Just like the subject says. I did a search and couldn't find out why, just that they wouldn't work. If the C4 HD's are a full 13" and the C5's are only 12.75, why won't they fit? Caliper hitting the spokes or the inside hoop of the rim? I think some people have run the C5 rotor and aftermarket (Wilwood, etc.) calipers in the stock wheel, but I want to keep stock replacement parts...

I'd prefer to have the C5 stuff as its a lot more available, especially the price. If not, I'm going LS1 for sure.

,
Jeff

 

I believe it's clearance of the caliper. Ed Miller would know for sure.

 

Yup, the caliper pistons (and thus the calipers) are larger in the C5 and GranSport C4HD calipers, causing interference. Some wheels can get away with grinding on the calipers, but not a good idea in general. You can get the C4 13" rotors and non-GS calipers (same as 1LE) to fit inside most stock 16" rims.

 

Can you use the LS1 caliper on the C5 rotor? I know obviously the C5 rotor is larger diameter but I think they are the same width, and I know the C5 caliper and LS1 caliper fit in the opposite abutment/bracket...

 

That's not the reason. C5s and all 1LE and C4 calipers (Grand Sport and otherwise) all use the same size pistons. The reason is the size of the C5 caliper, it's about 70% larger than a C4/C4HD/GS caliper. Please note that the Grand Sport caliper will NOT fit inside 16" wheels either as it's a thicker casting than the standard HD caliper.

It's just the overall design that limits you here.

Ed
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Yes you can. Just use the pad for the abutment bracket you are using and all is well.

Ed

 

So then it IS possible to use the C5 rotor, LS1 calipers, and either C5 abutment w/ C5 pads or LS1 abutment w/ LS1 pads and fit it all within a stock 92 5-spoke wheel? Or are you just saying that they could be used in that fashion (for 17" wheels, for example)?

Then the question is the bracket needed. Since I can't fab my own, I'm not sure if I need to buy the bracket based on the rotor, the abutment, or both...

If so for stock wheels, that sounds great, it just doesn't seem like anyone has done this. If it is that easy, why not!?!

 

No, let me clear that up a bit.

You can use a LS1 caliper on a C5 rotor and such but it will NOT fit into a 16" wheel regardless of which caliper is used, too big. You can use a LS1 12" setup with a C5 caliper and it will fit into a 16" wheel.

This is why a 13" HD rotor and caliper will work but the larger C5 and LS1 calipers on 12.75" C5 rotors will not, just how they're designed.

I have most brackets and parts available for most swaps.

Ed

 

Ah, ok, crystal-clear now. Thanks Ed, I always appreciate your insight and expertise!

Based on the marginal gains from the 13" C4HD, price, and availability, I'm going to stick w/ my original plan for the 12" LS1/C5 caliper setup.

Just figured if I could have my cake and eat it too, I would

 

we ground the c5 calipers and the fit the 92 16" 5 spokes just fine