Brake upgrade

[thorloki]

Pelicans,

I need some advice on upgrading my current brake system. I am not interested in upgrading for looks but for practicality. I have a 1977 911S wide body with Carrera calipers and 24mm rotors all the way around. I am upgrading the engine from a 3.0 to a swapped in 1986 3.2. The car will be used as my daily driver and not tracked. I am also reducing the weight of the car as much as possible using RS door panels, lightweight carpet, deleting sunroof, deleting air conditioning, deleting sound system, etc. I am running spacers with 16" Hartman wheels.

I have heard that because of the increase in hp I could use more stopping power, and I have heard that Carreras are just fine. I just purchased front and rear 944 Turbo calipers and I am aware of modifications required to fit 3.5" struts.

Can anyone share their knowledge and experience and advise if the swap from Carreras to 944 Turbo calipers is practical.

Thanks in advance,

[Jack Stands]

Eric Shea at PMB can give you some advice on what will fit, but if it's going to be street driven, I think you have plenty braking capacity in your current system. Just flush the brake fluid regularly and it should work fine. Porsche has always put great brakes on their cars, and your lightening projects should just help your current system perform better.

[reyan]

If you want to upgrade your car brake pads then go with Bosch Brake Pads because Bosch Brake pads have been specially formulated to give you assured stopping power, whatever be the driving conditions.

[IROC]

Since you're not tracking the car, your current brakes are more than adequate. I have the same brake setup with similar power and in all but the most demanding track conditions, it's fine.

[reddogmotrsprts]

You have plenty of brake with your current setup and lowering the car's weight will only enhance your braking performance. My only advice would be to let us know what master cylinder you are running and whether you have also installed the Carrera proportioning valve -- if you haven't, you have an over-abundance of rear brake bias.

[JeremyD]

Originally Posted by reddogmotrsprts

You have plenty of brake with your current setup and lowering the car's weight will only enhance your braking performance. My only advice would be to let us know what master cylinder you are running and whether you have also installed the Carrera proportioning valve -- if you haven't, you have an over-abundance of rear brake bias.

This - your car has more than adequate brakes - the 944T brakes look the part - but are hard to fit appropriately without extensive machining. The 993 brakes are actually easier to adapt. But you really only need the 993 brakes if you track the car.

[Jcslocum]

Upgrading will help but the system you have is good for what you need. I would suggest a full rebuild of the current caliper by Eric at PMB. He's rebuilt my 911, 912, 944 and Alfa GTV calipers to a better than new condition and I put my life...literally, in his hands every time I use the brakes.

I would ask Eric what the proper master cylinder would be for your current set up and get a new one. Change the rubber flex lines to a good Stainless Set. This will help firm up the pedal a bit, with less flex. Do you have a power brake booster in the car?? Adding this, if you don't, can help reduce effort needed to stop the car. The Carrera's do have a booster.

Lastly, good pads will help with feel and they need to be bedded in properly.

Good luck and nice looking car.

[moneymanager]

Upgrading is a waste of time and money for you. Your brakes are fine as is.

[Bill Verburg]

Originally Posted by thorloki

Pelicans,

I need some advice on upgrading my current brake system. I am not interested in upgrading for looks but for practicality. I have a 1977 911S wide body with Carrera calipers and 24mm rotors all the way around. I am upgrading the engine from a 3.0 to a swapped in 1986 3.2. The car will be used as my daily driver and not tracked. I am also reducing the weight of the car as much as possible using RS door panels, lightweight carpet, deleting sunroof, deleting air conditioning, deleting sound system, etc. I am running spacers with 16" Hartman wheels.

I have heard that because of the increase in hp I could use more stopping power, and I have heard that Carreras are just fine. I just purchased front and rear 944 Turbo calipers and I am aware of modifications required to fit 3.5" struts.

Can anyone share their knowledge and experience and advise if the swap from Carreras to 944 Turbo calipers is practical.

Thanks in advance,

Putting the 944 Brembos on the existing 3.2 Carrera rotors is not an upgrade and wouldn't be advisable even if it was a straight bolt on.

Calipers and rotors are matched to each other in size and thermal handling capability, putting a big caliper on a small rotor is not only a size mismatch but also a thermal mismatch.

What you have is fine as long as you also have the 33bar 3.2 Carrera p/v on the rear circuit of your car.

If you don't have the p/v I'd strongly recommend pulling the 3.2 Carrera rears and replacing them w/ the stock '69 -83 M rears w/ matching 20mm rotors

You want to stick w/ the stock 19mm m/c if unboosted or the 20.6mm if boosted, you could use the 23.8mm if you track the car and have a very strong leg and very strong desire for a rock hard pedal, this is not generally recommended unless bigger calipers are used, again there is a match between slave and master that needs to be observed.