Tomsk

Hi
Im a newbie to the forum but have just put an order in for a C4S for delivery in March/April- Seal Grey, Met Blue leather, Sports exhaust, Bi-xenons, Small Alu pack and PCM - never thought Id ever have the chance to own a 911 and i am so excited about it I couldnt resist posting about it <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" /> . I do have one question though....

Its the first time Ive driven a 911 <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> (or a 4WD at anything over 10MPH , albeit that was in the mud) but Ive had two Boxters before, latest an S, and when I test drove the C4S was completely blown away by the performance <img src="graemlins/burnout.gif" border="0" alt="[burnout]" /> and the way it looks. However, it did seem to understeer more than the Boxster, not vicious or in any way uncontrollable but definitely there- difficult to really tell on a fairly short test drive on cold damp UK roads but is this typical of all 996's or just the C4's? Or did I read it wrong? Does anyone have any advice regards mods or suspension adjustments to make to dial in the handling?

Very Happy New Year and safe quick driving to all...
Tom

03 - C4S
Boxter S
Suzuki GSXR750

Waz996

Tom,
Read my post about understeer it might help you a lot, though the C4S will behave much different, am sure the guys will help you out.

Waz

ltc

Tom,
As Tiff Needel was quoted during a 996Turbo test video, the predominant handling characteristic of the 996AWD platform is "understeer, understeer, understeer"; so what you experienced is normal for the stock setup of the car. It is also the safest right out of the box for most people (at least in Porsche's mind).
If you prefer a more C2, older 911 oversteer feel, please search the 996Turbo boards. There have been numerous postings on making the car more neutral to leaning towards oversteer.
Happy Holidays

Carlos from Spain

Tomsk,

Congrats! a C4S! you won't be disappointed

Why would you want to dial out the suttle understeer of a C4S?, its there for a reason. The C4S and TT do quite well in everyday performance with its set-up.

I've tried the Boxer on a wet skipad making it slide to get the feel of the oversteer and underster and the 996 4WD's definately behaves different in that respect, but its not a bad thing. Give it some time since you are used to the Boxer and you will get used to it, it just feels weird initially. Then, if you still don't like it or if you plan on using your C4S primarily for track purpose, there is always time to change the tire-suspension setup.

I came home from work today in the pouring rain in the highway and I was grateful of that understeer tendency

FTS

That type of understeer is quite normal as all mentioned, however due to the 11" rear tires and above average power from the engine it is quite easy to give some throttle when you feel the understeer and the car will go in-line right away.

Congrats on the order <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

GrantG

The easiest way to dial out the understeer (and I agree that it's there and I prefer neutral to oversteer) is to get yourself adjustable sway bars. Steve W. at Rennsport can probably help you out there.

Congratulations on your order. You'll be thrilled, but don't be shy about making a few well chosen mods (like the sways) to make it closer to your tastes. Porsche gave you ABS, AWD, and PSM for your C4S. Giving you understeer also is overkill, IMHO. But don't worry, you can banish it easily enough...

1AS

Maybe if you're going real slow, and have lots of room for a mistake, you can erase understeer with a huge dose of throttle in a four wheel drive car. In general, however, you'll make the understeer worse. So, about the only place to try that is in a parking lot.
At fast street speeds, the best way to tighten up the line (reduce the tendency of the car to push wide) is to lift slightly off the throttle. Obviously, the higher the rpm of the engine at the time you lift, the higher the engine braking, and the higher rear to front weight transfer, so more understeer will go away. Experimenting in second gear will illustrate the scenario best.
I found the Boxter to be a very significant understeerer at the track, unless you use the above technique, in which case you can make it do anything. My ttX50 doesn't convert to oversteer as easily as the Boxter. AS

Carlos from Spain

I haven't been able to correct understeer with opening the throttle even at slow speeds in a wet surface ever, it only made the understeer worse in my C4 (PSM off of course). I agree with Alexander. Once I lost the front end on the C4, any throttle input would keep the front further away from traction and closing the steering angle did't help induce oversteer because the front end did't have any grip to turn the car in. But thats my personal expierience and with a 4WD 996 (M030/18") and maybe others are able to do it.

Le Chef

What impact does changing tire pressures make? I wonder how sensitive the C4S is to pressure changes front to rear? Anyone tried it and if so what were the results?

MTIA

Le Chef

Tomsk

Thanks for all the responses -I am hoping to get the car in March, maybe April so Ill wait till then and see what i think...Ill let you know.

Tom

Mike in Chi

Tom

I agree with Chef.

Try playing with the tire pressure. I don't know about a C-4, but it's made a huge difference on my C-2, especially when autocrossing.

Try an archive search on this board and on 993 board.

Congrats on the purchase.

M in C

John Murray

I hate the understeer feeling. When purchasing a 996 I contemplated going for a C4, but after driving one, I said NO WAY.

The understeer can be lessened with tire pressure manipulation, changing of the factory springs, or adding anti-sway bars(as mentioned above). I think a C4 (or Turbo) would be great with the understeer dialed out completely!!


My preference is still a C2....


Good Luck.

PogueMoHone

I agree with John Murray's comments.

Kent M. Wood

Wait a second...one person says lift off the throttle, another says give it throttle to control the understeer. Ah, someone is wrong.

Undesteer has been controlled by giving it throttle during understeer since the 1950s. The person that says to correct understeer by lifting off....please explain your reasoning in more detail...

thanks, Kent

Carlos from Spain

Hi Kent,

Maybe both are right? depending on the way throttle is applied and when it is applied. But you sure have to be a brave and confident one to come in too fast and spin it around with throttle oversteer. I do this with my SportQuad in the dirt but not with my 996... <img border="0" title="" alt="[Eek!]" src="eek.gif" />

This article excert my shed some light:
</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva"> "The more tractive force we apply, the larger slip angle is created in the driving wheel. Therefore, for the RWD cars, we can use the throttle to control the degree of oversteer. When the car is entering a corner too fast and seems likely to run wide, we can correct its direction by increasing the throttle (not to do this before reaching the mid corner !), then the car oversteers. If we find the correction is too much, we can ease the throttle and let the car returns to neutral steer or even mild understeer, depends on the suspension design and weight distribution.
Only RWD cars or rear-biased 4WD cars can do this ! In the same situation, the driver in a FWD car has nothing to do other than easing the throttle, slow down the car thus reduce the centrifugal force, and hope the car can overcome the corner."
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">I deduct from this that if you do it before mid-corner you can apply the gas and oversteer so as not to run wide (understeer), but after that you can only use lift off.

The reason why you decrease understeer when you lift off the gas (both before or at mid corner) is because when you lift off the gas not only you decrease speed to gain more grip but you transfer more weight from the rear wheels to the front wheels hence reducing undesteer and if excesive inducing now oversteer (I've done that in the rain too) especially on a rear weight biased car such as a 911.