Steve_N Posted January 6, 2008 Report Share Posted January 6, 2008 I'm after some advice/settings for my Mk1 Roadster. I'm hoping to get the car handling as described below so any experience or suggestions welcome. It's sitting on Mazdaspeed suspension, which is lower than standard. At the moment it tends to bump wide on tighter turns and it just doesn't turn in like it should, too much toe in? I don't know what as I'm no expert but I also noticed what I think are the castor bolts set at opposite ends of the scale. It did have PAS but the pump was not included in the belt when the SC was installed. Obviously the steering is heavy when parking but I feel it is too heavy when driving too, is that caused by alignment? It's a mess! What I want from the car is very keen turn in, a smidge of understeer at the limit on faster turns to be on the safe side but easily switched to neutral/oversteer on demand (lift off/more throttle). Overall I want a fairly neutral balance with oversteer on demand and a small safety margin of understeer for the road. Does that sound possible? The majority of it's life will be on road but I do plan on tracking it when funds allow. I'm thinking camber somewhere between 1-2 degrees and with slightly more on the rear. As for the rest I have no idea! TIA. Steve Quote Link to comment Share on other sites More sharing options...
Tony Posted January 6, 2008 Report Share Posted January 6, 2008 Issue number one is the position of the castor bolts.... If they are set in opposite positions then the front cross member is off-line. To compensate for this one wheel is moved forward and one back. It's probable the end result is that the current castor positions are low. Consequently corner on the relationship with the castor and the camber is low...... Fundamentally the inner wheel is to high and set back during the castor sweep generating a under-steer feel on the apex. It reads like bad news...... But it's possible to force over-steer despite the cross member position "but" this is an aggressive move and not without consequence.... Mainly tyre wear and heavy steering. My concern with the chassis is your command for over-steer, this will reduce the drive wheels the ability of thrust?... A marriage between thrust and over-steer with a depleted front end calibration is a recipe for disaster mainly due to the fact the rear tyre saturation limits need to be reduced to a non-progressive level. Hardly a wise move if the car is also intended as a daily drive. An image of the chassis will speak volumes..... Quote Link to comment Share on other sites More sharing options...
Steve_N Posted January 6, 2008 Author Report Share Posted January 6, 2008 All I can say to that really is I'm open to (a lot of) guidance! What I really don't want is persistent understeer, that's all really. My car is currently still at P5 in Middlesex being tuned in the near future. I was hoping to visit you on the day I picked it up as it's a fairly long way to come from Bristol. Quote Link to comment Share on other sites More sharing options...
Tony Posted January 6, 2008 Report Share Posted January 6, 2008 All I can say to that really is I'm open to (a lot of) guidance! What I really don't want is persistent understeer, that's all really. My car is currently still at P5 in Middlesex being tuned in the near future. I was hoping to visit you on the day I picked it up as it's a fairly long way to come from Bristol. Well i'm sure Phil will be able to look at the cross member position while the car is there, if only to identify a possible reason for the off-set. Don't be to disappointed whatever..... I would say 4 out of 10 MK1's i see have the same condition.... It's a trait of the chassis.... Our issue is to deliver the track requirements you desire. I suppose this is my problem not yours? Quote Link to comment Share on other sites More sharing options...
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