993 Suspension Set Up

[neilw1001]

Can anyone recommend best bet for suspension set up on 993 C4S ? I had a 4 wheel alignment at an independant spec 9 months ago and was much better than original, but since then I'm convinced it has got a bit "tail end" snappy. Coming on and off power on steady cornering gives more under/over steer than I recall a year or so back, and I am assuming this is the kinematic toe adjustment. Had a specialist look at it and without putting it on a rig his view was that all was OK, but I'm not convinced. Equally I don't want to go to someone else and get the same story, so who in the south is the best for a 993 suspension set up ?

Backup data - tyre pressures as per book, on S02's, car has 30k, and original shocks. Never in any accident or been heavily curbed or similar.

Maybe the answer is that I've just got too at one with the car and am expecting more than a stock C4S can give ? Don't think so though.

Cheers

Neil

 

[phil993]

Try switching from the SO2's to Pirellis. Also if you are still on original springs and shocks you will find big improvement if you renew. I changed mine on the 993tt at 10 years and 35000 miles and was like a different car. You should find a good independent with the Beisbath set up equipment also. These guys are at Staples Corner NW London but there are plenty others. The skys the limit if you want to go for the various Bilstein options but imho not worth it if your not doing track days.

http://www.specialistdirect.co.uk/20506/service.htm

 

[RichardLW]

Tyre wear will account for a bit of lost rear end grip - how many miles have you done in that time? 5000 miles would be considered very good for a set of rears - how old are they too? Also, a lot of us run the rears a bit softer than the book suggests - I run 34 front/40 rear and this has evened out the wear a bit too. And the colder weather brings on a few changes too.

 

[clyde]

Neil

The suspension geometry on a 993 has quite a short life when set up and really needs to be checked annually. I certainly notice the handling on my narrow body (car not me) drifting off after about 8 or 9 months. It is also very sensitive to bumps, etc, it may be that it has just been knocked off slightly. As Richard says, the wearing tyres will obviously make a differance as well., although the 4 doesn't usually get tale happy because of this, my experience is that it tends to understeer more.

Got to question how your specialist could tell the geometry was OK without putting on his rig though.

 

[gresley]

I've got a C2 on 18" Turbo Twist replica wheels and am not overjoyed about its handling. Have had the set up sorted by a ( rightly ) highly thought of Beissbarth expert which made a substantial difference. Neverthless the car is still nervous on bumpy roads and in fact my BMW is definitely more reassuring in these circs.

Am running 34 F and 38R after experimentation.


My instinct tells me to go back to 17" wheel/tyre combination as fitted as standard by Porsche but can do without the cost.

Anyone got any thoughts?

AWW

 

[Guest]

Not much to add to the above comments, except that I'm running standard pressures for 18". You need high rear pressures to get even distribution of power through the whole width of the tyre. Porsche don't get such basic stuff wrong with all their years of experience - stick with factory pressures (on the road). Also Bilsteins have transformed handling on my car, which was dreadful before. Stock suspension only survives 20-30k. I'm delighted - and it's running on 18" rims & P-Zeros. I would expect any 911 to keep you on your toes - these are after all, designed for drivers who want some of the racing car experience. By the way, 9M in Warrington set it up beautifully - might be a bit far away for you.

Roddy []