wheels
Aren't R brakes actually Brembos?
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Old 06-03-2022, 10:14 AM   #12
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Originally Posted by dbarton View Post
For fronts R calipers only, there is no requirement or need for a MC change. Usually just larger wheels.
Dave B
The R calipers shift the bias drastically to the front when using a stock MC, and you get a squishy pedal. They work, but it is not what I would want for a track day car.
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Old 06-03-2022, 10:49 AM   #13
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Originally Posted by culberro View Post
The R calipers shift the bias drastically to the front when using a stock MC, and you get a squishy pedal. They work, but it is not what I would want for a track day car.
Squishy pedal is the exact opposite of what I'm after. I want a super firm pedal 100% of the time. Easier said than done on a 240...

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I would do the fronts first. You don't want better braking in the rear. Rears last a lot longer than fronts. Are you locking up the rears?
Yeah, figured. And no, I haven't really been close to locking up the brakes even on the track.

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Old 06-03-2022, 11:10 AM   #14
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Quote:
Originally Posted by Nickagriffin View Post

Say for the sake of the argument, I only could afford one set of race pads at a time. Would it be dumb to run race pads in the rear and keep the EBC yellowstuff (street/track) in the front? Or would that cause a dangerous imbalance in braking force?
Full disclosure - I owned a pre ABS 242; but, no experience with the 242 on the track.

First observation, race pads are more about heat tolerance than increasing the coefficient of friction at the disk surface. The limited number of race pads that I have experienced do not work well until they get hot. Because of weight transfer your front brakes do more of the work so they generate more heat and would benefit from the full race pads. However, my recommendation would be do not mix the race with non race pads.

Is this a track car or a track / street car? If this is a track only car then full race pads would be the ticket if you are currently generating enough heat to get pad fade. If it is a track / street car then two sets of pads (one for track use and one for street use) is a better way to go. The cold grip of street / track pads is not as good as straight street pads for stop and go driving and if you are really fast they don't have the hot grip of race pads. Plus, perfectly serviceable street pads are available from RockAuto for really cheap allowing you to fork over extra for the racing pads. If you have not experienced full race pads on the front be sure to test drive and warm them up. If you go into the first corner full metal with cold brake pads you may be exiting the first corner as twisted metal.

Make sure the calipers are completely flushed and rid of all old fluid. Whether you remove and bench clean or use a pressure bleeder is up to you. If you track regularly you are going to be flushing the brake system regularly so getting a pressure bleeder may be a good idea if you don't already have one. Follow recommendations for a high temperature brake fluid.

Brake ducts on the front would be a low cost addition that can't hurt. You said you are running 255 on 17x9 rims. Compared to OEM I am thinking that rim must shield the brake disk more from air flow which would make ducting even more of potential benefit. Are you running any kind of an aftermarket front air dam - those can reduce air flow to the front brakes making dedicated ducts more of a requirement.

If your rubber flex lines are relatively new they are probably not contributing to your brake fade. If you get serious about track use you will probably want to migrate to braided steel because the heat from the rotors will contribute to rubber deterioration.

So flush the hydraulics, add cooling ducts and try race only pads (for the track). If you are still getting brake fade then get out your wallet and start spending.

Last edited by 142 guy; 06-03-2022 at 11:18 AM..
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Old 06-03-2022, 11:25 AM   #15
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I'd recommend this kit, in the 310mm/ 12.19in rotor size: https://www.stsmachininginc.com/coll...240-brake-kits

It has offers slightly more front brake bias (~5% vs the 53(!)% of the R calipers) and a whole lot more tolerance to heat, and it's lighter. The caliper piston area is smaller than stock, so the brake pedal will be more firm than stock. The added braking force comes from the increase in rotor diameter.
You can get pads compounds from DD to GT/Prototype levels of pads, prices range from $85-280 for pads.

If you want a significantly lighter brake setup with stock bias, the "rally" or 300mm/11.75in kit is what you want.

Or just stock calipers with some endurance pads and ducting.
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Old 06-03-2022, 12:33 PM   #16
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We offer a "Medium" kit,

https://www.bneshop.com/collections/...ake-brembo-kit

Could use that with 316mm rotors and get a huge increase in thermal capacity compared to stock.


If you want to go front and rear and do a big upgrade there's always the 17z route too.

https://www.bneshop.com/collections/...o-17z-adapters
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Old 06-03-2022, 01:31 PM   #17
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A bonus with the ducting is your wheel bearings will also be happier.
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Old 06-04-2022, 12:33 PM   #18
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Given how nasty 240 brake systems are to bleed, I think you need to start with getting calipers with bleed nipples that work. My guess is that you have a bit of air/old fluid/Cookie Monster furr in them and that's your problem. It doesn't take much of that to make them feel crappy. We (successfully) raced a 245 in LeMons for years on a completely stock brake system (except for pads) and we NEVER EVER EVER NEVER had a brake problem or worried about it or pussy-footed it. We did remove the backing plates, but did not run ducting. If you're having a problem, it can be fixed without thinking you have to re-engineer the whole thing.

