Road Racing Brake Setup

[Elvenhome21]

This is what I am working on for next spring and all of my cars will get this.
Parts list for new
Brake Rotors 11.75x1.25 $45x2 http://www.stockcarproducts.com/brakes14d.htm
Brake Calipers Wilwood Superlite/ Outlaw $130-170x2 (1.75 piston x 1 1/4 wide rotor)
http://www.speedwaymotors.com/xq/aspx/paging.yes/dept_id.10/display_id.1349/qx/Product.htm
Brake Hat Custom 1/8 steel plate or 1/4 aluminum plate
Caliper Bracket $10 and tools to do it
Wheel spacers? (my setup requires 2" min. offset for wheels)
Brake pads Performance friction 83 or 93 $120-$150
Time
This setup WILL fit in 15 in steel rims (racing Rims) (not sure about stock rims)
http://good-times.webshots.com/photo/2085800540090774303sjvguO
The first picture is what i am using for parts. paper is for mock up because my plasma cuter is giving problems at the moment.
http://good-times.webshots.com/photo/2483314310090774303tjMdXn
This picture is just the caliper hat and rotor

http://rides.webshots.com/photo/2527633130090774303EXHavg
this is everything put together sorry for the darkness but you will get the picture in the next link


http://rides.webshots.com/photo/2680884990090774303tsAoec
I don't have a paper bracket made up but all you need is like a 1/4x1 piece of steel about 2 inch's long for both sides with two holes drilled in the pieces. Use 3/8" grade 5 or better hardware for the bracket a you will be fine. I strongly recommend using grade 8 on any brake or hub parts along with safety wiring


Once i get my plasma cutter back up and running i will gladly make brake hats for people if there is enough demand.


This whole setup can be done for $300-$400 if you get the calipers pads rotors off of EBAY.

 

[mavisky]

I'm curious here... it seems to me like you're just building a 4 piston version of the dual piston brake upgrade that came on later awd dsm's?

Any reason for keeping the rotor so light and so small. The rotor's main job it to dissipate heat and provide a large friction surface. I understand the concept of keeping them light to reduce rotating mass and the advantages of a 4 piston caliper with multiple compounds over a stock caliper, but why not do a larger caliper and rotor to dissipate more of that heat? This just seems like a slight upgrade of the 2 piston brakes on most awd dsm's and as light as those rotors are they may even crack more under repeated stress?

 

[Elvenhome21]

These rotors are good enough to slow Super Late Models down at Slinger Speedway (fastest 1/4 mile on earth) for a 250 lap event. Also these calipers have almost 10 square inchs of surface area PER caliper so around 19 sqaure total for front, while the 2 piston setup only has 10 cubes total at the VERY most. These rotors are around 10-13 lbs of iron. These rotors are designed to do 100 lap races glowing orange and be used for an entire season.

Heres my opinion on lets say a 13" cobra rotor setup with 2 piston stealth calipers. The advantage of the 13" rotors is lighter weight and have slightly more braking torque from the bigger diameter. (which is why I am using 4 piston caliper) However Lighter Rotors crack very easiliy and they are narrow causing the light weight along with low fin count (i think they measure right around an 1 inch thick) The more fins you got the sturdier the rotor (less flex and lower chance of breaking in several pieces)

Racing rotors are also a High Alloy Ductile Iron which is very high strength and fatigue resistant, versus the cobra and Audi rotors are normally low grade gray iron or engine iron at best which is quite weak. Stock rotors crack and chunck versus racing rotors mainly just heat check which can be ground out 2-3 times over the life of the rotor.

The fins do little to cool the rotors unless you have brake ducts to force air through them. The heavier the rotor the hotter they get but can tolerate it as long as the pads work hence why racing pads have 1000-1600 *f operatiing temperature. Light weight rotors are meant for Daytona or Drag Racing were they only get used one time before they cool down. Heavy rotors stay consistant.

