brake swap discussions.

Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.

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ericjon262
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Joined: Mon May 24, 2010 5:34 pm
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brake swap discussions.

Post by ericjon262 »

I've been considering installing bigger brakes on my 85 for a while, I've had a set of 02 firebird front calipers on the shelf, along with adapter brackets to mount them with 13" rotors on the front, but I had yet to come up with a real solution for the back. other than losing the parking brake, would there be anything wrong with using the same setup on the rear? 88's use the same piston diameter all the way around, and 84-87 uses very similar sizes front to rear, so that seems like a non-issue. it would be a bit heavier, but I think I can live with the increased weight if it's going to stop the car better/faster. I did a quick mock up on an 88 knuckle, and it appears as though it will work with minor clearancing to the caliper bracket and knuckle, and an adapter bracket. I'd probably want to set up to a bigger master cylinder to compensate for the huge increase in piston area, as well as an adjustable combination/porportioning valve, but those seem like easy enough things to fix.
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
The Dark Side of Will
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Re: brake swap discussions.

Post by The Dark Side of Will »

That's basically what I was planning to do, although with 2 piece rotors.
Up front, a two piece rotor can run an aluminum hat for unsprung weight reduction.
In the rear, it can have a steel hat with internal drum for a drum-in-hat parking brake.

Identical brakes at all four corners with an adjustable proportioning valve works quite well on a Fiero, from what I've heard (mostly from Series8217).
My one caveat would be to do some hot laps then measure brake temps. Try thinning down the rear rotors until you get them to run at the same temp as the fronts. Then you can run the same pads for the same temperature range and have the same brake grip and feel front/rear.

Also, thinner rear rotors drop weight. Of course you can't do that with the Corvette floating calipers, but CTS-V Brembos are cheapish on eBay and of course Wilwood still makes Dynalites for a variety of rotor thicknesses.
ericjon262
Posts: 2819
Joined: Mon May 24, 2010 5:34 pm
Location: Aiken, SC

Re: brake swap discussions.

Post by ericjon262 »

The Dark Side of Will wrote:That's basically what I was planning to do, although with 2 piece rotors.
Up front, a two piece rotor can run an aluminum hat for unsprung weight reduction.
In the rear, it can have a steel hat with internal drum for a drum-in-hat parking brake.

Identical brakes at all four corners with an adjustable proportioning valve works quite well on a Fiero, from what I've heard (mostly from Series8217).
My one caveat would be to do some hot laps then measure brake temps. Try thinning down the rear rotors until you get them to run at the same temp as the fronts. Then you can run the same pads for the same temperature range and have the same brake grip and feel front/rear.

Also, thinner rear rotors drop weight. Of course you can't do that with the Corvette floating calipers, but CTS-V Brembos are cheapish on eBay and of course Wilwood still makes Dynalites for a variety of rotor thicknesses.

long term plans aren't far off from what you described, I already have the c5 parking brake parts, only think I hadn't thought about was thinning the rear rotors to match temp. there are a ton of calipers similar to these, maybe there is one that would work with a thinner caliper?
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
The Dark Side of Will
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Joined: Wed Nov 24, 2004 11:13 pm
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Re: brake swap discussions.

Post by The Dark Side of Will »

You'd need fixed calipers for the different rotor thicknesses to work (unless you happened to find floating calipers with all the right specs).

Wilwood, for example, uses spacers in between the caliper halves to adapt the same halves to different rotor thicknesses. For those, just install the right spacers and crossover tubes (or order them configured for the right rotor thickness to begin with).

If you started with, also for example, first gen CTS-V Brembo front calipers, you'd need to split them and mill the mating surfaces of the halves down by an appropriate amount each, then reassemble with shorter bolts.
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