psiegel

I have a 93 964 C4. I run 16" wheels in the Winter and 17" in the summer. Both sets are standard porshce wheels that came with this model. Both front and rear breaks are 4 piston with bigger pistons in th front.
I would like to upgrade the performance of the breaks, but upgraded breaks will need to fit with the 16" wheels. What I am thinking about is putting "big reds" in the front and moving the fronts to the rear.
Does anyone know if the "big reds" will fit in the 16"? If not, does anyone have any other suggestions? Unfortunatly I need to keep the 16" since I live in the mountains of colorado.
Thanks
Peter

parsecnc4

I don't think the big reds will clear 16" wheels. Also, I think the correct spelling is "brakes" and not "breaks".

racer

Big Reds (essentially 993TT) will NOT fit inside 16" rims. You could ditch the 16"s and get another set of 17"s and put snows on them.

What do you hope to gain by the brake upgrade? What type of pads and fluid are you using? I have found stock Porsche brakes to be more than up to the task, even in DE environments.

You might look into getting more air to the brakes (not breaks, ) as a way of improving their performance.

Tom W

Big reds can/will fit 16" wheels, just not Porsche's 16" wheels. I have big reds on my car and 16" Jongbloed wheels.

You don't need big reds on a street car (or even a track car for that matter). Putting them on my car was a mistake, but it's too expensive to change after you make the mistake. (I added them for increased cooling thinking that my brake problem was due to poor cooling - it wasn't.)

I'd leave them stock and enjoy them and save the money. If you insist on "upgrading" the brakes, just get 993 brakes. You can upgrade the perfomance of your brakes by changing pads (but I've run stock pads at the track and think they do just fine for occasional track use).

Bill Verburg

Definitely don't move the fronts to the rear, that is a very bad idea

I agree w/ Tom, If you must do anything at all go to 993 calipers f/r w/ 928 S4 front rotors

Indycam

Why are you thinking of upgrade the performance of the brakes ?
Are you boiling your brake fluid ?
What is your goal ? A shorter stoping distance ?
Are you useing the most aggessive pads you can find ?

Steven C.

Bill,

Is this a simple bolt on...no adapters needed?

Heirsh

I am certainly not one to dissuade anyone from trying things, but everyone upgrading their brakes has always baffled me. By upgrade I mean bigger, like big reds.

I have pummeled my stock brakes(4 pot rear uprage) with very aggresive driving and I've never felt even a hint of fade. Of course, track driving is most certainly different (higher speeds at least). This suprised me as everyone was putting on big reds. I kept waiting for a reason to upgrade. Still haven't found one.

Just my .005. With exchange rates going where they are it will be worth even less by the time you read this!

Bill Verburg

Everything except the front calipers is a bolt on w/ no extras. The front 993 calipers will need a radial to axial adaptor, which is readily available from a # of sources.

Steven C.

OK So to get rid of my rear 2 piston I can use rear 993? What porportioning valve if I keep the front 964? Or is that a bad idea?

cobalt

I believe you will need to replace the brake reservoir on the earlier cars to accommodate the extra fluid needed to use the bigger brakes.

Bill Verburg

The 964 4 piston 28/30 rear should be used w/ stock 964 fronts and a 55 bar p/v

the 993 rear should be used w/ 993 fronts w/ a 40 bar p/v

You can use the 993 rears(yes a bolt on) w/ 964 fronts w/ a 40 or 45(stock w/ 2 piston rear) bar p/v

Bill Verburg

Not necessary even w/ bib reds.

W/ 993 or better calipers update to a 23.8mm m/c minimum is recd.

cobalt

I was just going off of Adrian's book. He recommends using either the C4, Turbo or RS m/c with turbo brakes and 993 m/c with 993 or 993TT brakes along with increasing the size of the rear brake pressure regulator to move the bias forward and the larger brake fluid reservoir.

He warns that the larger brakes when the pads wear more than 75% that there will be not enough fluid behind the brake pistons and you might lose all braking ability.

I am sure this is an extreme situation. Then again aren't the 964 91-92 turbo brakes are he same as the 993 brakes using the medium S4's?

ilko

Let me refer to Adrian's book again, like Anthony did earlier. From what I remember Adrian suggested that the stopping power and effectiveness of the stock brakes is excellent. He quotes something like a 1.6 ft 60-0 difference between 964 turbo brakes and the regular C2/C4 brakes.

I would first start with changing to a DOT 4 or DOT 5 brake fluid, switching to better pads, and using stainless steel brake lines.