Brett H. - 89GTA

The C4 brake swap that I have seen some people performing on their car looks appealing, but I have a few questions/concerns.

My first question has to do with the rotor thickness. It seems that the C4 rear rotor is the part of choice with the swap. The rear C4 rotor has a thickness of approximately 0.81". Compare this with the front rotor thickness of the 1LE or the "LS1" setup, which is well over an inch. Even the 10.5" stockers have a front rotor thickness of about 1". My concern is that with the thinner rotor warpage will become more of an issue. Remember that these were originally designed to be rear rotors, which do not have to do the kind of work that front rotors see. On the front of a third gen, they will probably reach temperatures during "spirited" driving that they would not see on the back of a Corvette, even one driven hard. Has anyone experienced this problem?

A related question is what the fade resistance of this setup? Again, with the reduced rotor thickness there is less mass than with a typical 12" front rotor. With less mass, it takes less time to heat the rotor to the point where fade becomes a problem. Anyone have any comments regarding fade resistance that has used this setup?

What proportioning valve have people ending up using? The 1LE piece seems to be OK according the threads I've seen, but I was wondering if anyone had experimented with this. I am considering an adjustable one.

Also, if anyone has any hard data concerning 60-0 distances with this setup I'd like to take a look at it.

My current 4 wheel discs are doing 60-0 in 199' in the first stop, and 213' in the second stop. They fade like crazy, and the performance has reached the point of being unacceptable. The braking performance has deteriorated over the years, even with normal maintenance (rotors, calipers, pads, etc.). I'm sure that with some more work I could bring them back to something resembling brakes again, but I feel that the money would be better spent in upgrades. I am trying to keep my entire front and rear suspension upgrade budget to about $1500, but that's a bit tough with a 1LE setup or Baer setup costing $850 - $1000. I already have a few trick suspension pieces, so I'm not that much over budget with the 1LE setup. But...the C4 setup looks interesting...hence my questions. I have looked at the LS1 setup, but I want to keep the stock GTA rims.

Thanks.

Dewey316

wow, thats alot to cover.

ok #1 fade resistance, i have yet to get my c4 setup on the road course here (this spring i will have more data on that for you) but this brake setup did see lots of auto-x this summer, and never once faded. it also held up through severl very long spirited drives on teh 'columbia river gorge hi-way' in oregon ( very windy, very steep road) and on this road my old brakes would fade very fast, the c4's never started to give.

the prop valve i am using is the stock one on my 90 disk/drum car, it seems to keep them proportioned just fine.

hopefully alloy and i will have some GOOD 60-0 and maybe 100-0 stopping times, we are needed to get a set of tires, and the equipment to really test the diffrent brakes, and we want to do it all on the same tires, so that the test is very accurate.

and yes wtih the C4's you can do quite the upgrade for $1500, i spent right abotu 1k on brakes, full front end rebuild, shocks and struts. just plan ahead, and don't forget all the little things.

Brett H. - 89GTA

Thanks for the feedback. It's good to hear that the C4 setup is working well...I'm going to look into this more. What braided steel brake hoses work with the conversion? The C4 thread said stock hoses work, but do they mean the hoses for the 10.5" units or the 1LE setup?

Dewey316

i used the earls kit for the factory 10.5"ers.

ebmiller88

iTrader: (7)

That is a lot...

Here's my input. BOTH the front and rear C4 (Non-HD) rotors are the same diameter and thickness (12" x .81"). The rear rotor worked the best due to the difference in offset and the bracket interference issue...it just fit right in there. Although the rotor is a bit thinner, the increased size seems to make up for it. I would loved to have been able to use the HD 1" thick rotors but I couldn't make them fit without having to do more mods than what it was worth. In this case, the LS1s do the trick. I don't Auto-X or race but the C4s work VERY well. If you feel you'd need more brake or that the C4s won't fit your application, I'd look into the C5s or LS1s, neither of which I've tried yet. I have the LS1s ready to go but haven't found time to do it yet.

As far as the brake lines, the stock Camaro lines appear to work fine, although I have Russel lines on my RS. I do recommend upgrading to braided lines for the best performance anyway but your stock lines should work. Kandied 91Z has a set of Earl's front lines in the classifeds for sale, FYI.


Ed

88TPI406GTA

Also, if you really wanted to do the swap and save $$$ (as I did in buying the swap kit from Ed), then buy a set of new rotors and have them cryo treated for strength...The next set of rotors I get for the C4 setup (after winter) will be cryo treated...with the kit cost being so reasonable...and having the rotor and hub seperated, plus the larger brakes, for the kit price that Ed has...is a great deal...

YMMV and I don't know Ed (other than dealing with him on this kit)...HTH

88TPI406GTA

Also, as to rotor thickness...keep in mind that the actually wear surface of the rotor may or may not be thicker on the 1LE rotor...since the rotors are vented, I believe that the manufacturer just extended the cooling fins and that the solid area of the rotor isn't that much more...considering that the hub is attached too...

I wouldn't worry about it...for a price difference of almost $1000...you better ask yourself if it is worth the upgrade for you...my car is street driven and I don't autocross it...I may, and will change the brakes accordingly (ie race pads), but for now, the 12" C4 brakes will work just fine...

HTH,

88Camaro350

What is the total price for the c4 upgrade?

88TPI406GTA

I would email Ed directly as there are some different options, ie turned as opposed to new rotors and a few other things. I was one of the 1st to get the kit and I know that what I got was turned rotors, rebuilt calipers (by Ed), the modded spindles and new bearings. The hub is assembled on the spindle (which is painted a nice gloss black and the hardware is included...

My kit was about $500 (with a $50 core for the spindles which I kept)...he also gave me a slight deduction for no pads as I ordered the Stillen Metal Matrix pads instead on my own.

I believe that Ed is now using all new parts...but the assembly and quality of the kit is excellent. Quite a bargain for the $$$.

I know that Ed can't really advertise without being a sponsor on TGO, so consider this a positive product experience...