Hey guys. Tried searching for this but never came up with a clearcut answer...

I just installed my BC racing coilovers (first set of coilovers, so I'm a noob when it comes to them) and am trying to adjust the height on the rears. They have the OEM setup. I'm trying to raise the rear and want to double-check that i'm doing things correctly. I've basically lengthened the shock and when doing that have been trying to lengthen the spring perch by the same amount (about 1/2"). Is that the way to go higher in the rear?? How do I know I'm not preloading the rear springs too much?

 

I would like to hear an informative response to this as well. I've never had a specific way to do this apart from the same method that the OP listed above. Seems so archaic...

 

I actually did some more searching and came up with a pretty good link over at myg37. Here's the link:

rear BC coilover adjust

Anyway, I think the way that I've been doing it has been correct, the BCs just sit sooo low in the rear from the factory. I've almost got no rear spring perch left to lengthen and the bottom of the fender is still at the top of the rear tire. Not ready to run that low just yet.

 

in for pics...

 

bump for some informative answers to OPs questions...

 

The perfect spot on the strut for compression would be dead center if the car were not lowered. Measure it out by the 'droop' you have when the car is being jacked.

I have about 2" of droop and its perfect...

 

The very minimalist guide included with the coilovers suggests that the distance the wheel should travel once lifted off the ground (on jacks) should be between 40-50 mm (50 mm = ~2 in). So I think FinallyGotaG is correct with his estimate. I'll have to check where mine falls tomorrow.

Otherwise I've just been going 1:1 as far as the distance the strut is lengthened to the distance the perch is lengthened.

 

^By travel do you mean if I manipulated it with my hand? Or stated otherwise, how should I be judging how much droop I have? When I contacted f&f (my coils) the rep, although he didn't seem super knowledgeable, basically said whatever I wanted to set the struts at would be fine.

 

^ when you lift the car with a jack you measure how much your suspension sags prior to tire/ground separation

 

Setting rear bump travel on coilover system's with full height adjustability (your rear springs are in the oem location and NOT on the rear dampers).

1. On a flat level surface, measure from the top of the fender arch to the middle of the hub. (Same way you measure oem ride height as described in the Factor Service Manuel, but your not measuring to the ground, your measuring to the hub center) write the number down.

2. Jack stand rear of car and remove rear tires.

3. Pull up your dust shield/boots on the rear dampers to you can see and measure the distance between the top of the damper body and the bump stop. Measure this distance and write it down.

4. Remember that first measurement your wrote down in step one. Using a floor jack, jack up the suspension until you get the same measurement from the top of the wheelwell arch to the center of the hub.

5. With the floor jack holding the suspension in place as described in step 4. Measure the distance between top of the damper body and the bump stop, write this number down.

6. Adjust the length of the damper so that distance you get between the top of the damper body to the bump stop is half the measurement you got in step 3.

Example, lets say your come up with the following numbers.

step 3 you get 4"
step 5 you get 1"
step 6 you would shorten the damper's length by 1"
Remeasuring you should have 2" as described in step 5.

 

Contact BC. The standard springs that come with the package are 210mm. They have a 230mm option. Mine should be in with the longer springs any day now and will post back after its installed.

Gsedan35, nice post. Question, does one also adjust the spring perch accordingly?

Thanks.

 

Gsedan - Very informative. Tho the same question remains that soundmike asked, above.

 

Set the spring perch to the desired ride height and set the strut length accordingly...

 

Thanks. So equal adjustments on both, correct?

 

it depends on how you set your ride height...

to make it easier and this will be a little more time consuming, set your ride height first with just the springs.

Then you adjust the strut until you have the 2 inches of down travel.

You cant just match the measurements between the two. Use common sense and adjust them separatly since they are separate from eachother.