C4 early vs. late vs. C5

Can anyone tell me the difference in the early and late C4 hubs? What is the diference in these and the C5s. I have the early C4(84-87). Noone makes an aftermarket brake assembly. Wilwood makes a hat/rotor assembly but no caliper. Others have calipers, but no adapters for the corvette stub mounts.
I am talking to one manufacturer, who has an interest in making the parts necessary. What are the later DRB/GT40 Australia cars running. What would it take to upgrade to the C5 stuff, since the C4(at least early stuff) is slowly becomming dated and a little hard to come by. I am trying to decide if it is worth the time, money, and effort to do it. Any help would be greatly appreciated. I am sure others would like to know some of this as well.
While we are on this, what companys make CVs for these hubs? Do they make adapters, or do they have to machine the Ujoints off?

Bill
 

Peter Delaney

GT40s Supporter
Hi Bill,

Have you tried "Vette Brakes & Products" in Florida ?

Other possible sources for C4 brake upgrades could be :

Ecklers
Mid America
Corvette America

I don't think that there was any difference in the front hubs pre/post 87/88, except that the later ones had the toothed ring for ABS.

The main difference between 87 & 88 rear brakes is the handbrake setup - pre-87 had a drum brake in the rotor hat, whilst 88 had a setup that pulled on the pads. I have the 88 setup & had all sorts of trouble getting the standard DRB handbrake & sliding bar arrangement to work ok (to pass the rego tests, we have to have the handbrake hold the car on a 17deg slope for 5 mins, & the effort on the lever must be less than 35lbs - mine just scraped in at 34lbs !).

I have to ask the obvious question - why do you want bigger/better brakes (unless you are going serious racing) ? I had an 89 Vette & the stock brakes were outstanding - so I figured that the same setup in a GT40 at almost half the weight would be A1.

When we did the brake tests for rego, they got a real hiding - 10 consectutive crash stops from 110kph, another 10 with the fronts disconnected, another 10 with the rears disconnected, then more with no power assist. The brakes coped with this perfectly (can't say the same for the tyres !).

Peter Ransom should be able to give you the info on what the latests DRB's are using - have you contacted him ?

Kind Regards,

Peter D.
 
I have emailed Peter and await his reply. Those rego standards look pretty tough. I would think that whatever brakes you had that had to stand up to that test would suffice for whatever was needed. When I started this build I was set for the corvette setup, but only marginally. I had read somewhere that the Corvette brakes were marginal for track use. Not so much from the test you had to endure but from the constant heating and cycling that goes on with almost any tracking of the cars. Their were fade issues which basicly is a heat dissapation issue.
When I finally got the car the brakes and suspension pieces were less than I had hoped for. All, and I mean all the bushings were dried out and cracking, which means that were the original and had never been changed since installed in the factory!! And that's 20+ years ago. No telling how long they sat in the bone yard as well. The front A arms were pretty well worn with a few divots in them. ALL of the calipers were in such bad shape they had to be thrown away. More than one had the cooling fins groiund off so as to fit the 15" wheels it came with. Since I didn't heed my own advice in the negotiation of the car(Article on buying a used or unfinished kit), and didn't go to see the car before hand, I decided that the car would have to be drastically rebuilt, and if I was going to do all that, then I would build a show and go automobile. That would require a somewhat better brake system. So I have for the longest been hoping to find something that I could get a matching set for the car, rather than mixing and matching, or settling for the stock setup. Since it has taken almost 4 years to finish(hope to be on the road by the end of the year), my patience may have paid off. I am on the trail to a cure for all the hub issues. Will post what I find soon. Thanks for the imput as it clears up some of myquestions.
In my searches I found that there were plenty of brake setups for the C5, just not much other than Corvette for the C4. From a show stand point I wanted a little more. Since my wife told me to finish the car, I don't want to compromise my dreams and ideas unless I have no other option. It's only money. Since I have to put out for new brakes, I had just as well spend the little extra and get what I want. True I won't be on the track that often, but I want that extra in the performance and looks category just the same.
It has been a while since I have updated the build and hopefully I should have something in the next week or two owrth showing. I have done a lot on the car, but most is in the category of background stuff like the wiring etc. I had to redo the wiring at least 3 times. There were some things that I have added to the basic wiring of the car, and then found out some wouldn''t work. Other issues were with the routing of the wires. In the middle of it all, I had to remove most of the wiring as some hose routing issues arose and some additional welding had to be done, most of the wire routing was close so it was easier to remove the wiring and reinstall it. It all takes time and makes ou feel that you aren't accomplishing much. At least not much that could be shown. But when you step back and look at what you have done, then you see the progress. You just can't believe it has taken so long to get there.

Bill
 

Peter Delaney

GT40s Supporter
BIll, one other thing I forgot to mention - don't be tempted by cheap Taiwanese bearing assemblies. I made this mistake & got 2 new front bearings that had more run-out than the ancient ones they were replacing !!

They got sent back & replaced by legit OEM units which were perfect.

Kind Regards,

Peter D.
 
That holds true for all the bushings as well. We first thought we would use a cheaper aftermarket setup like Moog and then some other that is suposed to be reputable. They just would not fit and we had to go the OEM route. Some of the bushings are easy to remove if you have a small press. The others require drilling out which I was uncomfortable with and had to turn it over to a Corvette shop locally. It was a piece of cake once they got the right parts. These parts rarely wear out, but if they sit innactive for a long time(read years) they will dryout or dryrot, especially the grease boots.

Bill
 
Bill

I'm pretty sure Peter offers an AP brake upgarde...but not cheap.
My recollection of US based C4 upgrades was limited.
The GS Vette setup requires 17" wheels which I didn't want to do.

I haven't checked lately with stainlessbrakes.com
but they seem to introduce new brake stuff every day for older cars.
I like their Force 10 calipers.

You can get C4 CV setup from Peter...beautifully done....big $$$.

MikeD
 
Bill,

Are you trying to hook up the rear parking brakes? If so let me know how you fare. I have a KVA which has the '84 hubs without the parking brakes. I bought a parking brake rebuild kit which seems to fit the right rear wheel oK - the left wheel parking brake setup seems to be upside down and I can't get the parking brake lever installed!

John
:pepper:
 
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