Anyone running the Wilwood 6 piston brake kit??

[03'Darin]

I have been eyeing up bigger brakes for some time now and keep getting drawn back to the Wilwood kit. The 2 piece rotor/hat design and 6 piston caliper set up make this kit an excellant deal for the price.

My concern is that I don't have any experience with Wilwood. I don't want to fall into "the best price isn't always the best deal". Brembo brakes command top dollar due to their proven quality, brand value and reputation. Wilwood's are almost 1/2 the price of the Brembo's, is this due to lesser quality or the fact the Wilwood's 6 piston kit is realtively new and they are priced to get them started in the market.

:shrug: :shrug:

Darin


I tried to post a picture of the kit but for some reason I keep getting told it's the wrong format.

 

[cito]

Where did you find them?

 

[jwfisher]

How is that suppossed to match up with the pathetic brakes in the rear?

This car does not have electronic brake force distribution... you can stick anything you want on the front but at some point it's going to be too large to retain balance.

 

[logan_yomtov]

jwfisher, that is a cool pic in your sig.

 

[cito]

Interesting idea. I would love to have a reason not to upgrade the fronts. Could you explain your point in further detail? Every time I see a big brake setup, I just salivate. It might be for the looks as much as anything.

It is a fairly common upgrade to put Brembo's in the front of these cars. Even the Cobra R has Brembo's with the regular Cobra rear brakes (I think?). There should be benefits with respect to heating, wear, and consistency of braking with an improved setup.

Heck, you are an instructor in driving, so I would love your input on this.

Wilwoods have been around for a long time. They have a bigger hold in the GM and drag racing market from what I can tell. They make decent brakes though perhaps not with the same rep as Brembo.

I have always wondered whether the front calipers could be adapted to the rears. On the FR500, I swear that Ford used LS front calipers on the rear with upgraded brembos in the front.

 

[maoun]

i agree.....if you leave your rear as is, you'll be screwed because you'll eat up your rotors, won't you?

on the other hand, can we move our fronts to our rears?

 

[Road Racin']

You can get away with a bit bigger front brake setup with out issues. If you worry about the rears(I wouldn't) you can buy a proportioning valve(less then $100) that will let you bias the rears. You can also change master cylinders. This is better, but more labor intensive. You cannot put the fronts on the rears. 1) there are no brackets. 2) the rear pistons are always smaller then the front to balance out the pressure. Even the same caliper(ie:4 piston Alcon/Baer) looks the same but DOES use different pistons front to rear to control pressure. The fronts would be WAY too much out back.

 

[maoun]

awesome info....

i completely forgot about using a proportioning valve...duh

 

[03'Darin]

Originally posted by cito
Where did you find them?

Go here http://www.wilwood.com/products/kits/sl6bbhk/index.asp Then scroll down and click on part #140-7191 (road race kit).

jwfisher: the rear brakes are in no way pathetic. Did you ever wonder why in your picture that only the front brakes are glowing red and not the rears?? First off the rear brakes can only do so much due to the front/rear weight distribution which gets worse the harder you brake. Under hard braking the car has severe weight transfer to the front. This creates increased traction and much better stopping power for the front tires (due to the addition weight on them). But drastically reduces rear traction and braking ability (due to the loss of weight).

By increasing the braking efficiency of the front brakes you will reduce fade and increase brake life. There are several ways to improve the front braking (better pads, cooling ducts, larger rotors/calipers, better calipers with more even braking force on the pads/rotors, etc. I don't have time to go more in to detail right now, but I am sure someone will chime in and better explain the braking characteristic and how to improve them. BRIAN "R" you out there???

 

[torquer]

This is correct. When I had a 2000 V6 I upgraded to the Cobra front brakes and left the stock V6 rear brakes on for some time. I finally decided to upgrade to Cobra rears and notice *NO* increased stopping ability. Its not an upgrade I would do again other than looks.

If the rear brakes were 'pathetic' then Ford wouldn't have used them on their production race car, the 00 Cobra R. The front brakes should receive most of the attention, with the major focus being on cooling. Those holes next to the foglights would make excellent spots for custom ducting.

