To your homebuilt locost chassis ?

Mine without doubt (I think) would be ditching the book front end geometry to eliminate bump steer and produce good self centering.

Cost, zero apart from my time.

Home brew IRS, as you have already booked out a decent front end.

Also made the internal frame suit the BEC, ie large pedal area as not symetrical in my car.

[Edited on 29/4/12 by mark chandler]

Remote and quickshift for my type 9 , total cost £0.92

I bent my pedals into a more desirable location and took time to set the clutch bit point.

Made the car feel and drive 10 times better.

Apart from the time it took DIY corner weighting
but this made a hell of a difference

Rescued attachment air filter mod.JPG

lightness, lots and lots of lightness, add as much of it as you can