Tom911

Anybody lend some advice on upgrading the suspenion. I have looked into H&R coil over kits, RSR suspension. I use the car for street as well as driver ed events. Appreciate any advice

Kevin

Tom

The question is how rough a road can you tolerate? What do you want for softness vs stiffness. Dopke spring perches with Turbo springs, is a good setup, shocks of your choice. If cost is no object, H & R coilovers, or the new bilstein setup.

Bill Gregory

Tom,

As soon as my Carrera RS suspension parts get here (on order from Porsche Germany) and get installed, Jeff Curtis and I are going to put together a tech article on 964 suspension upgrades. We're taking two similar, but slightly different approaches. Jeff recently completed his, with 965 H&R springs and Bilstein HD struts, in addition to larger sway bars. Jeff's gotten some days in on the track, so he'll have some great feedback. I'm going to set up a streetable-yet-track-competant suspension, with Carrera RS struts/shocks/coil springs/front sway and 21mm adjustable rear sway. I'm leaving in the rubber bushings at the top of the shock/struts, as a nod to the streetable goal. I suspect mine may be a little stiffer than Jeff's, but we may have to get together at a common track event next year...maybe we can both get to the TracQuest/Rennlist event in the Spring at the Glen.

Kevin's question gets to the heart of the matter. Do you drive mostly on the street with a here and there DE excursion, or do you tilt the other way where track performance may overshadow some minor ride inconveniences on the street (would friends in the know refer to you as a track junkie)? The other consideration is how deep are your pockets? Either of the upgrades described above put you into the $1500-$1800 range, just for the parts (although you can stop after springs and struts/shocks for a bit less). Consider if resale is important before you get too crazy on any modifications, too.

FlyYellow

I use my car for street & autox and I'm thinking of timetrialing next year. In any case here are my suspension mods that I'm very happy with

- H&R lowering springs
- Bilstien Sports all 4
- Upper Strut Brace
- agressive alignment
- 17" c2 turbo wheels
- s02 tires all the way around

I'm very happy with all the mods. My friends complain the ride is too rough but I enjoy it! (even the porsche owners).

I only am a little confused about the tires. I really could use race rubber for auto-x events but that aside I'm happy with my relatively cheap solution.

Bill Gregory

Boris,

That's a great setup you have. When you say aggressive alignment, are you talking like -1 degree camber or more?

FlyYellow

the agressive alignment was 1.5 degree of neg camber in front and 1 degree in the rear both set from factory stock position.

and I will tell you that the car tracks and responds very well. The car keeps its composure on an auto-x but the tires are loosing traction too eraly. That is definetely the weak link in my setup. My only problem is that I'm too lazy to change rim/tires for an auto-x.

has anyone found a slick that works on the street. i've been thinking of the kuhmo victor racers as they are street legal. anyone tried this and are they considerably better than s02's?

Bill Gregory

Boris,

Almost any, if not all, of the "r" compound tires will be stickier than a street tire, and are street legal. The rub, so to speak, involves driving in the rain, since the more rubber on the ground the less grooves to stop hydroplaning. Two "r" compound tires that are also decent in the rain you might look at are the Toyo Proxes RA1 and the Yokohama A032. If driving in the rain isn't a concern, then Kumho's can work OK. The new Michelin Cup tires, only available to PCA members thru Tire Rack, got some great reviews in a recent tire comparison in Pano earlier his year, but they're also pricey too.

Drew_K

Boris, I've always heard that tires are the single biggest performance enhancement, so perhaps changing to R compound tires are your missing link. On a 60 second autocross course, R compounds can shave 2-4 seconds of time (again, this is just what I've heard).

Here's what I've done: my 16 inch Cup rims were a little scratched up so I bought some 996 wheels to use for daily driving. I recently installed some Toyo RA1's on my old 16 inch rims and will be using them in an autocross this weekend for the first time. I'll post again if I notice any differences.

The real test will be next month because the SCCA is using the exact same course from a few months ago. I ran on street tires that time, so I can compare my times with street tires vs. the RA1's on the same course.

One final note- you may be limited in tire selection based on the size of your rims. I pretty much had to use RA1's because of my rim sizes.

Drew
92 C2

JC in NY

I would be interested in hearing about dedicated race suspension setups for C2 that do not compromise for the street.

Kevin

JC;

Any of the full threaded body coil overs with mono ball camber plates are your race setups. H & R's are a good place to start. With this setup you will have to add the stiffer larger diameter sway bars. If the car is going to see the street/track stick with the M030 suspension.

Bill Gregory

JC,

If the threads weren't lost in the recent disk crash, someone who recently bought a Euro 964 cup car was looking for online references, and several were listed. They gave information on how the cup cars were set up by Porsche. There's also a very good article in Volume 10 of Up-Fixin' titled something like "Lightweight Confusion", which compares almost every aspect of the 964 C2, RS America, Carrera RS, and US Cup car. I believe it's also in the 5/93 Panorama.

Essentially the Carrera RS track version and Cup cars had stiffer springs, matched shocks/struts, monoball mounts, stiffer rubber in the a-arm and rear suspension to limit camber change, adjustable sway bars front and rear, manual steering, lightweight flywheel (no dual mass), rubber engine mounts, different DME, matched P&C's, slightly different gearing, different interiors (more like lack of), harder steering bushings, lightweight glass, and some other things that escape me at the moment. The US Cup cars had to meet US safety requirements, so they also had side door beams, standard glass, etc.

Some of the Porsche racing parts are still available through Porsche Motorsport, and the Carrera RS parts are available through normal Porsche channels. As Kevin mentioned, H&R makes some good equipment in their "cup car" 964 components. Or, you can also go with Bilstein racing shocks and Hypercoil springs, with monoball mountings. Stiffer adjustable sway bars are available from Porsche and other vendors.