Board logo

Spring length
hughpinder - 31/3/10 at 02:22 PM

I have 13" *2.25 shock absorbers.
The AVO site says to use 8 or 9 inch springs.
Does anyone know of any good reasons why you would use the 8 inch over the 9 inch, or vice versa????

Thanks
Hugh

brianthemagical - 31/3/10 at 03:45 PM

The longest you can get in the damper is usually best as it alows more ride height adjustment. There's no dynamic reason, assuming the spring rates are the same.

Edited to add that above statements assumes pring will fit without being compressed.

[Edited on 31/3/10 by brianthemagical]

Frosty - 31/3/10 at 10:30 PM

It's purely down to intended ride height. The 8 inch spring will allow you to run the car lower should you find that the 9 inch spring still makes the car sit too high, even at the lowest height position.

brianthemagical - 31/3/10 at 10:51 PM

quote:
Originally posted by Frosty
It's purely down to intended ride height. The 8 inch spring will allow you to run the car lower should you find that the 9 inch spring still makes the car sit too high, even at the lowest height position.


That's assuming the spring seats will not hold the spring at full droop, which is bad or the longer spring is longer then tha maximum distance between spring seats.

Frosty - 31/3/10 at 11:44 PM

quote:
Originally posted by brianthemagical
quote:
Originally posted by Frosty
It's purely down to intended ride height. The 8 inch spring will allow you to run the car lower should you find that the 9 inch spring still makes the car sit too high, even at the lowest height position.


That's assuming the spring seats will not hold the spring at full droop, which is bad or the longer spring is longer then tha maximum distance between spring seats.

I'm not quite sure what you mean?

It's purely down to ride height requirements. If they are linear springs (which nearly all kit car springs are), the 9 inch spring and the 8 inch spring will both give identical performance, and the same ride heights will be achieveable on both to some degree. You would only see a difference in what's possible from the ride height.

As an example, the 9 inch spring might allow ride height between 150mm and 120mm on a given car, and the 8 inch might allow 130-100mm.

If the spring is slightly too large for the damper, it doesn't matter as the damper will compress it between the collars to your specified ride height.

If the spring is slightly too short at full droop and it can move between the collars, then a helper spring should be used to keep it in place.

hughpinder - 1/4/10 at 09:35 AM

Thanks for the info. I think I'll wait until is assembled, block to the right ride height and get the spring that will fit best at that then

Thanks again
Hugh