Couldn't find any post regarding fitment.So thought I would post mine.17" GTA hawk wheels with C6 vette 12.8 rotors.They fit, but barely.Had to file the "corvette" logo off the caliper & my wheel weights are hitting the caliper, but those are the only interference issues so far.Road test yet to come.

I'm using BBUs hubs/rotors & calipers/abutments/brackets I bought from a forum member.

 

That is the most disappointing brake clearance I've seen in a while...

 

Yeah, not thrilled with that either.Hopefully it works out well.

 

Pretty standard with the overall design of the wheel, there isn't much they can do without pushing the wheel towards the outside of the wheel to make the hub deeper. That would change the look/feel of the wheel IMO. This is essentially the same issue with the stock 16" wheels, you have to run a think spacer behind the wheel

 

Bear,

True - but they did have the opportunity to add some extra clearance when they designed it. You wouldn't be able to stick the 13" 4 piston Wilwood kit I have under these, yet they get swallowed up by other wheels in 17".

 

I wanted the z51 option, but w/ that 13.4 rotor, it would never work.

I did drive it today.No unfortunate sounds & i gained a bit more clearance.Guessing the pads weren't completely seated against the caliper.

 

Without adding to the hub depth, there isn't a whole lot they could do to get more space, from what I can tell, without changing the look of the wheel though

 

True.

But they could have done some to add extra clearance (another 1/4"?, maybe a bit more) and not change the look. With the wheels, you are stuck with 2 piston calipers and a 13" rotor - which is by no means weak, but those are 20 year old braking systems. Keep in mind that the kit will fit under 91-92 16" Z28 wheels with the same clearance.

 

I'll agree on that. I'm guessing the LS1 12" would fit under the 17" GTA wheels, but that's about it unless you're willing to mod/grind/customize a larger setup like the original poster.

Another thing I wonder is if Hawks comes out with a future 18" GTA wheel, will that size accept larger brakes than the 17" version? Or would the person be stuck with the same 12" brake size options.

 

Reid,

One should be able to fit the 12" 1LE system under any 16" OEM wheels. I fit the 13" Baer track kit (C4 HD) system under my 1992 Z28 wheels.

In theory you should be able to fit any 13" kit (2 or 4 piston) under a 17" wheel as well. The only caveat would be rear of the wheel spokes to caliper face interference such as the thread originator had. But they should clear.

Maybe I'm a bit biased since our 17" wheels fit all 14" kits, but to design a wheel that 13" kits won't work is really unfortunate.

Will Hawks offer an 18" version - time will tell...

 

Still looks like more clearance then the ronal firehawk rims I have. As the pads wear, the caliper will move inward more.

 

Yep, I was relieved when I realized that's the closest they would get, being those are new pads.

 

being a nearly 10 year old thread, are there any new updates/brake systems that work with these 17 inch wheels that fit better?

 

None that i know of, but i haven't bothered to look further. Ive been fine with this combo all these years.

 

Add a 10-12mm spacer and it'll fit perfectly

Don't bin a great brake system over such minor contact

 

hes had it on his car fro like 11 years now..
i think he's plenty fine

 

I tried to fit a C5 upgrade behind my 17" GTA's and I needed a .5" spacer. I was really disappointed. Can anyone confirm if the LS1 upgrade will fit the Hawks GTA's without a spacer?

 

You could get by with a .25 spacer as i did. If you dont mind the close tolerance.

 

I'm not sure why, but the .25" spacers that came with my wheels were not enough. I don't know if the 1LE spindles I used are the reason for the discrepancy. But I would prefer not to use any spaces at all. I'm willing to downsize to the LS1 set up, if I can firm the fitment is better. Worst case scenario I can assume the 1LE upgrade should fit. The car honestly will see nothing more than spirited street driving. Just wanted to "fill the space" and get as good as I could.

 

Nah, the spindles shouldn't have anything to do with it. But C5 and C6 brakes have the same fitment, and both type have raised letters on the face of the calipers, which apparently matters too, so that's likely why you needed spacers with C5 brakes.

LS1, C5 and C6 calipers are virtually interchangeable, so you might also need a spacer with 12" LS1 front brakes too.

*Edit: I had a comparison picture here, but I mistakenly posted the wrong calipers, so I've removed it and posted the correct pictures in post #24 below.*

Or you might not need a spacer. The LS1 rotor's hat is about 1/4" taller, which means it will sit about 1/4" deeper (farther back) than a C6 rotor. And with its bracket and caliper centered over that deeper rotor, that might give LS1 brakes (or your C5 calipers with the LS1 components) enough clearance without the spacer. If nobody else has tried it (and a couple of posts down somebody reported that he did it successfully), and if Hawk's hasn't test fit the combo, then it'll be trial and error for you.

On the other hand, according to Hawk's, that spacer is needed "for proper fitment on the front of the car." That might mean the spacer is necessary for tie rod clearance, so I'd suggest you ask Hawk's. Tie rod clearance is why factory 16" front wheels have about 5/8" less offset than the rear wheels (zero vs 16mm), so you might not have a choice but to use that supplied 1/4" spacer, regardless of the brake package. But if you've got tie rod clearance without the spacer, then LS1 might work without the spacer. And if you do need it for tie rod clearance, then, at least, you should have very good clearance with LS1 brakes.

