The new sway bars took a couple runs to get used too :)

[nikon]

My grandfather has all those books, have thumbed through some of them, never really read about over/understeer, now I wish I wouldda. My Grandpas got a couple years of racing under his belt, owns 3 cars now and has em all set up his way. Ill give him a call tonight. Compare what you said with what he says.

[John_D.]

Originally posted by FirebirdGT:
</font><blockquote>quote:</font><hr />Originally posted by John_D.:
Mine's an automatic. I've got 35/21 bars, and Koni SA's.

What size tires are you running with that sway bar combo. </font>[/QUOTE]I bought 18's when I was running in STX with the v6 in '03. 245/40/18 Goodyears. Still have those on the car now. Not too bad for street tires.

Oh yeah, the 35 front is a hollow bar.

I'd like to step up to a wider tire this year, maybe something closer to race rubber too.

[FirebirdGT]

Originally posted by John_D.:
I bought 18's when I was running in STX with the v6 in '03. 245/40/18 Goodyears. Still have those on the car now. Not too bad for street tires.

Oh yeah, the 35 front is a hollow bar.

I'd like to step up to a wider tire this year, maybe something closer to race rubber too.

Thanks.

I had 32/21 with 275/17, but went to 245/16 for winter. Here in AZ I cruise at 80-85 and the car handled poorly, so I got the 35mm from Suspension Techniques. Still not what I want so I will be going to the stock 19mm in the rear.

[zlexiss]

Maybe another piece to add to V6Bob's argument - I agree with him on needing understeer, but I think I like my understeer a little closer to neutral than he does.

Compare the coefficient of friction of a tire that's gripping vs one that's sliding. When you've got the back end spinning and slipping, it only has about half the grip that you do when it's planted. Think about the extra cornering and/or acceleration force you could have in the back if you had the full amount of traction (neutral to understeer) instead of the back end always sliding out on you (neutral to oversteer).

Nice example from the autocross last week. Course had a slalom with a pivot on the end - you came up the slalom, whipped over 180*, then back into the slalom again. See the course map here. Even the V8's who tried using the go pedal to whip the back end around lost time compared to when they just slowed down and cranked the steering wheel all the way over. I tried it both ways and going slow with grip was 1/2-1 second faster.

-Jeff

[John_D.]

Originally posted by FirebirdGT:
I had 32/21 with 275/17, but went to 245/16 for winter. Here in AZ I cruise at 80-85 and the car handled poorly, so I got the 35mm from Suspension Techniques. Still not what I want so I will be going to the stock 19mm in the rear.

The other piece in my equation, is an Eibach pro-kit. But... I put the stock rear springs back on to get some more travel in the rear. So that softens the rear back up some. I had thought about falling back to a 19mm rear bar, but the difference in the rear spring rates seems to have gotten me about where I want to be.

(and I have koni sa's all around, but that's a whole 'nother story)

[Vracer111]

My take on large bars is they work fine for me. Running Hotchkis Sport swaybars (37mm front/25mm rear) on stock springs with Koni Sport SA's all around - everything else stock suspension wise. I'm running in Street Mod only because of the rear seat removal technicality so I'm seriously underclassed in class (stock open differential and drivetrain/gearing, stock inadequate torque arm, stock brakes, and bone stock engine). Tony Jacobs and his Street Modified 94 Ford Cobra Mustang is target vehicle in class with my cars current state. At last event (in the wet) I was less than 0.7 seconds behind his time and closer to the majority of BMW M3's in class. BENJAMIN ONGOCO and his usually first or second place M3 will be my ultimate target once the camaro is actually prepared for SM class...I'll have to be a better driver to get up there though; still working on that.

So for me the Hotchkis bars work great with my setup: Koni Sport SA dampers with stock springs, 275/40-17 Nitto NT-555RII tires all around, and Hawk HP+ pads front with Hawk HPS pads rear. A full to 3/4 fuel load with damper rebound set around halfway stiff perfectly balances the car. No it doesn't come around violently with excessive oversteer on corner exit, no it doesn't lose traction that much more than most other SM cars in class, and yes it will bite you if you push it too far.

