My continuing big brake saga
#1
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My continuing big brake saga
So long story short, after trying out stock calipers and rotors, stock calipers and Corrado rotors, and wilwood calipers with Corrado rotors, I just ordered the TSE upgrade kit from Andrew and will be installing it in the next week or so.
To put this in context I am road-racing a track-prepared NA, with an LS1 engine swap (325 RWHP on the dyno), sticky tires, and aerodynamics, so my braking system needs are beyond anything one would normally experience. With much less power, for autocross, or for the street, Corrado rotors would be no problem.
Short story long...
I had tried the Corrado brakes with the stock caliper setup and Carbotech race compound pads. Though they definitely worked, I was chewing up rotors rather badly to the point where i was replacing rotors after 2-4 hours of track time. As a result I started looking for upgrade paths.
I was all hell bent to get the bbundy developed radial setup discussed in this thread. In fact I was just about to make the purchase. But then unexpectedly I had a chance to get a set of wilwood calipers and brackets for a Corrado rotor based setup. $200 bucks for everything so the price was right. But, once installed, I figured out after the fact that the pistons in the calipers were much too large to work correctly, at least not without a much larger master cylinder and larger calipers for the rear brakes (no easy solution there). So already having everything else in place, and a Time Trial event rapidly approaching, I abandoned the large piston calipers and ordered a set of the same Wilwood calipers used in the TSE kit (correct piston size). Fortunately, the mounts are exactly the same so they are a bolt-in fit with the Corrado adapter brackets already in place.
So at said TT event at Texas World Speedway I severely cracked a Corrado rotor while out on track. See the attached image. Even with ducting, and Hawk DTC-70 pads, the Corrado rotors could just not hang with the 325 RWHP of the LS1 engine on the track. So even through brake performance, pad wear, and rotor wear were much improved with the Corrado/Wilwood upgrade, it was still not enough and the crack was clear evidence of this... So, Mrs. Lincoln, that aside, how did you like the play?
So it was time to go to 11.75" rotors and proper rotor venting. Having already bought the Wilwood calipers, it made sense to get the TSE upgrade kit and reuse the calipers I already have. Otherwise I would have to sell off the calipers and pay additional money over that to go to the radial setup. I have ordered the TSE kit and have it on the way.
I also had a chance to buy a used V8R kit with the optional 6-pot front calipers. This is an insanely good brake kit, and right now AFAIK is the end-all of Miata big brake kits. But, it would have cost a lot more than Andrew's setup, and based on what I have read, and what I have seen personally with my car, I do not NEED the additional braking capacity in the rear. The sport brake rotor with the stock caliper, Hawk DTC-60s, and a Wilwood proportioning valve is just fine. The rear pad life is good, I am not chewing up rotors, and I have all the rear bias I need.
A side note worth mentioning... Another issue I was dealing with was bump steer related to the LS1 swap kit k-member that is in the car now. It has the engine located very low in the car (good for CG) but as a result the steering rack was relocated lower in the car and thus the geometry was not quite right. So I put together an adjustable bump steer kit that corrected the geometry very nicely.
The custom tie rod ends I built are bigger than the stock ends, but they fit with the Corrado rotor offsets. But, the rod ends are too large to clear the hat offset of all of the Wilwood rotor based big brake kits. And, after looking through all of the Wilwood based hat and rotor options, there is just no easy way to get an 11.75" rotor to fit with the Corrado brake offset. There are interface problems between the components, and even if there were not, the rotor ends up too far outboard for the calipers to clear even 6ULs. So I have bought the LE tie rod ends that are offset a bit more than the stock ones, and will be using those in place of my custom tie rod ends. The bumpsteer may suffer a bit, but I need the big brakes more. Besides, the bump steer is so non-existent right now, even if it gets a bit worse, it will not be a big deal.
Whew... that is a lot to write about.
To put this in context I am road-racing a track-prepared NA, with an LS1 engine swap (325 RWHP on the dyno), sticky tires, and aerodynamics, so my braking system needs are beyond anything one would normally experience. With much less power, for autocross, or for the street, Corrado rotors would be no problem.
