bureau_c

OK, here's a question that shows how many times I've changed shocks and springs on my car :-)

Does it matter which way you put the springs on? I just got some PFS Comfort Sports and while its not all that obvious, there is a definite difference in the coils at one end vs. the other. On one side, they're slightly closer together than the other. Which is the top, and which is the bottom? I tried test-fitting it onto the spring perch on my Illuminas, and it seems to fit either way, although it also seemed that one way fit a bit better. The only problem...that apparent better fit was different from the front to the back. On the rear shocks, the spring fit best with the closely-spaced coils pointing up, whereas just the opposite was true in the front.

Somebody please straighten me out here, I'm planning on doing this tomorrow (Sat).

Thanks!
jds

DamonB

It makes no difference. I would do just as you have done and place the springs the way they fit in the perches the best.

bureau_c

Great, thanks for the advice!
jds

VTAOE

Careful here. I'm pretty sure that these springs are progressive rate. Which means that they get stiffer as they are compressed. If you put them in upside down on say one wheel you may get some strange things going on in your car during hard cornering.

There is a lot of discussion about whether these springs are progressive rate or linear, but in the end I'm pretty sure the answer is that they are progressive. If you talk to the guys that live near PFS and started out with these springs you will find that they all say they are progressive rate.

The answer to your question is that you need to install them so that you can read the lettering on the springs. If the lettering is upside down then, well they are upside down.

Just as a side note:
PFS-SUS-009-SF -> Front Springs
PFS-SUS-009-SR -> Rear Springs

Check out the pictures of my old set before I sold them:

http://www.swvarx7.org/fileman/cody/...%20springs.jpg

http://www.swvarx7.org/fileman/cody/...%20springs.jpg

- Cody

DamonB

Doesn't matter. So you think that the spring is softer or harder if you merely turn it upside down? Or if it's a horizontal coil over on an F1 car for example that the spring rate is somehow different by orientation? Think about that.

It doesn't matter the orientation of the spring, regardless of type. All the spring knows is that it gets squeezed by the suspension. It has no idea which way is "up"; gravity has nothing to due with spring rate. Spring rate will always be the same no matter what orientation the spring is in; spring rate is a physical property of the spring itself, NOT the spring's installation.

Don't believe me? Take a coil spring tester and put a progressive spring in it and test. Turn it upside down and test again. Lay the whole thing on its side and test. Jiggle it around and test. Put it on a turntable and spin it at 1000 rpm and test. It doesn't matter. The spring rate will read the same in every orientation.

If you understand the above you will also understand why that statement is completely ludicrous.

bureau_c

Hmmm, well I got the fronts in today, and the lettering is upside down...they just seemed to fit better that way. For what its worth, the car feels great, and I still have to do the rears. Had some trouble getting one of my wheels off...damned 12" lug wrench that came with the car! Can't get any leverage with that thing at all.

One odd thing...the shaft on the Illuminas that sticks up and has the adjustable **** on it...its quite a bit higher than the stock shocks. I was worried it might hit my hood, but as it turns out it does not.

I guess I will need an alignment when its all done too...

jds