Heres my type of rotors

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This is what a stock rotor has

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You can get 12.18" tall rotors that are 1.38 to 1 9/16 thick which is a Martinville setup. But then you need gt 6000 calipers which are $900 a piece or 6 piston GN III calipers. My setup can fit in 15" racing rims without any problem and have plenty of room for cooling.

heres a piston size chart and surface area
My calipers have 4- 1.75" diameter pistons whichs equals 19.2 square inchs for 2 calipers
Stealth VR4 have 2- 1.5" diameter pistons which equals 7.08 square inchs for 2 calipers
My calipers are 270% bigger than the VR4s

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[mavisky]

That explains it very well. I was sure you had thought this out given your past history but it wasn't readily apparent to me why you'd chosen to go the route you'd gone. I'll be very interested to see the finished results of this project.

 

[RusherRacing]

Very good explanation but one question?

Are you changing the master cylinders and reservoir also? Because of the increased volume requirements of the new calipers? Also how will the pedal feel be affected by whatever master cylinder you are choosing. I will see if I can find the spreadsheet I made during college that calculates all that if you need it.

 

[Elvenhome21]

yes i plan on running either 1' or 1 1/8 master for the front, i am not sure what calipers i will be using for the rear. I plan or running something like this for brake and clutch assembly to give me more room and also be able to make all three pedals same height. The designers of this car get a F for room in this car for taller people 6'3 and 14 shoe is very tight.

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By the way what is stock master cyl size and clutch cylinder size

 

[RusherRacing]

Your stock Master should be 1" if you have the AWD (from memory please don't hold me to it). I believe the FWD is smaller, I am thinking 3/4".

 

[Elvenhome21]

I'm not to worried about what size im going to use for the time being, I got several masters to play with ranging from 5/8 to 1 1/8. I run a 7/8 for the front on my limited late model with similar brake setup and it works good, plus aftermarket masters have more stroke than stock and parts are cheaper to replace and rebuild/

 

[Slow old poop]

Those rotors of yours may stop Super Late Models, but how much do they weigh? Our AWD cars are HEAVY, dude. I've been running Stoptechs and cracking rotors like crazy. Five so far.

Also, how much are they really braking on a 1/4 mile track? From 100 mph to 80? That's a STAB. At Road America, I was braking from 140, three times a lap. That's HEAVY braking.

My Stoptechs work great on Greg Collier's car, but the banana only weighs 2,000 lb. On my car, at 3,000 lb, I crack rotors. I am having my Stoptech calipers widened by 1/4 in. with a spacer to accommodate thicker rotors in hopes of eliminating the cracking.

If your setup is equivalent to Stoptechs, you may want to reconsider your calculations and make the rotor bigger, heavier and wider.

Here's another problem you might want to address while you are in there fiddling with the brakes. When the pads wear down, I get a lot of pad knockback. It probably comes from the flimsy front suspension, ball joints, knuckles and whatnot flexing so much under braking and cornering. If you can figure out some way to strengthen the system, that would be very cool.

I'm committed to my modded Stoptechs, but if you develop a rear brake solution, I would be VERY interested.

Rich

 

[Elvenhome21]

actually slinger you go from 130 down to about 65 which is very similar to RA but that 2 cycles within a 11 second time period MUCH worse than RA
a SLM depending on the track is normally 2800lb which if you have a race only dam with no interior and lexan rear and sides a AWD should be the same.
and for the knockback you use a 2lb residual valve
http://www.stockcarproducts.com/residual.htm

 

[Slow old poop]

and for the knockback you use a 2lb residual valve
http://www.stockcarproducts.com/residual.htm

Tell me about the residual valve and where to mount it. I had a set once, but couldn't figure out where to put them. On the line going to the caliper? At the master cylinder? The resideual valves have since gone astray in my garage, but I could order another set if you think they would solve the knockback problem.

Rich

 

[Elvenhome21]

You put it right after the master

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put the mc side towards the master and the out side towards the tee.
Yeah get a 2lb for the front at least. It should solve most of the problems
$17.29
Part No.
2601874 2 lb. (blue)
http://www.stockcarproducts.com/residual.htm

 

[Slow old poop]

You put it right after the master

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put the mc side towards the master and the out side towards the tee.
Yeah get a 2lb for the front at least. It should solve most of the problems
$17.29
Part No.
2601874 2 lb. (blue)
http://www.stockcarproducts.com/residual.htm

Yeah, THAT's the one I had! I had two of them, one for each wheel (shows how much I know). Guess I better track them down again.