Short story long...
I had tried the Corrado brakes with the stock caliper setup and Carbotech race compound pads. Though they definitely worked, I was chewing up rotors rather badly to the point where i was replacing rotors after 2-4 hours of track time. As a result I started looking for upgrade paths.
I was all hell bent to get the bbundy developed radial setup discussed in this thread. In fact I was just about to make the purchase. But then unexpectedly I had a chance to get a set of wilwood calipers and brackets for a Corrado rotor based setup. $200 bucks for everything so the price was right. But, once installed, I figured out after the fact that the pistons in the calipers were much too large to work correctly, at least not without a much larger master cylinder and larger calipers for the rear brakes (no easy solution there). So already having everything else in place, and a Time Trial event rapidly approaching, I abandoned the large piston calipers and ordered a set of the same Wilwood calipers used in the TSE kit (correct piston size). Fortunately, the mounts are exactly the same so they are a bolt-in fit with the Corrado adapter brackets already in place.
So at said TT event at Texas World Speedway I severely cracked a Corrado rotor while out on track. See the attached image. Even with ducting, and Hawk DTC-70 pads, the Corrado rotors could just not hang with the 325 RWHP of the LS1 engine on the track. So even through brake performance, pad wear, and rotor wear were much improved with the Corrado/Wilwood upgrade, it was still not enough and the crack was clear evidence of this... So, Mrs. Lincoln, that aside, how did you like the play?
So it was time to go to 11.75" rotors and proper rotor venting. Having already bought the Wilwood calipers, it made sense to get the TSE upgrade kit and reuse the calipers I already have. Otherwise I would have to sell off the calipers and pay additional money over that to go to the radial setup. I have ordered the TSE kit and have it on the way.
I also had a chance to buy a used V8R kit with the optional 6-pot front calipers. This is an insanely good brake kit, and right now AFAIK is the end-all of Miata big brake kits. But, it would have cost a lot more than Andrew's setup, and based on what I have read, and what I have seen personally with my car, I do not NEED the additional braking capacity in the rear. The sport brake rotor with the stock caliper, Hawk DTC-60s, and a Wilwood proportioning valve is just fine. The rear pad life is good, I am not chewing up rotors, and I have all the rear bias I need.
A side note worth mentioning... Another issue I was dealing with was bump steer related to the LS1 swap kit k-member that is in the car now. It has the engine located very low in the car (good for CG) but as a result the steering rack was relocated lower in the car and thus the geometry was not quite right. So I put together an adjustable bump steer kit that corrected the geometry very nicely.
The custom tie rod ends I built are bigger than the stock ends, but they fit with the Corrado rotor offsets. But, the rod ends are too large to clear the hat offset of all of the Wilwood rotor based big brake kits. And, after looking through all of the Wilwood based hat and rotor options, there is just no easy way to get an 11.75" rotor to fit with the Corrado brake offset. There are interface problems between the components, and even if there were not, the rotor ends up too far outboard for the calipers to clear even 6ULs. So I have bought the LE tie rod ends that are offset a bit more than the stock ones, and will be using those in place of my custom tie rod ends. The bumpsteer may suffer a bit, but I need the big brakes more. Besides, the bump steer is so non-existent right now, even if it gets a bit worse, it will not be a big deal.
Whew... that is a lot to write about.
Last edited by ZX-Tex; 06-28-2011 at 01:05 PM.
#3
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With the speeds you and I achieve on the track and our lust for life, great brakes are more of a necessity. You made the right decision. I've already had 3 incidents where I could have been seriously injured or worse due to brake failure.
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Re: 6pots, the only reason to run them is if you want a firmer pedal, but with DL4s/DTC70s, our 11.75s, and an NB sport booster, my pedal is scary, scary firm.
There's no additional braking capability, virtually no increase in pad life, and pad costs go up by quite a bit. I had DL4s, I bought DP6s, ran them for ~3 events, then took them off and bought another set of DL4s. They look bitchin' cool and the pedal feel is definitely better, but IMO there's no performance or cost benefit. If there were, I'd still be running them - hell, I still own a set.