If you upgrade, upgrading the fronts is just fine. You may or may not need a proportioning valve, but we won't know until someone tries it.

 

[oldmodman]

Many years ago, just as an experiment we took a Ford LTD11 Wagon and put in a proportioning valve. Adjusted it all the way to front bias and beat on it for a while. Stopped just fine as long as you weren't in a tight turn. The harder you braked the more "normal" it felt. Since during very hard braking as much as 90 per cent of the weight is transfered to the front wheels. By the way, this old wagon had a built 351 cleveland and a two plate nitrous system in it!

 

[jwfisher]

No, I don't "wonder" about these things... how insulting.

And using absurd examples doesn't translate into track sense. An old station wagon, a car with no power - no relevance here.

As for why my front brakes were glowing... it was a stop from 150, DOWNHILL on an 18 degree embankment, and I had HT10s up front and some stock pads in back. My mistake after I wore thru the rear pads.

The rear brakes are particularly pathetic in the base car (V6/GT)... completely absurd for track use. The "Cobra" brakes are the same exact calipers... and a slightly larger vented disk. A very small update. Overall, the stock Cobra brakes are very poor. Poor stopping distance, poor heat dissapation, and especially poor after repeated use. This is a big haavy powerful car, and deserves far more than these outdated brakes.

Remmeber one thing about forums - just because you own a car, that doesn't make it the best car on the planet.

 

[jtfx6552]

With the substantial front weight bias of the '03, and it's tendancy to brake dive, I'd be surprised if the stock rear brakes could ever be pushed to the limit, regardless of what brakes were put on the front.

Even if you eliminated as much of the brake dive as possible given the weight balance, I still think the stock rear brakes could not be pushed to their limit.

 

[cito]

Thanks for the answer on why the front calipers won't work for the back. But I swear that the FR500 did use the Lincoln LS front calipers in the back.

Proportioning valves....duh....how could I forget those.

So have you upgraded the brakes jwfisher? And, if not, what would you upgrade to if anything.

The brakes probably are not up to the task of road racing, but they are fine for autocross and performance street purposes, IMO. I have no gripes about them whatsoever. They might not be great, but they are not necessarily "poor" brakes--except perhaps for road racing.

A valid question is whether the Wilwood or other kits (e.g., Brembo, etc.) would provide a significant improvement over the base Cobra brakes with performance pads and other various improvements.

 

[jwfisher]

It's not limit - it's proportion. The amount of braking the rears will do will decrease. The fr/rr weight bias (worse of all SN95s) makes it even worse, as does the brake dive (much more pronounced than on the 99 and 01s).

 

[TOC]

I can’t respond specifically to the Wilwood six piston caliper/front brake set-up, but I did have a full “competition” Wilwood front and rear set-up on a 3200 lb. Fox body Mustang. That car saw mostly open track and some street driving. I found that the track performance was quite good. On the plus side, pads were relative cheap and wide range of pad compounds available. On the downside I would get black-flagged periodically due to the fire works that hard compound pads would generate (The Porsche Club guys never see that sort of thing I guess). Additionally, I to had to perform considerably more maintenance the on the Wilwood set-up than on the PBR/Varga (Cobra) set-up that I have on my 93 Cobra under the same driving conditions.

I’ve only run my 03 Cobra on the track twice, but it’s readily apparent even with upgraded pads the extra weight of the 03 taxes the limits of the PBR front set-up, when driven on a fast road course. However, I found the Varga rear system seemed to hold up quite well with just a pad upgrade (didn’t even burn off the dust boots, while the fronts were set ablaze after 5 laps at speed).

I will be upgrading the front set-up on the 03. I’ve been looking at what available and find the system that appeals to me most is the StopTech kit (http://www.stoptech.com/). This system appears to be a well-engineered, super HD kit, and is matched to the Varga rear caliper. The kit lists for $1995.00, so it’s not cheap by any means, but then I find you get what you pay for.

 

[03'Darin]

jwfisher.....no insults were intended but for you to come off with a comment like that about the rear brakes on these cars rubbed me the wrong way.