The Hotchkis sport bars + Koni Sport SA dampers were the best things that have transformed my camaro into a precise handling machine that is absolutely manageable on course. The Nitto NT-555RII's have made it faster (street tires "ain't got no" traction with an open differential!)

[John_D.]

That oversteer will change when you get an lsd/t2r under there.... [img]smile.gif[/img]

[V6Bob]

"No it doesn't come around violently with excessive oversteer on corner exit, no it doesn't lose traction that much more than most other SM cars in class, and yes it will bite you if you push it too far."

I'm not talking about almost losing control of the car. I'm talking about delaying full throttle application by a few feet. With a 200 HP 3500 lb car you should be at full throttle at or slightly before the apex, even on a tight corner. If you can do that with a 25mm rear on stock springs I'd be surprised.

Sure it drives OK. Even "feels good". And you're a good enough driver to compete well in your tough class. But, on stock springs, I believe you'd post faster times with something smaller than a 25mm rear bar, a bit slower corner entry, and earlier throttle application.

[Vracer111]

Originally posted by V6Bob:
"No it doesn't come around violently with excessive oversteer on corner exit, no it doesn't lose traction that much more than most other SM cars in class, and yes it will bite you if you push it too far."

I'm not talking about almost losing control of the car. I'm talking about delaying full throttle application by a few feet. With a 200 HP 3500 lb car you should be at full throttle at or slightly before the apex, even on a tight corner. If you can do that with a 25mm rear on stock springs I'd be surprised.

Sure it drives OK. Even "feels good". And you're a good enough driver to compete well in your tough class. But, on stock springs, I believe you'd post faster times with something smaller than a 25mm rear bar, a bit slower corner entry, and earlier throttle application.

V6BOB, I actually might just take your advice on dropping down the rear sway a little. Been looking at run videos for a while now and seems like I am not accelerating fast enough in a few areas that I could be. Don't know if its my driving or the car setup has something to do with it. Watching the videos does always seem slower than the actual runs do too. There is an Evolution School coming up the end of this month and I will see if the car is holding me back; Ann Hollis said the Tacoma was holding me back last time and I would be "scary" in a properly prepared car (don't know if that's good or bad...LOL). If the feedback I receive is that the car could be faster with more rear grip (meaning the Hotchkis 25mm hollow rear bar is too big) then I guess I should have listened all along. The thing is I really don't want to change it's current handling characteristics one bit...it transitions quickly and precisely in the slolams and just grips and scoots around sweepers with a nice tire slip angle. I know autocross handling is all about compromising - to set up the car so the sum of all course elements (slolams, sweepers, tight radius corners, etc...) results in quicker times. I just don't want to detune the responsiveness of the car to get it to grip a little better in a select few instances on course (where most other cars are having problems on course). I'll let you know how things go.

[V6Bob]

"The thing is I really don't want to change it's current handling characteristics one bit..."

If you change the rear bar you must change the handling characteristics, of course. But in a good (decreased times) way.

"I just don't want to detune the responsiveness of the car to get it to grip a little better in a select few instances on course (where most other cars are having problems on course)."

Understood. But the car will feel a bit less "lively" since the tail end isn't trying to come around. But I'm not talking a select few instances. I'm talking being able to accelerate sooner off most all autocross corners. The effect is more noticeable exiting the tight ones. Sure, everyone has trouble there. But the guys who have the car setup and the technique to do this critical thing better win. Lots of tight corners in autocross.

You'll need to go just a bit slower (like 1 mph) going into corners. The payoff is harder acceleration coming out, which is more important.

"I'll let you know how things go."

We'll all be interested.

[nikon]

bwah, well my cars balanced finally. Oh and I said Id speak to my grandfather, for inexperienced drivers he says understeer is better, for the experienced driver, he feels oversteer is faster. Either way, I finally got the alignment done, -1* camber is all I could get out of it. 5* on the caster and toe'd out 1* got my tires set good, and flew around the course jumped from my usually 5-6th place to 3rd place 1st and 2nd are still 3 seconds away though, so I gotta little bit of practicing to do.