rv93

im planning on upgrading my front brakes to c5 in a few months, and i came across something pretty interesting. apparently the camaro caliper pistons are 44mm in diameter, while the c5 pistons are 40mm. so if i got c5 rotors and calipers, the front braking force will actually be something like 5% lower than stock. ive also heard that even stock, the brake bias is too far back. so i could upgrade the rotors, but use the camaro calipers (i know id still need the conversion brackets, and c5 pads), which would move the brake bias forward compared to stock. any thoughts on this? i know the camaro calipers are a bit weaker than the corvette ones, but i dont track the car, so i dont really see that being an issue. and keeping the calipers would save me some money. theres also the option of using base c6 calipers, which have 40.5mm pistons, which would keep the brake bias almost identical to stock. any thoughts would be appreciated

pgerst

The C5 rotors are thicker so not exactly sure they will work with LS calipers, they might, might not. Have you upgraded to braided stainless brake hoses, better pads (Hawk, EBC, or similar), and Dot 4 fluid? Also not a big fan of drilled rotors due to their likelihood to crack, but slotted rotors can help too. A well set-up LS brake system can be pretty close to the C5 for street use, and fits with the 16" wheels.

FirebirdGT

I upgraded my 96 front brakes to the 98+ many years ago. A couple of years I replaced the F-body calipers with C5 calipers (direct swap bolt-on). Still uses F-body rotors and pads. Never stopped better! And great pedal "feel".

BTW - You are correct - the C5 have 40mm and the F-body is 44mm - BUT the C5 caliper doesn't "spread" under hard braking.

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rv93

i havent done any of the upgrades yet, but i plan to at the same time as the swap. i need new rotors and pads anyway, and im getting a set of 02 SS wheels, so if i end up keeping the camaro calipers, itll be a cheap swap. im honestly not sure if i wanna go with regular or slotted rotors. has anybody tried messing with the brake balance? im really curious if moving the balance forward with c5 rotors and camaro calipers would help any. i also just checked, and the c5 rotors are actually 0.2mm thinner (this is according to autozone though, so it could be wrong)

FirebirdGT

From the Tech section on my car's web site:

The C5/ZO6 caliper will fit with the stock 98+ FB bracket if using the stock sized rotor. The C5/Z06 calipers have cooling fins that the 98+ FB calipers don’t have. The lowest fin may need to be trimmed. Use stock caliper frames (PAB) also. If you set a caliper from each next to each other, you will see that they are almost identical. Another diff is the mounting tabs on the caliper, the C5/Z06 ones are thinner.


The 98+ FB front caliper is very similar to the C5 caliper in appearance and function, but there are a few differnces.

C5 calipers are very similar to the standard 98+ FB calipers, except the C5's are manufactured by PBR in Australia.

The C5 caliper has full width stiffening ribs whereas the 98+ FB caliper does not.

The only dimensionally difference between a 98+ FB caliper and a C5 caliper is the gap between the ears and the caliper body ... the gap where the rotor spins.

The C5 caliper has slightly smaller pistons (40mm vs 44mm). Pistons in an 98+ FB are larger, but made of thinner material vs the C5.

The C5 calipers are pressure cast (not forged, but better than cast) and seem to eliminate "spreading" (under extreme use, the cast 98+ FB calipers have in some cases started to open up or bend outward). The 98+ FB calipers are regular cast aluminum.


C5 brakes have about 10% more pad area than the 98+ FB brakes. That will give you a large sweep area which translates to better braking.

The swept area of a 98+ FB brake is 65.7 SQ CM. The swept area of a C5/Z06 brake is 72.0 SQ CM.


The Z06's have red powder coating (standard is dark grey).


The guide pins are #13. The bolts (#14) used on a ZO6 caliper have a larger head on them than the 98+ FB. However, the thread size and pitch are the same. It's a direct bolt on.

The pad abutment bracket (#1) bolts to the spindle. The C5 pad abutment bracket (PAB) requires a larger bolt. So the holes in the spindle have to be enlarged. The PAD is ONLY necessary if you want to run C5 pads.


The 98+ FB front rotor is 32.2mm x 302mm (1.26” x 11.8”) - C5 is 32mm x 325.12mm (1.26” x 12.8”). Brembo website


UPGRADE - replace the stock caliper aluminum pistons in the C5 with heavier SS pieces which don't absorb as much heat as the aluminum.

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rv93

so does anybody have any info on the effects of moving brake balance? if i dont find anything out, the plan is to go with c6 calipers. theyre the strongest for that particular rotor size (id love to go with c6 z06 brakes, but cant find reasonably cheap calipers), and they have 40.5mm pistons, so by my calculations, the brake balance would stay virtually identical to stock.

pgerst

Bias Calculator

GM Brake Upgrade Option Measurements - Thirdgen F-body Brake Upgrade | Luke Skaff

First link is a calculator; second is good source for F-body/corvette brake dimensions.

rv93

thanks, thats some usefull stuff. though i somewhat doubt the accuracy of the brake specs page. it claims that the piston size in the f body and c5 is the same. i know theyre different

Kevin Blown 95 TA

Look, for one thing, if it stayed identical to stock, it wouldn't be worth doing. The real issue is that, if changing the front brakes alters the balance from front to rear, which it does, how do you adjust for it. The answer is that you can't unless you install a proportioning valve.

rv93

well, is the stock brake bias ideal? with the c5 rotors, i could use different calipers to keep it the same, or move it either forward or backward.

pgerst

You can also change master cylinders to offset changes to caliper piston areas but not a lot of combinations to work with. With an adjustable proportioning valve you can dial in/out bias.

FirebirdGT

I know it's not specifically for a F-body, but the concepts still apply:

Brake Proportioning Valve Install
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Kevin Blown 95 TA

Just do the conversion, then see how it is. It might be fine that way - mine seemed OK. It didn't nose dive or feel out of balance or anything - just stopped better. Most people don't do the proportioning valve, especially if they have ABS. When I yanked the ABS then I did a proportioning valve and got it dialed in a little tighter.

I think the C5 brake ug is one of the most rewarding and worthwhile mods you can do on a LT1 car. Looks nice, too!

pgerst

Pros: calipers (full rib and pressure cast) will spread less; directional rotor vanes and larger pads for better cooling; marginally better swept area (larger rotor diameter).
Cons: more weight in rotor and 17" wheel combo increases unsprung weight; smaller piston (reduced clamping.)

When I did my swap, I did the LT to LS as it was a lot cheaper than the C5 and the LS is still much better than the LT. My recollection of when I ran the numbers: the C5 would be better at repeated high speed stops (racing) but at more cost, probably not that much different braking as a daily driver. My long term plan is to add cooling ducts to the LS set-up and get better cooling: Blaine Fabrication.com - Race car engineering

Also, as you would have too much rear bias, you want to decrease rear line pressure, so valve would go in rear line, not the front like the RX-7 web page.

And, for a whole different tangent, if you go with 18" wheels you have the CTS-V option: Super Cheap Big Brake Kit - Info - LS1TECH

rv93

i already have ls brakes. and id rather not mess with the proportioning valve, so i can choose between 3 different calipers to adjust the brake bias. using ls1 calipers will move the bias forward, c6 calipers will keep it the same, and c5 calipers will move it back a bit. i wanted to know if anyone had any suggestions as to which would be ideal. if the stock bias is already good, ill just go with c6 calipers