If you want to call me i will give you everything I have. I think the fix is at hand, but You'll need to make a few calls. It sound like the calipers are already available and depending on how much vacuum your engine has will determine whether you will want to add a vacuum pump, either electric or belt driven.
I have some telephone numbers for you and would hope they would retro your car asap.
I see your on right now...call me. 916 791-7695 tom

Madmaxx......yes 41's and a pump.

hi, a lot of toyota desiels have a vacuum pump on the end of the alternator - best to use a vacuum tank with check valve as well

Just learned that SPF #2742 has PBR's and my SPF #2743 has Willwoods.

Very interesting thread.

A rear brake problem should not have prevented the front from locking up unless it affected front pressure as well.

My guess at what was happening judging by the cure, is that the master cylinder piston for the rear brakes is too big for the 34 mm caliper so couldn't generate enough force on pad and hence locked up the whole master cylinder early in the stroke preventing enough movement for the front brakes to reach full pressure and work properly as well.

Going up in size of the rear calliper to 41 mm increased the rear piston area by 45% and hence pad pressure by 45% and movement of the master cylinder pistons by 45% allowing the front system to develop full pressure and and hence proper braking is the result.

All the vacuum booster is doing is making the pedal softer and pressure easier to reach but if you have hydraulic lock because of missmatched master cylinder/calliper piston sizes improved booster operation would not have helped much.

Hello,

can someone please post what brake pads you guys are uging with the Wilwoods. I am currently using the "Q" pads and I am not too happy with them. It feels like I have brake fade. I see on the pads and rotors are glazed.

I am hope you guys use a different pad because I think this is my problem.

snake 2998..The master cyl issue has been present throughout this thread. I said what you said a few threads earlier .....but you made it clearer. I hope the 41's work. As for pads, I don't know which their going to use on my car. tom

Tom , whats the latest on your brakes? Have you driven a car with the 41's? Jerry

Thursday I drive it at the Bash. I'll advise......If they don't work, you'll hear me screaming all the way in S. Africa!!!!!!

OK-How are the new brakes?

...............:eek:

Tom 'How do the new brakes work? Jerry

Well, the verdict is in!!!
Steven at Reno Engine and Drive train (my engine installer), installed the 41mm Wilwood calipers and a BELT DRIVEN vacuum pump. I put 300 miles on the car during the Cobra Bash and driving home 160 miles to Roseville. Once here I conducted a simple test by braking hard from 70 mph with the clutch pushed in to allow the minimum vacuum generated by the vacuum pump at about 900 RPM. I did 4 consecutive hard stops with no time to cool the brake pads.
I have to say that I am pleased with the performance. The old HARD pedal feel is completely gone and even with the minimum vacuum generated at idle, the pedal feels progressive and similar to any other good brakes I have felt.
The fronts still brake harder than the rear as the fronts will lock up now, but the backs still WILL NOT lock even after the fronts leave double black stripes. I can tell the rears are working well now as the car seems to "hunker down" if that makes sense, which it didn't before. AND......before, as the fronts started to reach their limits of traction, the car WAS NOT stopping. Keep in mind that I only have 255's in the front which I feel were doing all the braking. Now, I would estimate the car will stop in half the distance it did before without locking either the fronts or backs up. I know that seems like an exaggeration, but it’s not.......The brakes were that bad before, and that much better now.
I can't say these brakes are race track tested and ready for 140 mph stops over and over, as far as I can tell, they are safe, feel really good, and stop to my satisfaction on the street.
As far as the belt driven pump goes, it runs constantly and completely by-passes the booster. I can't detect ANY noise coming from it even with the hood open and my face 2 feet from it. Steven put an electric pump on a car from Valencia, Ca. and it has already blown out 3 switches!!! The electric pump makes noise and vibrates from what I was told. I have no personal experience. Also, the belt driven pump is the same pump Steven has used on all the Roush and other engines with fuel injection, so its time proven.
I have to thank Lance Stander (CEO) of Superformance for picking the car up and delivering it to Steven in Reno, and the decision to upgrade the brakes to 41’s (which he should do to all the cars with the 34mm calipers). As far as Dynamic Motorsports West, the dealership where I purchased the car, other than an initial phone call to ask what the problem was, and one telling me someone else was working on it, that was about all they did! They did not accept ANY responsibility for the car I PAID THEM FOR!
Thanks to all of YOU that had input. As you probably have seen previously, the more ideas, the better, regardless of whether they’re on point or completely off base. This is one of those sites that provokes thought which culminates in a solution.
Finally, I want to thank Steven for all the un-paid hours he put into this project. None of the research and development was ever his responsibility, but he stepped up to the plate when no one else would. I can’t count the phone calls and updated emails I received during this issue. I know the owners of two of the other cars he tried different brakes and vacuum canisters as well as multiple road tests trying to find a solution the factory would not help with. Steven was the one on the phone with Wilwood back and forth and everyone else, trying to figure out why the 34’s didn’t work. Without him as a mediator, this would have taken a lot longer than 8 weeks. Thanks again Steven!
If any of you need assistance with this problem (and I know you’re out there) don’t hesitate to email me at wanab5150@comcast.net tom

Rear Brakes shouldn't lock!
 