I got the bloody things, but they don't come with instructions. Nobody knew what to do with them -- not local race shops, brake shops, or my buddies.

Thanks!

Hey, pal, you can stay! I am very happy that you joined our little group here. You bring a whole new level of expertise to this arena. Can't wait to meet you at the track.

Rich

 

[Elvenhome21]

if you have them try just one on the front right after the master, if you still get knockback you could try using two, one on each caliper line (before the line goes out to the strut)
Normally you only need one for the front one for the rear.

Also if you need a place to crash when you come to RA i live in sheboygan which is less than 15 minutes away from the track. Plus any parts that may break (got 4 cars to snitch parts off of) or If you need fabrication/repair fully equipped race shop and parts

 

[Elvenhome21]

slow poop: i was reading in NASA Race at Road America Oct 21-22 that you had big problems with cracked rotors, the biggest no-no is the cross drilled rotors, the slotted rotors are fine but when you cross drill rotors (not meaning you) it creates a stress crack no matter how good the company does it (counter sunk, stress relieved, and cryo treat) there is nothing that will stop it from cracking on the fatigue/stress line, just the nature of the beast, the only time cross drilled rotors are ok is if the operating temperature is ALWAYS below 1000 degrees and the brakes are used in light/medium braking or one time use braking such as rear rotors or drag racing brakes. Yes, you do see High end cars/race cars with cross drilled rotors but those rotors are normally high manganese ductle rotors or Carbon-Ceramic rotors which cost a boat load.

 

[Slow old poop]

Sheboygan, eh? Isn't that "the greatest little town in da woild"? (I bet NOBODY knows where THAT song lyric came from). YOu can mention my name in Sheboygan but don't tell them where I am.

Thanks for the offer. We usually have a whole gang come up to NASA and Speedseeker events, with as many as three race cars and sometimes 10-12 people. How many can you handle? (Just kidding). Actually, you may be astounded at the number of DSM and 3000GT people who show up sometimes. We have GOT to get organized!

Wish we had known you in October. We DNFed because we blew the line to the oil pressure gauge, and couldn't find a 7-cent crush washer in Plymouth on Sunday afternoon. We coulda got it off one of your cars!

As for drilled rotors, I learned that lesson long ago. I think my first instructor warned me about those things. It seems the only drilled rotors worth having are Brembos that come on Porsches, because the holes are cast in, not drilled.

I also learned the hard way about PowerSlop rotors, when I broke two of them in half at the hub. PowerSlop rotors are ideal for cruising the boulevard because they look great, but never try using them on a race car.

For some reason, I seem to have more trouble than anyone with brakes. I've broken three rotors into little pieces and cracked five Stoptechs. Set the front pads on fire once, too.

Rich

 

[drivemusicnow]

Wish we had known you in October. We DNFed because we blew the line to the oil pressure gauge, and couldn't find a 7-cent crush washer in Plymouth on Sunday afternoon. We coulda got it off one of your cars!

Rich Rich Rich...

Everybody knows you don't re-use crush washers ... I keep a few spares in my garage... I think I should put a kit of all the little crap to take with me racing of all the little things that should be/need to be replaced should I have to repair/replace something at the track.

As for drilled rotors, I learned that lesson long ago. I think my first instructor warned me about those things. It seems the only drilled rotors worth having are Brembos that come on Porsches, because the holes are cast in, not drilled.

Not to harp on you, as it is a common rumor, however porsche rotors do not have holes that are cast in. They are drilled just like every other drilled rotor. The only difference between porsches brembos, and joe schmoe's pimp drilled rotors is that A) brembo does not put too many holes in the rotor, and B) they make sure that the holes are not through the structural vanes of the rotor.

For some reason, I seem to have more trouble than anyone with brakes. I've broken three rotors into little pieces and cracked five Stoptechs. Set the front pads on fire once, too.

