Billyboy

This is a kit designed for the heavier 4th gen f-bodies. The part # is WIL-140-6744-D and can be purchased through Summit racing for $718.99 [For standard rotors(still 2pc, but no slots,drilled or zinc washed) just purchase kit # WIL-140-6744, Its a little less expensive]

This kit is a direct bolt-on for our 3rd gen's without any modifications to a current factory rear disc 10-bolt axle housing.

Here is the basic design- 4 piston FDL calipers and "2pc" hat and rotors 12.2"x .81" with an internal drum parking brake assembly.

Billyboy

diagram

Billyboy

stock setup- iron calipers, 10.5" rotors (before Wilwood install)

Billyboy

Axles removed, ready for new binders. If you do not have the rear "disc" housing flange, then refer to the ls1 brakes housing upgrage in the tech section for drum rear flanges to be converted.

Billyboy

backing plate caliper bracket w/ drum parking brake. This bolts right on, no modifications required to the 3rd gen 10-bolt axle housing flange

Billyboy

Rotors and Calipers installed

Rotors- 2pc 12.2"x .81' SRP w/ steel hats for parking brake assembly

Calipers- Wilwood FDL 4 piston

Billyboy

The only fabrication needed is to the brake lines. The stock passenger side hardline is good to leave but the driver's side line will need to be replaced with a shorter one and rerouted.

Parking brake cables can be purchased through Lokar (their universal kit)- stock ones will not work. Summit also sells them.

Billyboy

There is still lots of clearance with the 12.2" rotrs and calipers on a 16" Iroc rim. I can still run my fingers through the gap between the caliper and the inner rim.

91Z28-350

Cool info. How does the thickness vary with the stockers? In other words, does it push the wheel out further?

Billyboy

Not at all- Same exact offset as stock.

Billyboy

Parts list for Earl's products. All of these lines and fittings cost me $35 (but I have connections) probably cost retail about $75

alloy

iTrader: (16)

Just to add a quick note to try and help a little on parts sourcing, a Goodridge pre-made braided line with -3 AN female fittings on both end is available in a 9" length, part# D30309. My local cost is $20 each. And, these lines are DOT certified, which means they are pressure tested and certified before being sold.

These are the type of lines I now include with my front brake kit. I really like the idea of having DOT certified and tested flexible brake lines. Lets me sleep a little better at night knowing this.

Billyboy

Dan, I fully agree with the DOT lines. TMR (who is a local Earl's vendor- the best in So.Cal) does pressure test the custom lines after making them.

Here's a final shot of everything installed and system bleed. E-brake cables & clevis' will be here Friday.

YenkoZ28

Wilwood also makes a kit #140-7148 which uses vented disks and a drum style parking brake for 93-02 camaros. The only diff. I could see with it is it uses a one piece rotor instead of a two piece rotor. It also costs about a hundred less than the two piece rotor setup. I was planning on getting it to compliment the spohn big brake kit.

laiky

is there any advantage to these over ls1 rears?? they seem very similar and i believe the ls1's will bolt up to a 10 bolt?

laiky

oh yeah, welcome back.

Billyboy

For a little while anyway, but thank you. (Billyboy; geez watch 'em keep me around with this frikin name- It was close to wilwood-will-bill- get it)

I heat cycled them earlier, them drove them around tonight about 40 miles to bed them. I still haven't gotten on them more than about 1/2 pedal but can say "holly crap"- I am going to have to get the fronts together very soon. I never had a problem with stopping power on the old setup (only changed it because of the rattling/moaning crap that is associated with the clunky iron caliper design) but the bias ratio front to rear as gone way out of wack (which was expected) and I already have noticaibly less pedal effort with just the rears done. I also changed them for prolonged durability- the smaller discs were warping faster than startrek- I was turning them about every 3 months

LS1 rears are still the single piston "floating" caliper design- I wanted to get away from that. These are a "fixed" caliper design and my 10bolt has been built with minimal endplay due to some extra work with the c-clips. I have about a 1/32"max endplay on the axles and the carrier pin. Thus the fixed calipers have no adverse affect when corning hard/ and they will be more responsive on bite and release- no dragging like the floating design problems I've had.

laiky

sounds good, reason i'm asking is i'm getting ready to put them on my 9 bolt. I paid 50 bucks at a swap meet for them, a little more in keeping with my 04 budget

alloy

iTrader: (16)

It's nice to hear from another source that you felt such a huge difference. "Holly crap" as I recall

I've mentioned before that I can feel a quicker apply and release of the fixed calipers, but not anyone beside you believed me until now. The incredible response is almost breath taking. Until you have driven a car with brakes like this, you just can't imagine how much difference there truly is.

