The Snowman

In the future I def see a C5 brake conversion on my base coupe. From what I understand the sawblades won't fit over the brakes but some 17" wheels will. What exactly with the sawblades is causing problems? I.e how can I measure a wheel and see if it fits over the brakes? The reason I want to know is that I'm convincing a friend of mine that his 17" O.Z Mito's really needs to be mine and on the Vette. However I don't want to spend a good amount of money on great wheels only to find out I can't use them in a year or two.

Regards, Dan

c4cruiser

What year is your car? A C5 front brake conversion requires a custom adapter bracket so that the C5 caliper bracket can be bolted on. The custom adapter you need depends on the year of the C4; 84'87 or 88-96.

If you have an 88 or later C4, you may be better off going with the C4 J55 front brakes. The J55 brakes were standard on C4's with the Z07 suspension and were standard beginning in 1995.

The J55 brakes had a 13" front rotor and slightly larger front calipers. You can find J55 calipers and rotors at places like Rockauto and some brands even include the J55 caliper bracket.

The J55 front brakes can use any of the Corvette 17x9.5 wheels such as sawblades or ZR-1 wheels with no fitment issues.

The Snowman

I have a -92 and have the brackets already. �
I kinda figured that since I have to buy calipers etc the stock C5 brakes would be better than the J55. They certainly look beefier than the J55-option.

DMITTZ

C5 brakes are better than C4 J55 brakes.

I upgraded from C4 J55 brakes to C6 J55 brakes, lots of info on the swap in my thread:
https://www.corvetteforum.com/forums...vol-2-a-2.html


I don't have saw blade wheels but I imagine you could just use a small hub centric wheel spacer (say 1/4in) to overcome any clearance issues with the backside of the wheel spokes if you wanted to use sawblade wheels.

You are better off getting C6 calipers since they are a 25% stiffer than the C5 ones even though they use the same pads. You can go with the base C6 brakes (12.7in) if you want to use 17in wheels. If you don't mind going with 18in wheels you can use a the C6 J55/Z51 caliper bracket and run the 13.4in rotors which is the C6 J55/Z51 setup.

I had the same Brand of brake pads on my C4 J55 setup and now on my C6 J55 brakes and I can tell you the C6 J55 setup has much more bite and more fade resistance than the C4 J55 setup and there is only a marginal cost difference if your upgrading from the base brakes anyway.

It's your car and your call though, best of luck with which ever swap you choose!

The Snowman

@DMITTZ: So you think it's more an issue that I would hit the backside of the spokes rather than the outer diameter of the wheels?
The wheels I'm looking at are rather classic and hard to come by and I really want to make them work. The ones on the yellow BMW.

WVZR-1

OP - if the wheels on the BMW are "direct fit" 5 X 120 then they would require a "force fit" to be used on your C4 and you also would need to confirm offset etc.

Regarding the saw-blades - it's been mentioned many times that a 1/4" spacer should create sufficient gap for spoke clearance with the "painted" '91 & '92 wheels. Does it for all? Needs confirmed car to car.

The ideal confirmation for you would be to find someone "local" with C5 brakes and try your wheel "as is" now for confirmation. I'd think that shouldn't be an issue BUT in reality J55 C4 stuff should do nearly as well as a C5 conversion if quality hardware and hydraulics are used.

With the saw-blades the C5 visuals aren't seen so why the effort? I doubt also that "all" adapter brackets are created equal. I understand some require washer/shim. Joe, John, Jim, Bob and their cousins all claim to fabricate the C5 bracket. You believe them all to be equal?

C4 J55 calipers from the GS could be considered an "upgrade" and I believe that's what I'd consider.

The Snowman

Thanks for the input. The wheels needs to be modified to fit my car but they are quite rare, atleast in Europe, so I am willing to change offset, width etc. One of the perks with split wheels.

As far as visuals go, that´s the least of my concerns. I love the sawblades and want to be able to use them in the future if possible. I modify to make an improvement and I want the car to stop better but still be able to go through my yearly MOT. That´s why I want to use Corvette brakes instead of Wilwood or another aftermarket company. The guys doin the inspection usually don´t notice a brake change if it still says Corvette on the calipers. A perk of living in Sweden where Vettes in general and C4´s in particular are quite rare.

WVZR-1

Didn't realize your location. Trial fit of yours to another would be difficult!

I'd still just do the C4 J55 and consider it done but .....

I like the painted saw-blades myself, the machined face ? Not so much. I didn't think that spacers would fly for your inspections. Will they?

I've sent some D44 stuff to a fellow in Sweden with an AC Cobra with an LS7 (modified) with 550+ to the wheels.

