Monaro72

Hi
I've got an 88 c4, I'm going to upgrade the brakes with a c5 brake upgrade kit, my question is, will I need a bigger brake booster, and resoviour,

WVZR-1

I believe you meant "master cylinder" NOT "booster" and I believe that until you've actually accomplished the caliper/bracket/pad and rotor change you mess with NOTHING. Actually aside from just spending money do you actually have the need for anything other than the OE braking?

Monaro72

Your right, the master cylinder, my brakes are shot, and I've heard a good cheap brake upgrade is a c5 kit, corvette Pacifica, sell them for about $1500, straight bolt on replacement, I understand if the calipers are bigger, you need to upgrade your master cylinder

c4cruiser

The C5 front brake upgrade does work when you use the car for performance events such as autocross and track days. Otherwise, the standard brakes work fine and a pad upgrade will improve braking.

Doing the C5 conversion does not require any changes to the master cylinder or brake booster. I would recommend getting a brake bias spring for a conversion like this. Doug Rippie Motorsports has them for about $25.

That $1500 sounds waay overpriced. A C5 front brake upgrade should cost around $700-$750 tops. There is very little difference in the size of the stock C4 rear rotors or the size of the rear pads. The swept area will be very close. The big difference is that the C5 used an internal drum parking brake. IIRC, the 88 and later C4's use the rear caliper for the parking brake. Make sure to verify this!!

At the same time, you should replace the flexible brake hoses at each caliper. Can't hurt to consider stainless braided lines. You can use C4 lines on the C5 front calipers. Do a complete brake fluid flush using a good quality DOT3 brake fluid. Castrol LMA or the Ford MotorSports HD fluid will work well. A DOT4 fluid like ATE TPY200 or Motul is a good upgrade.

Monaro72

That's some good advice thanx, just on verifying the handbrake scenario of the c5 brake system, how would that affect the c4 system, the kit doesn't say anything about an internal hand brake, an it comes with new calipers, braided hoses, pads, brackets, rotors, the lot,
My plan for my c4 is, a nice clean ride, with plenty of horsepower, that can handle a day at the track, or down the drag strip, I'm still learning about it, but one thing I do know, she's a high maintenance bitch, but I love it

Tom400CFI

The C4 park brake won't work with C5 rear calipers and/or rotor. You should stick with the the stock C4 rear rotors and calipers. C4Cruiser is right; there is no meaningful performance gain in the rear C5 brakes.

I agree with others that for infrequent track days and drag track use, stock brakes w/good pads and fluid will work fine.

I also agree that $1500 for a C5 conversion is WAY too much. I did mine for ~$450.

tlong

You may have wheel issues too. J55s won't fit sometimes.

VikingTrad3r

if your brakes are shot, u may just need new pads/rotors with a full bleed then cycle the abs pump numetous times on s gravel road then rebleed. i did this snd the difference was staggering.

Monaro72

I've been looking at ecklers and corvette central for parts, would you recommend them, and also, I'm planning on doing a full suspension upgrade, the same place, corvette Pacifica, have full suspension kits for c4s, around the same price$1500, would you recommend coil over shockys or standard shocks

blackozvet

Im guessing your from AUS with that username ?

I have never heard of Corvette Pacifica, but those brake prices are a little bit high, its gonna really hurt when you add the Aus dollar at .72 and shipping.
Ecklers and Corvette Central wont do you any favours on shipping either, placing small items in very large boxes that end up costing a fortune.

you are probably better off shopping at Summit where you can put items in the cart and get an immediate shipping rate.

Monaro72

Yeah mate, I'm out in Alice springs, thanx for the advice I will check them out.

c4cruiser

There are a number of members here that are from Australia and New Zealand that could help you with the best way to get parts and help with projects.

If you mention where you live (you can do that in the User CP) and also mention what year Corvette you have, that's a very good way to get the best information.

2ooo-C5

I have been looking at a big brake upgrade for HPDE for a few months.
Don't waste the money on C5 its not enough of an upgrade. If you want it for looks then find
some used calipers. Go to the C5 section. They are always replacing there calipers with C6 calipers.

