GTD, Wilwoods

I have my wilwoods on my car and have sorted out the front to rear ballance issue. All is well with putting a proportioning valve into the rears. I did hit the curb doing some brake tests last weekend. Nothing serious but I had to take the whole front off to put the "horns" straight again. Those would be the 1 inch square tubes right in front down low that mount the front bodywork.

I still have the almighty squeal. So what should I use for brake pads on the street. I have c compound wilwood pads on the car now in Superlight 2A calipers. I have been told that Q compound would be better. Any ideas as to a favorite brake pad of yours for the street.

I'll try you anti squeal pads when they arrive Frank. Thanks again.

This is a wilwood hat that comes undrilled. I just drilled it for the GTD bolt pattern. In the end the fronts required a 1/16" shim between the hat and hub to get correct caliper to rotor alinement. Otherwise a perfect fit.

Another, 12.13 X 1.25 wilwood HD48 curved vane rotor and superlight 2A caliper.

Shot of caliper bracket. This shot also shows the end of the hose. I cut off the orginal metric fitting that came with the GTD granada caliper and put on a standard USA AN3 steel brake fitting.

Update to the squealing problem. Fred let me use a set of "Q" compound pads and I put them in the front calipers. Using them there has eliminated the noise from the front. Now that I can hear the rears, I will also have to get another set of "Q" pads for the rear.

I will tell you that the "B" pads that were in the fronts did have more torque for the same peddle pressure. They should have, they are ment for 1 mlie oval stockcar tracks.

I have again learned not to put race pads on a street car. I would think I would remember this. This is about the third time. I did stop at the second wife however.

When I get the other set for the rears I'll post some pictures of the rear setup and a final review with part numbers.

AND,,,,,why am I not getting all the credit here?!! /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/mad.gif /ubbthreads/images/graemlins/crazy.gif

I could have had recommended to change your set up to "17 pot", gold plated AP calipers for $6000 to get rid of your noise problem. That would be the "proper way", NO? /ubbthreads/images/graemlins/grin.gif

Howard,
You have the same callipers as me and I think you will find a further brake performance improvement by fitting bridge bolts to the callipers. there is a hole above and below the pad retaining pin designed specifically for this. It increaces the calliper rigidity significantly and improves pedal feel as well. just my 0.2c worth.
Cheers,
RV

Peter, Thats just what I had in mind, I would have thought that they would have come with the calipers. Ordered them today with the new pads.

OK Fred, you know I would be nothing with out you... I'll leave your "Q"s in the front and give you the new set. Should be here later this week.

Rears

another rear pic

Last one

Last last one

The "Q" pads on all 4 corners solved 95% of the screaching problem. I think that the rest will go away with use. If not a little leading edge chamfer on the pads should work.

After a little more front to rear brake ballance testing, I have a proportioning valve in the rear line, the car stops very well. I would guess its at least several times better than the GTD brakes and without any increase in peddle effort. I was unable to get any fade with several hard stops from 60-70 mph during testing. Also the rear pro. valve ended up being turned down 5 full turns. My best guess is that is about 10-15% reduction in brake pressure on the rears.

The last thing to do would be remove the vac. boosters and replace the peddle/ master cylinder with a 6 to 1 ratio type. I may do this at some point in the future but for now I am happy with the results.

All in all this setup seams to work very well. I can lock all four wheels at scary speeds but the peddle must be pressed on firmly. That may be a good thing as I really never really liked touchy brakes anyway.

Interesting to see you have your rear calipers underslung like the earlier GTD solid rear disc brake set up. I assume that is what you previously had. No wonder you feel a big improvement in stopping power! Howeever do you still have fun and games bleeding those rear brakes?

I was also going to remark on the fact that the calipers are mounted at the bottom - very Formula Oneish! Did you do this to keep the CG as low as possible? I've also heard it's difficult to bleed the system in this configuration.