This is 1st start with no mapping:

https://www.youtube.com/watch?v=xacf...ature=youtu.be

This is an older when it was with less power:

dizwiz24

c5 brakes arent really an upgrade over c4 j55 brakes (with the right pads).

first off the c5 brake rotor isnt a true 13". its more like 12.5".

people used to do comparisons of the rotors on here (c4 j55 vs c5). the c4 j55 was the bigger diameter.

next off c5 brake rotors are thicker (read heavier) than c4 j55.

there are some 'swept area' advantages to c5 rotors vs c4 j55.

i would be looking at c6 z06 brakes, but be advised you need bigger wheels to clear them

QCVette

The sawblades contact at the vanes. The vanes curve inboard rather than straight out to the barrel of the rim. However, they can be made to fit, but I don't remember exactly how. I think it involved grinding some clearance on the wheel or taking some of the ridges off of the calipers.

Some of the other C4 wheels will fit. The '88-'90 and the A-mold wheels (like ZR1/GS/CE/Pace car/or Camaro SS) will fit the C5 brake set up. I personally have put the 17 x 9.5 '90 wheels and the 17 x 9 Camaro SS wheels on my C5.

Good luck.

DMITTZ

As I mentioned I don't own sawblade wheels but I Would think it is likely a clearence issue with the back side of the spokes. C5 corvettes had 17in front wheels so the C5 brakes should fit inside a 17in diameter wheel as long as the backside of the spokes clear the calipers.

Also while everyone is entitled to thier opinion, I had the C4 J55 brakes, and they were in good condition and I now have the C6 brakes and I can tell you for certain the C6 brakes are better than the C4 J55 brakes. I Had the same brand pads (Hawk HP+) on both systems, same brake fluid, same brake hoses.

Bottom line the C6 brakes are better.

There are better brake systems out there but for the money and if you want them to say 'Corvette' they are pretty decent brakes. I would advise against the C6 Z06 brakes as a lot of C6 guys are unhappy with them at the track and they are pricey, especially for the rear brake conversion required on C4's, They do look good though.

dizwiz24

my point to the OP was , if he was going thru the trouble for c5 brakes, why not just spend $100 more and put on leaps-and-bounds better c6 brakes (assuming there isnt a wheel clearance issue)

i did not hear about issues with c6 z06 brakes.

MrVette90l98mt

I did Baer C5 Size conversion from J55's It wasn't a huge upgrade but still an upgrade. I also used their 2 piece rotor's and their +1'' rear rotor kit to make it 13" front and rear. I would recommend an actual after market setup over C5's if you already have J55's and get new wheels while you're at it. I fitted cooling duct work and experienced little to no fade on track with L98 power. I believe the issue with Saw blades wheels are with the cast enforcement web behind the spokes will hit the side of the C5 caliper.

not the best pic but found this on eBay of the saw blade spoke casting that might hit:


Known wheels that fit my car with Baer C5 size front calipers:
OEM '90 salad shooters 17x9.5
AFS replica Grand Sport wheels '88-'96 base offset
Replica C5 Z06 18x10.5 in the front...Wilwood 14" are next, I have an LS3 under the hood now

For the record: C6 Z06 front calipers will not replica C5 Z05 18x10.5 wheels...spokes will hit the side of the calipers.



Pic of me at Sonoma:

Note the Brake cooling duct work in air damn and a fender lip spoiler (Silver aluminum strip) in the front. The theory is to pull a low pressure area on the face of the wheel so cool high pressure air can flow from the inside of the wheel to outside...I have no scientific data to support this other than I had no fade on track and race cars have similar set up.

Kens94

I agree I'd go with the J55 brake setup, unless you are autocrossing the car. I have the J55 brakes and for regular driving they are quite good.

Cathul

Sawblades fit on my 95 Coupé with 15 mm spacers front and rear (8.5 wide front, 9.5 wide rear).

The Snowman

Quick update: I ended up buying a set of C5 brakes. Time to go disc and pad shopping...and wheels.

ElisTwoCents

Make sure you also get the abutment brackets with the brake calipers you bought as you need the C5 abutment brakets. I don't think the OZ Mittos would have a clearance issue on the C5 brakes. The mounting pattern difference between the BMW and the GM bolt pattern is so small that I would nearly argue that machining tolerance differences between wheel manufacturers might fall within the .65mm gap. I have BMW wheels on my 87 that I used while I was getting my OZ Futuras refinished and they mounted fine, no vibration/pulling etc. definitely didn't force fit anything. Likewise, sawblades or turbines are thrown on older BMWs, just run a google search. Anyways, examples could be found of each, just try it, wouldn't hurt - The key is the seating of the lugs so tighten accordingly & to spec.

Some sawblades will clear and some will not clear or need minor machining for the C5 brake upgrade and this is due to the wheel width (8.5" vs 9.5") sawblades - when they run narrow the wheel inner blades will hit the outer face of the calipers where the word "CORVETTE" is.

With the same pad substance (C5 vs C4HD) I would say the C5 brakes are an improvement, not just visually but in the performance category. Improved piston force, larger rotor mass/dimensions, reduced clamping flex/play....plus while in there throw some SS lines and some DOT4 with a clean flush. I've done the C5 brake swap, the C6 Z51 swap and DRM brake bias spring, with DOT 4 and back and forth while playing with wheel combos so I have faith ion the worth of the swap - The C6 Z51 brakes are excellent but need 18s to clear them.

Just my take - Goodluck with the upgrade bro