SH || NC

Wanted to run this through the 6-3 filter here and get perspective.

Last November I ran my fast lap at VIR with the following config:

• Stock alignment
• NT01s 235/315
• Front bar; one position from full stiff (stock)
• Rear bar; one position from full soft (stock is 2 from full soft)

May 2011 config:

• Differences
• Track alignment
• Rear bar; two positions from full soft (1 position stiffer) (stock)

I felt like the rear end was just about skittish all weekend and had to try really hard to keep it under me, unlike November where it felt planted almost everywhere. Besides feeling skittish, I do have video which shows it stepping out in areas where it did not before, when the speeds were sometimes slower.

Without a doubt, I am going to move the bar back to its former position, but I would not have thought one position change on the rear bar would have made such a difference.

Could it be NT01s don't play well with a stiffer rear bar and alignment?

Your 0.02?

996FLT6

So front is the same but u made rear stiffer? Is track bumpy at all? Mike

Mr Michael B

I run my rear bar full stiff, and front bar one from full stiff. I am here to tell you that my opinion is moving one position is noticeable to all who are tuned in to their car for sure. But with that said, if your style likes the car to stay beneath you - and your faster that way - then by all means keep the bar soft. I turn the car with the rear so dialing in over-steer helps, but that does not mean it will suit another jockey that way.

SH || NC

Correct. Left the front as-is. Not really bumpy; in fact that is why I moved the rear 1 stiffer , since I considered VIR pretty smooth and fast, and thought the stiffer rear would help manage the rear end weight transfer in the esses. I don't know if it did or not, but it certainly felt less planted to me just about everywhere.

Oh, I did remember one more change: I am now running the rear PMNA shock mounts.

Good data point.

Yeah, you know, I would feel like I was getting close to the edge in some sections, and when I reviewed the video/data, I said to myself, ‘wuss’.

Not only was having the rear bar softer faster, I have to say it was also more fun.

himself

The Nittos in 315 will tend to oversteer all the time, even with full soft on the rear bar. There is a lot of meat back there, but they won't hold the car from slight oversteer when driving at a fast pace. The good news is they will take a LOT of slip before they drop off. See example below.

I'm sure others will chime in, but the GT3 is (most often) driven fastest with the rear on full soft and the front on full stiff (or 1 off either side). Trail braking is essential to get the car turned, and you can't really do much with a stiff rear bar as the car will rotate too early in the turning zone. That is, you won't have the car under you at all times even with the soft rear setup when you are going fast enough. And this is typically much faster than getting rotation done early with a stiff rear bar. Also, this setup enables early application in sweepers as the back end will not have a tendency to rotate because the rear bar is on soft.

As to your original question, one notch is actually pretty noticeable on these bars. Some folks rig up a 1/2 notch position, or run different slots between sides [i.e., left on full soft, right on 1 from soft] give the level of precision you sometimes need.

-td



Here is an example of how forgiving the Nittos are. It's easy to drive them at their limit as they give you plenty of time to react, correct and continue. Coming from Hoosiers, it actually took a couple sessions on Saturday to get my correction cadence right for the Nittos. [note: the second time you watch it, pay attention to the corner worker station - it stays in the same spot in frame]

996FLT6

Your rear will have tendency to oversteer if set stiffer then your original setting. U should set it back to previous specs. Understeer is a good thing- very predictable and safer. As u progress and get real comfortable then start playing with the bars. I have same setup as mr. B on rollbar settings. Mike

SH || NC

Great info, as usual. Thanks for the confirmation that I am not crazy. I will most certainly be moving the rear bar back to pre-May setting.

+1

I did manage to match by best time (from November) in the first session with my stiffer rear bar.....on the lap immediately preceding my off.

I'll try to get that lap rendered and posted tonight.

996FLT6

I love watching track vids : ). Mike

SH || NC

Bah; don't get excited

FFaust

Of course, the answer would be clearer if you put the rear sway to where it was previously and tried the car again. I.e., is it only this change that transformed the car?

Although noticeable, I am surprised that 1 hole would transform the car to such extent.

Also, don't underestimate the effect that the alignment can produce. You say from "stock" to "track", but what were/are the numbers? If you kept the same rear end camber but increased the front, you could have a similar result.

Any chance that your LSD went "south" between November and May?

FFaust

Or... your skill level has increased, and you are now pushing the limits

996FLT6

SH//NC- u should try autocross. Really helps with throttle and steering inputs and the weight transfer. Mike

Mr Michael B

Ha! Now that's funny right there. Been there myself.

Really? I guess that is a different driving style then mine, but cool.

I knew that there had to be another nut like me.

Amen! Very helpful thread in my eyes.

himself

Indeed. You should try it and compare your times. It's somewhat about style, but more about how the car likes to be driven.
It is possible to drive the car at its limit with any setup. But, the GT3 really excels at trailbraking and getting to power early. So, you might actually get a different limit with a softer rear bar that results in lower lap times. That's the key with any setup/car, how to lower laptimes with different setups. With the soft rear, you can really brake deep and late, and transition to power almost immediately. Part of the trade off (with the rear bar on stiff) is that you have to get all your braking done in a straight line - for the most part - and trail braking can't be as deep because the rear runs out of grip faster. This may be appropriate for certain corners, but overall, may not be fastest for a particular track.

Also, check with Dell, who could wring out his GT3 and I'll bet his experience is that a soft rear setup with significant trail braking and early throttle results in faster lap times.

Of course, all of this is somewhat track and condition dependent. And certain situations may counsel for a stiff rear bar.

-td

SH || NC

http://www.vimeo.com/24248692