dnitake

Did a bit of searching, but am just going to pose a query for you guys here.
Friend let me drive his near stock '07 GT3. Don't know much about his setup, but he wanted some coaching on lines. It went quickly from lines to car setup. Not impressed, until we came off and started talking about his what he'd done. I realize some of the caveats about seat time, experience level, style, GT3's. So all that notwithstanding, and w/o telling you much, here's the question:

What would you expect of this car w/ front sways on full soft (5), mid rears (2)? Aftermarket GT3 bars. Brand unknown. 37-38 lbs all the way around. 295 rears (stock I believe) around 50 heat cycles (Michelin tread 300 Super Sports?)).

Don't want him to unnecessarily adapt to this if it's off the mark. It was the last session of the weekend. No time to make adjustments.

GT3DE

what is the question?

dnitake

Sorry, forgot the ? mark. Edited and bolded above.

tlarocque

Still unclear... with regards to what? Lap times? Grip? Resale value? Ability to pick up chicks?

LVDell

I'd expect some oversteer. But 50 HC street tires I'd say somebody isn't driving the car very hard.

NorthVan

I thought that was a typo

utkinpol

it is a natural progression to move to full soft front sway bars to improve turn in grip as you 'dive bomb' into corner and want it to 'bite' no matter what, then when you get smoother on brakes and 'feel' what a proper line is - a tendency is to make front bar firmer to improve mid-corner stability and apex speed.
so, for an example TPC leaves stock rear bar in place and uses way stiffer front bar. i tried such a car - i cannot drive it yet as i cannot master corner entry speed high enough where it works.

of tires - some fast people say 275/335 tires I run compensate for lack of skill and a properly ran car will be faster on narrower tires and point to cup car sizes. but those are slicks and not 'streetable' r-comps and, again, it takes a different skill to drive 9/10th around whole track and 'feel' your limits at that pace. any novice driver like me has to have a safety margin to regain grip and if it means wider tire that affects acceleration - why not. it works for me at this moment but i have no illusions that a reson why i like it so wide is only to compensate, again, for lacking the skill. but i am working on it.

so my 2c is that everybody must progress naturally, listen less to any forum crap and get as much seat time as possible to figure out his own setup. everybody on a forum is a Senna reincarnated while none of us is, but it does not help much when you have to fight your own reflexes.
All i can say from my own progress - advices from people who are 2-3 levels above your own skill set usually only confuse it make everything worse.

dnitake

I can see this open ended thing isn't going to work w/ this crowd. :-)
Picking up chicks? Now there's a proper digression. Tempted... but,

IMHO, the car was oversteering in an almost humorous way. Turn in
and track out were unpredictable. Couldn't feel the rear end sliding,
until going for a shift and nearly looping the car. Like the envelope is
straight line braking, straight line throttle, tiptoe in between. Turn in was
also tenuous. Not a car to toss into a turn. Trail braking was not in
the cards given my seat time.
With more time, I bet I feed in normal techniques into the envelope. But why do that?
I want my friend to put the bars back to mid/mid before doing this again.
But I don't know how dramatic an effect this will have other than it sure couldn't
hurt. He thought the car had too much push and he softened the front by 2 clicks.
I thought it was too easy to grease the street tires w/ a car like this, but I don't think
he wants to go that direction yet.
So looking for opinions in case we're staring out on the wrong foot.
* Setup to mid/mid.
* R-Comps, 315's rear in the future sometime.

NorthVan

I would have him check his alignment, and get new tires. These cars aren't like that at all. Set both bars in the middle, and start from there.

997gt3north

2 Pieces of info would be very useful
- What were his front and rear camber settings?
- Were these the GMG bars?

If they were the GMG bars (guessing) and you ran old tires with that much front psi + a 295 tire instead of a 305, then I'm going to guess you had a car with little grip that was ploughing on entry and tail happy on exit.

If you then added that the car had less front camber than rear, then I would be almost certain of this statement.

If you then further added that the car had done a bunch of track days and had a shot LSD, I would bet my first statement was a near certainty.

If however, the camber was more in the front than in the rear (-2.3,-1.7), that the front tire was a 245 and the rear was a 305, and that the tires even with 50HC were still reasonably ok, and the LSD was working, then I would guess that entry would be ok but the rear gmg bar on mid made it slightly loose on exit - unless the rear were HS'd out, in which case it could be very loose on exit (this car goes through rears faster than fronts 'generally')


how was my guess?

LVDell

Two biggest issues for this is what was just said above. Those tires are toast regardless of driving style so you are not going to get a good read of the car. Alignment needs to be checked and needs to be recent.

997gt3north

- now that i read the answer, i give myself (pats self on back) an A for my guess

solution for you
- new tires (245,305 Pilot Supersports)
- camber -2.3/-1.7
- front toe zero, rear toe to OE 'race' specs
- front bar mid, rear bar soft
- front rear hot tire temps (33f,37r)
- upgrade to Guard LSD

car will be totally different

NorthVan

Good point, LSD could be shot too

dnitake

FKNA,
Do you guys value this more than getting your work done too?
On tires, it was a given he needs to change out. Yes, no way to get a good read, other than they are both HC'd out equally (not happening). I was pushing for DOT-R, but settled on he'll change out the rear. He does have a set of Cups in his garage. I pleaded w/ him to consider it's raining right now. But I respect it's not my money as I'm on big budget also. At least it leads to
more push. It sounds' like 295's aren't stock? that 305's are?
He had recently serviced his Guard.
Has RSS control arms. Don't know his alignment settings.
He was my student as a first time driver in a brand new GT3, but that was 4 years ago. And damn well deserves to enjoy it even though there are a lot better ways to progress. I came across him in my lowly 996 pretty quickly. He offered me the wheel to drive drive some lines, but it quickly became, what is wrong w/ your car? In short, he's a good enough driver, but doesn't have experience in other cars to say his car is messed up. And neither do I. So really appreciate the direct feedback from you non-working guys.

FFaust

- Tires, so that they are a known quantity
- Pressures according to tire
- Sway bars mid/mid if you like, but the GT3 generally likes more front than rear (I'm full hard front, 1 from hard rear, YMMV)
- An alignment so that you, again, start off with a known quantity

LSD is probably shot, so that could factor in when your friend is ready to spend a bit of $$.

A well set up GT3 is a dream, nothing like what you describe.