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setting up for road racing?

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Old 04-14-2003, 03:12 PM
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Default setting up for road racing?

Hey I need some help setting up my car for the road!! So far I've lowered it and put performer IAS shocks all around on it...But I don't know what type of stuff to get for the rear end ...or who has good after market sway bars.... <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Old 04-15-2003, 05:47 PM
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Default Re: setting up for road racing?

Depends on what you actually plan to do with it. Are you going to run track days, or just want to set it up like it could run track days? I suggest heim joint rear control arms (LCA's) and matching panhard rod (LG Motorsports, BMR Fabrications, etc). SLP subframe connectors (or other "heavy duty" connectors). 2 or 3 point strut tower brace. That will get you started....then on to an alignment and some brakes. Just my thoughts....
Old 04-15-2003, 06:26 PM
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Default Re: setting up for road racing?

well so far I had just planned on trying to do some auto cross. but would like to be able to take it to a regular road track as well.
Old 04-15-2003, 06:59 PM
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Default Re: setting up for road racing?

If you plan to be "competitive" then find out the rules for your local region. Once you start throwing on aftermarket parts, it will bump you up into other classes, you could even find yourself with tube chassis racers with 650HP + depending on how the rules are setup.

I have poly on stock bars, Koni doubles, 600# front springs and 140-160# rears (Camaro), tubular subframes, STB, relocation brackets, etc The spring I have are unfortunately discontinued, some people think they are overly stiff for a street car, I love them. Coil overs would be a nice option, but it adds to the cost.
Old 04-15-2003, 09:47 PM
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Default Re: setting up for road racing?

If you want to be competitive....you absolutely must check the rules and then modify the car. I built what I wanted to build (after all, I have to drive it, right?) and would up in the SCCA Street Mod catagory against some really nasty BMW's. But, I am still having a blast (and one day soon, I'll catch those guys).

I'm running about 659 in lb front springs and 247 in lb rear (measured and calculated with the spring rate formula....that is probably within 10 lbs or so) and am loking at more spring for autocross (I have a national champion in our region that has set up a few F-bodies to get guidance from....why learn the hard way). I'm probably looking at 1000 in lb front and 275 rear, real soon.

I'm running stock sway bars now and am still having problems getting power down in hard corners on race tires, I'm afraid that a larger rear bar will reduce traction even more (the car is hard to throttle steer and wants to push....I'm still tuning the front shocks and taking out rebound adjustment though). I'd do the other things first and then look at bars if needed (I was told that my car was very "flat" on course and didn't have much body roll at all). Just my experience.
Old 04-15-2003, 10:43 PM
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Default Re: setting up for road racing?

Your alignment specs are rockin, toe out! That will help with understeer on these cars. I am running -1.5º camber and wish I went with more (it was -1.6 when I dropped the car before alignment), but I suppose for a street car that is good enough.
Old 04-15-2003, 11:00 PM
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Default Re: setting up for road racing?

The toe out does help turn in and yes, it is a daily driver (tire life is pretty good). I have 20000 miles on the front tires and over 1/2 tread left (and almost 8000 miles on this alignment). I am sure I can get most of the "push" out of mine with front rebound adjustment (except some of the push that the Torsen diff adds). Give it a try....

I ran out of adjustment at 1.3 degrees negative camber...it was at -1.5 until we set the castor, and it slid to -1.3 and that was all there was.....
Old 04-18-2003, 11:25 PM
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Default Re: setting up for road racing?

Sam,

Thanks for the info. This was my first event with the 4th Gen and I found myself "driving around" that differential most of the day. I guess I was trying to tune the car "in spite of its self" and didn't consider fixing the differential properly. I'm guessing a Torsen T2R will be a big improvement over a stock torsen diff (although, maybe I should consider a clutch type). I guess that may be the next thing to do. As always, thanks for the guidance.

Kevin
Old 04-18-2003, 11:37 PM
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Default Re: setting up for road racing?

Sam,

I may have to give you a call and look into a sway bar as well (I'll likely do that before a differential) and see how it does.

Kevin
Old 04-19-2003, 12:56 AM
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Default Re: setting up for road racing?

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by trackbird:
<strong>
I'm running about 659 in lb front springs and 247 in lb rear (measured and calculated with the spring rate formula....that is probably within 10 lbs or so) and am loking at more spring for autocross (I have a national champion in our region that has set up a few F-bodies to get guidance from....why learn the hard way). I'm probably looking at 1000 in lb front and 275 rear, real soon.

I'm running stock sway bars now and am still having problems getting power down in hard corners on race tires, I'm afraid that a larger rear bar will reduce traction even more (the car is hard to throttle steer and wants to push....I'm still tuning the front shocks and taking out rebound adjustment though). I'd do the other things first and then look at bars if needed (I was told that my car was very "flat" on course and didn't have much body roll at all). Just my experience. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You already have what are very stiff springs for a 4th gen. 1000's and 275's are, IMHO, out of this world stiff. I run 500/125-150's on ESP and SM 4th gens. I only ran 800/150 on the 3rd gen I won my Solo2 Nat'l championship in, and the front springs on it are a LOT further inboard, necessitating the need for more spring to get a workable wheel rate. Let's not forget that Koni themselves only valved their shocks to handle 600 lb. front springs (and I've seen DESTROYED DA's that were run with 840's).

I am a bit confused though. If the car is flat, then why would you want to run more spring? A switch to softer front springs and more front bar will keep the body roll in check, but help you get power down better than just stiff front springs. I don't think a huge rear bar is a good idea either, but I usually use a 21 rear bar with a 35 front and the springs I mentioned before. You have to be careful in the rear, we are basically driving pick-ups. Just like truck, a lot of rear spring or bar makes the rear jittery and all over the place. Further, there isn't any reason to have to run a lot of spring or bar (relatively). Being a solid axle, we don't have a camber curve issue. You don't gain or lose any with body roll, and softer setups make more grip than stiffer ones if camber curves are not an issue.

What you need is a real differential, not the weak stock one. That will solve a lot of your power down issues. Softer springs and more front bar will help the mechanical grip. And you then use more shock to keep and/or tune the transitional response you want.

<small>[ April 18, 2003, 12:57 PM: Message edited by: Sam Strano ]</small>
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