track brakes discussion

[atomicEGT]

continued from Jim's build thread:

Wow---5-600HP!!!! I didn't realize you could get that much and still have axles/hubs/gearbox left after a few laps!!! I'll be interested to see how that works out---as far as brakes, you'll need at least what I have, probably more rear like you suggested and a bunch of air ducted to the center of the rotors---honestly with that kind of speed I'd use a water sprayer in the ducts if they allow it---that's pretty extreme stuff.

Any idea what size tire you'll be trying to fit under there??? At 200HP with an lsd we can spin the tires (225/50/15) a bunch after the apex on the slow corners---I drive a 700HP SRT4 (305's in front/285's rear) from time to time and have to run at about 300HP (low boost mode) until I hit the front/back straights---and even then there's this hump at Willow Springs that we run over at about 85mph and I leave black stripes down the back of it when I try for full boost mode to early. When you get closer, let me know I'd be interested in helping with the development of the brake system---I'll send you out some temp paint and what not---figure out what temps your seeing to determine what you'll really need.

I'm not sure why they wouldn't allow a water sprayer, but it's been a while since I looked at the rules so I'd have to double-check.

As far as tires go, I'm not really sure at this point. It will likely be a few years before the car is ready, but the goal is to run as many HPDEs at Lime Rock as I can afford once the E153 is in the car next summer. At that point it will likely only make 300whp, which ought to be interesting enough. From your description, it sounds like I'm just going to vaporize the tires- I may be better off running on low boost for reliability and traction. I definitely appreciate the insight- I spend most of my time trying to go fast in a straight line, so this kind of stuff is new to me!

also, don't underestimate the power of brake cooling ducts. The biggest problem I've run across is just a lack of enough surface area to actually dissipate the heat generated.

Pad compounds that are able to deal with the heat for longer periods of time are awesome (I'm using Carbotechs currently), but if you can't dissipate the heat, you're still going to boil fluid, and burn away the grease in your wheelbearings. Then when you slow down and pull into the pits, your hub, already hot and smoking, spontaneously starts with the flames. They look pretty, but it kinda sucks.

--sarge

Duly noted- I've got some ideas on how to run the ducting, and I'm working on getting some Astina knuckles to be able to run bigger Miata rotors front and rear (for the first, low-power version of the car). Since the event is 5000 miles, reliability is definitely going to be important.

[MATT91GT]

5000 miles in one event? damn are you crossing the country and coming back?

[atomicEGT]

https://www.onelapofamerica.com

[MATT91GT]

oh man thats awesome

[Mazda_Powered]

yea i was thinking to myself last time i was under the protege it would be fairly easy to get some type of ducting system to work. I hope to be autoxin my car so keepin the brakes alive and cool is important lol

[XelderX]

It's been awhile since I've read the One Lap rules as well, but don't you have to do the entire event on one set of tires? If that is the case I would look into bolting up some 949 Racing 6UL rims in 15X9 with a set of 225/45-15 Toyo R1R tires. To get anything wider on the car you would have to go up in diameter and that would really start to screw with the gearing.

[atomicEGT]

are the R1Rs DOT-legal? my concern with 15x9s is trying to fit them in the rear, though I suppose I am not opposed to rolling/pulling the rear wheel arches to make them fit.

[crazycanadian]

yea i was thinking to myself last time i was under the protege it would be fairly easy to get some type of ducting system to work. I hope to be autoxin my car so keepin the brakes alive and cool is important lol

Ducting in Autoxing isn't something you need to worry about... You aren't hard enough of the brakes to over heat them during autoxing... A good pad will more then due good enough...

[Mazda_Powered]

oh cool lol good to know

atomic, you planning on doing any body work to the wagon? if so, you should radius the rear wheel wells, i did that to my old EGT and was slammed on 15x8 w/ 205/50r15 with a 25 offset and no rubbing lol.

[SgtRauksauff]

the stupid flat fenders of the escorts are a frickin' PITA. running with S/R strut / Eibach spring setup, with 15mm spacers and extended studs in the back, on SSR 15x7s, with 205/50-15 Hoosier R4's, I had only about 2, maybe 3mm of space between the rear strut and the tire sidewall. I had to roll the rear fenders, and actually give them some visible outward rolling as well Just parked, I could barely fit my index finger between the tire and the fender, up at an angle. It was actually tucked between .25 and .5 inches. Running the 6UL's is in my plan for the future, but so is re-doing the fenders with some sort of flares/arches so I can actually FIT the darned things in there.

crappy part is, the rear fender's forward curve is basically part of the back doors, so just slappin' on some flares isn't going to do the trick, it's going to take some careful work.

I've been mulling it over for a few years, I think I might have something finally figured out, but it'll be awhile before I can try it...

