Front Torsion bar setting

[Wess-RA]

Eric this is your photo from the steering arm thread:


I notice you are using the inner bolt hole on the torsion bar for greater stiffness.

When I was running street tires and experiencing severe understeer, the school mechanic switched my torsion bar bolts to the outer holes-thereby softening the suspension and helping against the under-steer. It really helped alot.
Now that I have installed my 550#/350# springs and am going with track tires I have moved my torsion bolts to the same position as you (stiffer). Does that seem correct? The tires should help the understeer-but the springs make the suspension stiffer-Is the stiffer setting on the torsion bar best in your experience? Should the torsion bar be preloaded-I just tightened it up in its relaxed position.

[panozracing]

Originally Posted by Wess-RA

Eric this is your photo from the steering arm thread:

I notice you are using the inner bolt hole on the torsion bar for greater stiffness.

When I was running street tires and experiencing severe understeer, the school mechanic switched my torsion bar bolts to the outer holes-thereby softening the suspension and helping against the under-steer. It really helped alot.
Now that I have installed my 550#/350# springs and am going with track tires I have moved my torsion bolts to the same position as you (stiffer). Does that seem correct? The tires should help the understeer-but the springs make the suspension stiffer-Is the stiffer setting on the torsion bar best in your experience? Should the torsion bar be preloaded-I just tightened it up in its relaxed position.

Sway bars are always set up nuetral or unsprung. Also, you have this backwards. The inner hole generates more torsion in the bar thus more resistance to sway in the chassis. The outer hole is less. It is opposite to torque. The suspension moves a fixed amount. The further away from the sway bar the less "twist" the bar will exert with the same amount of movement. Make sense?

PS...how did you embed the photo? I could cut and paste this pic like I was in word or something?

[eric1h]

yeah the settings are what I have found to be the best for me and my car. The stiffer springs(did you have or add a rear sway?) will help

[Craig245]

Wess, you can't completely predict where you should have the sway bar set. I replaced the front springs with 500# and the rear with 250# and started with the bar in the soft setting. My reasoning was that the GTS uses 550# in the front and also add a bar to the rear effectively stiffening the rear. Sooo.... the front of my car is a little softer than a GTS (due to springs) and the rear is a little softer than a GTS (due to no rear bar). I would suggest that you start with the soft setting and then if you get understeer you will have to add the rear bar. I go lucky and the car came out very neutral with the tires and alignment that I am using.

Understeer - Soften the front and/or stiffen the rear.
Oversteer - Stiffen the front and/or soften the rear.

[Cobra4B]

Yep... these guy have it right... it'll be interesting playing w/ the car when we get it back. We'll have fresh Konis w/ 550lb springs up front and 350s out back. Also upgraded the trailing arms and got the rear swaybar kit.

[eric1h]

Originally Posted by Cobra4B

Yep... these guy have it right... it'll be interesting playing w/ the car when we get it back. We'll have fresh Konis w/ 550lb springs up front and 350s out back. Also upgraded the trailing arms and got the rear swaybar kit.

now hurry and get the car done and sign up for the Feb 26th event at VIR and come play with us!

[panozracing]

Originally Posted by Cobra4B

Yep... these guy have it right... it'll be interesting playing w/ the car when we get it back. We'll have fresh Konis w/ 550lb springs up front and 350s out back. Also upgraded the trailing arms and got the rear swaybar kit.

NICE

[jmimac351]

Gary Jones is convinced the rear swaybar is the wrong way to go and has mentioned running 600/350 with iron heads and 550 with aluminum heads. Brian, you're running 550/350 in your current setup?

Many forums have galleries that you can post pictures to then link to the picture. I paid 40 bucks for a smugmug.com account because I take a lot of pictures and it allows full resolution hosting. That site is really good. If you want to imbed a pic you need to copy the address for where the picture is hosted online (in .jpg format). You can right click and select "copy image location" or go to properties and copy the address. When you find a way to get the picture online, copy the address then put this bracket in front of the address [img] and this bracket at the end of the address [/img] and paste that all together in your message without any spaces. That makes your post link the the pic and it will appear.

You can use this coupon code at smugmug and you'll save 5 bucks: 2dX5P20QwNi2w

It was well worth it to me.

[Cobra4B]

I haven't run the car w/ any mods... last time at the track was on the "as purchased" suspension. This winter's overhaul is certainly extensive. I'll be running 550/350s new konis, bigger trailing arms, rear bar, and Hoosiers... so it'll be a new car. Oh... and add a 400 horse 5.0 into the mix w/ about 100lbs less to lug around.

[panozracing]

Originally Posted by jmimac351

Gary Jones is convinced the rear swaybar is the wrong way to go and has mentioned running 600/350 with iron heads and 550 with aluminum heads. Brian, you're running 550/350 in your current setup?

yes I run 550/350 sometimes. We end up running diff. springs at diff. tracks if there is competition or handling issues otherwise its mostly 550/350. For instance Mid-Ohio did not like 550/350 so we ended up at 500/350 with no rear bar. At sebring, homestead, barber, and road atlanta 550/350 w/rear bar all worked well. Of course we are changing bar settings and messing with the rebound clicks on the shocks.

[jmimac351]

That's good to know. Thanks for sharing. Several of us around here are going in on some scales to corner weigh our cars. Hopefully that will remove some variables as we play with the setup.

[eric1h]

If anyone is in the Raleigh area next Tuesday Devin, another friend and i will be doing some corner weighting at the Hangar/garage.....


I am also installing my new 750lbs springs. So I'll be trying out 750/550

[Wess-RA]

Originally Posted by panozracing

Sway bars are always set up nuetral or unsprung. Also, you have this backwards. The inner hole generates more torsion in the bar thus more resistance to sway in the chassis. The outer hole is less. It is opposite to torque. The suspension moves a fixed amount. The further away from the sway bar the less "twist" the bar will exert with the same amount of movement. Make sense?

PS...how did you embed the photo? I could cut and paste this pic like I was in word or something?

Sorry for my late response to my own questions-I've been working on the car getting ready for Sunday's track day.

Brian G. Thanks for the clarification on torque vs stiffness.
I cheated on posting this photo-I copied/pasted it from Eric's thread. He presumably posted it on a photo hosting site and I just copied from there. Otherwise, normally I use Photobucket which is a "free hosting" site. Also, I have created a nice sized folder of photos on my computer-thanks to everyone's postings.

Here's my setup for this weekend: 550/350 springs-ride height 3.5" front 4" rear-new Nitto NT01 tires-front torsion bar on stiffer (inside holes) setting-No rear torsion bar (I don't have one). That's alot of changes all at once. I think most suspension tuners will advise against this many changes all at once because of the interplay of variables. But in my case my tires and springs were so crappy that I decided to take your collective experience/advise and create a new starting point. Thanks for everyone's input.

[Wess-RA]

Back from driving on Sunday. The new setup worked phenomenally. The car is rock solid and controllable at much higher speeds through the turns. We monitored tire temps which resulted in a LF camber change which made a really noticeable difference in the few right turns at Thunderhill. (T-hill is predominately left turns) I think one more round of adjustments and the car should be well dialed in for several of the local tracks. The downside is that after running down cars in the turns I was quite often frustrated with them repeatedly pulling me in the straights. More HP will soon be necessary!