55.2-59 Spring Rate for an Angle Install

[SARBlade]

Hey all, got my Welderseries 4 link all burned in, now working towards the rear coilovers. I've done some research on the site et al. I have decided to go with QA1 for a ride height of 14.5". Its the spring rate I'm worried about at the moment. From what I've read, most put in a spring of 250 lbs. I can't determine if this is a vertical install or one that has gone in at an angle. Mine intend to be at an angle of about 28º. This gives me an angle correction of about 27 lbs, so I would need a 280 lb rate at 28º to get 250 lbs. Or, has most people installed a 250 lb shock giving them essentially a 215 lb spring rate? I've been using a .87 angle conversion for a coilover spring mounted at 30º. Appreciate any insight, thanks.

[SARBlade]

Further to my above query, I can probably get a spring that has a 250 lb rate based upon the following guestimate.

Assume truck weight 3200 lbs, with a 60/40 weight ratio front to back would give me a 1250 lb rear weight. Minus 4 link and differential weight of 200 lbs, add the rear fuel tank with full fuel about 150 lbs gives me 1200 lbs. divide that in 2, is 600 lbs/side. With 250 spring 12” long compressed to 9” per QA1 application at 30° (.87 angle conversion factor) is 650 lbs/ side needed to compress the springs to the 3/4 compressed ride height. If the coil over was installed vertically, the weight required would be 750 lbs at ride height. So I’m good with that. Anyone with experience, please add your 2 cents. Maybe I’m way off lol. Thanks

[bowt1ed]

When I got my No Limit 4 link w/QA1 coilover kit, they recommended the 12-200's for my 57. That's what I went with. Cheers, Jim

[mongocanfly]

When I bought my coilovers, I went with the recommended weight..due to the unknown weight of the finished truck, they said when I get up and running I could trade the springs for diff weight rating if needed...as long as I didnt paint or powdercoat them

[SARBlade]

Thanks guys, Jim, yours looks to be at about 10º angle so a little less than 200 lbs/side would be the spring rate. Yeah, I guess it boils down to whether or not you put anything into the truck.

[dsraven]

coilovers have the little adjusty nut on the one end, so it is ride height you worry about then that can be overcome some, within limits. if it is ride harshness you worry about you will likely have to do a trial and error experiment. you could also ask about variable rate coils that give a good ride but get tougher to compress as they are made to shorten with loads etc.