Suspension removal

[Honcho]

I'll go with your measurement top hat to shock bolt to start and then adjust for my 10k and 8k springs. Grab a tape measure!
Maybe Dave can chime in too?

I couldn't say off hand but I think you can get to it with some back of the napkin math. I also can't measure my set for you since i'm running 9k/11k springs so my compression rates will be different.

Let's say your car weights 3,000lbs. Let's also say it's 56% rear/44% front bias. I dont actually know what the true numbers but i'm sure they're here on prime somewhere.

So 56% of 3,000lbs is 1680 to both rear wheels. Let's divide this by 2 to get 840lbs on each wheel.

Now let's say you have 500lb/inch springs. So this says you need 500lbs of weight to compress the spring 1". With 840lbs you will compress the coilovers 840/500 = 1.68" when the car is on the ground..

If all my variables are correct (they're not) your car at rest, on it's own weight in the rear, will compress 1.68". So you measure your unweighted shock and adjust the lower shock bracket to take into account this compression. This assumes 0 droop and doesn't take into account that the further you compress the spring the stiffer it gets.

Hopefully this gets you a rough idea. I think...

 

[RYU]

I'll go with your measurement top hat to shock bolt to start and then adjust for my 10k and 8k springs. Grab a tape measure!
Maybe Dave can chime in too?

your running 10k vs. my 9k and 8k vs. my 11k. We're all over the place! lol

but for you Honcho.. anything. I'll try to get at them tonight. My car is still up on jackstands.

 

[Honcho]

Thanks! My car is still on stands too, so just measure from there.

your running 10k vs. my 9k and 8k vs. my 11k. We're all over the place! lol

but for you Honcho.. anything. I'll try to get at them tonight. My car is still up on jackstands.

 

[Mac Attack]

Follow-up regarding install. The distance from the top of the top mount to the middle of the shock lower bolt hole on my old Comptechs is 22" rear and 21.25" front. What lengths should I set my new coilovers for a "rough" OEM height setting?

I can measure mine tonight for you (my car is all apart). Same 10/8 springs as you, but I still use the 15/16" OEM wheels with OEM-spec tire sizes. My car isn't lowered much because of my darn driveway.

Dave

 

[RYU]

At full droop with 0 preload on the springs measuring from top of perch to middle of bottom bolt.

Front: 19 1/4"
Rear: 18 1/2"

 

[Honcho]

Thanks Ryu!
Given my springs, maybe I should just set them to 19" front and back (2mm preload) and go from there. After all, I just need a rough height setting to get me the ~10 miles to the alignment shop.

At full droop with 0 preload on the springs measuring from top of perch to middle of bottom bolt.

Front: 19 1/4"
Rear: 18 1/2"

 

[sharkwerks]

Did it tonight on mine too. Even on a lift the front was a PIA and it really helped to use a 2x4 and a second pair of hands. The rear is easy peasy but the front.. I had to use a 2x4 and a couple of wood blocks as well to angle it correctly for prying. Loosen the sway bar mounts so it has no load and careful with the lines.

 

[biscuits]

Did it tonight on mine too. Even on a lift the front was a PIA and it really helped to use a 2x4 and a second pair of hands. The rear is easy peasy but the front.. I had to use a 2x4 and a couple of wood blocks as well to angle it correctly for prying. Loosen the sway bar mounts so it has no load and careful with the lines.

Did you use a spring compressor?

 

[sharkwerks]

Did you use a spring compressor?

On one side I did but it would be easier if so...

 

[haveblue]

I didn't get enough leverage with my 2x4 when I removed my stock shocks. Either I needed more distance (but then I wouldn't be able to reach the shocks myslef) or I needed more weight (I'm 170lbs). I put on a backpack with 50lbs of dumbells in it and got the thing low enough to pull out the shock. I also used spring compressors for the front.

Putting coilovers in is a cakewalk since they're a few inches shorter. No 2x4 needed.