a little help needed.

[quack]

hey, just wondering what the deal is with longer shackles?

is it just a matter of making longer ones and it will increase the hight?

its for a 90 MU.

is there any rule of thumb like if i make the shackles 40mm longer it will increase the hight by Xmm?

i know that its meant to be certed but im sure i can get away with it.

any help appreciated

[geeves]

Very simply the axle is located half way along the spring so this cuts in half any lift created by longer shackles. Also because of the longer length the leverage is much higher so they need to be made much stronger. There is a good pic in another thread on this subject to give an idea.

[quack]

yeah i was thinking of making them out of 10mm mild steel and addign a bolt in the middle for more strength. so do you mean if i make them 40mm longer then itll give a 20mm raise?

what is the maximum that is recomened in raising with this method

[geeves]

I think most people have gone for aprox 190mm total length giving a lift of 50mm They generaly weld a solid bar in the middle rather than a bolt. If you go the bolt way you will need to make a spacer to stop the whole thing crushing the bushes at each end.
Personally I don't like extended shackles because they put a huge strain on the mount, they should be certified and as they are twice as long as the final lift they actually can end up being very vulnerable. I prefer to use replacement springs which completely solve the last 2 problems and minimize the first. Other people have seen different results in this regard.

[quack]

hey thank geeves, think ill try out the shackles for now, i will let you know how i get on.