I'm using a Fireblade in my car [Locost ish, which will be used as a road car only]. What are your opinions as to the axle/diff best to use with this engine?

Depends whether you want LSD or not. If you're not particularly bothered, go for a 3.38:1 open diff. Otherwise a 3.62:1 Limited slip diff from an XR4x4.

Oops, just seen you're building a Locost'ish. The above applies only for Sierra running gear.

[Edited on 23-7-05 by Hellfire]

i used cortina 3:89 & 15" wheels on my 893cc blade engined locost, top speed was around 130 with 70mph motorway cruising just under 7k revs

Depends on what axle and rear set-up you are going to use.

Live, de-dion or fully independant.

That's the decision you need to make first.

Pat...