Coilover Help - Can't work out lengths and rates

[Pete K]

I'm having some trouble working out how to put some stiffer springs in to my rear coilovers without having them loose at full droop.

They are currently 225 lb/in, 10" long, with a 3" helper spring. I want to go to 400 lb/in. Corner load is around 550 lb static. So if I go with 10" again, I'll have to drop the seats by about 1.1" to maintain the same ride height.

At full droop, my helper springs are about 1/8" compressed (maybe less) so dropping the seats is going to make the whole assembly loose.

Am I missing something? How do I get this to work? Do I need to shorten the stroke of the damper somehow? Is it possible to get longer helper springs?

Cheers

[Peter Florance]

I'm having some trouble working out how to put some stiffer springs in to my rear coilovers without having them loose at full droop.

They are currently 225 lb/in, 10" long, with a 3" helper spring. I want to go to 400 lb/in. Corner load is around 550 lb static. So if I go with 10" again, I'll have to drop the seats by about 1.1" to maintain the same ride height.

At full droop, my helper springs are about 1/8" compressed (maybe less) so dropping the seats is going to make the whole assembly loose.

Am I missing something? How do I get this to work? Do I need to shorten the stroke of the damper somehow? Is it possible to get longer helper springs?

Cheers

Wow, I just saw this. I don't think you need 10" springs. I'm using 300 8" and they are barely loose at full droop.

Sorry I missed your question.

[Pete K]

Are you using the Bilstein "circlip" mounts for your rear springs? My helper springs are only 3" long (extended) and they are least 2" extended at full droop. If I go down to 8", they will definitely be loose, I'd have to wind the seats up.

Doesn't really matter now though. The car had her last run on Satruday before stored in the shed for the next few years. We're off to Utah in January and the e12 can come with us. The good news is, I broke the lap record in my class, so it was a pretty sweet way for the e12 to leave.

I'll be on the lookout for a new car and I don't think the wife will let me turn this one into a track car!

Cheers