Do Rear Suspension Springs Orientation Matter?
 

Do the rear suspension springs orientation matter?

I've read on an old Chrysler engineering book on Google before that the left side and the right side of the coil springs should coil at opposite direction to reduce wheel hop. But as to which direction the pigtail ends of the springs should be facing, would that matter?

The reason I'm asking is that I recently got new suspension installed (STI pink springs with matching STI Bilstein shocks), and on the rear I think the installer got it wrong;

Before I had a different set of STI pink springs with different rates and stock shocks, the pigtail ends point to either side of the car (just like how it came from the factory actually, and I've checked a lot of Japanese BRZ literature to confirm the orientation). After this new install, the pigtail ends are now pointing to the front and back of the car. Does that mean the springs orientation are wrong because they are not aligned properly with the top hats? (they are like 90 degrees off on the rotating axis, both sides do coil in opposite direction right now) I can imagine this can potentially affect handling?

According to directions with the TRD springs is does matter.
I can tell you that my car had uneven camber in the rear from the factory. From the factory my rear springs were not installed according the TRD directions. When I installed the TRD springs and put them in the way the directions said I now have even camber in the rear.

Watch this video and note the position of the spring perches:

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Notice how the spring perch on the left side of the car isn't even lined up properly, and that the left spring is basically coils in the same direction as the right side. So it doesn't matter afterall???

I've never heard of it mattering.. the springs with the top hats should be the same height, they have the same stiffness and are the same diameter.. left to right shouldn't matter at all, unless you ordered springs to be different for certain racing applications.

The top hat will specify this. If you look at the part of the hat that receives the spring it has basically a negative mold of the spring's coil in it. The cut end of the spring sits against a small rubber wall in the top hat.

I didn't notice a difference in the top hats when I installed my Eibach springs and they both fit correctly. I guess I had a 50/50 shot of grabbing the correct spring but both my springs matched the tophat indent correctly so I'm going to say that the springs wind in the same direction. If you google a picture of an Eibach Pro Kit you will see that both fronts and both rears coil the same way.

Ok, I reread your post and understand better now. You're not suggesting the coil turn direction is different but where the end stops matters.

I didn't remove my top hats when I installed my springs, so the hats are in their original factory configuration. I'll look when I drive home what their orientation is and get back to you.

Okay so I dropped by my local shop today (not the same shop as where I got it installed) and asked this... They said that it would matter if the shock assembly has a lot of negative camber since the height would need to be the same on both sides.. They think for the BRZ rear suspension design it probably will not matter but again they are unsure..

I googled more on this and it seems that H&R thinks the coils should wind in opposite direction of each other relative to both sides... But cars like the Mustang both sides are exactly the same and not a mirror image of each other... And most seem to think that the pigtail should be pointing laterally.

I'm going to get the shop to remove the shock assembly and see if we can rotate the perch caps on the Bilstein shocks.

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The perch caps cannot be rotated. I think I just answered my own question with this picture:

http://www.sti.jp/parts/catalogue/br...20310ASXXX.jpg

So my rear shock perches have the exact orientation as in this picture, which results with the spring lower pigtails both pointing to the rear of the car (like a foxbody Mustang), this is different from the production BRZ tS from the video I posted earlier.

So I must be smoking crack then. :bonk:
The perches can be rotated. They are a separate piece.
If you want to change the direction you need to unbolt the complete shock assembly and rotate it then bolt it back in.
Page 14 of this is what I was talking about. http://www.trdsparks.com/install/PTR07-18130inst.pdf

Thanks for that PDF file.

On page 14 it reads:

NOTE: Make sure that the left lower coil
spring end faces toward the front of the
vehicle and the right lower spring end faces
toward the rear.

So that was exactly how I had it installed initially. The weird thing is the left and right side of the car in the rear seemed to be ever so slightly uneven in terms of height.

I have since got the shop to have both sides of the rear installed the same exact way and now it's even (this is actually recommended by Eibach's literature).

@krayzie Waking up a subject from the dead.

So, just to get it clear. Your initial orientation was different from the video and then you switched to this orientation?

LEFT
http://i64.tinypic.com/2ilj3hd.jpg

RIGHT
http://i68.tinypic.com/n19ly1.jpg


I am asking because I have also the impression with the Sachs suspension that the rear car height is a bit uneven. I measured also the height and one side was indeed a bit lower. A couple of millimeters? I don't want to have the same issue with the Bilstein.