Cerberus Posted August 9, 2012 Report Share Posted August 9, 2012 Ello! I'm running a 1.8L 1994 MX5 MK1. It's lowered, the gap from arch lip, top centre to wheel centre is 320mm. It's running Rota Slipstreams 15" x 8J ET20 Shod in Khumo KH31 195/50/R15 V tyres. Since going onto these wheels and tyres (from the standard 14" wheels) I've picked up some pretty awful tramlining. I also think the car understeers a bit too much. I had the car aligned (on a Hunter rig) When it was running on the 14" and I've had it realigned now that I am on the 15"s. I asked the tech to address the understeering and if possible the tramlining. This is my most recent berfore/after printout : A trusted friend has looked at this printout and doesn't feel it's correct in terms of correcting understeer or removing tramlining. I've also posted it on an MX5 forum and one of the guys who is involved with mx5 race prep has said : "I do not profess to be an expert but I would say that you are almost guaranteed to get understeer with those settings and tram-lining. You are on strong offset and wide wheels so more toe in would be required and to kill the understeer you either want more camber on the front, up to 1.8 deg total (what ever that is in minutes)or reduce the back to 1.2. I would go for increased front with as much caster as they can get." I really have very little idea what does what in the geometry of suspension. I'm an electronics man myself. I'd be interested in the thoughts of others please! Quote Link to comment Share on other sites More sharing options...
Tony Posted August 9, 2012 Report Share Posted August 9, 2012 Hello The current settings will push so no good for you. For a progressive oversteer i would suggest... Rear Camber -1 degree 30' Toe +10' total Front Camber -1 degree 30' Castor +5 degrees 30' Toe +6' total During turn-in and inertia transfer the front camber will gain much more than the rear. In addition the lower castor position will speed up the camber migration aiding the polar moment during transition. Quote Link to comment Share on other sites More sharing options...
Cerberus Posted August 9, 2012 Author Report Share Posted August 9, 2012 During turn-in and inertia transfer the front camber will gain much more than the rear. In addition the lower castor position will speed up the camber migration aiding the polar moment during transition. Show off! Whats that all mean then? Quote Link to comment Share on other sites More sharing options...
Tony Posted August 9, 2012 Report Share Posted August 9, 2012 Some might think it odd to have the same camber on the front. What i explained was the front cambers / \ will during a ( left turn ) migrate to | \ or even \ \ depending on how much lock is applied, in addition inertia transition toward the front will reduce load on the rear tyres allowing them to saturate grip, the hard part is making the saturation progressive rather than snap. Quote Link to comment Share on other sites More sharing options...
Cerberus Posted August 9, 2012 Author Report Share Posted August 9, 2012 Ahhh that actually makes sense! Thank you! Looks like I'm off to have this done again then. Quote Link to comment Share on other sites More sharing options...
Tony Posted August 9, 2012 Report Share Posted August 9, 2012 When the front camber is added it will lose some castor despite having an independent adjuster. Don't worry about that unless the castor goes under 4 degrees 30'. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.