Hi,

I was just reading your wilwood story and wanted to reply. I'm about to change my complete braking system, as it is old and standard ford, to wilwood. You've gone through the whole proces, do you have good tips for me, regarding the type of rotors, callipers etc etc. I would like to have crossed drilled discs cause it looks real sexy. Did you have to make new brackets to hold the calipers or could you install the calipers direct at the hub, in other words does it directly fit? I allready took out my boosters, didn't want those there, so big, so ugly and so havy. As I understand from your story when you use a 6:1 master cilinder it is not needed right? I have a 2 master cilinder set up on my pedalbox (new) so it has a balancer. Does the balancer control the ratio brakepower front/rear? Do I still need a proportional valve installed for the rear?
Since I'm rebuilding the complete suspension and hubs, I want to replace the wheel bearings. Any advise on that? Are there special heavy duty or racing types of bearings to make it stronger/longer lasting?
I'm also changing my revolution modular wheels. I want to install wider inner rings, so the rim size in the front will be about 7,6". In the rear the inner and outer rings will be replaced till total with of 12". I want to use the racing tires: the dunlop CR82, 430/1160-15 in the front and 530/1360-15 at the rear. I do have the clearance and the space. Any tips or advice about this change ?? I know the tires are not street legal, but I recon if a dutch cop will pull me over, he won't bend down and check if my tires are street legal. I hope you, or any one have good tips and advice. At this moment the are building a 347 stroker engine for me in the states with of course the weber 48mm set up which I allready had and a 930 4 speed trans, complete rebuild and made stronger with electric oiling system and LSD etc etc, so I'm really excited! The last step there will be a 180 cross over exhaust system, stainless steel, high polished. Any tips or advises??? thank you very much.

Daniel the flying dutchman

I would have to begin with I had a serious buget issue when I began this upgrade to wilwood parts. This is the main reason for wilwoods in the first place.

Compaired to alcons, baer, and others wilwoods are alot less money. I bought my calipers from stockcar products for $120 each. They are superlight 2a's and have been replaced in the wilwood lineup with billet superlight 3's. These are a 4 pot caliper that is used on short track stockcars that run 1/2 and 5/8 mile ovals. The cars themselves weight about a 1000 pounds more than our cars and usually run 50 mile races. Thats about 100 laps with two big brake zones per lap. 120mph down to about 65mph or so.

Rotors are the wilwood 1.25" X 12.13" curved vane HD's This is also the same rotor used on the same stockcars but limited to 11.75" in diameter.

I believe that I will be hard pressed to stress my brakes more than that.

The hats where the major issue. I wanted to use stock item wilwood hats so that I would save some money and stay away from a lot of expensive custom machine work. I ended up with the undrilled 1.41 offset 8 mounting hole type. It was necessary to drill them to fit the GTD bolt pattern and make a ring to fill the center hole on the fronts because the hole in the hat was about a 1/2" larger in diameter than the hub.

On the rear the fit was just about perfect and the hats only required having the 5 holes drilled.

To mount the calipers I had to make adapters. The fronts came out to 3/8" thick as did the rears. Again simple and little machine work. Th rears did not require shims but the fronts did need 1/16" thick shims to get the calpiers centered on the rotors. I will say that if you used 11.75" dia rotors on the rear I think you would be able to simply bolt up the calipers to the orginal GTD hub with a little opening up of the holes on the hub bracket. Less that a 1/16". I kept the caliper on the bottom to save money. The caliper adapter is a very small 3/8" thick piece that we welded to the orginal hub ears. The caliper then bolts to it. Again I think that 11.75" rotors would not need this step.

Now as to wheel diameter. I have 17" wheels. I did this because I knew that I wanted to upgrade the brakes and I also wanted to make it as simple as possible. 17" wheels left me with plenty of room for 13" rotors all the way around.

I also needed to install a porportioning valve in the rears. I have a little front pad chatter and have ordered a residual valve to fix that. Also from the above posts you can see that the wilwood "Q" pads worked well for me.

As to the master. At this point the standard GTD setup works well enough. I have kept the vac. boosters. At some point in the future I think I might change over to a wilwood duel master with ballance bar.

A first time design of the brakes as to cylinder diameters and such could be done of course but I think that a ballance bar still would be needed to get the front to back pressures just right.

As to bleeding the rears, The caliper needs to be unbolted from the adapter and swung up to vertical. This is something that is added work but to mount the caliper on the top would have required cutting out a notch in the upright. A front or rear mount would have needed a much more extensive adapter. Again a money issue. Its OK I don't need to bleed the brakes all that offen anyway and when I do I just swing them up like I did the old GTD ones.

I also needed to cut off the euro fitting at the caliper end of the brake hoses and put on a an3 fitting to fit the wilwood calipers. No big deal.

Daniel, The duel cylinder master with a ballance bar you have is ideal. A 6 to 1 peddel ratio also is ideal for most cars including GT40s. I think a 5 to 1 would also work ok but it looks like the orginal GTD setup is about 2.5-3 to 1 or so and thats why they used the boosters.

Hi Howard,

Thanx for your reply!!!
I'm a little confused about the rotor diameter, cause I have the 15" revolution wheels. In the rear my calipers are mounted verticaly. I prefer to have the biggest rotors possible eventhough I have to make new brackets for the callipers. Could you give all the partnumbers on the rotors, rotors and hats, so I can check the spec's and start to order. Thanx very much !!

Daniel