When the brakes are applied very hard the rear of the car unweights and there is very little weight on the rear tires. If the rear wheels lock on hard braking at 70 mph the car would likely swap ends braking from 130! It sounds like you have a favorable brake bias setup at this point. It is always SAFER to have the rear brakes a bit less effective than to have them lock the rear tires when all the weight is on the front of the car and have the back end pass the front as you approach the corner. I agree that at some point if you are being rediculus you could OVERBRAKE all 4 corners and flat spot all 4 tires even when the bias is correct. You don't really want to find that point on a car that is not a dedicated track car. It is excessive to say the least. If you can lock the front tires at 70mph you have plently of brakes to drive the car on track and have a great time safely! You may be surprised to find that the fronts will not lock so easily if you begin to run a race tire with more grip. Glad to hear you have you problem SOLVED! Go out and have some fun.

Mine are fine....
 

Stephen in Reno did the installation on mine SPF 2811 and my brakes are more than adequate for "spirited" driving in the Cascade Mountains involving repeated breaking at relative slow speeds ( 65 mph).....no fading ...no locking.... very smooth....very predictable

Which brakes do you have in the back? Which engine? and do you have a pump?

Put my 41's on this afternoon, Lance overnighted a set from Wilwood
tuesday. Took about an hour and a haft to put them on , will drive it to the ocean tomorrow.and see how they work. Leaving for the east coast monday afternoon. Jerry #2773

As I recall...
 

I have a 351W Ford Racing motor. Stephen installed some new calipers from Wildwood and a pulley pump and a reseviour and a electric pump with a underdash toggle. That is what I recall him telling me, but I don't pay much attention to details. I can tell what time it is, but don't have a clue about how a clock works so you need to ask him. One thing I do know is that my "spirited driving" was the most brutal abusive repeated use of the brakes in my experience on a very tight twisty mountain road with grades in excess of 10% for about 25 miles and there was no problem. My original purpose for the posting was that there is a cure at least for normal use. I will never be on a track...sooooo...

41mm part numbers >?
 

So as the guy who is building SPF 2734, that HAS the 34mm Wilwoods on it , what is the solution here>?

Do we have part numbers listed somewhere we can go get our own sets>?
Do the 41's work with the "E-Brake">?
What is the factory stance on this issue >?

- stumped for info here. --Steve

Steve........Contact Lance Stander or Barry Block at the email address or phone numbers earlier in this thread. The e-brake works exactly like the 34's did....pretty good.
Barry Block called me Wednesday to ask how the brakes were working. He said he has some new, more aggressive pads coming and will R&D them shortly. IF, (I say) IF they work, he stated he would send me a set. He said, (in so many words), that the rear pads will be more aggressive than the fronts to help with the imbalance that still seems to still exist.
The brakes feel good now, but could be better. They're still not as good as my '07, 4000 lb. Tahoe, and not nearly as good as my '01 BMW Z3 (3000 lbs.). Not M3,....Z3! the lower performance version.
I also went to Vegas this week and talked to "Tom" of Tom's Motorsports at the Vegas Speedway. He is a Superformance engine installer for the Superformance dealer in Vegas. He does about 20 Shelby CSX cars to every Superformance as he is right next door to the Shelby's CXS shop and warehouse. He has not done a Superformance with the 34's so he could not elaborate on the brakes. He did say something surprising to me. He said the 4 pot Wildwoods are better than the Baer brakes that come on the “Shelby” Cobras. I could not believe my ears, but he repeated it again as I peered through the shop at the numerous CXS, Kirkams, and a few Superformance cars being prepped. Also 4 CSX pure race Shelby’s sat just inside the door!!! I’ve talked to him on another trip and found him very knowledgeable. Another thing he said was, that there is NO WAY that a “single” master cylinder could operate odd sized calipers equally (4 pot fronts and single pot rears) that are on the Superformance now. He said it would require a dual master cylinder with a (I forget what he called it…a jet, orifice, plunger?) …one for the fronts and one for the rears.
I have talked to Wilwood and everyone else and they have side stepped the master cylinder issue.(maybe another replacement cost factor) I believe Wilwood did not want to comment as they are connected to Superformance in this issue and didn’t want to open themselves up to liability! How could they not know why the calipers did not work when I talked to the Sales Manager (see earlier in this thread). I specifically asked him for a caliper/master cylinder combo for the Superformance and he said he just didn’t know at this time! Politics!!!!!!!!!!!
I forgot to mention that Barry said he provided a master cylinder to Wilwood for testing and a possible match up for a bolt-on fix to the existing Superformance cars. He would not speculate how long this would take………...Politics again! At least he called and it seems as if they’re still working on it. I was surprised he even rolled over that there was an issue, as when I called him the first time he said he had not heard of a problem with the brakes at that time.
Anyway, any progress is good and hopefully soon the brakes will be as good as the used to be. Tom