Concerning the brake lines.

I had major problems trying to get what I wanted made up locally. You are very fortunate having such a good hose supplier near you. After much money spent and numerous trips around my area here, I stumbled onto the Goodridge hoses. And the adapters like you used. When I send a kit out, I include the adapters for both standard flare, and bubble flare cars. It's much easier to do that that to try and figure out what type of brake lines are on each car.

I'm very interested to see what your e-brake cables look like when they are done. Please take lots of pics of them

92 zzz28

Would using those rear brakes with a front setup like an LS1/Z06 cause anything like rear lock up to occur. I know I would need to use a proportioning valve to adjust everything, but I want to know about any other adverse possibilities with a twin piston front and 4 piston rear.

I am going to be installing my updated fronts soon and want to start on the rears soon after that. Until now I was thinking about using LS1 type rear brakes. Those rears look great. I want them, but I don't want to have an unsafe car...

Thanks

z28cdoyle

Ryan,
I suggest you use an adjustable proportioning valve to correct brake bias if you go with the 4 piston rear calipers. You may or may not have rear lockup problems. This depends on the piston area of the front compared to the rear calipers. Even though the rear calipers have 4 pistons, if the surface area is less then the front, you will have reduced tendency for rear lockup. Of course, the master cylinder and proportioning valve are huge factors as well.

I preach the virtues of adjustable proportioning valves to anyone who will listen (of course my car has one). I will be sticking with my stock rear calipers/rotors because ever since I dumped the stupid stock proportioning valve I have had plenty of rear brake (often times too much).

By the way, I finally stumbled across the PM you sent me in November abd replied. I guess I should look there more often.

92 zzz28

Thanks for the info.

I definately will be using an adjustable prop. valve. Any recommendation for brand? Would using a master that was installed in my car with orginal drum brakes be okay with rear discs? I don't know if they are different or not.

How would I go about determining the piston area of the calipers? Would Wilwood supply that info on their website?

Thanks again.
Ryan

alloy

iTrader: (16)

Easy high school math.

A = pie r2 (no symbol for pie, so had to write it out)

This formula means that the area is equal to 3.14 times the radius squared.

George

Wilwood has an adjustable prop for about 40 USD and I think there's an article in the tech section on how to install it

I'm looking at this brakes post with great interest as I think I'd go with the 13" setup from Spohn and the rear setup that's being talked about here. Only problem is that I want to install a zz4 or fastburn this summer and the brakes will probably have to wait until the following year.

92 zzz28

I know the math, I need the info on the Wilwood calipers. I should have been more clear of that. I checked their website after posting to see if I could find it and I could not. Do you know what the piston area is or maybe the diameter of one piston?

This quote is straight from the Wilwood site:

"A calipers piston area is calculated by finding the total piston area from one side of the caliper (this is true for a single piston caliper also). The graph provides the piston area for individual piston diameters. Note that differential piston bore calipers will be the total piston area of the different size pistons."

I have a question about this. Would you calculate a 4 pot caliper using only the 2 pistons on one side? That is what it says, but that sounds strange to me. I would think you would calculate using all 4. I dunno, help me out.

Thanks,
Ryan

BTW, pie is pi

alloy

iTrader: (16)

What calipers do you need info on? If it's for this rear 4th gen kit, then look up the kit on the wilwood site and find the part number for the caliper, then find the listing for that caliper that comes with the kit and it will tell you what piston size it is.


Edit,

Ok, took about 1 minute to find the info on the wilwood site.

part# 120-6807 1.38"

92 zzz28

Thanks for the info.