If the oil fill cap was seized on the valve cover and you couldn't put oil in it, would you swap the motor or just put a valve cover on it? Goofy analogy, but you see where I'm coming from.
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Old 06-04-2022, 05:54 PM   #19
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If the oil fill cap was seized on the valve cover and you couldn't put oil in it, would you swap the motor or just put a valve cover on it? Goofy analogy, but you see where I'm coming from.
Post that as a suggestion some time. You might be surprised at how many takers you get looking for an excuse to 'go big'.
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Old 06-05-2022, 02:37 AM   #20
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Full flush
Broken nipples

Can't have both.

240 stock brakes with good pads (Feredo) was more than enough for our road racing 242.
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Old 06-05-2022, 08:04 AM   #21
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Originally Posted by culberro View Post
The R calipers shift the bias drastically to the front when using a stock MC, and you get a squishy pedal. They work, but it is not what I would want for a track day car.
I don't know how many people have done this over the last 18 years, but I think a LOT. I've received a lot of emails about results. Not all are perfect and there are many variables with people trying different master cylinders, removing or not removing rear reduction valves, different vacuum boosters (yes, this makes a difference too), and some with new plumbing and some with a Wilwood proportioning valve. My result with a stock MC was a perfect, firm pedal. I don't know why you got a mushy one, but I don't think it was a related to the R calipers. The R calipers only have 11% more piston area that stock 240 calipers, so any thought of a "drastic" shift in bias is BS. The primary performance change (or bias change) is from the leverage of the larger rotor. This can be managed other ways as I show in my page.
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Old 06-05-2022, 08:07 AM   #22
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Originally Posted by Nickagriffin View Post
Dave, I'm sure you've tried every brake setup under the sun. If only doing fronts, would you recommend R brakes or Willwood/brembo? I'd like to stick with 17" wheels
The reason I went with Wilwoods on my 242 (with 12.2 inch rotors) was because I couldn't get the R calipers (13.2 inch rotors) to fit with my 17s and I didn't want to to buy 18s. With the Brembo kits that BNE offers now, that's the direction I would go if I was to do it now.
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Old 06-05-2022, 10:05 AM   #23
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Post that as a suggestion some time. You might be surprised at how many takers you get looking for an excuse to 'go big'.
Trollvo.
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Old 06-06-2022, 12:54 PM   #24
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Originally Posted by dbarton View Post
The R calipers only have 11% more piston area that stock 240 calipers, so any thought of a "drastic" shift in bias is BS. The primary performance change (or bias change) is from the leverage of the larger rotor. This can be managed other ways as I show in my page.
The radius for clamping is ~1.3" more than a stock 240, and that's where the biggest change comes from. Both of these combined increase the front bias to ~45% higher than a stock 240.

While this might be okay for a street driven and spirited driven 240, this is not what you'd want in a track car... especially if the track was wet.

I've helped numerous t-brickers get their alternative brake systems sorted out due to the bias being shifted one way or the other too much. With regular driving, it's usually ok. But when someone is drag racing and hits the brakes at 150mph and locks them up.... that's an issue. When someone is road racing in the wet and has chronic front brake lock-up, that's an issue. These are all issues that didn't show up until the car was pushed way past normal driving.

R Calipers and Explorer rear axles with stock brakes offer 40-60% more braking than stock, If used together with a larger MC it's a decent setup. Using just one of them will shift the total bias a significant amount, and that's an issue.

While a brake proportioning valve can be used to help, they have a "knee" pressure point that limits max pressure. Before the "knee" they do not limit pressure. I think the wilwoods lowest limit is ~150psi. So you have to build more than the lowest knee or break-over pressure before it starts to limit outlet pressure, and after that point it's not flat... just a slower pressure rise vs the inlet pressure.
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Old 06-06-2022, 01:24 PM   #25
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After installing the R fronts in my 245 I tracked it and found the fronts were easy to lock up prematurely if I wasn't precise. I removed the rear reduction valves and tracked it again and any bias limitation was no longer noticeable. I did not try a proportioning valve, but I think it could have tuned out any issues with the reduction valves removed if needed.

The 245 rear reduction valves are different from 244 valves, but I'm wondering if anyone knows or has more closely estimated the bias changes with or without them.

Greenbooks describe their operating pressures, but doesn't offer much more.
242/244 (1975): 3.0 MPa (435 psi)
242/244 (1976-): 3.4 MPa (480 psi)
245 (1975-76): 4.5 MPa (640 psi)
245 (1977-): 5.0 MPa (730 psi)

Dave

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