As for brakes, since I haven't driven my wagon in awhile, this experience is with my corolla. Just before a 2-day weekend event at Brainerd Int'l Raceway, on their 2.5 mile "competition road course", I installed Carbotech XP10's in the front, and XP8's in the rear. I had some really crappy ducting, just some 3" dryer duct zip-tied through a hole in the front bumper, and squashed between the frame rail and swaybar. Not a lot of air, but it DID help. I didn't have to do anything to my brakes the entire time I was there. I was out there for most sessions for about 30 mintues, the final one was about 45, with only a 5-minute break between the previous 30 minutes. On the very last lap, when I'd already decided to come in, the brakes finally got hot enough to give me a different pedal feel. flushed 'em that week, and things were perfect once again for the following weekend's lapping day at Shawano.

At BIR, I was hitting 115 (hey, the corolla only had 108whp) into turn 2, actually faster than a couple of my buddies in their EVOs and STis. I'd brake late, get through the apex, and be on the gas, harrying their asses until they got to a part where the 350whp would pull away from me. I love those Carbotechs.... kinda pricey though, but worth it. I'd like to try the Porterfields someday as well.

--sarge

[atomicEGT]

atomic, you planning on doing any body work to the wagon? if so, you should radius the rear wheel wells, i did that to my old EGT and was slammed on 15x8 w/ 205/50r15 with a 25 offset and no rubbing lol.

I'd like it to look as stock as possible, but I'm not against putting some subtle fender flares on it to fit the wheels I want.

the stupid flat fenders of the escorts are a frickin' PITA. running with S/R strut / Eibach spring setup, with 15mm spacers and extended studs in the back, on SSR 15x7s, with 205/50-15 Hoosier R4's, I had only about 2, maybe 3mm of space between the rear strut and the tire sidewall. I had to roll the rear fenders, and actually give them some visible outward rolling as well Just parked, I could barely fit my index finger between the tire and the fender, up at an angle. It was actually tucked between .25 and .5 inches. Running the 6UL's is in my plan for the future, but so is re-doing the fenders with some sort of flares/arches so I can actually FIT the darned things in there.

crappy part is, the rear fender's forward curve is basically part of the back doors, so just slappin' on some flares isn't going to do the trick, it's going to take some careful work.

I've been mulling it over for a few years, I think I might have something finally figured out, but it'll be awhile before I can try it...

As for brakes, since I haven't driven my wagon in awhile, this experience is with my corolla. Just before a 2-day weekend event at Brainerd Int'l Raceway, on their 2.5 mile "competition road course", I installed Carbotech XP10's in the front, and XP8's in the rear. I had some really crappy ducting, just some 3" dryer duct zip-tied through a hole in the front bumper, and squashed between the frame rail and swaybar. Not a lot of air, but it DID help. I didn't have to do anything to my brakes the entire time I was there. I was out there for most sessions for about 30 mintues, the final one was about 45, with only a 5-minute break between the previous 30 minutes. On the very last lap, when I'd already decided to come in, the brakes finally got hot enough to give me a different pedal feel. flushed 'em that week, and things were perfect once again for the following weekend's lapping day at Shawano.

At BIR, I was hitting 115 (hey, the corolla only had 108whp) into turn 2, actually faster than a couple of my buddies in their EVOs and STis. I'd brake late, get through the apex, and be on the gas, harrying their asses until they got to a part where the 350whp would pull away from me. I love those Carbotechs.... kinda pricey though, but worth it. I'd like to try the Porterfields someday as well.

--sarge

what offset were the SSRs? I have 15x7 Rewinds on my 93 GT, and I've had 17x7 wheels on the old GT (GR2/H&Rs) and haven't had strut clearance issues... those 17s rubbed on the fenders any time I took a corner/hit a bump/had someone in the back seat, since I didn't roll them.

I've heard a lot of good things about the Carbotechs, the Miata guys love them. I'll definitely be using them when I upgrade the brakes, and I'll be adding some ducting as well. The Corolla sounds like a fun little momentum car- I think I made 107whp in the Miata, and it was always fun annoying people in faster cars on back roads.

[SgtRauksauff]

it is a BLAST, and momentum for SURE.

Part 1 8:15
Part 2 9:25

I like the rewinds, I just wish I could afford minilites or panasports instead. I've got a set of 14x7 -9mm rewinds for the Corolla.
The SSR's are 42mm offset as far as I know I should measure them to make sure one of these days. Mounted in back with a 15mm spacer, so an effective 27mm offset. These were Hoosier 205/50's, though, which physically measure over 220. I ran some kuhmo ecsta 712s when I first got the rims, 205/50, and not even close to rubbing.

--sarge

[Lex]

Shameless plug, but I have the 11inch Corrado rotor setup using stock calipers still here if you're interested in a bit more surface area, more leverage, and keeping the car looking fairly stock.

[atomicEGT]

Sarge- don't feel like being mad jdm tyte and rocking a set of Watanabes? I'm going to have to see what fits when I buy new street tires- I'm a bit disappointed they don't make ES100s anymore, I loved those.

Alex- I'm kind of curious- what's the benefit of the bigger rotors if you're still using the stock calipers and pads? More surface area to dissipate heat?

[SgtRauksauff]

more surface area will help dissipate heat a little bit, but the largest benefit of it is that the larger diameter moves the clamping point further out, which increases the braking torque.


-sarge