And 12" LS1 rotors and calipers wouldn't interfere with the wheel weights in the barrel of the wheel.

 

Arent those the rear calipers though. I assumed ( you know how that goes) he only had issues with the front wheels since he mentioned 1LE "spindles". I think thats why hawks supplies 2 spacers only. Ive no issues on the back wheels.

As for the weights, the tech just moved them closer to the edge of the wheel. Again, only on the front.

91formula, are you using a standard (non 1le rotor/hub)? The 1LE rotors have a taller hat than standard rotors. This taller hat moves the wheel out another 1/4 at least. Combined w/ the 1/4 spacer this gives you the needed clearance, but only by about 1/8.

 

Oops, lol, yes, those are rears. I scrolled through a bazillion pictures on my laptop, and it took a long time to find that one. I transfer from my phone to my laptop and upload from my laptop, so the fronts must still be on my phone, which has a bazillion more pictures. Pretty sure I clicked some before I sold the LS1 calipers, so I'll look. But the fronts are interchangeable too. When I was test fitting C6 Z51 brakes, I mocked them up with both calipers. Sorry 'bout that lol.

 

I have the LS1 brake upgrade behind my 17” hawks GTA and it fits with no spacer.About an 1/8 of an inch between caliper and wheel.Tie rod plenty of clearance.I’m using the kit from BBU with the aluminum hub which has the 1le bearing upgrade.This automatically pushes the wheel out a bit so no spacer needed.

 

Found 'em on my phone. Here are two pictures comparing the C6 front caliper to the LS1 front caliper; pictures I meant for the previous post. One is a side-by-side comparison of the two. The other shows an LS1 caliper in a C6 base/standard (not Z51) abutment bracket, for people who might want to use (or already have) the cheaper and easier to find LS1 calipers with C5 or C6 brake upgrades. I apparently didn't take a pic of a C6 caliper in an LS1 abutment bracket, but it fits and so will a C5 caliper, for people who might want those better and stronger calipers with an LS1 brake upgrade. Pretty sure most people don't mix-n-match though, but there it is.

 

I'm using the exact same hubs, just with std C6 brakes. So there's probably a difference in the rotor. Placing the caliper farther back.

Or does the stronger C5/6 caliper not clear maybe because its thicker than the ls1 part? What makes those C5/6 calipers better/stronger, i guess is what I'm asking?

 

Thanks Guys! That's helpful. I just have the standard bearing hubs. I didn't realize the 1le's had a taller hat. If I can get some confirmation the LS1's fit, I'll probably get those brackets, and sell my C5 stuff. Or just buy the rest of the 1LE upgrade stuff... I would prefer the LS1 set up due to parts availability.

 

Id go with which ever option is gonna cost the least, i guess. Are C5/6 parts hard to get in Nova Scotia?

 

C5/6 and LS1 stuff is easy enough to get 1LE stuff, not so much. I'm thinking I need to either get ahold of hubs made from 1LE rotors, or get a set of 1LE rotors from rock auto and have them turned down. At least then I don't have to sell all my C6 stuff.

 

The manufacturing process changed. 1-piston and 2-piston aluminum calipers for 3rdgen, C4, LT1, LS1, C5 and C6 are from PBR. C6 calipers are pressure cast, which makes them denser and stronger. Prior to C6, the calipers were gravity cast, which was always sufficient but can leave inconsistencies in density and strength.

LS1 calipers were good for 12" brakes (and probably fine for larger brakes under normal duty, but under extreme duty, probably too, but you never know). C5 calipers were fully ribbed to make them more rigid to handle its larger brakes. But then C6 Z51 (Heavy Duty) brakes got even larger, so the manufacturing process was changed to make the C6 calipers stronger, not larger, just stronger.

 

Ah! pressure casting. Reminds me of back in the day when manufacturers started making sport bike frames that way vs the old gravity cast method. Didn't know that about the calipers. Learned something new.

 

Wouldn't this work on your 1991 Formula and fit under Hawks 17x9 GTA style wheels?

Isn't this more or less the C4 J55 13" HD PBR front disc brake conversion for 3rd gens except using the Baer branded PBR front calipers?

This kit uses a more robust/rigid high pressure cast caliper, similar to the ones found on the 96 Grand Sport & Collector's Edition C4 Corvettes rather than the earlier finned type gravity cast 1LE caliper.



Baer Brakes 4301678R Baer Brakes 13" Classic Series Front Brake Kit

MSRP $1,406.95
On sale for $1,123.95

Seems like a reasonable price for the massive upgrade it would be over the stock junk.

 

I'm not sure if that will fit behind my wheels or not. I was hoping to salvage the C5/6 Kit i have. Looks like I will be ordering some 1LE rotors, and have them machined down to make hubs.

 

if it would fit, then im buying it..
but need a definite yes or no on it

 

Did you check the fitment template against your Hawks 17x9 GTA style wheels?

D082H.vc6

 

If that kit is anything like the C6 Z51 kit, probably not.