Sounds like the Wilwood rears and the Z06 fronts, from the research I have done tonight, will work just fine; with adjustable prop. valve of course.

Thanks to all of you.

Ryan

Billyboy

Just for the record, I just about have worn through the Zinc coating on the rotors and should have them entirely bedded at another 50miles or so, and can say deffinately from the bias that there is no way in heck that an adjustable prop valve would decrease these enough to even things out with the iron caliper fronts (My fronts, though only 10.5", have all the trick goodies including racing compound carbon pads, braided hoses, slotted rotors)They will lock at about 5/8 brake pedal downhill- feels as if the fronts aren't even working anymore until after the rears are locking- there is that much if an increase in pressure.

This car was perfectly balanced before and did a 60 -0 in 102ft with the 4wheel 10.5" rotors setup I had (Note; I'm a lightweight V6 car, not V8) I will not gain any stopping power "distance wise" with the larger setup on street tires- what I am gaining is reliabilty/prolonged life of rotors without warping. Am also gaining less pedal pressure which I am not keen on, but its a fair tradeoff for durabilty. I like a larger sweetspot feel of the older brakes better, the new ones will take less pressure to stop the same- meaning if you press on them too hard they will just lock easier(a smaller sweetspot in pedal feel). A car will stop only as fast as the tires friction level. I run the best street tires money can buy in a 16".

Brake cables are delayed delivery till monday- I will take lots of pictures when I install them.

alloy

iTrader: (16)

What you are saying about the decreased pedal pressure needed to apply the brakes now, and stopping power doesn't suprise me at all. It really amazed me how little effort is needed with a fixed 4 piston caliper verses a floating caliper on my car. I can't wait to have the rear kit on my car.

When you get the 13" brakes on the front of your car, and after some time you will find that sweet spot again. Just have to get used to maybe 1/3 the pedal effort verses your stockers. It took me awhile to get used to the pedal feel and how little effort is required, but not all that that long. I think you will learn to like the feel after you get used to it. It's really a very comforting feeling when you tap the pedal over the stock brakes.

Billyboy

I agree I will get used to it but waht my biggest problem is- is my height. I am 6'4" and do not fit well into any car. It is not comfortable for me to lightly work the pedals because of leg room issues- much easier for me to press them harder (extend my leg more) to get the same result. I have better feel that way rather than holding back/lifting my legback off the pedal to prevent harder pressure. Time to cut the seats like I did in the Vette years ago. My head still sticks out the Vette's t-tops slightly with a helmet on.

Wife loves the new feel of them so far, says it is noticiably more comfortable for her to depress the pedal- but shes ONLY 5'11".

Time to pay off some X-pensive X-mas bills first, sould be getting to the fronts in a month or two max. Had to get to the rears first because of clanging B.S of the stock rear calipers- it was getting embarassing.

Chickenman35

I hear ya on the decrease in pedal effort. I also like a fairly heavy pedal...easier to modulate.

If you can change the Master cylinder to a slightly larger bore, that will icrease the pedal effort. Or you can redrill the brake pedal with the clevis pin hole slightly higher. I've done this a couple of times with different production race cars.

It doesn't take much, measure the pivot lenghts and calculate the ratios to get the correct amount.

Justins86bird

Me too.

z28cdoyle

Billyboy,
Since the rear setup you now have has so much more clamping force than the dinky stock fronts, I agree no proportioning valve will have enough adjustment range to make up for such a gross mismatch. However, I think a proportioning valve will allow you to properly tune the brake bias once you upgrade your front brakes to something more matched with your rears.

Billyboy

My point was- why put an adjustable bias valve on and crank these rears all the way down to match PBR style front calipers? I would only suggest (like I stated in the post heading) that they be a match for Spohn's "Big Brake" kit- They have larger Wilwood superlite calipers-FSL's (larger pad surface area) combined with 4- 1.75" piston calipers. If using LS1 fronts, I would recommend just using LS1 rears- otherwise- why turn these way down, it would be a waste of money and effort in my opinion. The Vette floating calipers are no match to the FSL calipers clamping force.

