doctorpcar

I believe you're right. It's called the circle of traction. It's explained here:

http://autopedia.com/stuttgart-west/...Physics07.html

ECS

Here is my track camber set-up. I would highly recommend it for better tire wear and less understeer. Use GT3 control arms for the front with shims. Total cost about $1,300. I now have -2.5 front and -2.0 in the rear. The GT3 control arms also give a bit of a wider stance in the front making the car more stable. Front toe should be very close to 0 for very good turn in. Makes the car a bit more touchy on the highway but very good turn in. Also, before the GT3 control arms, my front outside edge of the tires were getting eaten up badly. Absolutely a waste of a good tire. Add, GT3 front brake ducts, GT3 seat, harness, harness bar, and neck restraint and I am good to go. Perfect set-up for DD and DEs (my commute to work is short so not worried about wearing my tires out with this set-up.

WaltB

I'm not talking about the difference while tracking the car. The typical turns on a track are not high angle. Here is a test for you. While in your car sitting at a stop, turn the front wheels 40-45 degrees and then hit the gas. How far forward do you go and what turn rate do you estimate you have? If I do the same thing, and I have, the front wheel drive pulls the front end around with minimal scrubbing of the front tires.
Again I am talking about typical road driving situations where the 4 wheel drive gives me capabilities the 2 wheel drive does not. How about making a U-turn as quickly as possible. I can make a smaller min radius turn with the 4 wheel drive if makeing that turn power on in an agressive fashion.
Sure, if you are tracking your car, get the 2 wheel drive. But if you want incredible turning performance on the road, especially on turns greater than 90 degrees the 4 wheel drive offers much more capability.
I've had both cars and in the C4S the high angle off cornering an turn rate is eye watering.

RonCT

This entire thread is all about track driving and understeer... There's simply no situation where AWD is superior to RWD in a Porsche unless you are talking about traction in the snow. As to making a U-turn, the C2S can do it as well if not better than a C4S. Heck, if you want to be extreme, w/ RWD we can leave the front tires sitting pretty much still and have the rear end walk around and do a 180 in half the distance as AWD.

mglobe

I beg to differ on this point. Yes the cars are much more stable than the earlier models, but a lift at the wrong time will most certainly initiate oversteer very quickly. ask me how i know...

Mr. Brown

I've done a lot of SCCA races and, in the rain, I would prefer a FWD to RWD any day, and, better than either is AWD.
Mr. B

fuenfer

I'd prefer AWD any day on snow, but I'm partial to RWD on dry tarmac.

fuenfer

+1. I love how the rear end rotates around nicely at Summit Point (in the Karussel) when I lift just the right amount.

lawjdc

I learned the same thing from David Donahue at the Porsche Driving Experience. It works well on the GT3 also.

Mr. Brown

Summit Point is my home track and, in the dry, RWD is the most fun.
Mr. B

Crazy Canuck

When I test drove a Carrera S I also drove a Turbo. Although I liked the acceleration I did not like how heavy it was. The front end felt heavy.

2wd is more fun. AWD understeers more.

RWD for me.

drmarkp

PASM doesn't help as it makes it harder to load up the front of the car. Understeer is a problem with the GT3 and RS too. Trail braking gets rid of what's left after optimising your geometry - just make sure you do it right!

mkk62

ECS
wtih those camber settings with the gt3 control arms what is the toe and total caster? on the alignment..

thanks
thinking of getting those arms too..would get the gt3 control arms first, switch to R compounds (r888's or MPCS ) or do both at the same time?

thanks

ECS

mkk62 - can't remember the caster, but I believe my front toe was 0.02 per wheel. I will be getting a full alignment before Barber on the 8th so I will let you know then.

pbarch1

I had an 89 911 before and I'm telling you tire pressure made such a huge difference in handling I was amazed. I could completely change the car from under to oversteer just by adding a few pounds or taking a few pounds of pressure.