Superformance Brakes (or not)

[wanab5150]

Well, this may be a closing post on the Superformance brake issue.

For those that haven’t read the entire post (but some of it) …….. I have put 1600 miles on the car since Superformance swapped out the rear 34mm caliper for a 41mm, as the 34mm was outright trash and the car was actually dangerous. After numerous contacts with Superformance, and the development of this post, Superformance started replacing the sub-standard caliper with the 41mm Wilwood.

After the conversion to the 41mm, and the addition of a vacuum pump producing 20+ inches of vacuum, the car stopped worlds better, and safely, but it’s still not stellar. It seems good for the street but requires quite a bit of pedal pressure to stop from 100 to 0. It stays straight and requires a real boot to lock up the front wheels at any speed. Only the fronts lock up, but because of the extra effort required, panic stops are without surprises. Never once has the rear end shown any signs of locking, chirping or any sliding around. It still seems a bit deficient, but the car seems to hunker down at least and I know they’re at least providing some stopping power compared to the original 34’s.

During this last 1600 miles I have been waiting for a new pad that was to be the salvation to the still puny rear caliper. Barry Bloch called me and said these pads better matched the new 41mm rears that were previously installed. When the smoke cleared, I found that the rear caliper already had the most aggressive pad that Wilwood had to offer, the BP-10 compound. The fronts have the “Q” compound, the next less aggressive compound. Barry Bloch, the Superformance GM sent me some BP-10 pads for the front which were described as the fix for any further issues regarding braking.

When I read the E-mail, I called around and asked WHY we were putting a more aggressive pad on the front when the rears are still deficient. It seemed like we were going backwards again. I called Willwood direct and talked to the tech department. I was told by Wilwood tech support that there is no way the use of a 41mm single piston on the rear would ever really match the performance of the 4 piston Dynalight fronts….ever! So unless I wanted to do a complete swap out for a complete new system I would have to live with it or have Superformance make some other change. Well further caliper changes are probably out of the question.

The reason for dropping the 4 piston Dynalight on the rear was to find a caliper that incorporated and emergency brake, so the e-brake that was used for 2600 cars or so could now be eliminated as it was its own separate unit, completely separate from the brake system…..plus, it wouldn’t hold back a 10# bag of SH*t, much less the 2500# car. So….It was basically a trade off….E-brake for some rear brake power.

I placed the new BP-10 pads on the front with some apprehension as it just didn’t make any sense to add more braking force to the front with the back still anemic. Hoping everyone else was wrong and considering the ease of changing the pads, I did it anyway. I followed the bedding procedure to the letter. When all done….I was right! The thing turned into an unmanageable beast that locked up the front end with only moderate pedal, and acted as if there were no brakes at all in the rear. Apparently, with the addition of the extra bite in the front, the rears barley engage the rotor because only light to moderate pedal is required to completely send the front to another planet. Complete loss of control and the car still not stopping because the rear cannot engage.

I called Wilwood again and talked to a different tech asking if this was to be expected. I was advised almost the same as the first tech I talked to. “You can only expect so much progression with 4 piston calipers on the front and single piston on the rear." The fact that other cars may have a similar set-up has no bearing as the master cylinder comes into the equation, as do pressures at the calipers, and the pads of course, and other factors that are unknown.

One thing Wilwood did advise is the heat curve on the two different pads was completely different. The graph is on their web site. The Q’s are greatly affected by different temps, whereas the BP-10’s are almost linear and heat does not change the degree the pad grip very much. Basically, the “Q” pads have less braking force than the BP-10’s at lower temps but as the heat builds on harder stops, the pads increase their grip.

THE BOTTOM LINE:

I put the “Q” pads back on and went back out to test while the previous test was still fresh in my mind. I feel that the “Q” pad in the front (less aggressive) and the BP-10 in the rear (more aggressive) is a better/ safer combination on both the street or the track. I don’t have to track the car to know what would happen at 120 MPH on a race track with a wall in front of you and the front end all over the place!

For the street and maybe even track day the “Q’s” will probably be OK even if they are not perfect. I did do two 100 to 20mph stops one after another and the car stopped straight and reasonably quick. It takes quite a bit of pedal, but it’s very predictable.All in all I can live with the beast and feel comfortable and safe as I have for 1600 miles. I think I’m done and probably will never drive the car beyond its capability. Meaning…the car is more capable than I am.

Anyone with similar experiences please add to the post. I’m done with the changes, but would still like to hear about your Superformance (34mm / 41mm) experiences.Thanks to Lance and Barry at Superformance for listening and making changes. Thanks to Steve at Reno Engine and Drive train for his support and doing the swap and vacuum pump as well as the engine install and set-up. Tom