Project "Payback"

[bmwwksmarc]

Todd: I thought you were running NT01's? How bout those or R888, they have a pretty stiff carcass for that weight of car?

Marc

[rogue]

Todd have you ever read the rear sway bar info from David Pozzi? Might give you some insight into correcting your oversteer issues.

REAR SWAY BAR?

There is less need for a rear sway bar on a multi leaf spring Camaro BECAUSE...

1. The rear roll center of the Camaro leaf spring design is inherently much higher than the front suspension, which is below ground level. This transfers cornering forces at the rear at a much higher rate compared to the front. The closer the roll center height is to the center of mass (at that end of the car) the more the cornering forces are transfered directly. (not through the springs or swaybars) to the tire tread.

This is why the old sprint cars with cross spring suspension didn't need swaybars. The roll center is about 1 1/2" below the center of mass, or mass centroid axis on those cars.

The disadvantage of the sprint cars high roll center is, if the cornering weight transfers automatically thru the high roll center. There is nothing the springs or shocks can do to absorb bumps and keep the tires from breaking loose (cornering). The car will act like there is a HUGE sway bar on it but the springs and shocks will not see those loads.

2. When a Camaro leans, it is twisting the stock leaf bushings. This adds a small amount of resistance to roll. If the bushings are solid aluminum, the leaf is going to be loaded in twist much more severely.

You can see this all adds up to higher roll resistance at the rear than you might normally think.

Later 80's Camaros had bigger swaybars on the rear but they have coil spring rear suspensions.

I am NOT saying you absolutely don't need a rear sway bar. If you stiffen the front much at all, you will cause the car to understeer and have to add a rear bar.

If the Guldstrand mod is done it raises the front roll center and adds traction to the front suspension at the same time. This combination may require addition of a rear bar.

The higher front roll center transfers weight when cornering similar to what the suspension does, but is independent of the suspension. If the roll center were raised to the same height of the front center of gravity (about 15") there would be no need for any front roll bar to prevent the car from leaning.

If the front roll center were raised HIGHER than the front center of mass, the car could very well roll the opposite direction in a turn!

Notice that on most rear bar kits, the arms are fairly long and the diamiter is usually small. The rear bar winds up making a small difference, if that difference balances an understeering car, fine. If not, it's not needed.

Guldstrand does not recommend adding inkage to the rear suspension, a rear swaybar or other stuff like panhard bars, or watts linkage. He feels it will wind up hurting rear traction on corner exit. I agree, except I have not been able to balance oversteer/understeer without using a rear anti-roll bar. I've seen cars with their suspension binding because of incompatable suspension "Add Ons" - usuualy traction bars. Make shure you aren't fixing a problem you didn't have in the first place. The best solution is a properly made leaf spring.

Wider and stickier tires on the rear of the car will increase the need for a rear sway bar.

More weight on the rear, or less weight on the front will increase the need for a rear sway bar.
This is just my opinion on the subject, of course you should do whatever works for you, but with the understanding of how the front and rear suspensions relate to each other. What you are after is a suspension that is compatable front and rear, balanced, and not binding or bottming heavily. If there is any binding the suspension is not tuneable.

Tire pressures adjustments can fix a lot as well. I'm running nitrogen in my tires now and it improved temperature variation at track days greatly. FWIW Guldstrand told me a rear swaybar is a bad idea with a big block car. He said understeer is my friend, and to dial in oversteer with tire pressures etc. Glad to see you out there enjoying it. Especially with the new motor. Love it and it definitely increased the desirability of your car should you ever sell.

I think I'm due for some engine bolt ons this year. Shooting for 800hp on pump NA. At least 650-700whp would be nice on tap.

[Vegas69]

Not sure I understand you question G356? Assuming you mean like it?

It's got magnaflow with dumps at the rear axle. Big blocks just sound great.

Marc, I am running the R888's and honestly have no idea about the sidewall stiffness. I've found them to be predictable.

Dane, no more saying I don't like to track my car. I beat the living **** out of this thing. This car definitely needs a rear sway bar. Keep in mind it's all aftermarket suspension with the DSE sub and Alston rear. I'm close on teh setup. The road course set up was really close. A little tight if anything. I changed it for the autocross and forgot to let some air out of the tires. It was just crazy loose. I'm going to try some shock adjustments next autocross with the rear bar in teh road course hole. Then tweak it with air pressure. 800hp NA is tough unless you run a massive cam, single plane, race gas, etc. The most average torque wins. This engine does that beautifully. Not only does it zing to 6800 easily, it makes power at 2500.

[g356gear]

Originally Posted by Vegas69

Not sure I understand you question G356? Assuming you mean like it?

Yes....how do you fine the clutch working for you...feel, engagement,chatter, etc.

[tones2SS]

Originally Posted by Vegas69

It's got magnaflow with dumps at the rear axle. Big blocks just sound great.

MY MAN!!!