GCMan

Wilst waiting for my new Konis to arrive, I have been undecided whether it makes any difference to get my autocross alignment before or after I install the new shocks. I assumed that it would matter but was recently told it doesn't change much to do it before. Opinions/suggestions? Thanks in advance.

AU N EGL

after

derty01

2000BSME

I doubt it will change any.

mousecatcher

doesn't matter

wallyman424

not necessarily true.

Many times when people change shocks they need to reset their ride heights and thus alignments. This has to do with changes in shock canister pressure and length of the shock.

I know of several people that had their cars riding an inch or so higher once putting fancy shocks on.

autoxer6

I autoX on Konis. The ride height will increase a little with the Koni's, therefore changing your alignment.

Do shocks first, then ride height, then corner weight&alignment.

gkmccready

Yup yup. When I put the KONI 3013Sports on (replacing stock, low mile C6 Z51 shocks) it made a real difference in ride height and it was not an even increase front and rear... shock guy warned me about it and said I would need an alignment after putting them on...

mousecatcher

hadn't considered shock pressure ... you're right. i don't see how shock length comes into the picture though.

GCMan

I'm sure it would make a slight difference but since I'm very camber challenged on stock settings and my konis won't make it before the next event, I'll report back on how it changes. I am getting awhole bunch of OPR build up on the insides of my A6's and am guessing it might be due to lack of camber. Just a guess but thanks for the input.

gkmccready

Same as shock pressure if you already agree canister pressure is added "spring rate." :-)

mousecatcher

i still don't get it

gkmccready

Now you've got me thinking... in the case of leaf springs the shorter shock may not matter because you're going to have to compress (ie. preload) the spring to install the shorter shock. So you still overcome the equivalent shock+spring "rate" and should settle at the same static ride height. This assumes you have to add preload to the spring due to the shorter shock...

In the case of a coilover, a shorter overall shock length would change ride height... ie. changing out the end-eye on the shock for one an inch shorter you'd start an inch shorter but have to compress the same amount to find static ride height but end up shorter overall.

Nope, you're right, I think. In the case of a leaf spring, OA shock length shouldn't matter, assuming some amount of spring preload...

mousecatcher

You are assuming that different length shocks would come with the same length springs, and also a design where preload and ride height are not independent adjustments. But more fundamentally, that preload affects ride height, which shouldn't be the case for normal (minimal required) preload.

In any case, as you noted we are talking about the OEM leaf spring. A different shock length from OEM will just place the shock at a different part of its travel. Unless there's some effect of gas pressure vs shock extension I don't see how this would affect the ride height.

gkmccready

Pretty sure we're in voilent agreement.

Zenak

put in the new shocks. drive them on the street (bumpy street) for a few days. then get the alignment done.

GCMan

Too late! Already done the alignment. Shocks won't be here for awhile. The tech let me "help" him. I was running on -1.4ish both frt and rear all messed up -.73RR and -1.42LR. Now I got -2.6 both front and -1.1 both rear. I will stay with 1/2 " total toe in rear and 1/16 toe out front and see what happens this weekend. Interesting discussion but I had so much "other peoples rubber" built up on the inside fronts it was crazy. I had to scrape all that off to get to real rubber before they would align it. Its put up or shut up weekend and I'm tired of getting second. I do appreciate the input though and will install the konis and report back what the changes were. It was interesting to sit in the drivers seat after everything was tightened and see how my weight changed things. My frt camber INCREASED on the RIGHT side by roughly .06 *. Left side stayed very close to -2.6*.

mousecatcher

increased meaning more negative?

GCMan

Yes, more negative on the right side. I did it several times to make sure I wasn't getting weird readings. I thought it would be a bigger difference by adding my weight but didn't expect it change the passenger side and not the drivers side.