Suspension Tuning

The Oily Bits S1 Specific Topics
1

Does anyone know how to play with the adjustable bits underneath?!!On airfield days I’ve noticed extremely heavy wear on the outside edge of the nearside front together with moderately heavy wear on the nearside rear. The circuits have all been clockwise and included some high speed long corners. Its also been noticable from pics taken that the car does lean a considerable amount - wear on the mudflaps also confirms this!So is it possible to adjust anything - the front rollbar for instance - to lower the loading on the nearside tyres?

2

Steve,Try this months (June) CCC. “At the clinic” has an Exige featured. Dave Walker suggests the following(for optimised competition use):- 1.Set front roll bar to full soft2.A touch of toe-out at the front.3.If that works, rear to parallel.4.If that works, a touch of neg. camber at the front.HTHp.s. - this chap has Toyos, and Dave Walker rates them.

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Steve, a small increase in front negative camber will hold the tyre squarer on the road under hard cornering, and will therefore help to reduce shoulder wear. The car actually rolls over the tyre slightly with the standard set-up, thus giving the shoulders a hard time. Softening up the front anti-roll bar will also help slightly. These changes will make the car understeer less; the downside is slightly less straight-line stability. I’ve been meaning to make these changes to my car for ages, but haven’t got round to it yet. If you do yours first, please let me know how you find it.

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Now it’s just a case of finding someone competent/trustworth enough to do the job for me…

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Russ - Thanks for the info will have to buy CCC and read it myself.Tony - which way to move the antiroll bar - from memory its 2 holes off the front setting.David - have you noticed the same problems at Donnington?

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Steve, move the attachment towards the end of the bar to soften it. This increases the leverage on the bar, thereby reducing its effect.

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quote:Originally posted by stevegreen:David - have you noticed the same problems at Donnington?I don’t think so. After a few laps the rubber starts peeling off across the whole tyre, but I’ve not noticed any major shoulder wear.I’ve not noticed any understeer after the tyres are warm anyway.A touch of negative camber at the front sounds good though.With the car so close to the ground any leaning will make it look like it’s bottoming out.

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quote:I’ve not noticed any understeer after the tyres are warm anyway.Try harder! [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]

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Steve as you know from Elvington I have the same tyre wear on the shoulder.Have you tried what Tony suggested yet? If so what was your conclusionI attempted hardening the front springs resulting in extreme understeer FUN But no use to anybodyCheersBran

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Nice post TonyThe advice was spot on! I moved it right to the end just to try it as I have never messed with this sort of thing b4, I just wanted to feel the difference.All just as your post said, sits in the corner better but really crap straight-line stability. It was very windy to be fair!CheersBran

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quote:Nice post Tony The advice was spot on!Glad to be of service! [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image] You have to bear in mind the vast expertise down at Lotus. Basically they�ve set the car up to be what they consider the best all-round compromise for the expected usage, and to be honest I think they’ve done a good job, even though like you I really hate understeer. Sure you can make changes and see improvements, but there will always be a payback. If it weren�t for the fact that it would stop me driving to circuits, I would have fitted my motorsport front splitter a long time ago, as this seems to be the best way to reduce the understeer, especially the high-speed understeer, without affecting the general feel of the car. However, I�m curious: did you change the camber as well as soften the roll bar? If you only softened the roll bar, I suspect you were getting more wind buffeting than you thought you were, as just softening the roll bar shouldn�t make much difference to the straight-line stability when travelling in a straight line on flat tarmac.

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Tony I am very new to this gameOne thing at once for me, it lets me learn at my own pace what does what.I was amazed at the difference just from these simple changes to the anti-roll bar.However you have now given me the confidence to take a look at step 2: CAMBERIt’s the garage for me tonight, got the bug!

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quote:One thing at once for me, it lets me learn at my own pace what does what.Definitely the best way Brannan! [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image] As for the camber, I would recommend making adjustments in the smallest possible increments (around 0.25 degrees from memory) as camber can have a marked effect. Take it easy when you first try the car afterwards (no offence intended), and let me know what you think. [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]

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Tony!Sorry to be a pain [image]http://www.exiges.com/ubb/NonCGI/images/icons/confused.gif[/image]THINK I have worked out how to change the camberplease see pickeesIs this the camber adjustment ?Pickee of the shimsOld BootsNew Boots1: I seem to have 2 thickness of shim does the thickness of them relate to any specific degree of adjustment as they are not marked in any way?2: I have around 3mm of tread on the inner wall of the tyre and about -1mm on the outer wall, How much would you guesstimate adjusting in you infinite wisdom? 3: I know the wear is probably down to the right hand circuit at Elvington as Steve said b4 but should I adjust both sides at once as the other side seems to wear even.Bran

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Hi Brannan. Sorry about the delay in getting back to you, but I didn�t want to post a hasty reply as there are safety implications to what you�re proposing.>> Is this the camber adjustment ?Yes.>> does the thickness of them relate to any specific degree of adjustmentYes. The different shim sizes provide different levels of adjustment, and from memory you’re right, they’re not marked up.>> How much would you guesstimate adjusting in you infinite wisdom?Start by removing the thinnest shim and try the car; as I mentioned, small changes to the camber can make a significant difference to the feel of the car. If you decide that you want to go further, don’t just remove a second shim, replace the thinnest but one shim with the thinnest shim that you�ve already removed, so as to obtain a further small increase. >> but should I adjust both sides at onceAbsolutely! DO NOT make uneven changes to the LHS and RHS camber; the car would be a liability!Hope this helps. [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]Finally, and please don’t take this the wrong way, I’m not recommending that you do this, and the advice is only offered on the strict understanding that you accept 100% responsibility for the consequences of making any changes if you decide to make them. Sorry, but I�ve got to cover my bum… [image]http://www.exiges.com/ubb/NonCGI/images/icons/blush.gif[/image]

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Thanks mate i will give it a whirlYou will no dobt see me MondayIn your mirror!!! [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image] [This message has been edited by Brannan (edited 19 September 2001).]