I haven’t posted too much since my 996 turbo days and since then I’ve had an E46 M3 Competition with Dinan S2 package, Cayman S, 135i, Cayman S (had a TPC turbo kit installed), M6 SMGII, E92 M3 DCT, and now a 997 C2S.

My 997 C2S is 6spd, Midnight Blue with tan interior, has navigation, sport exhaust, sport shifter, sport chrono plus, and upgraded Bose Audio.

A question hopefully you guys can help answer. I had a set of 997 C4S wheels installed on my 997 C2S and I’m feeling a lot of understeer since. Is this due to the different offsets and wheels being pushed out further in the rear? The C4S front wheels only push the wheels out further by a couple mm, but the rears push the wheels out by ~16 mm.

Are the C4S wheels causing the major understeer?

Should the dealer have aligned the car to different specs with the C4S wheels?

Should the dealer have used different (maybe longer) stud bolts?


Appreciate all your help!

 

I have a C2S. bought it with the factory lobster wheels.
changed for the turbo wheels which are the same offset as the C4S I beleive.

I just changed the wheels. kept the same tires.
no differences in handling.

a few months ago I put new rear tires. (P-zero rosso, same as the front)
now car handling is not very good.
I believe it's due to front tire been MY2007 and tread about 75% gone and rear are new. (about 5000km)

so have you just switch wheels or tire too?

 

Idk but you have wide body rims on a narrow body maybe the offset is the problem? These cars do have major understeer atleast mine does and i had the car balanced at the dealer helped a little.

 

Thanks for the responses. The tires are all new.

The car is understeering under very normal turning conditions; I'm not pushing it. It's feels different from the typical 911 understeer when pushed hard.

Sounds like dealer missed the alignment??

 

Like you I have C4S wide body wheels on my C2S in the rear and 7mm spacers up front. The normal setup for a C2S had too much under steer for my liking. I've since upgraded to Bilstein damptronics, dropped the car about a 1/4", corner balanced and had the alignment done maxing out negative camber. The car drives like a dream now!

I recommend going with an aggressive negative camber alignment to start. This will cut down on under steer. But to truly setup the suspension in a more neutral stance it will cost money. The track guys over on rennlist start with mods similar to mine and then go further with GT3 lower control arms, GT3 sway bars and even more negative camber, all to get to neutral.

 

Congrats on the C2S! Even though you swapped-out to the C4S wheels/tires, I'd get an alignment first to set a baseline or at least see how close you are to factory spec. Then go ahead and make a change at a time.

Don't know where your tire pressures are but if on the high-end of the spectrum, you can always take some pressure out of the fronts just to see if you can gain a little initial turn-in bite back.

Post some pics of the new 997 when you get a chance!

Mark/Pelican Parts

 

Thanks for all the responses. Decided to go back to the C2S offsets. Will post pictures soon!