I'm about to install a complete Wilwood D8-6 and D8-4 aluminum brake caliper system and their rotors on my car. Decided I needed to do some baseline 60-0 testing to see how my old stock stuff is actually doing.

My car has pure stock manual brakes on it that have actually served well over the years. They've always had a great pedal and have hauled this 3750lb (race weight) hulk down from 140+mph on many a drag strip. Some quite short!

I made quite a few back to back stops and didn't have any fade issues. The biggest variances were with how hard I actually worked it to make it stop.

1- 151 ft- nice quick stop but not anywhere near full brake application to get an idea of how hard I could push it on that surface.
2- 123 ft- Worked it much harder-no brake lockup or drama.
3- 118 ft- back to back-but now I knew I could work it harder.
4- 109 ft- hit it hard and kept it right on the edge of lockup.
5- 135 ft- real hard and locked up front wheels early and rears near the end.
6- 111 ft- very similar to test 4.
7- 113 ft- another good one!

I am planning some major HP and speed increases in the future and want to make sure the brakes are up to snuff to handle it, hence the new system. I'm sticking with stock sized pieces so I can continue to use my 15" wheels and tires.

Though I always felt it stopped well, I was pretty impressed with how it did considering the tires are nothing sticky at all...just stock street rubber. The fronts are skinny, drag suspension, heavy weight etc. etc.

The bad boy Z06 Corvette's of a couple of years ago do 60-0 in the 105-110 ft range and the newest baddest of the bad ZR-1 Vette's with 15.5" carbon rotors and huge tires can get down in the sub 100 foot range. But of course they are a few hundred lbs lighter too!

More to come!

JIM

 

what brake pads in the test you did ?
i have recently put Hawk HP+ front and HPS rear and i'm impressed!

 

Good move Jim - 'real' world brake testing - too many guys have changed-out calipers and rotors, replacing with after market set-ups and there has been no recorded reference as to how much better (or otherwise) they are than stock components - and we have the 'old school' guys telling us how good the stock set-up is and that we don't need any improvements in braking. Vette 4 wheel brakes were (when introduced) quite an advanced specification only seen previously on a few higher priced European cars - having said that is 40+ years since 4 wheel discs were introduced on Vettes and it is not unreasonable to expect improvements in technology relating to braking, especially with 'certain' cars running far more horsepower than stock. So, 'roll-on' the tests Jim, we'll all be watching with great interest I'm sure!

 

Its not the brakes that stop a car. It is the tires. I do not know if the stock calipers do not have enough clamping force with existing pads. Or if the Wilwoods have a larger piston area.

My big Wilwood brakes probably don't beat out stock calipers at slow speeds like 60 mph. because it is all about tires. but where they shine, is in the ability to shed heat for repeated stops and with bigger square inches of piston providing increased clamping to actually be able to lock up sticky tires at way over 120 mph.

Pad compound is extremely important to haul down something like your 140 + mph drag vette. Jim I use BP-20's on my Wilwoods for street driving and BP-30 fronts for track days.



http://www.wilwood.com/BrakePads/Bra...compound=BP-20


http://www.wilwood.com/BrakePads/Bra...compound=BP-30

 

If your brakes don't fade, and they are strong enough to lock up the tires, then what do you expect to gain by a new setup (other than huge weight savings and much better looks)?

 

The brakes didn't show fade in these 60-0 tests....but I have had them get weaker on some drag strip testing where we had to stop from 140+ and run back to back with no cool down time between runs. In the final rounds of some of these *street events* you never even shut the motor off....you pull right back to the line.

The piston area is the same on the new calipers..so no big change there. The pads are B-10's. They aren't quite as aggressive as the B-20/B-30's but remember, they still need to be decent street pads. We discussed how the other pads have been working and I believe these are going to be a good jump in fade resistance yet still work great from dead cold. When I pull out on the street or pull to the line for the first run of the day, they are cold and I can't afford for them to need to be heated up before really working well.

Haven't weighed everything yet..but should be a good improvement.

As mentioned, tires are one of the biggest factors of stopping and with my sort of *unbalanced* setup of big rears, little fronts and then drag slicks at other times, I need to have good modulation and feel to allow confidence to brake hard when needed. Hoping to get even more of that!

JIM

 

Your tests proved what I have always said. The stock system is a phenomenal braking system especially since it was designed over 40 years ago. You are right at the stopping distance of the newer ZO6 and you have old school 15" street tires. Put a set of modern tires comparable to the ZO6 and see how it brakes. The tires are the weak point of stopping these cars. Good thread.

