kmetros

Hey all, long time lurker, first time poster. I recently picked up an '08 Carerra S with 40k miles on it. I'm coming out of a moderately track prepped C5 Corvette. Both cars were/are predominately street driven non-daily drivers that see track duty a few times a summer. Whether on the track or not, my motto is APEX EVERYTHING. But, when I take the Carerra through turns at high rates of speed I can feel the a$$ end becoming unsettled - it's like a wag, or a side to side sway as I go through the turn. The movement is so great that it requires steering inputs to correct, but it's limiting my interest in going any faster until I know what I'm dealing with, which is a problem. I've searched the forum on terms like 'wag' and 'sway' but come have come up with little. I've read a couple of references to soft rear suspension bushings that could be the culprit, but not which bushings specifically. Maybe this is just part of the 911 experience, but I don't think so? Any input or a fix would be great!

TheBruce

linderpat

Welcome to the world of rear engine 911's. This is why folks buy these cars. Rule of thumb, slow in, fast out. Do a couple of DE's and learn the foibles. It's a blast to drive, feeling a bit on the edge.

Doug H

Maintenance throttle . . . It will understeer if you are driving it correctly. 911's layout makes them a gem to throttle steer and a very stable platform once one develops car control skills. HPDEs are okay, but we used to do an advanced car control class at Skippy. See if they still have that or something comparable. One can develop more skills there than perhaps 20 HPDE track days.

mikemessi

There is a lot of rubber in the bushings of all the control arms in the rear as well as the soft springs of the 997.1 contribute to this "wallowing." It's sort of a rhythic up and down and side to side that is definitely discomforting. The 997.1 PASM seems especially prone. Upgrading rear control arms/bushings as well as the TPC module help. If you track I recommend coil overs to lowering springs.

kmetros

This would be the best description so far. I don't think I'm going into the corners too hot. Plus, these aren't even technical turns - they are simple constant radius turns where there are not steering or throttle input changes occurring, just wallowing. So I'll start looking into rear control arms and bushings.

What do you mean by upgrading the TPC module? Is there a software update for it or is this a module that plug in to update it?

mikemessi

And while the slow in fast out has been repeated forever regarding the 911, the only way to be truly fast in this car on track is fast in with trail brake then pause for the rear end mid corner pendulum and settle with a little throttle.. That all depends on the type of corner of course. If you drive it like a front engine car it will understeer. Similar to most other cars, high speed corners best approached traditionally with setting the car early and a little gas through the corner to keep the rear settled. I assume this is where you are feeling the wallow as I call it and recommend as above in previous post.

kmetros

Agreed. Another class is on my list. Over the years I've gone from front engine front drive 1st Gen Taurus SHO's (don't laugh they are very capable track cars) to front engine rear wheel drive C5 Corvette to rear engine rear wheel drive Carerra S. My brain is confused! LOL

mikemessi

TPC module is aftermarket module from TPC racing that basically upgrades the 997.1 PASM to function like 997.2 PASM. Module is plug and play but needs addition of extra accelerometer which isn't too difficult.

kmetros

Since I'm on the street and not coming into these turns that hot, braking and setting the car isn't a factor here, but otherwise, yes, this is what I'm doing - throttling to maintain forward momentum only rolling into the throttle post apex. It's the point of constant radius and momentum throttle that it wallows. I'm not even going fast enough to worry about understeer yet. LOL.

Doug H

kmetros

aaks38

Do you have new tires on the car, most tires except the N rated ones will deflect when new due to tread squirm which causes this weird shift under hard cornering at medium to high speeds.

Bruce In Philly

2009 C2S 125K miles

Same for me.... I tried replacing the engine mounts... maybe helped, maybe not. The TPC module really did the job... took most of it out. You have to have PASM to use it.

Peace
Bruce in Philly

FZP

If you haven't done so already, I'd be getting a top geo shop to wave their wand over it. My initial set up was factory, but after getting it set up properly(outside of Porsches parameters), it took all the weirdness out of its handling. If you're running Michelin tyres, they can be sensitive to pressure so have a look at those as well. They are probably going you 2 cheapest things to check first.