There's no additional braking capability, virtually no increase in pad life, and pad costs go up by quite a bit. I had DL4s, I bought DP6s, ran them for ~3 events, then took them off and bought another set of DL4s. They look bitchin' cool and the pedal feel is definitely better, but IMO there's no performance or cost benefit. If there were, I'd still be running them - hell, I still own a set.
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I've been thinking about running my front goodwill brake kit on the back and a 11.75" set up on the front with some 6 piston calipers. I've never had problems chewing up motors with the cobalt pads I use and sell but I do crack them, and with my new set up going into the insane category I will need more.
#6
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I also had all of those little micro-cracks that I can see in Hustler's rotor picture. Pretty amazing. As an aside comment I set my fastest lap of the weekend with the cracked rotor shown above. It could have ended badly but instead is an amusing anecdote. I had pedal vibration of course while out on the track. But I thought I had warped a rear rotor, not severely CRACKED a FRONT ROTOR. I had a 'holy crap I could have died' moment when I was back at home and started looking for the source of the pedal vibration. If I had known, I would have immediately tried to find some replacement rotors or put the car back in the trailer.
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Re: 6pots, the only reason to run them is if you want a firmer pedal, but with DL4s/DTC70s, our 11.75s, and an NB sport booster, my pedal is scary, scary firm.
There's no additional braking capability, virtually no increase in pad life, and pad costs go up by quite a bit. I had DL4s, I bought DP6s, ran them for ~3 events, then took them off and bought another set of DL4s. They look bitchin' cool and the pedal feel is definitely better, but IMO there's no performance or cost benefit. If there were, I'd still be running them - hell, I still own a set.
There's no additional braking capability, virtually no increase in pad life, and pad costs go up by quite a bit. I had DL4s, I bought DP6s, ran them for ~3 events, then took them off and bought another set of DL4s. They look bitchin' cool and the pedal feel is definitely better, but IMO there's no performance or cost benefit. If there were, I'd still be running them - hell, I still own a set.
Or at least not unless I turbocharge the LS1
Last edited by ZX-Tex; 07-08-2011 at 07:12 PM.
#8
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Brake failure FTMFL.
#9
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Now you can run the cheap ****. I Run Ate but could probably run LMA and never have a problem. I have 3.5 days on my Wilwood fronts and there is no cracking, very little wear, and pad life is crazy good. I started with a tick less than a backing-plate width of pad material and ran 2-days at Hallett and 1.5 days at HHR and both of those tracks are pretty hard on brakes, Hallett is a brake eater. I might be able to get 8-10 days on a set of pads. Hell, we might be talking about 1-season on a set of pads.
#10
Do you have brake ducts set up? They are almost mandatory on track driven subarus, but they are quite a bit heavier than a miata. If you can't add more thermal capacity then all you can do is add cooling right? I wish someone made some bolt on ducts that work with abs sensors. I am not nearly fast as you guys so I won't need them for a whille though.
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Do you have brake ducts set up? They are almost mandatory on track driven subarus, but they are quite a bit heavier than a miata. If you can't add more thermal capacity then all you can do is add cooling right? I wish someone made some bolt on ducts that work with abs sensors. I am not nearly fast as you guys so I won't need them for a whille though.
Don't those rado rotors vent from the front? I didn't have any issues with cracking rotors while using my 10.8'' Sport rotors with the Chikara bracket and 4 pot dynalites. New set up will be using the same rotors, but with DP4s and a custom bracket to fit under the Panasports.
One of the best parts about the big kit(s) is that the brake pedal feels the same, every time. This was not always the case and it was a guessing game as to what the pedal would feel like and at which portion of the track I'd overheat the pad and require additional pedal pressure. It doesn't matter how many times I brake the car down from 100mph, how many time I touch the pedal between threshold braking, the pedal feels exactly the same, every time. It was a real trip to get behind and close in on the huge-rubbered Porsches and Panoz, see their brake lights light up, wait a couple car lengths, then brake.
