Front Calipers in the Rear of race car Options

[porsche4me]

Hello - looking for opinions --and info --- are all 70-76 rear rotors the same ???

are all trailing arms the same ??? - are all the rear calipers the same ??

- I have a 914 race car that has no brakes mounted - the body is a 76 --- front suspension is 71 and I bought new rotors for all 4 corners. I have 6 stock front calipers (new and old) + the 2 early ones on the car --

-- and 6 rear calipers (new and old all of them need rebuild) -

-- I have heard people put front calipers in the rear , but should I put early or late front calipers in the rear --- I have both ---- dont care about the e-brake ..... thanks for ideas -- I need to buy pads ASAP ---- going to do Porterfields --- but dont know which ones to buy for the rear ------

[Eric_Shea]

I don't recommend this at all.

1. Your bias is set by piston size, from the factory.
2. Your "Pressure Regulator" is not a proportioning valve. It acts exactly like a "T" (until you come to a panic stop).
3. You will be putting a larger piston in the rear... not the place to be "overbraked" on a car with polar moment inertia.
4.

I as running the stock 73 front calipers on the back without spacers or machining

No you weren't. They don't fit. Only "early" front calipers will bolt on (70-72).
5. The best piston to use in the back is a 38mm if you have a 48mm up front. This will give you the correct bias. This can be accomplished by removing the spacers from a 911 rear caliper and going solid or, by spacing back a 911 rear caliper 4.5mm off the ears and use a stock 911 vented rear rotor.
6. I would want to be front bias heavy vs. rear bias heavy in any 914, especially a race car. My friend here in UT was overbraked in the rear with a T at Sears. He lost his 914-6 and nearly lost his life.

Summary, the best solution for this application is a rear 911 caliper. It is cast from the exact same mold as the early 914 front caliper but has a proper 38mm piston so... you'll get:

a ) A larger 38mm piston but not too large as to where you can lock up your rears before the fronts (if you have a 48mm piston up front).
b ) Bolt on availability.
c ) Use the same pad compound front and rear... no mysteries, no experimenting.
d ) A larger #31 pad vs. #30 (same as the 914 front swap again but with a better piston for bias)
e ) The option to use a vented rotor if you space them back a bit.