UUC's Wilwood Big Brake Sport Kit (11.75" rotor)

[emi325i]

I picked up this kit and attempted to install it using a set 15" wheels. I tried my brothers 15" wheels (some old crappy 15's).. I tried the 15" euro weaves, and the 15" Team Dynamics Pro Race 1.2. Neither one fit over the caliper.

I got pissed off for the fact that they falsely advertised that the kit fits 15" wheels (not some, or maybe, but "fits"). I called them up and asked Rob which wheels fit, and I couldn't get a good answer. He gave me nothing but vague answers, and kept recommending some ridiculously wide spacers. I wasn't going to drive around with tubbed-out wheels..

I returned the kit with a 15% restocking fee, and bought Massive Lee's kit, which, even though it requires some cutting, does fit 15" wheels.

UUC also claims that their kit is designed to fit 15" wheels better than Massive's., In reality, the Massive race kit (thicker rotors) fits the 15" TD pro race and the UUC sport kit (thinner rotors) doesn't.

[Rob@UUC]

Emanuel,

I am sorry you did not find satisfaction with our kit.

However, as far as "pissed off" and "falsely advertised" go, I would not think either of those statements appropriate. Our 11.75" kit certainly does fit under 15" wheels. To state the obvious, 15" is a diameter measurement and has nothing to do with offset. As is commonly understood, and discussed on our website, is that a BBK will often require a spacer. Your statement of "ridiculously wide" spacers is likewise inapplicable; a spacer of even up to 20mm is a common size used for improved handling. As I recall, you were unwilling to consider spacers anywhere near that.

I do need to review the return of the kit you sent me, for I suspect your fitment issue may have been due to a reversed installation of the rotor hat and caliper bracket. The reason I say this, is that your fitment comparison to the kit you have now simply does not make sense... the UUC kit is "tucked in" as close as possible to the minimum interference point (steering knuckle hitting backside of rotor), the rotor is narrower, and the caliper is narrower. Total assemblage therefore has less offset interference when installed correctly than the "Massive" brand kit.

I know they work for other people perfectly fine, as in the very short time we have offered these kits, none of the dozen or so other 15" wheel users (including real racers) have had fitment issues.

In further comparison to what you have now (and yes, I helped a local enthusiast to install his Massive kit recently which did require "special" wheels with great offset, and frighteningly enough scrapes them!), the important difference is brake bias. Quite simply, the UUC kit maintains correct, matched bias with the OE rears. In other kits, "massive pistons" leads to way too much front bias, which is detrimental to braking performance and trail braking/handling.

I suspect we're qualified to discuss what braking aspects make for superior performance, as UUC/Wilwood-equipped cars in BMW Club Racing have been dominating and winning regional championships now for a couple of years (results on our website at http://www.uucmotorwerks.com/pbc ).

I wish I had time to review this before leaving the office for the weekend... it will be very interesting for me to review your returned parts on Monday and see what I find.

- Rob Levinson
UUC * http://www.uucmotorwerks.com

[golde30]

Rob, how does your kit compare to the now discontinued RPI wilwood kit?

[emi325i]

Rob, you can understand my frustration with purchasing 2 sets of wheels, one of which you recommended, just to find that they don't clear the caliper. Racers may be able to run wide spacers but that isn't an option for me, because the wheel will stick out and it's just plain ugly. The massive kit requires only a 3 mm spacer.

The reason this kit fits better is that it uses the superlite caliper (I think I have the name right); it has less obtrusive edges, and slips into the wheel all the way to the spokes. I opted for the small pistons (I believe they are the same size as your kit) in order to keep brake bias in check, like you mentioned.

I think both kits were good quality; your kit was more straight forward to install, and it didn't require any cutting like the massive kit does.

In retrospect, i think I should've bought 16" wheels. I would've had any of those problems. I think, at the very least, you should make some wheel recommendations on your website. You should fully disclose the kind of fitment issues someone would run into with 15" wheels. I know it would've helped me a lot.

[10/10ths]

emi325i

Why are you going to bigger brakes? What is your car setup?

[emi325i]

I was unhappy with the performance. I was spoiled by a brembo kit on my previous bmw. I do driving school, but absolutely no racing. I don't have the skills.

[Borat]

is it hitting on the back face of the spokes? if so then robs correct in saying that its not the diameter thats the problem. 16" wheels probably wouldn't help. If yout went with something like a 38 or 40mm offset with a 20mm spacer you'd be fine and your wheels wouldn't stick out. sounds strange that the massive kit fits with thicker rotors and calipers???

[emi325i]

Nope.. the wheel barrel gets narrower close to the spokes. I was unable to slide the wheel all the way in. The wheel is 15x7 et25. I estimated that I would need a 15 mm spacer, and that would reduce the offset to 10.

