Another Spring Question: Asymmetric lenghts?

I asked this question on a general sports car board and didn't get a lot of help. Wondering if some you may know the answer:

Let's say I try adjusting weight balance by by using springs with different free lengths. For example, in the case of my Golf, I want to run 500 lb springs on the front, 400 rear. If the free length of the driver's side springs is 10" (I'm using hypothetical numbers here), and the pass. side had, say, 7" springs, would this have effect of jacking the weight to the right side? What I'm trying to do is achieve weight balance, or as close as I can get, without spending the money for coilovers.

Springs are available from Speedway Motors in lenghts from 5 to 14" and in just about any rate at a cost of about $40 each.

Am I all whacked out in my thinking? Would that work?

As I read what you are proposing, no, this will not work. The total weight on the left side will always remain the same, regardless of the spring length (within reason of course). Weight can only shifted diagonally. While open for discussion, typically you want the LF+RR=RF+LR If you put a longer spring in the RF, the RF and LR will carry more weight. Think of a four-legged table in which you vary the length of the legs. The major problem with what you are proposing, is the difference in spring lengths. You don't need differences of inches, but rather fractions of an inch. If you are really trying to lo-buck it, you can make washers out of 1/8" plate to slip under the springs to adjust the corner weights.

I'm guessing on some of the details of your situation but, if you can use "real" racecar springs (like SM sells), then you already have "coilovers" - right? It sounds like you don't have the adjustability (threaded body bits).

To be correct, stock struts are "coilovers" in that they have the coil spring wrapped around the shock. I am using the term to define strut housings that will accommodate small-diameter springs, rather than the big, stock type.

If my guesses are on, I think that you can change your corner weights with different spring lengths. I do NOT think you can [i]control/[i] them, if you get my distinction - ie. get them where you want them.

It kind of depends (I think) on how a 10" 500# spring differs from a 7" 500# spring. If they have the same wire diameter and number of coils (free length being the only difference), then yes - you will effectively be doing the same thing installing different springs as you would putting in the 7# spring and a 3" change of perch height.

However, it is far from certain that the springs will differ only in free length. Besides, a 3" change in perch location would be a hugely radical adjustment.

John's points are well made and got me thinking that you could test with washers that were cut into "C" shapes - so you could slip them in and out - and then build up permanent spacers to the height determined by your corner weighting exercise. Spacers can go either above or below the springs but this approach has the disadvantage of only being able to adjust one way from the original location.

Frankly, I would look into sleeve kits! In the big picture, they are not out of site.

Kirk

You'd spend more money on various springs that aren't needed than buying the adjustable coil-over kit.

And like what John said, you normally adjust the threaded collar in 1 to 2 turn "threads". Which could be 1/8" or 1/16".

BSI has either 5" or 7" coil over kits for $99.95. http://www.bsiracing.com/bsi_products.asp

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Tim Linerud
San Francisco Region SCCA
#95 ITB GTI, GP for 2002
http://linerud.myvnc.com/racing/index.html

If you can afford breakfast, you can afford adjustable coilovers.

Do a web search for Coleman Machine. They make roundy-round stuff. Buy one of their 7" threaded adjusters, and two threaded perches. Cut the threaded sleeve in half. Weld a fixed perch onto your strut tubes. Install each half-sleeve on the front (or the rear...it really doesn't matter). Voila. You have a fully adjustable suspension that you can balance out the corner weights on. Total cost about $30.

Is it cool anodized stuff ? No. Will you impress the wings/bodykit/NOS crowd ? No. Will it work just fine ? Yes.

If you want to feel like a real National racer (I'm taking a shot at another thread here), just take two $1000 bills outside and burn them. You'll get the idea soon enough.

Excellent information, thank you very much. I think I will go with the sleeves sold by BSI, as I would likely be re-inventing the wheel by going with my idea.

I intend to prep my Jetta coupe to IT specs and campaign it in Autocross next year, then maybe move on to IT.

Thanks for the tip, John. I believe I will do just that!

I like the National thread dig. http://Forums.ImprovedTouring.com/it/smile.gif