Travis.. Was that an ATB or ZF type diff you tested?
I've driven an Esprit (89SE and 91 X180-R) with and without LSD on street and track (back to back) and I can tell you the LSD makes a big difference. So much so that I bought an LSD from GTO for my 89SE.
I am in the process of ordering a complete upgraded UN1 from GTO Racing and was discussing the ZF or ATB diff option. Each type seems to have its advantages and disadvantages. I was concerned that the ATB would go into open mode if one wheel broke ground, upsetting the car. The ZF on the other hand could create added understeer on power-on lock-up. If you can shed more light, that would be helpful.
Lee and Kevin at GTO seem like upstanding sorts to deal with. Any feedback on their product and service?
Edited by f1karting, 28 October 2010 - 11:08 PM.