lowering a starion

[thrash]

The ride height of the car is determined by the length of your strut and the height of the springs. Reducing the height of the springs comes at the cost of suspension travel. So by reducing the length of the strut and putting in a shorter shock you keep the same suspension travel and get the lowered ride height

What's the theory behind this? It doesn't quite make sense to me :(

[redzone]

if you lower the ride height of a car, there is less suspension travel before it hits the bump stops. if you shorten the strut BODY, then you regain suspension travel.

[RiceThief]

Thrash I made this image just for you with my leet paint skills.



As you can see in the pic, the strut on the right by lowering it with lowered springs you lose shock travel. The strut in the middle maintains the same height as the strut on the right but has the same travel as the stock one on the left.

[thrash]

Thanks for the picture RT, that does explain part of it, but I must be really stupid or something :( If you shorten the strut, isn't the suspension travel still limited by the length of said strut? I mean, the strut piston still cannot move any further than the strut body, so a shortened strut means that the suspension travel is shortened too? What am i missing?

[RiceThief]

The ride height of the car is determined by the length of your strut and the height of the springs. Reducing the height of the springs comes at the cost of suspension travel. So by reducing the length of the strut and putting in a shorter shock you keep the same suspension travel and get the lowered ride height

Thanks for the picture RT, that does explain part of it, but I must be really stupid or something :( If you shorten the strut, isn't the suspension travel still limited by the length of said strut? I mean, the strut piston still cannot move any further than the strut body, so a shortened strut means that the suspension travel is shortened too? What am i missing?

When I said same suspension travel, i should have said you lose less suspension travel by using a shorter shock.

To illustrate it better i fixed the orginal pic to make to more to scale and added numbers



Ok, so with the stock strut you have the body of the shock at 30cm and the rod at 30cm to give total height of 60cm and suspension travel of 30cm.

So what if you wanted to lower you car by 15cm you can:

A: Mod your strut to fit a smaller shock, by taking 7.5cm from the shock body and 7.5cm from the rod, it gives you a height of 45cm with 22.5 cm of suspension travel.

B: By just moving the rod portion down to get your lowering, you still have your 45cm total height but only 15cm worth of suspension travel.

Obviously this is a simplistic explanation, but illustrates my point.

[WidebodyWoody]

Wow those length images are very useful thanks mate. Very informative.

[thrash]

perfect! thanks RT, i get it now.

just one further question - I was under the impression that it's the springs that hold up the car, and that the struts were there to dampen the "springiness" of the spring when your car goes over a bump.. is this not correct?

if that is correct, then that means you'd have to get lowered springs as well as shortening the strut to get the lower ride height, right?

if it's not correct, then the same springs will work eh?

[RiceThief]

Yes the springs job is to hold the car and aborb the bumps, the shocks are there to dampen the energy created when the springs compress.

While you could probably cut the strut below the spring seat and use the stock springs, it would make more sense to weld on a threaded sleave.

[jk]

Shortening the strut body above the spring perch and using a shorter stroke shock insert will also help in keeping lowered springs captive when the insert is fully extended.
Otherwise when your doing dukes of hazard style jumps the springs can move since they're not captive and may not re-seat into the spring perch without a big clunk and shudder, it will also change the ride height on that strut while the spring isn't seated proberly.
Shortening the strut body below the spring perch would also reduce tyre clearance to spring perch, something Starions don't have much of to start with.

[Komeuppance]

http://home.comcast.net/~DriftAbility/g ... serts.html

Here's my guide on this subject which I finally finished.

-Robert

[enthuzed]

Shortening the strut body above the spring perch and using a shorter stroke shock insert will also help in keeping lowered springs captive when the insert is fully extended.

In our state, as I'd imagine for most in Australia, if the spring is not captive when the car is unsprung (jacked up, no weight on it) then it's considered illegal.

Nice instructions there too Robert.

[jk]

Yeah illegal and potentially very dangerous.

My first project was a TA22 celica with a 3tgt turbo conversion (still got it) the fool before me had some ridiculous cut down springs from a cortina in it that looked absolutely awesome in terms of ride height but were rock hard in spring rate and turned the car into a fully functioning death trap.

Not to mention the clunking and so forth when reversing down kerbs because they weren't anywhere near captive.

[enthuzed]

Yeah illegal and potentially very dangerous.

My first project was.....but were rock hard in spring rate and turned the car into a fully functioning death trap.

Even with shortened but improved travel, not cutting the bump stops can give this effect too. It's scary stuff the moment the car throws total "unexpected" handling at you.

[thrash]

like going straight despite you turning the steering wheel?

[thrash]

or continuing to turn after you've brought the steerign wheel back to normal position?