court76wi Posted June 3, 2007 Share Posted June 3, 2007 I was hoping someone can help me out here. I have a '89 Honda CRX that I use for autocross that has developed a constant oversteer problem. The strange thing is that the oversteer goes away when transfer weight to the rear of the car. If I trail brake into a turn the rear end wants to swing out, if I accelerate while performing the turn the rear end sticks. Current set up… Koni yellows all around Eibach Pro-Kit (1" drop front 1.2" drop rear) Strut tower bars front/rear Lower tie rods front/rear All bushings replaced with polyurethane ST 7/8" front sway bar ST 7/8" rear sway bar with 3 stiffness settings Approx -2 deg front camber, approx -1 rear camber Front toe out a bit, rear toe in within factory specs 205/50R15 Kumho V710s on 15x7 Last year I had a similar setup except the following differences... No lower tie bars Bushings were old stock rubber Last year I could easily alter the handling from oversteer to understeer by changing the rear sway bar between its middle setting and softest setting. Currently I've tried all the following things I could to reduce oversteer, but its still too great… 1. I've set the front shocks to max, rear shocks to min 2. Rear sway bar is on softest setting 3. I've removed the lower tie rod and strut tower support from the rear 4. Decreased front tire pressure and increased rear pressure (and vice versa) I though about trying one of following steps, I want to avoid changing the front/rear springs if possible 1. Making a bracket assembly to increase the rear sway bar moment arm by 1" (soften it) 2. Get adjustable rear upper arms to increase negative rear camber Does anyone have a suggestion on what I should try next, or if neither what is the answer? The car is a lot faster with the new bushings, but if I can reduce the oversteer I could go a lot faster. The front of the car is solid, a power induced understeer is the only way I can get it to push. Again, the most perplexing thing about this oversteer problem is that it goes away when I transfer weight to the rear. Any suggestions?? Thanks. Link to comment Share on other sites More sharing options...
Kegger Posted June 3, 2007 Share Posted June 3, 2007 Put a couple sandbags in the back. Your ass doesn't have enough meat on it. Link to comment Share on other sites More sharing options...
Kastigir Posted June 3, 2007 Share Posted June 3, 2007 The weight distribution isn't right for autocross. Either shed some pounds up front, or add some in the rear. Link to comment Share on other sites More sharing options...
court76wi Posted June 3, 2007 Author Share Posted June 3, 2007 Put a couple sandbags in the back. Your ass doesn't have enough meat on it. Interesting comment. Seems to be a popular one.:-) Just to ask, what's your experience with poly bushings. I know a lot of people running them (especially the big rear trailing arm) and are doing fine. There's this big rash of comments around the forums how the rear trailing arm should be rubber - quite a few plugs for Mugen. Is this just a forum virus going around? Link to comment Share on other sites More sharing options...
Kegger Posted June 3, 2007 Share Posted June 3, 2007 The poly bushings help stiffen everything up. Which is good, but the ass end of a rex is really light and naturally has a tendency to oversteer. Putting some weight in the back will help. If you haven't re-located your battery yet, do it, and throw something else heavy in the back. It will help out alot. Link to comment Share on other sites More sharing options...
Joe W Posted June 3, 2007 Share Posted June 3, 2007 If its a track car only you could weld some steel blocks in the back for some weight and they would be attached and not move around Link to comment Share on other sites More sharing options...
Blizzard Posted June 3, 2007 Share Posted June 3, 2007 Is there any difference in the beginning of your run to the end, depending on how hot the brake system is? I don't know if you can put rear discs on that car, but that may help. Oversteer while trail braking usually comes from the back end of the car not slowing as much as the front. Link to comment Share on other sites More sharing options...
court76wi Posted June 3, 2007 Author Share Posted June 3, 2007 Thanks for the info guys. I'm getting a lot of responces regarding the 3" trailing arm bushing. Most are saying that the poly is a little too stiff for that one and causes the ass to fly around too much. I'm going to try replacing that with rubber first and see where that leads me. Link to comment Share on other sites More sharing options...
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