Lotus Chat?

Well put.

But the reason that not that many people mess about with springs, shocks etc on Lotuses is that they get it right from the factory.

Its the Chapman heritage. He was often asked why they didnt make the suspension on their cars adjustable and didnt publish dimensions or spring rates and his reply was always "Because people will bugger it up".

There is a great example of this on the Esprit. All the early cars had a deliberate designed-in bind condition on the front suspension bushes, to fine tune the spring rates over the travel distance. This is great until someone comes along and fits crappy "upgraded" poly bushes, which then destroy this tuning and even become dangerous as they cause the suspension itself to twist.

 

Old thread. Can someone educate me on the suspension settings on the Exige? Ackerman? If not, hazard a guess which Lotus forum would have it?

Thanks
Philip

 

Which exige?

 

Sean,
Supercharged, 4 cylinder car.
Philip

 

You can find the factory specs online.
The question also is if you're running on street track or both

In general these cars need 120 mm ride height in front and 125 in the rear. Or 125-130 all around if street only.

If trackuse front toe should be neutral to 1 mm toe out per side. For street can be neutral to slight toe in. Toe out in front will take away straight line tracking and sharpen turn in.

Rear must be toe in between 1-3 mm these come down to personal preferences and use i.e. Road or track. Rear toe gives rear emd stability but the more you have the faster inside tire wear and it scrubs speed.

Best to start with factory settings and make slight adjustments from there.

There is also amber to play with, but once again intended use is a big factor. More negative camber in front reduces oversteer at the expense of straight line tracking, but then you can also play with toe.

 

Sorry this site won't let me edit

More negative camber in front reduces understeer.

What tires are you using and where do you drive

Sean

 

Thats useful, thank you. And do you know Ackerman ?

 

Ackerman?

 

Ackerman angle Sean. Named after the guy that developed the steering linkage for horse drawn buggies. Enables steered (front) wheels to make different turning radii. Can visualize as a line connecting the steering arm at the tie rod end drawn through the wheel axle and extending back across the centerline of the car. Perfect Ackerman is where the point of intersection is around the middle of the rear diff.

I believe positive Ackerman is where the intersection is forward of the diff and creates greater on-center feel. Apparently, this is how the Esprit was set up. I'd like to know how the Exige is set up.

 

Sorry do not know, Ackerman, thats new thing to me and to understand.

I set up the caster to factory specs, For the track car I do as much negative camber as the front end will allow, even l shaved the uprights to go past -1.9 to -2.4. the rear on my car is -2.5 also although we have some debate as to whether to go further. In front I went - 1.5 total toe out which I dont like although others go more. And +1.5 per side toe in rear, which works for me although others do more.

My camber settings were arrived at based on tyre temps across the tire and tire wear. It was track and aback to adjust a few times. I also set everthing with me in the car and 1/2 tank of gas, that is after setting ride height and corner balancing with me in car.

For example at -1.9 front camber the outer 1/3 of the tire was wearing fast and clearly overheating, more negative camber was needed. In the rear the car was loose so we went more toe in, maybe now with the rear working better I can go more negative camber there. Its drive change test.

Someone told me that these cars are handbuilt they are all different, so specs slightly different and of course the track driving style and shocks all come into play too.

For street its all far less agressive on the elise. To me its a tradeoff between turn in, stability, limits vs feel on road. I think my road car front camber is -1.5 and the rear slightly more with front toe neutral and rear +1.5 per side.

 

I love seeing some Lotus information here. Keep it up you all!