New to 964. Therefore, some questions.

RideShoot&Drink · 05-28-2006, 06:53 AM

Hello all,

Well, it seems like I'll be picking up 90 964 C2 in several days. Therefore, several questions:

1. Weight: OMG that 964 felt...HEAVY, no offense to anyone here, but it felt like a pig compare to my SC based car. What can be done to reduce weight on those cars? I don't want (yet) to go fiberglass all around, throw seats out (well, maybe rears). AC seems like the obvious thing to remove, but what else?

2. Suspension: The goal is to lower the car and firm up the ride for aggressive street/AX duties. What are the proven ways to improve stock suspension without spending to much $$$$$? Looking for suggestions on shocks, springs and sways. BTW, the car is 90 C2, and I understand something has changed in 91 in the rear.

3. What are the maintenance items I should check specifically on 90 964. PO claims that head leaking issue has been addressed. Anything else I should check?

4. Does anybody have an experience with NBD chips? Installation of the chip in my former 85 Carrera gave me marginal results, does it worth experimenting with performance chips in 964?

Overall, I'm very much looking forward to enjoyable 964 ownership and hope to get your feedback on the above mentioned questions. Thanks in advance.

plain fan · 05-28-2006, 07:28 AM

You're comparing a 78 3.3 turbo to a 964? Completely different vehicles. I've got a 90 with a 92 engine and I would ask to see proof that the head leaking issue was indeed fixed. Deleting the A/C on the 964 isn't the same as deleting the A/C on the earlier cars. The condensor is in the front driver wheel well and the evaporator is burried in the HVAC system behind the dash. You could pull out all of the sound insulation in the cabin, there is more in the 964 than in the earlier cars. I would really recommend going to rennlist; there is more support for the 964/993/996/997 cars.

Don Plumley · Don Plumley's Garage

Tyson is very familiar with 964's - he'd be a good resource. Based on my conversations with him, he's a fan of the AC because it works and is not nearly as heavy as in older cars. Ditto what Grady said about sound insulation - there is a bunch.

For suspension, Koni's are a good choice plus they have adjustability. Stiffer springs (H&R, Eibach) will help a lot with the feel of ponderous weight - from the factory these cars were more "civilized", hence softer supension, hence more of a heavy feel.

The issues with a 90 C2 are the cylinder head seal, dual-mass flywheel and distributor vent. The vent is an ovbious hose from the distributor. If the clutch has been replaced, you'd like to see a receipt for the flywheel. On the leak, at this point in its life, it leaks and needs to be fixed, or it does not leak, and either was fixed or never did leak.

Don

RideShoot&Drink · 05-28-2006, 06:58 PM

Sounds good! Thanks guys.

ChinSCoupe · 05-29-2006, 05:34 PM

Bilstein/HR or Bilstein/Eibach. Koni no longer makes the rear struts for the pre 91 cars.
H&R makes springs for the standard C2/C4 and also for the Turbo. Either set will work, the turbo's being stiffer. You could also find a set of row M030 springs. USA M030's do not lower ride height.

I went form a 79 Sc to a 90 C2 and it does not take long to get used to the more comfortable ride. I'm guessing the 3.6's power output is about the same as a 78 "Stock" turbo. I am getting 254 rwhp with the addition of a cat bypass, gemballa primary muffler and Cyntex chip. Factory had the 90 3.6 rated at 252 hp at the flywheel.

I'm in the middle of a turbo conversion now as you can never have too much power.

good luck with the new toy, As Grady stated, check out rennlist, tons of great people with lots of knowledge.

Colin

RideShoot&Drink · 05-29-2006, 09:40 PM

Thanks Colin, I figured that Bilstein HD with H&R springs would be the way to go. Which H&R springs? Sports? I think they also offer race set, but that would be too much for my application.

Well...stock turbo is rated at 282 US, 300 ROW main difference being exhaust, possibly fuel distributor. My chassis is 78, but my motor is from 87, have full GHL exhaust, fuel enrichment and B&B intercooler. Still plan on doing K27HFS. My friend had 92 C2 and I've driven it many times, so I'm familiar the way C2 drives. But man, turbo rush is something else. What components are you using for your turbo conversion? I guess, something like RUF BTR clown would be nice.

Bill Verburg · Bill Verburg's Garage

Here are some 993 spring rates, 964 should be pretty similar
US factory M030 150-200 fr 225-275 rr
Eibach 7209 120 fr 200 rr
Weltmeister 180 fr 268 rr
H&R peformance 240-260 fr 280-310 rr
H&R coilovers 290-310 fr 350-370 rr
H&R supercup 310-350 fr 385-435 rr
BIlstein PSS-9 225-250 fr 400-685 rr
"Motorsport" 600 fr 800 rr

RideShoot&Drink · 05-30-2006, 07:01 PM

Bill thanks for the info. Now let's get to the brakes, shall we? :-) I have a set of rear brakes from 92 964, which I heard will bolt right on, but I would need to update brake bias as well. Just couldn't find the location of the unit, do you know where is it? I also heard that Big Reds will bolt right on...true or false. Thanks in advance.

Bill Verburg · Bill Verburg's Garage

yes, the 28/30 4 piston rears are a bolt on. Rotors stay stock, and the p/v should be changed from a 45bar to a 55 bar version.

The p/v comes off the ABS pump

Big red fronts ona 964 is like on a 911 you need the correct hats for 993TT front rotors and a caliper adaptor.

the issue is what to do in the back. Best, but not ideal, is 30/34 993 rear calipers on your stock rotors and probably no p/v but that depends on chassis setup and driving preferences.