Porsche 996 Cabriolet Suspension

This is my first post so bear with me ! I have a 2004 996 C4 Cab (56000miles ). This is my first 911, having had a 996 Boxster. I've had the car over two years and remedied a few minor issues, based on Indy recommendations, this has included new top mounts and subsequent alignment, which produced good results relative to recommended figures. However, to me the front end of the car does not really feel 'planted'. It is easily disturbed by road surfaces and sometimes a strong hold is required to maintain a line. My Indy things the car drives fine, but having never driven another car, I'm not sure. I do not want to spend great amounts over improving the feel, but wondered whether others had encountered this. Is it the flexibility of the cabriolet, in conjunction with the front drive ? Where do I start to derive a route to improvement? Any comments or recommendations would be good to hear. PS I love convertibles, and while some suggest there are not the real thing, every minute of driving brings a smile !

Hi Chris Just my thoughts, If your indy cannot find any issues then tire pressures can have a huge influence in this area, also how old are they? Good luck Andy

I echo Richards comments. I had a hairy moment in the wet on the M1 at 70mph and always felt that I was having to grip the wheel tighter. I had a slow puncture on nearside front, that massively had an impact. The tyre tread was great, but were old, so I replaced both fronts and keep an eye on the pressure and Ive bee much more comfortable with handling and relaxed driving. Also, just what I do, but keep a fuller tank of fuel, or heavier items in the frunk (I had bricks in my E36 boot as that had no traction control, and it made life less tank slappy) , it'll give you better grip too (thought slightly less mpg and 0-60 ) Check the basics first

Guys Thanks for quick responses, really appreciate. I had wondered about swapping the tyres. They are PZeros, 6 years old, but still with 4+mm. I changed the rears last year because of age, so, as you say Mark, look at the basics first. Many thanks for comments. Chris 996 C4 Cab

Driving a C2 & C4 side by side there is a subtle difference how the cars feel. The former feels light on the front, whereas the C4 feels planted. I am surprised it feels this way on your C4 cab. As well as tyres I would have bushings, roll bar and steering rack checked on the front for any play. If all looks good, then investigate front shocks and springs. Was any of this changed with the top mounts? I am assuming you have standard suspension and not the M030 sports option?

Thanks for your comments Tony. You've used the word 'planted' which it is not, when compared to my daily modern Mercedes drive. In view of the relatively low mileage and the fact that two Indys have done various work on the car, I was concluding that there were no significant problems with the suspension and bushings. It is still on the original suspension, nothing was changed when the top mounts were done, I was hoping they would be the culprits. I was not intending to upgrade the suspension, but I certainly want to improve the current feel. I'm just concerned I embark on a long (and expensive) route. Looks like tyres first then, and see how it goes. Thx

Hi Chris My C4s used to be clunky and wander at high speed, I’d already been advised the top mounts needed changing so I decided change all four coffin arms as well, originally I was going to do it myself but with work commitments etc it keep getting put off. After a discussion I contacted Centre Gravity in the midlands http://www.centregravity.co.uk/ they carried out the work and I can honestly say they transformed the car it drives like new now.

Soon after I bought my 2002 996 C2 Coupe, my first 911, and started to driv it ‘enthusiastically‘ I thought it felt rather unstable on some road surfaces and a bit skittish so had 4 wheel alignment done. This made it feel very much better, however, about 4 weeks later I had the 111 point check carried out by the independent I now use, Revolution Porsche. To my surprise they said alignment was required so I told them it had recently been done and I showed them the report. They said it had been done to within tolerances that might be ok for a family car but not good enough for a 911. I went back to where I’d had it done and they willingly did it as Revolution had said. The difference that very small adjustment made was almost unbelievable and the car felt totally stable and planted and has remained a joy to drive on road and occasionally on track. It‘s 3 years, several thousand miles and a recent pair of front Pirelli’s since it was aligned. Last night I attended a Pirelli Performance evening at Tyre Pros in York where free alignment checks were offered. I had mine checked and the front was slightly out so I had it reset at a special rate of £50 Instead of the normal £125. Whilst I’d thought the car was fine, that small adjustment was immediately noticeable and on the near 40 mile drive home it felt absolutely brilliant, very planted and nimble, a joy to drive. The point of my ramblings is that totally correct alignment makes a huge difference and I guess that may well be the problem with your 996. I’m sure you will be able to get it checked, preferably by a Porsche independent or a Pirelli Performance Centre with Hunter alignment equipment, free of charge and only have to pay if adjustment is necessary. It may be the best £125 or so that you ever spend on the car. I hope you get it sorted and can really enjoy your 996 cabriolet. Roger

I agree w what's been said already. First port of call - tyre pressures and even tyre wear. Then a good geo from a proper porsche specialist or preferably from Center Gravity (who WILL transform your car) Chris will also let you know if any parts need changing. Your car should feel absolutely planted and have go cart like steering. You should never be fighting it over bumps, it's should flow smoothly and predictably. Enjoy the magic within! ??

Thanks for all the input. When the topmounts were replaced by the Indy, they did a full 4 wheel alignment and were keen to explain that the results and cross checks were some of the best they had recorded, so I thought the job was done. But clearly, based on the comments of other, the front end is not how it should be! I have read about Centre Gravity, but thought my problem could be more easily resolved. Fortunately, I am in Staffordshire only half an hour from CG, so it looks like a visit. It would be great to really sort the car, and make the 'transformation'. I'll post an update. Thx Chris 996 C4 Cab

+1 for Centre Gravity. Some years ago I had a lot of problems with tyre wear and handling. Even after supposedly having the wheels aligned by two Porsche specialists the handling didn't feel safe. Centre Gravity found the fault and corrected it and the handling was transformed and tyre wear very reduced.