997tt steering is very light at speed

[GaryD]

Hi all,

I swapped my 996C4S for a 997 gen 1 Turbo (2009 model year) about a month ago.

I first had some problems with the steering 'squirming' a little in my hands at higher speeds (75mph+), not massively so, but enough to be irritating. A new set of Michelin Pilot Sports and a 4 wheel alignment has since mostly sorted that.

However, since then I've been shocked how light the steering as at higher speeds. My old C4S felt really planted at speed, but this makes me positively nervous! At town speeds and lower road speeds it's perfectly fine, but getting up past 70 and 80 is scary if the road is not totally flat. It feels like it's going to take off if it hits a bump or change in surface.

Is this me, or is it the car? Are they all light in the steering department, or is something amiss here?

I was wondering if it could be the geo (surprised if this is the case as it's just been done, but you never know), or I real about a power steering valve that might reduce the assistance being stuck open?

Anyway, if anyone can point me in the right direction or tell me not to worry I'd be very grateful.

Thanks

Gary

[phillipj]

I have an 07 TT and that is not normal...My Turbo feels way more planted at speed than my 06 Carrera did,, What abouit your tire pressures? Sounds like something is not right..

Did a dealer do an alignment? As much as I don't like taking my car to a deaker they do great alignments and for not much more than an indie.

The Turbo is sensitive.. If your shop is not skilled in aligning these cars then there might be an issue there...

[GaryD]

Thanks Phillip

I took it to an independent to do the alignment as the dealer that sold me the car doesn't have the facilities (he's not an official Porsche dealer). He drove it after the alignment and said he was fine with it, but I have to admit it's too way too light for me.

The indie has a very good reputation though, he looked after my C4S and has a GT3 of his own which he races, so I thought he'd be fine with this.

Tire pressures are fine - the TPMS is accurate (tested with a digital gauge) and the pressures are spot on as recommended in the manual. And the tyres are new, we eliminated that issue first.

I thought it might be me, but I can't see how a £100k car should make me nervous of bumps at 70-80mph

Thanks

Gary

[biopsea]

i've always felt the 911's steering feels light (when traveling in a straight line at higher speeds). The rear weight bias, coupled with the added downforce created at speed with spoiler deployed, may be contributing factors (anyone know the downforce numbers ?) The car definitely likes a little trail braking to get the front end to bite. But man does she jump out of a corner when you get on the gas and the weight transfers to those giant rubber patches in the rear. Nobody ever said a 911 drives like all the other cars out there. but few are more fun, or quicker. ;-)

[phillipj]

One thing I disliked about my car when I got it was how much understeer it had entering corners. I lowered my car with H & R springs. It dropped it about an inch and is a HUGE improvement in handling.

Even before this modification I drove my car repeatedly over 125 mph and never felt the steering getting light...But I have had many Porsches so maybe I'm just used to it. I dove my friends BMW M6 and although that car is a pig it is much more stable feeling (in a straight line) at 125+ then my TT is..

What kind of tires are you running?

[GaryD]

Michelin Pilot Sports, they're new (200-ish miles on them now) but they replaced P-zero rossos which were awful.

However, although the p-zeros squirmed about all over the road these do feel lighter than the p-zeros at speed.

Maybe I'm just being over sensitive. Anyway, the local indie is going to check it over on Thursday again, will post back if we find anything.

Gary

[phillipj]

I'm getting a set of those Pilot Sports this week.. My friends have them and love them.. You tires are obviously not the issue. Looking forward to hearing what you find....

[GaryD]

My local tech had a look at it today.

Apparently the steering is OK but the rear dampers seem to have an odd intermittent fault, and at times they are not damping properly. As a result you end up with the back of the car oscillating up and down over undulations in the road, which can make the front lighter and a bit more exciting.

Hit the sport or PASM button and it sorts itself out though, so the theory is that it's the damping that's the problem.

It's going into the Porsche dealer next week for them to look at this, and hopefully fix it. I'm hoping that will then resolve the issue. These cars are too **** complicated!

Gary

[phillipj]

Let us know how it turns out.. If you think the 997 TT is complicated wait untill the 991 TT comes out.. 3 turbos and 4 wheel steering and God knows what else. A whole bunch of computers on that beast...

Edited September 21, 2012 by phillipj