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I wonder if part of your temp delta is due to the aluminum hats and small surface area between the rotors and hats. Too bad you weren't able to do your temperature analysis on 2 piece 11" rotors. Those friction rings are $80 a pop though.
#16
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Yeah, I think rotor ring price was a big reason why we have the kit we do, $32 per ring is nice.
# WW160-0471
http://www.hrpworld.com/index.cfm?tp...action=product
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One of the best parts about the big kit(s) is that the brake pedal feels the same, every time. This was not always the case and it was a guessing game as to what the pedal would feel like and at which portion of the track I'd overheat the pad and require additional pedal pressure. It doesn't matter how many times I brake the car down from 100mph, how many time I touch the pedal between threshold braking, the pedal feels exactly the same, every time. It was a real trip to get behind and close in on the huge-rubbered Porsches and Panoz, see their brake lights light up, wait a couple car lengths, then brake.
+1. The old Wilwood/Corrado setup did what we wanted it to do (extend pad life significantly vs. stock calipers), but the new 11.75 kits blow the old Corrado kits away. The pedal feel and consistency is a big step up, and the reduced operating costs are the icing on the cake.
Link in my sig is fixed, thanks for the heads up.
We do stock replacement rotors as well, just haven't gotten them onto the website yet.
#19
I went through the same issues with the Corrado setups way back in time. I have been running my 11.75” Dynapro radial setup since 2004 it basically cured all my braking concerns especially since switching to Cobalt Friction XR2 pads. And then add further refinements of sport calipers for the rear and a 1” 929 master cylinder.
The advantage to the Dynapro Radial caliper is ¼” smaller clearance radius fits inside 15” wheels better than any other caliper I have seen and it uses thicker pads that last even longer than the Dynalite setups. I also suspect the caliper is marginally stiffer.
FWIW Miataroadster is working on something and Bill has been asking questions. The off the shelf kit for the Mini cooper like I have works pretty darn nice though.
I had no issues braking down hill at 130mph into a second gear corner at Pacific Raceways just last week. If it wasn’t for traffic I think I would have been able to beat the Spec Miata lap record by a full 10 seconds down in the 1:31’s
Bob
The advantage to the Dynapro Radial caliper is ¼” smaller clearance radius fits inside 15” wheels better than any other caliper I have seen and it uses thicker pads that last even longer than the Dynalite setups. I also suspect the caliper is marginally stiffer.
FWIW Miataroadster is working on something and Bill has been asking questions. The off the shelf kit for the Mini cooper like I have works pretty darn nice though.
I had no issues braking down hill at 130mph into a second gear corner at Pacific Raceways just last week. If it wasn’t for traffic I think I would have been able to beat the Spec Miata lap record by a full 10 seconds down in the 1:31’s
Bob
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I am definitely looking forward to good performing, trouble-free brakes.
So allow me to summarize for future reference. If you are going to hard core road-race your FI (or V8 swapped) Miata, the baseline configuration is:
- 11.75" Wilwood rotors, hats, and 4-pot calipers (radial or standard) for the front
- Sport rotors for the rear (via the M-Tuned bracket for example)
- Cooling ducts on the front (backing plates are not strictly necessary)
- Race compound pads all around (Hawk, Carbotech, Cobalt Friction)
- Wilwood proportioning valve on the rear brake line (with a cockpit adjuster if you want some additional awesomeness).
Anything less may be problematic. Feel free to chime in on this list gentlemen.
So allow me to summarize for future reference. If you are going to hard core road-race your FI (or V8 swapped) Miata, the baseline configuration is:
- 11.75" Wilwood rotors, hats, and 4-pot calipers (radial or standard) for the front
- Sport rotors for the rear (via the M-Tuned bracket for example)
- Cooling ducts on the front (backing plates are not strictly necessary)
- Race compound pads all around (Hawk, Carbotech, Cobalt Friction)
- Wilwood proportioning valve on the rear brake line (with a cockpit adjuster if you want some additional awesomeness).
Anything less may be problematic. Feel free to chime in on this list gentlemen.