Front wheel lift during turn

[865]

This image is from the last SCCA event this past weekend on 10/23. The front passenger side wheel is in the air at what looks to be the start of turn-in.

Click pic to biggie-size.

68421344-978A1083_e.jpg

There's a similar photo of Jerrett driving my car at the NTAXS #6 event on 10/15 where the driver side front wheel is in the air, again looks like on entry to a turn. http://www.lightspeedimages.com/NTXA...16/i-6Bd65NK/A

I've never seen anything like this in any pictures of my car taken at events that occurred prior to the installation of my Progress front anti-sway bar. I'm guessing this is caused by that new bar. Is the sway bar coupling the two sides of the car at the front, reducing the independence of the suspension at each front wheel?

It seems like this might not be a good thing. If the wheel is not on the ground, there is no grip at all there. I don't know how long it stays up like that. The bar has three stiffness settings; I currently have it on the middle one. Moving it to the loosest setting is going to increase body roll, which I'd prefer not to do if I can help it.

How bad is this, really? Should I try to eliminate the wheel lift, or let it be?

[modernbeat]

Too much bar, not enough spring rate. And it's unbalanced front vs rear vs bars vs springs.

[sammm]

It's bad....hard to turn the car when the tire isn't on the ground (aka, understeer). At the very least, soften the bar and maybe crank down the rear shocks a bit too.

Body roll isn't always a bad thing. If you want to eliminate some of it, you'll have to increase your spring rate(s).

[865]

Street class compromises. Can't change the springs. Can only change one sway bar.

Bump stops affect the spring rate when you're on them. I've got FCM bump stops, 58mm soft in front, 58mm medium in rear. Theoretically, a firmer stop in the front plus spacers to extend them to the max length allowed under Street class rules would keep the front of the car on the stops more, increasing the effective spring rate. I want to understand all the possible consequences before going down that road.

So I'll try the softest setting on the bar. That's the easiest thing to change.

Sammm, what did you mean by "crank down the rear shocks a bit"? Do you mean make them firmer, or softer? I'm guessing firmer.

Anyone know how I can decrease front ride height or increase rear ride height slightly? A little more rake might help too, if I recall the suggestions from my other recent thread.

[sammm]

^Yes, I meant firmer shocks in the rear. I know you can't change springs and remain in Street/Stock class....coilovers would bump you to STR.

The bumpstops will effectively increase spring rate as you described, but if you're riding on them you've got no rebound left for the shocks.

What it comes down to is the NC isn't a great autocross car in stock form or under stock rules.

[POS Racing]

Is this why the cool kids in C-Street are playing with Rear Sway bars??

[865]

What it comes down to is the NC isn't a great autocross car in stock form or under stock rules.

Yep, I know. Even in STR the NC has a hard time beating the S2000s, and it isn't likely to be competitive against an STR-prepped ND.

[sammm]

Is this why the cool kids in C-Street are playing with Rear Sway bars??

That's the theory, and the one I'm going to try. (Got my new, rear bar yesterday actually) The NC is prone to understeering, and installing a big, front bar just exacerbates that.

[POS Racing]

Looking on the old interwebz ya got a three position front bar?

http://www.progressauto.com/ecom/download/61.1132.pdf

What is it set on now 865??

[865]

^-- Yes, that's the bar I have. I'm on the middle setting right now, so I'm going to move it to the outermost (softest) setting tomorrow.

[POS Racing]

Let us know! Less may be better in this case.

[OZMDD]

Don't let the S2K's in STR scare you; they really haven't shown an advantage at the local level as long as the class has existed. I ran my 06 NC there for the first 4 years of STR, and was able to compete at the very top locally and even regionally (back when we had divisionals.) At Nats, the S2K's are dominant, but I still am not sure if its an inherent advantage of the car or simply the best drivers choosing that platform.

The NC is SO MUCH BETTER of a car with some suspension upgrades that I'd personally prefer to run one in STR, even if its underprepped. Just my $0.02

[OZMDD]

Too much bar, not enough spring rate. And it's unbalanced front vs rear vs bars vs springs.

This is absolutely correct. The Progress bar is immense, even for some STR spring rates.

[general default]

Shock gas pressure or mix type of shocks. Example: Koni on the front. Mono tube like a Bilstein in the rear. You are looking for a rear shock with higher gas pressure. I guess you could have the Koni pressure increased in the rear also but I don't know how much higher you can go on a Koni. The added pressure increases the rear ride height and also acts as a stiffer spring.

You can also degas the front Koni but that is considered taboo now days.

Street class compromises.

...Anyone know how I can decrease front ride height or increase rear ride height slightly? A little more rake might help too, if I recall the suggestions from my other recent thread.