964C4

Hi folks,

I own a C4

Just put 225/45/17 tyres up front

Also installed a strut tower brace

And put a 21MM rear sway bar


Understeer is gone, but now I am scared with oversteer... I know it's the effect of the changes, but is this normal ? Is this safe ?

Maybe I just need time to get used to the changes ?

Let me know your experiences, thanks !

dfinnegan

I do not have a tower strut, but I do have 225/45/17 front and 255/40/17 rear and a 21mm rear sway bar.

Depending upon the tire pressure and the alignment settings I can get understeer, oversteer or neutral handling. At least at my level, which is pretty low with no DEs yet, that is what I feel.

When I first got my car the front alignment was setup for track use (so I'm told) and I wore the inside of the front tires off in 1k miles. Had to replace them.

After realigning and playing with the tire pressures a bit (got to 36/36 f/r) I feel the car is rather neutral. It'll still push a bit depending upon how I enter a turn, but most of the time I just like it.

Recently I had the front end realigned after changing the cv boots and find that it oversteers much more. I'm still getting used to it and it may be that the setup just isn't quite right for my snow tires (205/55/16 fr, 225/50/16 rr).

From what I've read, which is pretty much everything I can get my hands on, you have the correct setup for a C4. I'm sure you can get it dialed in to just what you like. Hopefully, just with tire pressures as that's free!

I'm sure there are others hear who know much more about all of this stuff and hopefully they will chime in, but I thought I'd add my (limited) experience to the mix.

Red rooster

I have had that combination for years and dont ever remember oversteer on the road . I run 2.5 bar tire pressure all round , 36/37 psi.
Have you had the alignment all round checked ? Does the 21mm bar move up and down OK ? Oversteer sort of indicates that something isnt right .

Good luck,
Geoff

dfinnegan

Hmm. That's not what I wanted to hear. I recently had the front alignment re-done after boots were replaced and have noticed the oversteer a few times on my snows. Left me feeling a bit uncomfortable, but figured I'd wait to mount my summer tires to get some additional data points. I guess I'm off to another alignment. Arg. My luck with so called specialists has been absolutely dismal. I really must remove that "sucker" tatoo from my forehead!

Red rooster

Dave,
Maybe being a bit enthusiastic on snows !! You are absolutely right that it is tough to get a good alignment . 911s are so fussy with the short wheelbase and wide track. Just part of the whole thing I guess.
I would definetly wait for the summer tires and then see how it goes.

Geoff

dfinnegan

I live in the country and get plenty of opportunity to push things a bit where it's safe. I do "forget" that I'm on snows about this time of year and have to remind myself that this is still the "down" season even though I get to drive my car all year.

I'll wait for spring and see how things feel then.

ilko

Dave, if you need an alignment go to Advanced Automotive in New Windsor. They do a great job at alignments, really take their time and test drive the cars to make sure everything is correct. I've spoken to Geoffrey about them and he also recommended them.

dfinnegan

Thanks! I was getting ready to ask that question. Do you have a rough idea of what they charge?

ilko

I have to double check my receipts but it was in the $200-250 range IIRC. Money well spent, though.

Mark in Baltimore

Despite the weight distribution from the rear engine, your car should not be exhibiting brittle oversteer.

dfinnegan

What is "brittle oversteer"?

Mark in Baltimore

If the car wants to oversteer if you sneeze, it has what many people call a brittle feel where the car seems like it will fall over the edge of neutrality into sideways oversteer. It feels "hard" or brittle, especially disconcerting at high (100+ mph) speeds.

A car that understeers too much is soft. Others use the words loose or push to describe the same thing, oversteer or understeer, respectively.