ACSGP

A non-accident 964 C2 manual has come up for sale.

If I were to do an RS replica, did that car have the hydraulic system from the C4, or the vacuum assisted from the C2?

I also take it that the Mg Cup 1s would be prohibitively expensive. But even if you could get some, wouldnt they have oxidized over the years? I understand that electrolysis between 2 different metals (ie the Mg of the rims, the Al of the nuts and steel of the hubs) could be an issue. Correct?

Also, the RS doesn't have fog lights?

ThomasC2

1 vaccum

2 the cost of the wheels is a bigger issue than the mag-factor

3 correct, only a dummy plastic lens.

Thomas

Steve Weiner-Rennsport Systems

Hi,

If I might,.....

1) The RS had vacuum systems like the C2.

2) A client of mine has a perfect set of magnesium RS Cup 1 wheels, just refinished by Harvey Weidman. These have not been on a car; the previous owner bought them new and had them painted to match his car without ever using them and my client had them restored to the original silver finish. Not cheap, but they are NLA.

These will be just as durable as the aluminum ones IF one is careful with the paint as that's what protects them from oxidation.

ACSGP

Thanks Steve.

But if you mount the rims on the car, when torquing the nuts, you would definitely strip some paint off, no?

But please PM me the price.

Best
Andrew

ACSGP

Thanks Thomas.

Didn't the RS have plastic ducts instead of a lamp, and which sent air to cool the brakes?

Best
Andrew

GeorgeK

The brake ducts are Cup parts. The RS in original guise had dummy lenses indeed.
The braking assist is electro hydraulic, exactly as on the C4.

Geoffrey

The RS system is not exactly like the C4 system, but similar. The RS shares the hydraulic boosted brake system from the 964 Cup has which has a different pressure pump than the C4 has, but otherwise is the same system. The "assist" is less due to the different pressure pump.

ThomasC2

The cups actually also had the dummy lenses. The brake ducts are from the 3,8 RS and RSR.

And just to be clear in my first answer, I meant that the C2 is using a vaccum system, the RS not. So that would be a differene if you're going to build an exact replica.

Thomas

GeorgeK

Geoffrey,
Can you expand? The Pet only has one reference for the pressure pump (964 355 901 01 superseded by 993 388 953 01).

Geoffrey

The brake booster component specific to the Cup and RS has been superseded by 993.355.025.80. My 964 Cup manuals are in my trailer so I don't know the original part number. They reduce the assist pressure from about 5 to 3.8, again the numbers are in my trailer. I used the street car part in my race car for awhile and switched to the 993 RSR part listed above and it makes a large difference in pedal feel.

Atgani

Hi Steve,

The front mags are still available (just). I think the factory have 10 or 12 left.

ACSGP

Geoff, are the 993 versions hard to source, and expensive?

Not thinking exact RS replica, but a cross between an RS Touring with Cup parts. Example, I would like to get the 993 GT2 wheel carriers as roadsleeper did that with the bumpin pumkin, and said that they were extremely light.

Thanks
Andrew

GeorgeK

Thank you Geoffrey,
Good to know. Is that pump useable on the street at all for someone who likes a firm brake pedal?

Bill Verburg

Hmm could you follow up on this when you get a chance

here are the booster #s I have
964.355.904.80 964RS & 993RS & I believe 964Cup

993.355.025.80 993GT2 Evo & 993RSR

the biggest difference besides the electronic brain component and abs pump is the m/c size
964C4 used 23.8mm as does the vacuum operated 993
964RS/993RS used 25.4mm

most people building an RS clone from a base 964 will t/p in a 993 vacuum operated booster & m/c

Geoffrey

Bill, yes, you are correct, however, there are no more 964 Cup components and the offered replacement is the 993RSR/GT2 part. You can buy the street car part from your dealer, and the race car part from Porsche Motorsports. When you buy the part, it consists of the master cylinder and pressure pump as a single assembly.

The 964 RS/Cup and 993 RS/RSR/GT2 all have the same size master cylinder (in fact, the same as 993 C4S/Turbo). The Pressure assist is the same as well, even with the different part numbers.

In my race car I initially I installed the hardware from a 993 Turbo with a GT2 Racing brain. This had the softer street car power assist. I then found only the pressure part of the master cylinder assembly from a wrecked 964 Cup and installed that. Much better feel.