Excessive oversteer

[CTE]

I have an S1 which is quite well set up but having just done a trackday in it I can confirm that once the back end starts to go, there is not a great deal that can be done about it. Now the conditions in the morning were damp and I am running some pretty basic road tyres, bought more for cheapness and long life. In my mind though I think this helps expose a characteristic at slightly slower speeds.
This car has 700lb in springs at the rear and I think 425lb in at the front. The rear also has assistor springs to help the bump stop. In the dry the car is certainly more forgiving and predictable, although I still managed one spin!! Ha
I used to have a standard road spec S2 and it seemed far less twitchy in this respect.
Is this characteristic typical for an S1?

[danwebster]

The rear seems massively over sprung in comparison to the front there, that would certainly make it pretty tail happy!

[Fastpedeller]

When I was a passenger in one around the Lotus test track many years ago the back end went out - however I ought to add it was being driven by Alastair McQueen the drift king. I didn't feel too good when I got out!

[The Bandit]

danwebster said:

The rear seems massively over sprung in comparison to the front there, that would certainly make it pretty tail happy!

This most definitely. You would normally have ~125lb difference front to rear so yours is way too stiff at the back.
Add in some cheapo tyres and you have hedge finder central.

[CTE]

Ah apologies, just checked and the rears are 600lb in with 250lb in assistors for the bump stops...the guy who set the car up said that fitting slightly softer front springs would induce some understeer...guess the only way to get to the bottom of it is to try various springs and settings?

[Jodele]

CTE said:

Ah apologies, just checked and the rears are 600lb in with 250lb in assistors for the bump stops...the guy who set the car up said that fitting slightly softer front springs would induce some understeer...guess the only way to get to the bottom of it is to try various springs and settings?

That is the exact opposite! Just think about it... The stiffer the spring, the more weight gets transferred, and therefore less lean, and the higher load on that tire. If I was in your shoes, I'd stiffen the front a bit to 475 or even 500...

[CTE]

Yes I agree having read something elsewhere...I think some fine tuning is required with spring rates and toe in...at the moment there is very little rear toe in.

[alanS1]

I would take it somewhere to get the current set up checked.

Anywhere that knows what they are doing will then be able to advise what needs to be done for your style of driving.

Speak to Dan Webster (HPE Automotive)