I don't think the factory brakes are outdated at all. Basically you get what youy pay for. 390hp/390tq, irs, 6 spd, good looks, sweet ride, reasonably good spring and shock/strut combo, respectable brakes, nice seats, etc.. No they aren't the best brakes available on the market but your only buying a $35,000 car. What do you think the car should come with?......6 pot Alcons up front with 14" rotors mated to a nice 4 pot rear with 13" rotors?? I'd be in for that. The only problem is that brake set up or one comperable would cost Ford 3-4 times more than the current set up. These brakes are plenty adeguate for spirited street driving and even an occasional track event. These cars are not being sold as track cars so Ford isn't going to put a track style brake on them. I have sold twelve Cobras this year.......two of those people have been to a road course (me being one) and one has gone to the drag strip. The dealership also sold three more Cobra's.....none of which have been to any tracks. My point being the vast majority of owners of these cars will never come close to using the stock brakes to their full potential.

Just to give you some back round of my Mustang braking experience. I raced a fox body mustang in SCCA SSGT for one year on the stock 11" front disc and rear drum brakes which were required. I rolled the car at WGI while leading due to a brake failure. The front pads (Motorsport HD-which were illegal) had worn completely through the backing plate to the point where the piston came out of the caliper from over extension. That was eleven laps into a twelve lap race. I then moved up to AS where I ran the same stock front brakes with the rear disc conversion and a propotioning valve for one year. After several incidents of boiled fluid I upgraded to the 12" Baer fronts with the same PBR calipers that the Cobras came with (which was the legal brake upgrade for the class). For the last six years of racing I ran the Baer fronts (with large cooling ducts) with the Motorsport rear disc conversion. Running a more agressive brake pad on the front than on the rear I still had the ability to dial more rear brake in than the car could handle. I never once boiled the rear fluid or lost rear braking ability from the 10 3/4 " rear discs. My car with driver weighed 3400lbs. which isn't far off from what the 03' Cobras weighs. I held track records at two different times, had many wins and podium finishes along with one points championship.

It all boils down to the fact that if you are going to use your car for more extreme things than it is built for......you will need to upgrade certain components.

 

[03'Darin]

TOC while checking out the Stoptech brakes you provided the link to I came across some very good information about rear brakes. I have copied it below for anyone interested to read.

The Stoptech brake kit looks pretty interesting. I am going to research those as I have time. TOC have you had any previous experience with Stoptech or do you know anyone that has? I don't know that I have ever seen or heard much about them. Thanks for the link.

copied from Stoptechs web site:

February 18, 2001

One of the most common questions received from new owners of our front brake upgrade kits is "Do I now need to upgrade my rear brakes too?" To answer this, we need to look at the role of the rear braking system from a few different perspectives. The answer may surprise you, especially hearing this from a company that sells big brake upgrades!


Rear Brake 101


One of the many design factors that goes into the development of a base braking system is the mysterious "bias" or "balance." Truth be told, it's a pretty simple concept to grasp: for vehicle stability under braking, it is required that the rear brakes do NOT lock before the front brakes. Simple, right? Most of you probably knew that already.

OK, so what governs the 'lock up' point of the rear brakes? Drum roll, please:

1. tire tractive capability (friction)
2. tire normal force (weight on the tire)

This can be proven from looking that the fundamental relationship for maximum sustainable tire force: F=µN, where:

F = the lock up point, or peak force
µ = tire-road coefficient of friction
N = normal load sitting on the tire

So, when the OEM is designing a brake system, they 'size' the system components (calipers, master cylinder, rotor OD, etc.) to generate the proper amount of torque at both ends of the vehicle so that the front brake force ('F' above) exceeds its peak traction first. At this point, the front brakes lock and the car slides in a nice, stable straight line. (Note that at STOPTECH, we design our front brake upgrade kits in the very same fashion for the very same reasons.)


