As promised here's the first pics of the drum conversion plates which will allow you to run C5/C6 rear discs including the 4 piston C6 ZO6 brakes. They are totally bolt on meaning no mods to your drum flange and will give you a night and day difference in rear braking performance. Obviously the only drawback to my plates is that they do not have the internal emergency brake feature so you manual tranny guys won't be happy along with the guys who need a working e-brake, sorry fellas. For the rest of you brake upgrade fans and racers and track guys, this should be a very nice swap to make to give you some extra rear brake.

Darkness caught me so I'll get more pics tomorrow.

Ed
[IMG][/IMG]

 

OK, more pics. Test rotor is a ~13" Z51 rear rotor and I'll get shots of the C6 ZO6 rear brakes in a day or two.

Rotor and caliper installed:


Rear view:


Overhead view (excuse the curious toddler):


More later.

Ed

 

Awesome.

Ed, 1 question, do you have any idea if these will fit on a Strange 12 bolts housing?

 

Sure, but which flange style do you have? I'm sure I can adapt it to what you have.

http://www.strangeengineering.net/catalog/index.html

Ed

 

Hey guys I'm new here, and you all seem like a great group!!!

Ed, I would absolutly love some front and rear C5/C6 plates for my '85 IROC

 

How come there is no way of making the internal e-brake work with this setup?

 

The C5/C6 backing plate is a totally different design than a standard solid axle and there's no way of making it bolt up to our cars. You can purchase plates with the e-brake from some vendors that do allow you to use the e-brake but the plates alone, without any brakes, are $700. They are nice but out of the price range of many owners. At this time I am unable to make them, sorry.

Pics with the C6 ZO6 rear brakes installed. I know the caliper is on the wrong side but it was the first one I pulled out of the box. I'm sure you guys get the picture:
[IMG][/IMG]

 

4 piston rears? damn, that'll need abs wont it lol
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Is it possible to get that 4 piston caliper on the fronts? We seem to eaither have 2 or 6 piston brakes.

 

I work with a lot of 4 piston Wilwoods as well so there's other options out there, just not to match that rear caliper. The match to that one is 6 piston unit. Those are monoblock calipers as well.

Ed

 

what about making the rears work on all 4 corners?.....this would make it great for the people with 17 inch wheels and still have the updated c6 zo6 brakes

 

Different piston diameters, rotor thicknesses and such..the hydraulics would be off. We do what we can.

Ed

 

So what is the price and how long would it take to get a set of these? Goodbye rear drums, hello discs!

 

Sent you a PM..thanks!

Ed

 

Ed,
I don't have my technical manuals handy, but don't the LS1 F-bodys use a parking brake set-up that is in the same diameter drum? I know the C5 Z06 uses the same shoe for the parking brake...

 

Similar, yes, but the caliper abutment brackets and rotors have different offsets and other small differences. I hope to get really familiar with both of them over the winter and come up with some way to make the bolt on a bit easier. I'm on the hunt for C5 backing plates right now.

Ed

 

I am some glad to have found this thread. I am looking at C5/C6, C6 Z51, and C6 Z06 upgrades for my 4th gen. Basiclly I have a partial understanding of the options, for the front brakes anyway.

What I know about the front brakes is that with the matching caliper, caliper bracket, and rotor C5, C5 Z06, C6, C6 Z51, and C6 Z06 are all interchangable on any C5 or C6 given that you change out all of the parts. Wheel size and clearance of course has to be considered. I also think I know that a LS1 4th gen front caliper is dimensionly the same as the C5/C6 one but the rotor diameter and hence the mounting hole location is different.

What I am assuming from your work is that the rear brakes are also interchangeable from C5 thru to C6 Z06 when all parts are swapped out.

What I would like to know is if this is in fact true?
Another thing I would like to know about is the differences and simalarities between the rear C5/C6 brakes and the 4th gen LS1 rear brakes. I'm not sure you have worked that one out just yet.

Thanks in advance for your comments
Derek

 

Hi Derek, yes this is true. Front and rear brakes will interchange on C5s and applications using them given the correct parts are used. I'm still working on the rear LS1 and C5 swap stuff.

Ed

 

Ok I bought the exact same ZR1 rotors for front and rear for my 85 irocz. I also have Ed's plates for the C5 calipers front nd rear and I went to install the rear calipers and rotors yesterday. The rotor for some reason sits like a 1/4" too far back to allow the abutment bracket on the caliper to fit in between the rotor and the plate. Has anyone had this problem??? I really need some help here!