The 16" wheel barrel would be no problem. Also, the caliper is quite narrow and doesn't require a lot of room behind the spokes.

[Rob@UUC]

Rob, how does your kit compare to the now discontinued RPI wilwood kit?

I have not seen the RPI kit, so I reall cannot say. Anybody have a link to some info on it? I'd be glad to take a look.

- Rob

[Rob@UUC]

I think both kits were good quality; your kit was more straight forward to install, and it didn't require any cutting like the massive kit does.

In retrospect, i think I should've bought 16" wheels. I would've had any of those problems. I think, at the very least, you should make some wheel recommendations on your website. You should fully disclose the kind of fitment issues someone would run into with 15" wheels. I know it would've helped me a lot.

I wish we could make wheel recommendations, but it becomes a fruitless exercise as wheel designs come and go. Even the set I bought for my own '89 iX were recently discontinued, and I'm thinking of picking up a spare before they're gone!

- Rob

[Massive Lee]

In further comparison to what you have now (and yes, I helped a local enthusiast to install his Massive kit recently which did require "special" wheels with great offset, and frighteningly enough scrapes them!), the important difference is brake bias. Quite simply, the UUC kit maintains correct, matched bias with the OE rears. In other kits, "massive pistons" leads to way too much front bias, which is detrimental to braking performance and trail braking/handling.

When prospective buyers ask for 15" wheel fitment, I will either recommend Kosei K1 or Team Dynamic's Pro Race 1.0 or 1.2. I have always been upfront to many clients letting them know that the wheels they suggest will not work at all. I have been making the e30 kit for 5 years and have tried many wheels, but obviously not all. Not making a sale is preferred to a frustrated client in my opinion. Many other wheels in 16" size will fit without any spacer - but always checking with the profile is indicated. As with any BBK, picking the proper wheel is crucial. Obviously, using a wheel with a high offset will command a thick spacer. But with properly selected wheel, it is a perfect fit. Many will remember that I very often mention that it is NOT the wheel's offset that counts, but the shape of the wheel.

As for brake bias, and as is the case for any brand of brake kit, choosing the proper piston size is important to keep a balanced bias. Which is why I ALWAYS recommend 1.38" front pistons if stock rear brakes are used (wether it is for the Sport or the Race kit). HPDE drivers and Club Racers have returned excellent comments on this set-up and reported a perfect brake bias and pedal feel. Anyone deciding to pick other sizes of pistons is then responsible for a major change in bias. Nonetheless, it is possible that some customers will temporarely drive with big 1.75" pistons, expecting to soon install the rear kit with 1.12" pistons.

There is no secret in a good brake set-up: stiff calipers, thick rotors and properly sized pistons - and a lot of testing. Anybody can make their own kit. Even mom and pop. It only takes time and experimentation, which is why many will choose to buy ready-made kits.

[Rob@UUC]

As for brake bias, and as is the case for any brand of brake kit, choosing the proper piston size is important to keep a balanced bias. Which is why I ALWAYS recommend 1.38" front pistons if stock rear brakes are used (wether it is for the Sport or the Race kit).

Then it's odd that the "front only" kit you sent to a local customer was equipped with 1.75" pistons. Apparently he was sold this as "maximum torque". Well, that's true, but also results in 2-wheel braking only.

Nonetheless, it is possible that some customers will temporarely drive with big 1.75" pistons, expecting to soon install the rear kit with 1.12" pistons.

A car like that would never leave my lift. I'd consider that dangerous.

Anybody can make their own kit. Even mom and pop. It only takes time and experimentation, which is why many will choose to buy ready-made kits.

Sadly, that is a common mis-conception.

If there was no engineering in the braketry strength, including metallurgy, machining techniques, stress-testing, and fatigue resilience... plus the same concerns about the hardware... then the "experimentation" would be hit that wall, hit that car, lock that wheel with failed components, etc. Despite appearance, safe brake kit development should not be something to be taken lightly, or undertaken by a hobbyist.

- Rob

[Ray Smoodiver]

Do you have a brake template to test potential wheels Rob?

[Charlie]

I was unhappy with the performance. I was spoiled by a brembo kit on my previous bmw. I do driving school, but absolutely no racing. I don't have the skills.

So you want the extra performance, but won't make the negligible change of a 15 mm spacer?

-Charlie

[Massive Lee]

So you want the extra performance, but won't make the negligible change of a 15 mm spacer?

-Charlie

Hi Charlie.

I am sure you'll agree that not everyone will call a change of offset by 15mm just "negligeable". You are right to mention that many racers will use 10 or 12mm spacers on their et25 wheels to increase their track. But the drawback is that they rub their wheels when turning (both on the fenders and on the footwells). It is perhaps only an annoyance around a track, but it is a major problem around town. 15mm may be just too much.

And not everyone likes to use thick spacers and longer bolts. And it cost $100 extra per axle.