want my car just a touch lower

[RomanV]

A spring is just a bent piece of steel.

Cutting a spring does not unleash nuclear energy or kill kittens or tear a hole in the space time continuum.

The net affect of cutting a spring shorter, is increasing the spring rate - Which is is generally half of the idea anyway, or what people want to do when lowering their cars regardless.

I disagree about cutting the end of the spring that has all of the coils bunched close together though, as these are what give the suspension droop and act like keeper springs.

Better off shortening from the other end, to reduce from the 'hard' spring rate part of the spring.

compressing the springs reduces the spring rate, which is not ideal when your car is now lower.

If the springs are no longer captive, or the shocks are no longer able to appropriately control the spring,, this is when it starts to get ugly.

And IMO the reason for the 'no cut springs' rule.

[wde_bdy]

At the end of the day you can choose to do it, however if recommending it to others the least you should do is advise of the potential consequences. It's like a lot of car mods, everyone is happy to say such and such is great but never give you the downsides. So for cut springs, compressed springs or shortened shocks etc you need to mention the need for cert and that if you choose not to cert your insurance is out the window and in an accident you could face some fairly stiff penalties. Then it becomes an informed choice and anyone doing is taking their own risks. Personal opinion on cut or compressed springs though is why would you bother? Custom wound are so cheap these days and generally don't need cert like the other options do.

Callum

[Bling]

$&#$% here we go again, lets all jump on the goodie too shoes bandwagon

Yeah I bet you have a FTP sticker on your car too? What a tough guy.

At the end of the day, people are free to do whatever they like. But there is nothing wrong with people liking or disliking something. Cut springs is always something that divides the camps. No need to get upset if people have different views to your "right" view..

Informing people of potential downsides to car mods is not something i'd consider a bad thing. Bandwagon or not.

Just get some customs made imo.

On the topic, is it possible to get springs made that sit lower but still remain captive when not under load? Or does that just equal soft springs that would be crap? A way to avoid shortening shocks, or just not worth it?

[tsoob]

possible, but the ride would be average and they would most likely sag over time.

shortening shocks is pretty cheap and really painless, I have an engineer that works in the unit next to me, he can do a pair in about 30 mins.

[h8wrxs]

get some fat friends, problem solved and wont have to spend a cent

Or bags of cement

i do actually know someone who filled the spare tyre well with cement in a s1 rx7 thinking it would help give him traction and lower it at the same time....

oh and cheapest option for the query = $29 grinder from bunnings :d

or just buy adjustys

[wde_bdy]

shortening shocks is pretty cheap and really painless, I have an engineer that works in the unit next to me, he can do a pair in about 30 mins.

Ad then that needs cert as well....

[coupekiwi]

Cut the springs.

If you have inactive coils cut them out half at a time.
Don't cut from the other end as that will reduce the spring constant much more than taking out the inactive coils.

They should still be captive. If not next wof get the shocks shortened.

Keen to cut the top off the strut and weld it back on with 30mm missing.

[TazzieDevil]

Take the springs out, then wyhen you go for a wof, put them back in

[tsoob]

shortening shocks is pretty cheap and really painless, I have an engineer that works in the unit next to me, he can do a pair in about 30 mins.

Ad then that needs cert as well....

only if you go below 100mm

[wde_bdy]

No, shorter stroke shocks are fine but shortening a shock by machining requires cert for pretty obvious reasons. Very easy to get it wrong and if you have the shaft fail on a macpherson strut front end it won't be pretty. It is a modification that is not excluded from the cert requirements.

Callum

[rx7guy]

http://www.lvvta.org.nz/stdSuspensionSystems.pdf

I cant find anything about shortening shocks?

[Flannelman]

chop the top of the shock tower and weld in a new section. raises both shock and spring keeping ride quality the same yet lowering the car. make sure the cut and shut job is accurate as it affects camber/caster if its not square. and make sure the person can weld!

[tsoob]

No, shorter stroke shocks are fine but shortening a shock by machining requires cert for pretty obvious reasons. Very easy to get it wrong and if you have the shaft fail on a macpherson strut front end it won't be pretty. It is a modification that is not excluded from the cert requirements.

Callum

What are the obvious reasons..?

I don't know of anyone who can shorten a shock in their backyard, you need a lathe and some kind of idea how to use it, its not just a matter of hack something off and way you go.

A skilled engineer (such as the one that I use) would be very unlikely to 'get it wrong'

As far as certification goes until you go under 100mm or you have an adjustable shock you are not legally required to cert. As long as the thing is captive and has no leaks it is legal.

[Mr.Phreak]

[wde_bdy]

Have you actually read the rules?????
Try reading them again, it specifically lists what you are allowed to do without cert. You might notice the AND in front of every single requirement. If it's not listed, it isn't allowed.

You will notice it says direct replacement shock abosorbers, NOT shocks some lathe jockey has cut the top off to keep your springs captive.

Callum

[tsoob]

Actually you are wrong Callum, I have my certifier here right now and he has just gone over it with me.

As long as it still uses the original mounts, does not travel out (bump steer) and does not go under 100mm your suspension is legal.

[shihad]

Actually you are wrong Callum, I have my certifier here right now and he has just gone over it with me.

As long as it still uses the original mounts, does not travel out (bump steer) and does not go under 100mm your suspension is legal.

lets not forget the law is interpreted differently by diff cert guys.

try ringing up all the cert guys and ask this simple question can a car be certed under 100mm its a 50/50 what they will say back.

[wde_bdy]

Your certifier can say what he wants, it is written in black and white. You may only fit shocks that are a direct replacement, cutting the top off and re-threading it in order to keep your springs captive is clearly not a direct replacement. Why don't you ring up NZTA and tell them you want to cut and re-thread the main part holding your suspension to the car in a macpherson strut front end and see if they say it is sweet to go through a WoF which is only a visual inspection?

Callum

[tsoob]

awesome well being that he deals with lvv all the time i think ill take his advice on this one. thanks for your input however

[85AW20v]

And what if the shocks aren't replacements but the originals that are being modified? Getting picky I know......