mx5cartalk.com

Hi All
I am thinking about having the coils reset, Question, is there a ratio, ie if the coils are 13mm shorter does it drop 13mm.I appreciate it is not an exact science and that I can buy aftermarket springs.
Cheers
Steven

One place that could have done it Industrial Engineers and Spring Makers closed last year. Ring around places that actually produce springs as they need to be essentially reforged.

Actually it is an exact science...
No the compressed length of the spring depends on the weight on the spring ceteris paribus.

However the motion ratio will have an effect:
Front a 13mm spring length change will move the wheel almost 20mm, for the back this will be about 18mm (based on a NA6).

Issues will also come into play with coil bind, by decreasing the length and keeping the wire diameter the same reduces the amount of travel the spring has before it binds.

Personally I would rather use cable ties as it is easier to put back to OEM.

Thank you ,most helpful, Never thought of cable ties
Steven

Is it worth resetting springs though? I did this back in the 90s and after a while, the springs will sag. For the cost of the labour, it's not much more to get a set of lowered springs.

NA spring motion ratios are 0.660 front and 0.735 rear. i.e 1mm deflection at the front wheel gives 0.66mm deflection of the front spring.

NB spring motion ratios are 0.686 front and 0.721 rear.

I wouldn't bother resetting though. It's much more dependable to just buy new springs. Tein USA's site gives you a good starting point: http://www.tein.com/products/standard_spring_price_list.html

Resetting springs is a dinosaur practice. Just buy new springs.

I agree but the OP did say he could have purchased aftermarket springs but really wanted to 'reset' them.

I had it done for my AU IRS Falcon as I wanted to go higher after having LPG fitted. You generally cannot buy higher springs for road cars so this was the path I had to go down for a sensible price.
I did 120000kms on them before selling the car with a total of 260000kms with no issues.
It was initially a bit too high but settled after the first month and stayed at that height.
The place that did it was called All Springs in Moorebank NSW.

If you want to go lower, just buy new aftermarket springs.
The guy that did my Falcon thought I wanted to lower at first and even said to just buy new springs until I pointed out to him I wanted to go higher.

Out of interest, I fitted KINGS rear springs KMRL89.Ebay $174. Dropped the ride height from 365mm to 338mm,got rid of the 4 wheel drive look. Very happy
Cheers
Steven