 

The BP-20 is good even cold very dependable. If you look on the Wilwood chart they increase a little in tq with heat and no glazing out to 1100 degrees.

some what dirty your wheels get a grey black dusting. The wilwood "H" "C"'s are just plain dangerous until they get up to 500+ degrees. cold I never knew which way my car was going to go.

 

If these work like I expect, I think it could be a no brainer upgrade for folks with leaky stock calipers. You can rebuild the old ones with stainless sleeves, but you need to make sure to get them done right. I've seen some parts store replacement ones replaced multiple times under the *liftetime warranty* before they got some that didn't leak. And even if you get some from one of the big name builders that do them right, if you have to pay to ship those heavy iron suckers back to vendor it can get real pricy.

These should give lighter weight, great performance and much improved life. At least that's my plan!

JIM

 

Bump, for all your hard work on this review.

 

A 46 yr old braking system may look like it compares well at a very slow 60 to 0. World of difference trying to pull weight down at 170 to 200 mph or even 145 mph+. Can you kick your baseline test up to 100 or 120 to zero then see the difference in length of stops with new brakes. Some better non drag racing front tires for both tests would better show the results of the new brakes. What your doing would be a real help to someone considering spending the money. At higher stopping speeds you could really show the difference if you had the most front tire you could get under the car.

 

Lets see a video/s next time with the new brakes....

Gotta admit, I am jealous. You look like you got a nice long piece of uninhabited road where you can do all the testing you want without worrying about anybody or the local authorities. I cannot even rev my engine without 20 + people hearing me anywhere I go.

 

Sure...I'd love to. Got a good place to do it? I'll meet you there!

No doubt things at 150 mph are a lot different and especially if you do it repeatedly. I used 60-0 because it's always been a *std* test forever and it's easy to find comparable data. Plus it's reasonably easy to do. I dunno if that's true...I rode around a pretty good while before I found a safe place where I could test for a few hours and it was out of the way enough where my wife could be with me and help. Even at that we had some traffic stopping wondering what the heck we were doing.

This car goes down the dragstrip fairly regularly with 140+ mph trap speeds so I have a good idea how it stops...just no data at those speeds. I know of one little short 1/8th mile track where it takes ALL of the track and I sometimes have to back up to the return road..and that's only from 110-111 mph.

The front tires for this test weren't my drag tires...but they are relatively skinny..205/70's...which are similar to what a lot of Vette guys use on midyears. I was able to get them to stop pretty decent without locking them up..but it took pedal control. When I did work them too hard I locked them up. For sure the brakes on there now could do even better with big front tires.....but this car will never have them...so I'm testing it like it will be driven and raced.

JIM

 

Hey Jim - that little old road you've been using there could just as easily be a country road over here in UK (in fact so much so that I'd had sworn it WAS the UK ) make sure thought that the car doesn't pull to the right under heavy braking or you will need Air Sea rescue !

 

As I look at it..I realize it really does look similar. I spent some time driving all over the UK a few years ago.

See...Texas isn't all dust!

JIM

 

You may be old enough to remember the album bill cosby made called 200 mph. Before he buys the cobra from carroll shelby he has a ferrari that is out of tune takes it to a mechanic to have it tuned. Mechanic tells him it just needs to be drove fast blown out lol. Tells him to drive it at some real high speed. Cosby is in LA county says where can i do that. Mechanic says "any side street".

 

Well - I have 255/45/18 & 285/40/18 Toyo's and I'm not convinced about the quality of stock brakes - Hawk HP pads were a good move though!

 

What size rims do you run?

Have you got any pictures of the calipers installed?

//Ricky.

 

They are 15" wheels. No pics of installed yet. I spent time tearing down trailing arms and repacking rear bearings since it's been a long long time since they've been touched. Got the rear rotors drilled to fit my 1/2" studs and got them mounted and runout ck'd. Next will be calipers and lines, bleeding etc. Getting closer! Also changed diff and trans lubes today while I was under there. Just doing some preventive maintenance.

Spent tons of time running around trying to find a drill bit! Misplaced my 9/16" one somewhere and all I had and all I could fine were 1/2" bits. Finally got one though...just wasted a lot of time!

JIM

 

GREAT!!

I have missed that the had a 6-put caliper that fitted behind 15" wheels.

Must be the bottom one on this page you got?

http://www.wilwood.com/Calipers/Cali...6%20and%20D8-4

Is it the top ones with piston area 3.00 you got for the rear?

What rotors did you go for?

Sorry for a lot of questions but this is interesting..

//Ricky.