Just words for thought- thats why I posted "for the record" above.
Agood2.8- Dean

Billyboy

Chickenman, You have specs and #'s on a larger MC option for our cars. I have heard that a larger bore was availiable for eligibilty in production racing back in the late 80's and that many "sofa on wheels driver's" complained about the cars that came with that option and needed a stronger brake foot. If I recall they were a 1" bore?

Any info on this from anyone would be greatly appreciated.

Chickenman35

I'll dig through my Raybestos catalog to see if I can come up with some numbers and info. I seem to remember that a mid-eighties S10 Truck m\cyl had a 1" bore and will bolt up to our cars...but I'll have to check.

Billyboy

I positively know the f-bodies had a larger bore master cylinder as a factory option on some performance versions. I just can't locate the info, but I have read about it in the past. This was late 80's performance package options. It may have come on the policecar packages also (BC4?)

Justins86bird

Some of the iron rear caliper cars came with a 1" bore. If customers complained, the 15/16" bore drum MC could be switch in by the dealer. PBR rears used 15/16" bore.

Billyboy

This car was originally rear drum so I am positive it has the smaller master cylinder bore(master cylinder is factory- never been changed). You wouldn't by chance have a part # on the larger bore MC's? I have searched to no luck. I know when I switched to a 1LE prop valve in the past that it was a nightmare figuring out what the part# was that I needed. The dealer and I came up with 5 or 6 different part#'s at that time and I had to research from there (dealer couldn't help any further- they don't have specific specs on part #'s) turns out a few #'s were upgrades and the others were old #'s and obsolete. At that time I had posted my findings for any to reference based on year and threadpitch, etc(basically labeled all the different options). It would be great if anyone had any such info on all availible mastercylinder part #'s.

92 zzz28

That info would surely be helpful.

Justins86bird

From my catalog, it shows
1984-92 J50 drum mc p/n 18014286
1989-92 ('88 1LE) J65 disc mc p/n 18014268
1984-88 ('88 exc 1LE) J65 disc mc p/n 18014287

p/n 18014287 would be the 1" bore.

Billyboy

Thank you very much

One last favor- Anyway I can get my "Agood2.8" name back if you guys are going to keep me around- this "Billyboy" is killing me- It was only what I thought to be a short term gag name. You don't have to answer that if it will get you in trouble, I will assume its a no.

vexter

iTrader: (3)

I've been going over my options for upgrading the brakes on my '88. I'm just tired of the chronic fading of the stockers. I excitedly read about the diy C4 & C5 (and LS1) conversions as opposed to the rather expensive pricetag associated with a Baer kit and even your "Big Brake" kit offered by Spohn. Then I ran across an eBay seller and this auction.

Does that seem like a reasonable system as compared to the C4/C5/LS1 conversion for the $$$? Am I missing something?

:edit:
Seems Billyboy is banned...

Can someone else chime in here?

Mavrick

Why do you guys keep banning Dean? He's just giving out useful information

Matt87GTA

You're a newb and don't know the whole story. If all he ever did around here was give out useful information he would not get banned. Think about it.

92 zzz28

Seems too good to be true to me. However, I don't know from that description what that kit is designed to fit. Maybe it is just a universal front brake setup, unless I am missing something. Might be a good deal if you are prepared for possible modification and fabrication. Good luck...

alloy

iTrader: (16)

Yes you are missing something. Go to the wilwood web site and look up the specs for kit# 140-2992-b you have linked to and you will understand.

www.wilwood.com

br()bert

hahaha deans banned again! " can i have my old name agood2.8 back? lol i guess not! LOL , He once laughed when i asked for help because my head gasket went, so i now say what i said then"cars can be fixed, dean will be an *** forever" Is sad really because he does know alot about 3rd gens.:lala:

br()bert

Do a search on his old name agood2.8 youll see why hes banned.

92 zzz28

I see with that kit, a smaller rotor, much smaller than the Spohn offered kit. The spindle mod looks like what most of the brake kits call for. Other than that I dunno. I bet it fits in a 15" wheel!!!