ivangene

+1 good info

springgeyser

I was curious about that also and measured the tempersture (infrared) of my r888 after a long cruising trip back home from AX. The front and rear tire temp differential was close to the FR temp differential I get on the track.

One thing to note (AX) is a wider front tire (~same diameter) allowed me to brake a bit deeper without ABS kicking in when I swappped wheels. Does it mean a actual shorter stopping distance, dunno.

JimB

Hey Andy,
I stop by from time to time but seldom post. You guys know a lot more about 996s than I do and frankly I don't care what oil people use. I teach our region's racing physics class so I couldn't keep myself from jumping in. There's a bunch of mis-information out there.

I'm going to look for Twist of the Wrist. If you are bored sometime Google "The Physics of Racing". It's a series of articles that are dry but have a lot of good info. I think they are all on one of the Miata racing sites.
Later,
Jim

911h20

I think is sould be low front and higner rear.

JimB

That surprises me a little bit but it's good news for you. My only real experience with wide fronts was when I tried to run 265 MPSCs on the front of my 996 race car. The track I was on (Brainerd) is very fast with long sweeping turns. I had a heck of a time getting the fronts as hot as the rears and the car pushed like a pig for the first two laps.

If you can stay out of the ABS you will stop faster so that's more good news.

eDoug

+1 - great book

Honestly, this thread is a little confusing, and I "think" I understand this stuff pretty well. Read the book, you'll get a much better explanation. amazon...

himself

Hmm, I took the OP to be in jest mocking the search function being broken. But, then the thread actually took off, lol

Sorry if my post came across as critical, as this wasn't my intent. I was only quoting you top give context for my replies. Please don't take it personal.

And although loose/tight is driver dependent, there are universal changes that should affect the car's behavior on an objective level. However, as JimB noted, without actually saying it, the tire patch/friction/grip/etc issue is much more complicated than we can probably every discuss or understand.

-td

eDoug

Oh hell - I was going to pass this up - but I'll respond mainly because I used to think my car was an understeering pig. I went to my first DE last year, full of myself, saying how bad the car plowed. Of course, track junkies and other knowledgeable folk let me spout off - I guess out of kindness, or not wanting to get into a debate. So, from my perspective, I USED to think my car was push-happy and I appreciate some folks' tolerance.

I solved this, as many in this thread suggested, by trail braking at the track my first time out. It actually worked quite brilliantly. My instructor was reasonably impressed, I think. He too was driving a 996 and felt that it's basic setup was to push in the front. But I also agree with a previous post that you shouldn't be practicing trail braking on the street - it's really more for driving at the limit.

Then I started reading more, driving more, listening more to the track folk and to my mechanic. By the time I went to VIR last Fall - I had slotted the strut towers in the front just to get another 1/2 degree of negative camber in the front. But I was still running the stock US suspension. Let me tell you, hitting triple digits on the climbing esses at VIR was a bit of a roller coaster in the middle - car was floating enough to "almost" set sail off the track. However, the front end, just with an extra 1/2 degree of negative camber made a huge difference in my cornering and my cornering technique. I was doing very little trail braking - car was rotating better, even with some very light throttle at apex.

Now, I installed PSS9s this week and dropped the car 30mm from the stock US ride height - looks better, and now I have over 1.5 degrees negative camber in the front. I added a bit more rear to compensate too - so the car is still reasonably neutral.

So - once you get the car handling somewhat neutral (to perference), then it's all driver controlled and it's up to you whether you want to set the car up to have a bit more oversteer/understeer at the limits. The power in the 996 is plentiful enough that you can push (understeer) the car under hard acceleration, you can break the rear wheels loose (maybe) and generate oversteer, you can use braking/trail braking to generate more front grip to rotate the car, or you can use trailing throttle oversteer to lift the weight off the rear wheels, causing more oversteer.

So - in addition to lot's of replies here that are technically correct. My point is that you can drive the car well however it's set up - it's up to the driver and the driver's skill. But then again, you probably have a preference as to how it's set up. If you feel the car is not gripping enough "naturally" in the front, you can add wider tires up front, adjust suspension, or use driving methods like trail braking.

In short, there's no "right" answer - too many options. But it's good you're learning (I know I'm learning) and I don't think you could have a more fun car to learn with.

Cheers and good luck.

springgeyser

none taken, it's the internet. I was just sharing my experience from a AX perspective.

Everyone's driving style is different. My driving bud's 911 rear end is loose (midturn/exit) IMO but he comments it is balanced. It is very complicated since every factor is interrelated and comes into play.

springgeyser

I ran Pss9 with slotted towers also on all my tire combo.
-1.8 f
-2.0 r

Wife doesn't have an interest driving the 996 so now it will sport some 700/900 JIC setup. Make sure you check your strut top, upon disinstall I found one of my rubber strut top was torn.