SRL

There was a loss of grip in general. It wasn't tremendous. But remember, we were measuring the tire's performance in terms of tenths of seconds.

An initial heat cycle will help longevity, but not eliminate a tire's tendency to lose grip with additional heat cycles. We didn't initially heat cycle the Toyos because we didn't want that additional heat cycle in them. Qualifying was their initial "heat cycle".

Tire strategy was: brand new shaved set for qualifying, then put aside for the race (rules required same tires used for qualifying be used for the race). 2nd heat cycle was the race, then last 1 or 2 heat cycles was the practice sessions for the next race weekend, then the tires were thrown out, even though they looked fine. Typically from last practice to new tires for qualifying, you could pick up 1-2 seconds just from the new tires.

JimB

To give advice on how to get rid of understeer, don't you really have to know under what conditions it's happening? i.e. into a corner under braking, after the apex under acceleration, on a sweeper at neutral throttle. The answer to correcting the problem is very different in each case.

Sanjeevan

Jim,B,
Oh, I hate to do this....but I think it will help Bowman too..
How about for after apex and under acceleration (I know it's mostly inevitable, But...),

I'll be curious to know the answer for a sweeper at neutral throttle, mine does'nt do it, but I could'nt dive in like a car with JRZ suspension, he was diving in in the middle of tracking out to pass a car, and I have barely enogh track to track out.

SRL

That's why I asked way earlier in the thread if it was for a track car or a street car. You're right when it comes to fine tuning, but for overall "balance" and eliminating the "type" of understeer these cars get from the factory, I don't think you have to analyze it that heavily.

The GT3 bars on my car GREATLY reduced the natural tendncy for my car to understeer, in pretty much all of those scenarios you mentioned. Optimizing the suspension for max. performance in EACH of them would be a whole different thing altogether, requiring much more adjustability than he sounds willing to pay for.

bowmanm98

So what settings did you put the GT3 Sway bars on? Are they adjustable. I was thinking Stiff in the back and Med in the front so that I have barely any understeer. I mean I don't want to exit any track back end first. December 1st there is a track day at Laguna Seca. Long way off but I want to get a couple track days in before. I'll probably get the H&R rear sway.

JimB

SLR,
I agree with you. I just think that these threads lack a good dialog on what's happening that causes a car to understeer or oversteer. If you don't understand that, which I know you do, how can you understand and make good choices on how to fix the problem. It just doesn't seem to be enough to say "slap on a xxx" and everything will be fine. Does that make any sense?

Jeeva,
The short answer is that while accelerating after the apex your understeer is likely caused by weight shifting back. Sway bars don't help as much here. You need to reduce the shift. You can do that by reducing lift in the front or reducing squat in the rear. If you have adjustable dampers, you can tighten up rebound in the front or compression in the back, or both. Any sport suspension helps just by reducing the movement of weight around the car. With stock suspension you just need to be aware of what the car is doing and adjust your right foot accordingly.

Just my 2 cents worth.
Jim

bowmanm98

Yah know, I was looking for a fairly inexpensive way to improve the cars hanling characteristics on an otherwise stock car. Just forget it Jeez. And if you don't like my "Dialogue" then don't read it. I certainly don't need you making me feel stupid.

KJinDC

bowmanm98,

I don't think anyone was trying to insult you. It's just that it helps to understand where in the corner you are experiencing understeer in order to provide a solution. If you read Jim's answer to Jeeva you can see how increased data helps. It'd be a shame to pass up on some of the knowledge that's available here from people that really know these cars.

-KJ

Sanjeevan

Man, Calm down, they are spending their valuable time trying to help you.....what's so bad about a dialogue ?, do you just want to go blindly without knowing the reasons, no one is making you feel stupid here,...they are just trying to help you.

I did'nt see KJ's answer, well said.

bowmanm98

Sorry about getting a little defensive. I do appreciate the help. Well like most cars that I have experienced with front engine and rear drive you can usually mash the throttle and the back end will come around. But this car is totally different to me. When I mash the throttle it seems to almost pick the front end up and understeer. I also know that if I am carrying too much speed into a turn and I am on the brakes it's on rails. I basically understand the dynamics of what's going on. I know I need more experience but that is the whole point of this forum for me. It's to ask the people who have already gone through this learning curve what they would do first. I mean there are thousands of 2000-2001 996s out there so I basically asking where to start on a stock 996. How about I simplify the question? I am asking for your opinion, obviously there are a million variables.

You have a stock 2000 996 and someone gave you $1000 to improve the suspension, what would you select and why?

SRL

Jim, you and I are 100% on the same page.

Bowman, you're taking some of the comments the wrong way. Jim's questions were totally applicable. Remember that you're asking questions here that for the most part are answered with opinions. Opinions tempered by personal experience. So if you're looking for the "be all and end all of all answers", this is not a great place to find it, especially with regard to questions that have much to do with driving style and balance preferences. In other words, you may take a setup I and Jim are perfectly comfortable with on track and hate it! So in that case no answer we could give would be applicable to you.

As far as your question goes, the GT3 bars have (if my muddled brain remembers correctly) 5 adjustment holes in the front and 3 in the rear per side (I may have that backwards). Anyway, mine is set up midway front and rear and understeers ever so slightly close to the limit. I do have H&R coilovers, though, so your mileage may vary.

SRL

Great comment. Bars are not going to help if that's where your problem is. The only cure is to stiffen the rear (springs/shocks) to eliminate the weight transfer rearward under acceleration (just like Jim said above) to keep more grip on the front tires.

Unfortunately, if someone DID give you $1,000 to improve the suspension, they'd have to give you about another $1,500 more to cure that problem. Sway bars won't do it.

stiles_s

Jeeva, you're not going to significantly change the height of the front tires in relation to the rears, are you? If so, you're going to have to be sure you're not causing headaches for teh AWD system. Typically they are very sensitive to differences in front-to-rear rollout.

SRL

My feeling is that messing with tire sizes to control overall handling balance is an excersise in futility. I mean, what if you're not happy? Keep buying new tires until you are? What about the effects tire wear has on the balance?

Go through 3 sets of tires and you could have had a coilover/bar setup with some good adjustability.

Adjustability is King.

JimB

Yea, all those things the other guys said.

Bow,
I certainly didn't intent to come off as an ***. That's not what this board is about. My comments were more on the general topic than on your question. Understeer is a big topic on the 996 board. I think we could all benefit from a discussion on 996 suspension dynamics and I'm just enough of a geek that I find this stuff to be very interesting. Anyway, welcome to the board. I assume you'll find us all facinating and become a member very soon.

BTW, I have 1300 lb springs over Motons on back and if I mash the throttle my car will push like a pig. I think changing that includes buying a vette.
Jim