How much of a real-world improvement does a front BBK really make on the performance of the car for track use only? Car currently weighs in around 2600-2700lbs on stock internal S52 power. In DE duty, even with double duty stints at the faster end of the fast run groups, the car is exhibiting zero fade. I have a custom cooling setup and am using stock rebuilt calipers with solid guide pins and PFC08 pads. Stock $45 rotors. I am having minimal rotor/pad wear.
This past weekend my bleed valve stripped off (grrr.. I did not do the last bleed) and subsequent extraction failed in a bad way. While I have ordered a new stock caliper, I am exploring perhaps just biting the bullet and getting a BBK now (specifically the AP racing kit).
The car is being setup for endure driving events like AER where street tires are going to be used (RE71Rs). The stock brakes can already over-brake these tires. Does it make sense to upgrade now or wait until speeds are higher with more aero, engine upgrades, and possibly even tire upgrades.
I have AP CP5200s on the front with 330mm rotors; and personally I absolutely love them.
As with a lot of things, I find it's the "area under the curve" rather than peak values that really counts. While stock brakes can over-brake the tires, the APs have a significantly improved ability to modulate and "control" the deceleration vs just mashing the pedal. I find the increased braking capability gives me a great advantage in braking zones, simply because I have more options than I would mashing on stock brakes.
Again- I love my setup, I'll admit I'm biased, YMMV.
The performance of bigger or BBK brakes is not going to be in stropping power. The stock brakes, as you say, are already tire limited. They will make a difference when you go to bigger slicks, like Pirelli or Michelin. Where you notice the difference is in feel, modulation, predictability, and fade changes. Proper brakes will be consistent for the entire race (stock seem to change after about 20 minutes). Also when properly sized and without a booster, the feel is SOOOO much better.
When we compare data on our Brembo GT-R equipped e46 with out stock 330i equipped e46, the braking force and deceleration slope is identical, but for feel, there is no contest.
Thanks for the note. Oddly enough, with the cooling setup we have and the PFC08s, consumables have been incredible to date. The major annoyance for me are the BW guide pins without the dust boot getting dirty and requiring constant maintenance.
Appreciate the comments... I hate spending money on things that I *know* I will replace down the road, yet I have a huge list of things to do that are all big money. Going to get a cage put in shortly (either during summer or at end of season). I also want data, improved aero, more spares, and possibly even some engine work in the off season. It's a $20k list of stuff. Where does the BBK really fit in?
I use the ECS pins/bushings which have an o-ring and a plastic caps on the inside end of the bushings. You still have the exposed pin where it goes into the bracket, but they seem to stay pretty clean and free. I still drive my car on the street, and I clean/lube them about twice a year or before track days.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
Race calipers? You definitely rebuild yourself ... takes about 15 minutes, and the seals are like 10$. We've ran ours for a couple seasons between rebuilds ... because lazy.
Oh, you mean stock calipers ... we removed our dust boots, and rebuilt only when leaking or sticking ... which only happened once or twice I think. Just now I got a set of rebuilt M3 calipers since the price was right.
Last edited by ScotcH; 07-11-2018 at 11:40 AM.
Well I decided to cheap out given the long list of other things to do and ordered from BW their new ATE calipers (did not want to go with Centric calipers for a race car application). When I took off the stock caliper, I was honestly very surprised to see the dust boot to still be 100% okay. Not sure if it is my cooling solution, the pads, or whatever... heat is not an issue yet on the tracks I've run on (NJMP T-bolt, Lightning, WGI) with this car.
I am most definitely seeing the wear on the *rest* of the car though.... seems like a constant maintenance event...
Last edited by tripitz; 07-11-2018 at 03:47 PM.
My car's original caliper boots and seals were still intact and fine after something like 135K street miles and several HPDE events. I only rebuilt the calipers because I was doing rotors/pads/lines along with solid bushings so I figured I might as well.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
How often do you need to clean and re-lube the solid caliper bushings to maintain proper operation? The E36 in question is dedicated for track, not used for tooling around.
If God meant for man to motor-swap LS engines into track cars, He wouldn't have created Corvettes.
You should do it before every track weekend/event. No reason not to, as you should also be checking the pads and it only takes like an hour. They're probably fine for multiple events, but cleaning/lubing them is pretty easy so there's no reason to risk it. Under sustained track use in addition to dirt and stuff getting in them, the grease/antiseize can burn off over time which makes them more likely to stick.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
Thank you. I have a set on my workbench, and I have been pondering whether to install them.
Clean & lube every event is more maintenance than I had anticipated. I have track pads on the car all the time and just check thickness with a flashlight.
If God meant for man to motor-swap LS engines into track cars, He wouldn't have created Corvettes.
My car sees 1-2 track days a year and is a street car otherwise, and I probably pull the pins and clean them maybe three times a year on average. They seem to stay pretty clean in my case. All I do when I pull them is jack up the car, pull the pins, clean the bushing bores with a q-tip and brake cleaner, clean the pins with brake cleaner and a scotch brite pad, and then replace the pins with fresh copper anti-seize. You don't need to take the calipers/pads off or even remove the anti-rattle clips. The pins will come out and go back in fine with the caliper in place.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
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