I have just purchased a 1990 JC Cosmo. I was wanting some advice on suspension upgrades. Not too many JC Cosmos around but surely there's someone out there on the forum that has already done it.



It's currently sitting on lowered springs (120mm clearance) and is low as, alright for the road but scrapes the front on the driveway. The plan was to get the D2 Racing 36-way Adjustable Coilovers. Just not sure on the spring rates, D2 offer from 4-22kg/mm. Does anyone know if they are any good and what spring rates other people are using. I am keen on doing some track days and occasional drags. Does anyone have any suggestions on other coilovers or suspension configurations. Thanks.

 

boy thats a tough one! no experience.



what you want is to plant the tire in its happy spot, this varies with the tire, some tires want more camber than others for instance. i think im telling you to start tuning it, with the suspension you have.



looking at the pics, its sorta like an fd suspension. fd's like 8kg front, 6kg rear springs, or 10/8, cosmo is heavier, although how stiff you go depends on how much track time you see vs street. there are some equations to find spring rates, try google for that



ride height is up to you, at some point the suspension geometry is optimal, and lower or higher isnt as good. it might be worth it to pull the strut out, and just watch the suspension (camber change) as you go thru the travel.