New cheap big brake idea

[Stupidnewbie]

I've been planning on doing the 13" rotors and C5 calipers on my '68 Firebird for awhile now but I recently stumbled on a possible caliper that would be an improvement over the 2-piston LS1/C5. The '93+ Supra turbo/TT front brakes use a 4-piston caliper that is considered part of the finest braking system to ever be used on a widespread production vehicle. Lots of guys swap these turbo Supra piston/calipers on all sorts of Toyota and Lexus vehicles because of their proven effectiveness.

The C5 rotor and the Supra rotor are very similar. The C5 rotor is 325mm and 32mm thick, while the Supra rotor is 323mm and 30mm thick. The Supra bolt pattern is 5x4.5" so I'm thinking of using the C5 rotor with the Supra caliper. I'll have to adapt the brake lines and figure out a caliper bracket, but other than that can anyone see problems with this swap? I figure the 4-piston calipers will give a bit more bite to the braking and loaded Supra calipers are easy to come by and not expensive. Lemme know what you guys think!

Dan

[69boo307]

sounds like an interesting idea to me!

[Pzary3233]

That sounds like a really cool idea... do you think that the mounting of it might be a problem? Let us know what you find out!

[RatMalibu]

heh I wanna know if they'll clear TT2's ;)

[David Pozzi]

that 2mm (.078") diffeence in thickess might cause problems, it depends on how much room there is in the caliper. If you do try it, make sure to mock it up with new pads, or else the caliper might fit fine with old pads and new pads might not slide in!
David

[Stupidnewbie]

Yea David, I figure the difference in rotor thickness will be the deal-breaker. I'm going to try and have someone take some measurements for me when they do their Supra brake swap on another forum I frequent. I'll keep you guys updated.

[CarlC]

What about milling 1mm of each pad?

[Pzary3233]

heh I wanna know if they'll clear TT2's ;)

I'm with him... Maybe that is an excuse to get rid of my TTII Wheels!

Carl also had a good point about milling 1 mm off the brake pad... it's not that big of a difference... though it might be a pain when you're out in the middle of no where and you need pads...

[Stupidnewbie]

I talked to one guy who has these calipers and he's 99% sure they'd spread the extra 2mm with no problems. I'm still waiting on exact measurements. As for clearance, I guess it depends on which rotors you use them. I know for Supras, 17" wheels are necessary (with the 13" rotors) and not all 17's will clear. If you went with the 12" LS1 rotor or possibly something smaller, they could probably fit. I think the biggest issue is that they are wider than other calipers due to their being 4-piston.

[Pzary3233]

How about a 13" C4 Rotor? I know that with the C5 Caliper and C4 Rotor the caliper is moved back just enough to clear TTII wheels... But you're right it depends on the over all width of the caliper... I am really interested to see how this turns out! Went to look up the price of a caliper, they are about $150 a piece, not bad in my book!

[indyjps]

anybody want to scam the auto parts place and pick up a set for mock up and pics then return them. my brake swap pieces are still in the boxes and i have not purchased calipers yet.

[Stupidnewbie]

Someone just sent me a measurement of 35.8mm, which means it should clear no problem! Woohoo! I'm going to verify with him that this is with new pads, but the consensus seems to be that this would easily work. However indyjps, you'd have to figure out a mounting bracket on your own, as I haven't yet tackled this swap yet. I'll have the garage workspace to tear into the Firebird after the holidays so I'll develop a bracket then. If you go forward with it, keep us updated.

[Conekiller13]

I've mounted a set of 300zx Turbo 4 piston calipers on a 76 Toyota Corona with Willwood rotors.............worked awesome.........


P.S. I want My old post count back.............

[spanky the wondermuffin]

it's not the number of pistons,it's the size.figure your total piston area and make sure that it is an improvment.also you need to measure your rear piston size and see how that will relate.a rule of thumb is rears 60% size of front.

[Pzary3233]

Spanky,

I was just thinking that same thought... it is really an improvement over the C5 Caliper? Also, if the calipers are bigger... you need to refigure your rear brakes like you said to create a good balance.

For a long shot here, maybe supra rear calipers on the LS1 Rear Rotors? The Master Cyl also comes into play here...

It does sound like a good alternitive idea to the traditional Cheap Brakes route.

[Stupidnewbie]

Hrm, well here's a comparison of the different pads. The LS1 pads have a slightly higher surface area, but not by much. I'm still trying to find specs on the piston diameters for the two calipers.

[79_EFI_Z]

OK, I have some questions and some answers.

The c5 calipers use a twin 40 mm (1.575") piston caliper.
The TT Supra uses a 4 x 42.85 mm (1.687") piston caliper.
That is just over double the piston area.

The only thing i want to know is, according to your picture of the pad specs.. it seems that the TT pad is 22mm taller than the C5 pad, that is nearly an inch. Is the C5 rotor going to accept nearly 1 inch more in pad height? Especially on a slotted rotor, I dont imagine you would want the pad to be taller than the slot itself.. it would undermine the whole idea of putting the slot there in the first place. Also since the TT and C5 rotors are nearly identical as stated in a previous post.. one could argue it should theoretically fit. BUT, since the TT has a 5x4.5 wheel pattern and I beleive the C5 to have a 5x4.75 pattern, one could argue that this is where the TT rotor gains the extra height because of the smaller hub circle.

Thoughts? Ideas? I am serisouly interested in putting this set up on my car.

[79_EFI_Z]

I have an update.. I didn't notice but you listed the LS1 pad.. I found out the C5 uses part number D731 (Hawk pads) and is 185mm wide by 63mm tall, that is then a difference of 20mm which is still 0.74803 Inches more than a C5 pad.

[pdq67]

By chance do they make a thicker H-D rotor and matching wider caliper for the Supra in the Race-Parts section??

I ask this b/c on my "pdqCBB" with wide Van calipers and Seville rear e-brake calipers, I had to use pad backing plates as inner new pad shims!

If I would have known that there is a stock, 1.25" thick, 13" H-D rotor I would have used it instead of the 1.10" thick stock 1988 'Vette front one is all and wouldn't have had to shim the front pads..

Otherwise as said, I would have had to trim .050" off each pad to clear the 1.10" thick rotors vs stock '69 calper rotors at 1.00"..

pdq67

[Richz68]

Here is a photo and price for the calipers....


Supra Caliper photos: