kedvesh

Will front rotors from a C6 work on a C5 (i.e., concerns over wheel/caliper clearances, etc. given the designs)?

Other than a few slight spec differences in the Centric-brand example I use below, the dimensions seem correct, but the "look" is not the same.

Example, via www-rockauto-com:
C5 2002 Front Rotor Profile (Centric Brand)


C6 2008 Front Rotor Profile (Centric Brand):

Bluefire

Next week I will be installing C6 Z51 rotors and C6 Z51 caliper brackets on my C5. I know those fit. I would assume stock C6 rotors would fit a C5.

mre1974

OK, so I'm curious...what is/are the expected/preceived advantages to using the C6 braking components over the C5? Very curious about this idea for in the future...

r.hillenbrand

Call Patrick at GMPartshouse.com I sold my C6 and bought a C5Z06 and had new rotors left over and he said they will fit but could run hotter since C5 rotors have directional veins for cooling. I sold them and bought the proper ones

kedvesh

Reason I'm asking about the rotors is that I can pick up a full OEM C6 set from someone. I was planning on using them as backups for HPDEs.

However, if they're going to run hotter because of the different internal construction, I may not want to get them. Concur?

TheWildcat

the base c5 and c6 rotors are the same I have C6 z51 rotors on mine
and they do NOT clear a 17" wheel John

mickey_7106

my guess will be none. i want to go with the C6Z51 calipers only for looks. i like the font better on those than my C5

TheWildcat

wont work if you have 17 inch fronts.... and yes I can tell they stop better than a std rotor size..John

mickey_7106

i dont

Bluefire

For me the reasons are two-fold. I purchased larger wheels/tires (CCW 505A's). The C6 Z51 rotors will:

1.) Perform better. Due to a larger diameter (1").
2.) Fills up the larger opening in the new wheels more.

kedvesh

Other sources, such as z06vette-com concur in your assessment and say one will need at least 18" wheels to use the C6Z51 rotors on the front of a C5 due to the Z51 rotors being 13.4" vice 12.7" for the C5 (measurements differ slightly between manufacturers. Z51 rears are 13.0; C5 rears are about 11.8.)

Referencing the schematics I used in my OP, the design 'look' of the base C6 rotor is different than the C5's. (The used C6 rotors I'm considering buying have the same design as the C6 schematic.) So technically, while the rotors may appear to fit on a C5 per the C6 rotor diameter specs, etc., at least these 2008 base Corvette replacements are on the whole not the same as a stock C5 rotor.

I suspect that as the C6 progressed from 2005 to current, they've slightly changed the rotor design, allowing for the newer design to be retrofitted onto older base C6s, which meant that any base C6 rotor could be used on a C5. (A check of rockauto-com shows C5 design rotors as one of the listed replacements on a 2005, but the same rotor does not show up as a possible replacement for a base 2008.)

Still wonder if I'm safe using current base C6 rotors on my C5 for the track. I'm getting a sour feeling in my belly that may be telling me something. It's either rotor related or it's the spicy food I had for lunch today.

Bluefire

Not yet. CCW is shipping my wheels to me either today or Monday. I will probably do the swap next weekend. I'll post pics when I am finished.

xtech

As previous members have noted, C6 Z51 rotors will fit the C5 BUT you will need the Z51 caliper mounting brackets to move the calipers out to fit the larger rotors. You will also need 18" wheels. I run the GM mags w Z51's front & rear with 275-35-18's front, 295-35-18's rear with no TCS/ABS issues.

The Z51 front rotor has a "heat dam" built into it. (The base C6 rotor doesn't have this feature.) If you look at a C5 rotor, the section between the top of the hat (where it bolts to the hub) and the friction surface is flat. The Z51 rotor has an S shaped "wrinkle" in it - for lack of something better thing to call it. This wrinkle performs two functions:

1. It provides a slightly flexible expansion zone or 'buffer' between the hotter friction surface and the cooler hub surface, which flexes with temperature changes across the different sections of the disc. This stops the rotor from warping as one section gets hotter than another - especially with heavy braking, which causes the temperature of the friction area of the disc to jump suddenly. The rapid expansion is taken up by the S shaped 'wrinkle'.

2. It provides a longer heat path that allows more time (and area) for heat to dissipate before it gets to the wheel bearings.

Comparing C5 and C6 front calipers, the castings are slightly different, mostly noticeable due to the different font. The C6 caliper is a bit stiffer as it has thicker webs, but is otherwise identical to the C5 caliper. Same piston diameter, same mounting points. There is little reason to change them unless you like the look of them better, They would provide a slightly better pedal feel, but not much.

Although the front rotors are slightly larger than C5's the rears are MUCH bigger, and actually look like they're supposed to be there. As opposed to the tiny little C5 rotors that look like they came off a Cobalt in comparison. You obviously also need the matching Z51 rear caliper mounts.

The rear Z51 caliper looks identical to the C5 caliper, but it isn't, as it actually has smaller pistons than C5 calipers. This reduces the pad pressure against the rotor slightly, as the leverage is much greater due to the substantially larger rotor diameter.

I didn't bother changing mine, however and have noticed no ill effects. The rears don't lock before the fronts, so it isn't worth the hassle, at least not on the street. It might be more noticeable if the car is tracked, however. Not sure, as I haven't tracked mine.

It's very important to thoroughly clean the hub surface and the rear mating surface of the rotors before you mount them. Remove any corrosion or any other crap, or you may get runout which can cause the pistons to be pushed in and out, ending up as a pulsation in the brake pedal. Runout as little as .001" can often be felt.

Before you mount the rotors, I suggest that you grab a micrometer, and measure the thickness of the rotor at the same distance from the edge at 6 locations around the disc @ 60° intervals. They must be flat and parallel within .0005", or you will get pedal pulsation.

After they're on, use a dial indicator to measure the runout. If it's off by more than .001", try pulling them off, rotate them one bolt position, put them back on and try again. Use a stack of thick steel washers under each lugnut and torque them to spec before you measure the runout.

Is it worth all the trouble to change over? In one word - YES! Noticeably better braking and far better looks. How can you lose?

voda1

There is a very recent post on the forum about this. The guy stated that the C6 calipers are also required for use with 17" wheels. Something about different cooling fin for caliper. IIRC he is using the Z06 17" wheels also.

Here's the link: http://forums.corvetteforum.com/c5-z...51-brakes.html