Brembo GTP's & Master Cylinder Ideas

[doozer]

Ok I am installing Brembo GTP's front and rear but someone said the Turbo Master Cylinder upgrade still was not enough for these brakes.

True or False?

I have the 84 boosted master setup and was going to go up to a turbo master but if this is not enough then maybe I could build a mount for the booster to push dual 25's.

Has anyone done this??

Any Input from the Brake guys??

[Bill Verburg]

Ok I am installing Brembo GTP's front and rear but someone said the Turbo Master Cylinder upgrade still was not enough for these brakes.

The 23.81mm boosted 930 unit will be ok, for sporting use most of us will prefera higher harder pedal which can be provided by a bigger m/c bore. Unfortunaely adapting the hyd. boosted 25.4 from a 993tt is non trivial.

The other alternative is a Smart Racing boosted dual master setup which can be had w/ twin x1" masters.

[doozer]

So is it a straight swap on the 23.81 or do I need a bias valve?

Woo 35.4 993tt not trivial - sounds like my kind of fun

[Bill Verburg]

the 930 m/c is a straight swap, there are some wiring differences for the stoplight and warning switches on some cars, its a matter of 2 wire vs 1 wire hook up.

The preproduction #s supplied to me by Race Tech(Brembo) indicate an extreme front bias(another reason I didn't like them) the production versions currently being supplied may be better in this regard, I really do not know. Please check and let us know what pistons they are being shipped w/. A better evaluation of bias can be supplied at that time.

[doozer]

Thanks Bill,

I will let you know what I find!!

Anyone want to buy a new 84 OEM Master??? I have one

[jpachard]

Ran the GTP-LW with a 23 MC with no issues at Sebring. Pedal was high and hard...

Cheers, James

[Bill Verburg]

Ran the GTP-LW

different calipers, hey you were supposed to get back to us w/ some #S on that set up

[doozer]

Thanks James!

[jpachard]

Hey Bill, I'll get them in the next few weeks. Sorry about that but I have had a very steady stream of cars coming in for some major fabrication work and haven't had any time.

Cheers, James

[Bill Verburg]

One last thing, if the GTPs are as front biased as the preliminary #s suggest, then a dual master setup will be very desirable.

[doozer]

Ok back to that:

What about taking the 84 OEM booster, removing the OEM master , CNC'ing a dual master mounting system with ballance bar and having the booster drive the two masters?

Power brakes + dual masters?

Any input??

[doozer]

Bill?

My idea too off?

[rdane]

Russian Blue has this set of brakes on his '72, 3.6 using a Mercedes M/C. Not impressive as the bias was way too much up front. To the point of being dangerious. We added a bias valve which was easy enough to dial in.

930s are a cleaner solution imo.

[Kahuna]

Originally posted by rdane
Russian Blue has this set of brakes on his '72, 3.6 using a Mercedes M/C. Not impressive as the bias was way too much up front. To the point of being dangerious. We added a bias valve which was easy enough to dial in.

930s are a cleaner solution imo.

Where did you put the bias valve to cure too much front bias?

Just curious

[Bill Verburg]

What about taking the 84 OEM booster, removing the OEM master , CNC'ing a dual master mounting system with ballance bar and having the booster drive the two masters?

DUnno, guess it depends on your skill set.

The smart Racing setup is a bolt in for your car.

I'm also curious as to where a bias valve would be put to cure front bias.

930 rotors are great, 930 calipers were great in their day, the same thing may be said of Big Reds shortly.

[rdane]

Wrong term obviously.

What is the correct term? Proportioning valve?

Back brakes locked up too soon under hard braking.

[Moses]

Originally posted by rdane


Back brakes locked up too soon under hard braking.

Ain't that rear bias?

Anyway, I'll have a set of GTP's on in a week. I'll let you know if the car stops.

[rdane]

Originally posted by Moses
Ain't that rear bias?

Yep. Not sure what the new M/C had to do with it or the weight of the car...but it wasn't fun. Fixed now.

My 930 set up went on without a hitch and worked very well from day one. No extra excitement involved.

[Bill Verburg]

Not sure what the new M/C had to do with it

If the m/c is too small, combined w/ the small early lines means the rear will lock prematurely even w/ proper native bias.

[doozer]

I need to run new lines anyway, should I run larger lines??

If so what size?