I have a C5 and C4 J55. The C4 with carbotech pads stopes better then the C5 with StopTech pads.

Try a real set of pads. Get steal lines, replace fluid with DOT 4 Motug 665
and see what you think. $300 and it will likely be more then you need.

I am amazed at the J55 brakes with real pads. The only reason I am thinking about upgrading to
wilwood or baer is for replacement parts. Im doing like 12 HPDE a year and wear stuff out very fast.
Full set of Hoosier R7 are hard on everything. 1 or 2 events a year and the factory will last a long time.
If your on street tires you wont out perform the factory brakes with good pads.

Monaro72

Thanx 2000c5, after the all the great info I've read on hear, I think I will stick with the original j55 calipers, an upgrade the rotors, get a set of hawk pads, and stainless steel braided lines,
My next mission is a full suspension upgrade, any recommendations

2ooo-C5

Friend did that last week and forgot the fluid. I loaned him a bottle of mogul 665 and watched as
he flushed the fluid in the pits at the track after boiling it in the first session.

He loved the set up after he changed fluids. huge improvement.

I have a z51. I lowered my car and currently I am very happy with the suspension.
I might get upper control arms to get more camber. I was only able to get -1.2 on stock. Hoosier says to go for -2.5

I would get tires before you change much on suspension.

2016 C7 Z51 still on temp tags ran a 1.48. Driver was an instructor with over 15 years experience.
His jaw fell to the ground when I told him I ran a 1.52. Our cars are still very capable. It was also
my first time on that track. I will get faster with more days there.

pologreen1

That seems very strange to me. Maybe because the cars are different it feels different. C5 brakes on a c4 have been proven for years.

2ooo-C5

They work fine. And for years C5 guys have taken the brakes off a C6.
And soon they will probably be taking them on a C7.

But... in racing the C5 brakes really are not much better then J55's. They are better... just not $1,000 better.
If your going to spend the money get C6 calipers. Not much more and they stop better and hold up better.
Just seems like a good idea to actually need them. A set of 285 street tires will let go before the the brakes
have any issue. its jsut a waste of time and money unless he wants it to look better.

I never said they don't work... I said try saving the money and try better pads first. I was given that advice
a few months ago and have been very happy. I gave that advice to a kid 2 weeks ago and he is very happy.

I have a C5... I have tracked the C5 and the C4 on the same day on the same tires. Same steel lines and same fluid.
The base C5 brakes are nothing special and need upgraded if your really going to race it.

Don't waste the money... go to C6 calipers. If you google it for a while you will find at least 3 threads in this forum with guys saying the same thing. I almost took the calipers off my C5 and decided to try Carbotech pads first.

pologreen1

I agree c6 is better, but C6 is a huge step up in cost and pads though. Also need larger wheels etc, C6 is a completely different ball game. For price of J55 he could have c5 and put great pads is all I am saying.

Tom400CFI

Say what? The C5 upgrade is most certainly "enough" if you're tracking with good pads and fluid, and are still overheating your brakes. The rotor is substantially larger, thicker, the caliper is bigger and more rigid and the pads are much larger. It is a meaningful and worthwhile upgrade if the stock brakes aren't sufficient. Second, C5 calipers and C6 calipers are functionally the same.



I did. But there are so many variables that influence this.

beerme

I did a brake kit on my 87 from VBandP, basically it had C5 front calipers, the adapters and C4 rear calipers. I bought my own rotors and HP pads, I also did the bias spring upgrade and used my stock master cylinder. Everything worked fine except I had to upgrade to 17 inch wheels to clear the calipers. As for actual stopping power, incredible difference on my car as an occasional driver not track use car. I almost kissed the steering wheel the first time some idiot stopped in front of me for no reason, thank God no one was behind me. I stopped well short of the idiot but I know I would have got rear ended if someone was behind me, I was not expecting that kind of difference in performance.

Best of Luck