Potential Impacts of Big Front Brakes


Fortunately (from a safety standpoint anyway), when most big-brake suppliers adapt a mondo rotor and caliper package to a vehicle, they end up actually increasing the FRONT bias. How? By increasing the effective caliper piston area and the rotor effective radius, these two factors work together to increase the 'mechanical gain' of the front brakes, building more torque for the same pressure, everything else being equal. So, from a bias perspective we are not pushing the vehicle toward instability, but rather just the opposite - we are underbraking the rear axle! The obvious impact would be an increase in stopping distance - probably the one thing the new owner was actually hoping to reduce. Ironic. So, say you chose to install these big brakes on the front axle but want to maintain the OEM bias. What's the answer? Well, one way would be to invest in big rear brakes too which increase the rear mechanical gain to the point that the system is balanced once again.


So, What's The Harm In Doing That?


Well, let's look at why we upgraded the front brakes in the first place. Contrary to popular belief, the real reason sports- and racing cars use big brakes is to deal with heat. Period. There has been a bunch of stuff published which will disclaim this, but when you look at the braking system from a design standpoint, making them 'bigger' doesn't fundamentally do anything for stopping distance. It's all about the heat. So, you upgraded the front brakes because of thermal concerns but as a hidden surprise got a shift in brake bias. As a band-aid to this condition, you now spend thousands more on a rear brake upgrade because the front system was not sized correctly in the first place. Sure, it looks great, but there is another option...


Which Is?


When upgrading your front brakes, it is possible to size the caliper pistons and rotor effective radius to maintain the original brake system's pressure-torque relationship. Yea, it takes more engineering know-how and you can't sell the same part to everyone anymore, but you are not altering the base brake balance from what the OEM intended. This design philosophy stands behind every brake upgrade kit STOPTECH manufactures. Now, if you sized the front brakes correctly, why would you need to change the rear brakes? Good question. If there are no thermal concerns with the rear brakes (and on a front-engine street car there rarely are) then by installing a rear big-brake kit all you are doing is (a) spending money and (b) adding unsprung weight. This is not usually viewed as favorable, unless you like driving a heavy, expensive car.


Oh Yea - One More Thing…


Finally, under an OEM bias condition, the rear brakes only contribute about 15-20% of all the braking force the vehicle generates, and when you install sticky tires you actually DECREASE the amount of work they need to do. Why? Because at the higher deceleration levels afforded by race tires, there is more weight transfer taking place, reducing the normal force on the rear tires and increasing it on the front (remember F=µN from above?). If anything, we now want to decrease the rear effectiveness. Ironic once again.
Of course, if you decide to upsize your rear brake system components you can also impact the front-rear torque relationship, and consequently you can "bias" the "balance" more toward the rear. Go too far, and the rear brakes could lock before the fronts. Again, not the end result you were expecting, right?
It has been said that "The folks at STOPTECH should consider developing a rear kit to match their front setup. They'll be very happy with the performance improvement if done properly." Well, since our FRONT systems are designed properly, we save you the need to spend your money on the back axle.

Let's reword that quote to reflect the STOPTECH philosophy: "Our competitors should consider developing a FRONT kit to match their stock bias condition. They'll be very happy with the performance improvement if done properly, AND will save their customers the cost of a rear brake upgrade in the process."

[email protected]

 

[AMB]

03' Darin

I have the Wilwood 6 piston brakes on my 03 Cobra, with the BAER EradiSpeed Plus brakes on the rear. Wilwood makes racing brakes for all kinds of racing. We used them on our race cars, so I know that they are good quality brakes. They are a little noisey and dustey. I would not use the ITEM NO. 8(P/N 230-6001) Nut,Self-Locking Hex Head; "USE ARP 12-POINT 3/8-24 NUTS ONLY". P/N 300-8332 (10pc PACK). The stock ones will not hold the 47ft-lbs REQUIRED. DO NOT use any LOCTITE on them. Use only ARP Assembly Lubricant or antiszise on them. Also use the Optional S/S Brake Hose Kit.

AMB

 

[torquer]

For those of us looking to upgrade our front brakes without having to worry about screwing up bias, I'd highly suggest looking at the 00R brembo setup. They are balanced for use with the same rear brakes we have and will fit our stock wheels in terms of backspacing. I believe the rotors are the same directional vented brembo units, with a 4 piston brembo caliper and SS brake lines. They generally go for around $1000, but you can sell your stock front cobra brakes for an easy $300-400.