Legalities of spring "Modification"

[OSM Garage]

Ahh the opposite to what I was thinking. Good.

Autolign charge $50+gst each to shorten inserts/shocks.

Chur

[FuzzayD]

Any one know how to get springs made custom that actually do what you want? i got some made for an old fiat that were much harder and way shorter but they took the car up like it was wearing stilts. Is there an equation or group of tests to measure and take in all the info you need to get the springs made correctly?

[Testament]

what was the old fiat?

its all hookes law stuff, F=kx

if you know the weight on each corner, the spring rates and free lengths of the original springs you can then work out what free length is needed for a spring with a different rate to get a desired amount lower.

so you tell them the spring diameter needed, the free length, spring rate and compressed length with the weight of the car - but the wire diameter, number of coils material etc. you leave that to the spring people.

[Alfasprinter]

It retains the same spring rate but resets them to a lower height. They will be soft and the car will likely hit its bumpstops etc.

How does it keep the same spring rate but become soft? isnt spring rate whether its soft or hard or am i missing something?

That was a little poorly worded. A standard spring is designed for a relatively large amount of travel. For example, at the original ride height the car may be able to travel 200mm before hitting the bumpstops. Once lowered, the car can no longer travel this far before hitting the bumpstops, it may be reduced to something like 150mm of travel with a 50mm drop. If you compress the springs you still have the original springrate, which will likely be too soft with the vehicles new ride height.

Choice makes sense to me now

[NaN]

You dont actually need to cut them.

I would sell them after I tried this.

Measure the springs. The width of the coil, inner and outer, then then overall length, and the compressed length. and the OD of the coil.

Drop into your local mag and turbo, or similar see if they can supply what you need and get a price. thats the top dollar you'd think about spending. lets say it's $250.

So, at most, the job costs X ($250).

Then drop by a suspension specialist, like the one on Wairua Rd (sp?) on the North Shore, by Tristam Ave Exit, out the back they have a huge selection of car springs, old ones. Take your measurements with you, a vernier, and a measuring tape, ask them nicely if you can sit out there measuring springs and if you find something you want, you'll come back inside and talk to them about a price. Chances are they will probably give them to you for a the Box of 20 Beers you take with you.

Spend time out there on a not rainey day, boring as hell, measuring springs.

Best to go alone, or with female who wants to 'spend time with you' (that'll teach her). otherwise you if you go with a group of mates they might say no.

I've done this heaps, and it's always worked out for me.

[Jase]

true enough gemini springs uncut in b1600 puts it pretty close to the deck

with full captive

[Hemi]

yea and cefiro springs with r32 struts put my swaybar, fuel tank and exhaust on the ground .