Thanks

 

You have a PM, Ron. The rotor looks like they're wayyy too far inward and this shouldn't be the case. You mention ZR1 rotors...what year car did you order them for? There were no C5 ZR1 cars so this may be the issue but that seems odd that I would be that far off in my measurements/spacing.

Ed

 

I have a new design for the backing plates sent off to my cutter yesterday. I'll post up when I get around to messing with them. I think you guys will really like this new concept.

Ed

 

Ed,
do you have a bracket for the 9-bolt, or is this a 10-bolt only kinda thing?

 

Wait so Ed all i have to do is buy your plates and then i'll have mounting for c5/c6 rear disc brakes? will this work on a stock 87 Trans Am rear?

 

C5 for 9 bolts? Sure. The plates I mentioned above are for drum rears but when I test them it wont' take me long to convert the design over to discs. 9 or 10 bolts, I'll have it covered.

Ed
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Yes, I'll have an update soon.

Ed

 

:UPDATE:

I've had this test setup done for a few weeks now but due to a few issues I haven't been able to post up with my new findings. So here you go...

I was able to install true C5 rear brakes including the factory C5 backing plate with the e-brake...yes, it works. You guys are sure to enjoy the following lot of pics. I tested the brakes on a stock 10 bolt drum rear but with just a little work they'll fit up on practically any rearend with about 2.75" of offset from axle flange to axle housing flange, all I'll do is tweak the flange pattern as needed so this setup will be able to fit your disc or drum rear, 9 or 10 bolt with minor changes from what you see here.

Just a few things to note:

1- I have a bit of tweaking and shimming to get the parts exactly where I want them so it's not ready to go at the moment, but at least we know it will work. I'll finalize my spacer sizes then.
2- I almost forgot that with these axles you have to push them in, insert the C-clip, and pull them back out. I'd like the C5 backing plate to come back out the thickness of a spacer washer I used but at this time, it cannot. One idea I have is to install the plate and axle first, install the C clip and differential pin, then install the plate spacers and bolt it down through the axle flange. You may need to drill a small hole in your axle flange to do this but I'm not there yet. Give me some time.
3- The two lower bracket mounting bolts will need to be drilled for a larger mounting bolt during actual assembly, as it will hold both custom plates to the housing flange. I'll do it for real later but I'm just testing here.

Pic of the parts I'll use in the final mod: The bracket pair, aluminum spacers, various bolts, stock C5 backing plate. I tested this setup using a Z51 13" rear rotor but stock C5/C6 brakes will also bolt on.... and yes (gasp) the 4 piston C6 ZO6 stuff as well.



Install the outer plate using a bolt through the old wheel cylinder hole and the two lower bolt holes. (These will be drilled for larger installation bolts). Install the inner plate using the same holes as the outer plate.



Install the C5 backing plate with the 3 mounting bolts and spacers:



Reinstall axle, slide the rotor on, bolt on the caliper and abutment, hook up the brake lines and go:






Aluminum spacers will be used on the backing plates and the abutment bolts. I totally forgot about the e-brake pics...a universal cable kit should take care of it and I'll incorporate a standard GM click type cable mounting bracket on it somewhere. As they are currently installed, the e-brake cable will pull to the front of the car as usual. More to come, let me know your thoughts, feedback, and input. Thanks!

Ed

 

Hey Ed,
They look great! They look like they would fix the problems im having with my abutment brakets not fitting. I'm looking forward to trying these new ones.

 

Are the LS F-body rear bracket similar to the ones you used in this setup? I would think it may be easier/cheaper to get that. I think what you have done looks cool and should help me when I decide to redo the rear brakes. I would like to put matching Wilwood rear calipers on my car but they dont have an ebrake setup and I think something like this may work.

*edit*
I think I am a little ahead of myself once again. I do not have a drum rear in my car.

 

Wow Ed! You did it again man. Im VERY impressed with those. Sounds like my ebrake problem is solved!

 

Wow, I was just about to ask about using a separate wilwood style mechanical caliper as an ebrake only thing but you've got a fix for it already. Sweet. Can I email you or set myself on a list or something so when you're done I can buy these for an original disc axle? I don't know that I'll see the post...

 

These will fix it. I'll finalize the spacers this week and PM you when they're ready to go out.