Rich

What pads do you use? If the pads are not right for your application, you can easily crack rotors. A common example is using Pagid Black pads can in the wrong application, crack rotors in a single day of open tracking. I prefer using endurance compounds, as they tend to not be quite so agressive in wear of the pad or the rotor, and still provide excellent braking. You can get an entire season on one set of Pagid Yellows. I would possibly suggest going to a different compound. Also, you should definitely have some ducting to the fronts. I'd suggest before you spend a bunch on wider rotors and spaced calipers, you try to easy things first.

 

[Slow old poop]

Rich Rich Rich...Everybody knows you don't re-use crush washers ... I keep a few spares in my garage... I think I should put a kit of all the little crap to take with me racing of all the little things that should be/need to be replaced should I have to repair/replace something at the track.

I am no wrench, but we just needed something to make it stop leaking so I could finish out the day. The line broke, was spraying too much oil to continue, and Brent the Wrench could fix it but he needed a crush washer. We didn't care if it leaked a little. Alas, none were to found, not even a used one. When we got back home, Brent found what he needed at a hardware store for 7 cents.

What pads do you use? t.

Carbotechs, at the recommendation of Supercar Engineering. The rotors lasted almost all season before cracking, so the pads worked pretty good. No fade, and they wear pretty well. As we've discovered, while Stoptech rotors work on lighter FWD DSMs, they are inadequate for heavier AWD cars, which is why they crack.

You gotta understand, I USE my brakes. I mean, I STOMP on the suckers. I outbrake Porsches and M3s. My philosophy is: There's no coasting in racing. It's either flat on the gas or hard on the brakes. No set of pads would ever last me an entire season.

Rich

 

[Elvenhome21]

Drive: the porsche's use Carbon-Ceramic rotors which are very high grade , it all in the material, doesn't really matter to much the amount of holes (still create the stress crack), or if they are cast in, which would work very well but it would cost a fortune to cast the damn things, (I work in a foundry)

Carbon-Ceramic is a carbon fiber reinforced ceramic silicon carbide composite with excellent material properties. It can be tailored to specific applications, for example very low density with high strength.
http://www.sglcarbon.com/sgl_t/brakedisc/index.html

 

[MIdsm]

To calculate the caliper piston area, only one side of the caliper is used, i.e. on a four piston caliper only two pistons (on the same side) are used.

1.75" piston x2 = 4.80 sqin per caliper
and the same is true for sliding calipers:
1.50"piston x 2 = 3.54 sqin per caliper

which is a 36 percent area increase.

In order to have the same pedal pressure(while still using the power assist) if starting with a 1" MC the new master cyl would have to have a 1.16" diameter.

If you go with a custom non power assist setup then you would have to play with rear calipers/mc as well to retain a decent balance.

If you start with a 2 piston x1.5" calipers why not get 4 piston x1.5" calipers? Then you could use the stock MC, pedals and not need to mess with aftermarket pedals.

Or, if the aftrermarket MCs are a must, just remove the booster and stock MC, bolt a mounting plate for aftermarket master cylinders where the booster went, and add a balance bar to the stock brake pedal.

You would also have to keep an eye on the proper wheel offset, rotor and wheel runout (which might be hard going with non-hubcentric 4.5x5 to 5x5 adapters), lower ball joint on 1G that is very close to the stock rotor in compression, strut/spring to tire contact, tires rubbing on fenders, etc.

I would suggest that you try it first with a plywood hub and/or caliper bracket mock-ups and mount everything on the vehicle, with knuckle supported at ride height.

Good luck with the project.

 

[stealthTT]

I am no wrench, but we just needed something to make it stop leaking so I could finish out the day. The line broke, was spraying too much oil to continue, and Brent the Wrench could fix it but he needed a crush washer. We didn't care if it leaked a little. Alas, none were to found, not even a used one. When we got back home, Brent found what he needed at a hardware store for 7 cents.

It was a collet for the 1/8 inch compression fitting. It's broke before and it's one reason why I prefer electronic senders for pressure gauges.

I/we need to make a list of parts like this to take to the track.