Ed
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The LS1 plate is similar but won't work exactly like this. The rotors are different in size and offset. Wilwood does offer a rear kit with e-brake but they're specified for 4th gens but they will work on our cars as well (mods to your drum flange would be required)

http://www.wilwood.com/BrakeKits/Pages/12/index.asp

Kit #140-7148

Ed

 

So Ed, How do I make my LS1 rears work with your system of brackets. Id rather do it this way than cutting and drilling my drum housing. Can I use these same brackets with the LS1 backing plates? Also, do you think this will push the rear wheels out any? Check your PMs Im sending you one now, Id like to upgrade to someting bigger than my current LS1 fronts.
Matt

 

That's a hard question...since they're designed differently you can't really install LS1s like these, the LS1 has it's own backing plate which holds the caliper abutment. The C5 abutment is bolted to the rear spindle of the IRS. These brackets won't hold the LS1 backing plates either due to the different design. This will have no effect on rear offset, rotor hat thickness = brake drum thickness so it's even. If you like this way of installing C5 rear brakes, sell the LS1s and go this route. I'll be checking PMs all week, I'm very behind in replies and communication.

Ed

 

Where would you recommend finding the C5 backing plates?

 

You can get a pretty much assembled kit from GM. Part number - 12455801. then you just need one piece per side, a plate thing. 12455802 for the left and 12455803 for the right. Right @ $160 for it all.

 

Thank you for the PNs.

Guess they are dealer only?

Edit; Just found them at gmpartsdirect.com

 

Well, dealer and junkyard.

I'm trying to get my boss to approve sponsorship of tgo so I can actually say I'll sell all that stuff to you guys. (I work at a dealership in the parts department and I'm happy to offer cost + 10% to any tgo'ers. WAY under even trade price, let alone list price.

 

This would be a great thing.

Ed

 

Any news yet? I've got my finger ready to order the rest of the parts I need...

 

So, what all is needed to do this type of conversion to a drum rear? Your plates, the c5 backing plates, rotors, and calipers?

 

Pretty much, I'd swap brake lines and such as well but I'd supply all that in a full conversion kit.

Ed
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Sorry man, I'm backed up with orders that I need to get out the door so this kinda got pushed.

Ed

 

Keep us posted! Looking for a set as well. Got the C5 fronts so all I need is the rears! They look great!

 

Any updates on these?

 

updates ?

 

Nothing solid yet. I did manage to get a custom Wilwood parking brake cable set so I can use it to get my measurements on the cables and out to the vendor. I won't be moving on them until July due to my current work schedule. I'll update as I can.

Thanks!

Ed

 

Ed,

Very Cool Stuff. Of course my interest is putting corvette brake on my 1997. Different bolt pattern on the end of the axles tubes, but that isn't for me just yet.

You know, now that you have tackled the C5/C6 brakes and you know that C5, C6, C6 Z51, and C6 Z06 brakes work. The next challenge will be to see about C6 ZR1 brakes with those carbon fibre rotors, hmmm just thinking

Derek

 

I would assume (we all know what happens then...) that the ZR1 stuff uses that same mounting as all the other c6 stuff. In which case it's the same bracket as a c5.

I priced out those rotors the other day and at $1200 a pop I think I'm waiting a bit. Calipers weren't too bad. I think they were around $400 or so a piece.

 

any updates on this yet ? I have these C5 brakes sitting here just begging to go on.

 

Sorry, no. I just haven't got to it. You'd think I would have got the time. I do know the first design plates for the drum rear cars (without e-brake) will work on a G body though:

http://www.pro-touring.com/forum/showthread.php?t=50132





Ed

 

Why not cut a slot in the c5 backing plates like I did on my LS1's so the c-clips and axles need not be touched? Just not strong enough then, or not trusting it that much?

 

Wow, that looks way scary. No way I'd ever do that.

How long does it take to pop the axles out??? Definitely not long enough for me to ever consider doing that to my backing plates. And I just did the rear LS1 conversion.

 

The C5 plates are totally different, held on by 3 bolts and not 4, and they are only the thin stamped steel piece, they have no cast backing plate like the LS1s do. (See post #24 for a good shot of it).

Since they have no cast backing plate there's a need to space it off the axle flange and then mate the Vette 3 bolt plate to the stock 4 bolt flange, see the issue? And I'm trying to make this whole thing bolt on without any need for cutting stuff. I have something done and bolted up but I have to actually try it out on the rearend. Time is what I don't have, especially this time of the year.

Ed