Pre- loading the suspension ?

PostPost by: l10tus » Wed Oct 29, 2014 7:07 pm

I was wondering what the script was for preloading the suspension travel, before tightening up all of the suspension nuts and bolts?

I notice the Plus 2 Manual recommends adding various considerable weights, prior to "tightening-up", what's the recommendation for the Elan.?


UK S4 / Sprint - road use

Any recommendations or ideas how to complete, greatfully accepted.

Regards,

Phil.
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PostPost by: rgh0 » Wed Oct 29, 2014 8:43 pm

I jack up each wheels one at a time until the suspension for that wheel is at the normal loaded ride height then remove the wheel and tighten the suspension nuts. Much easier to do than when the car is loaded and sitting on its wheel.

Make sure you jack at a suitable point under the uprights and don't jack on the middle of the suspension arms otherwise you will bend them.

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PostPost by: AHM » Wed Oct 29, 2014 9:55 pm

+1

What springs / dampers are you using?
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PostPost by: john.p.clegg » Thu Oct 30, 2014 8:39 am

..but a job you don't need to do if " Polybushed "

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PostPost by: Hawksfield » Thu Oct 30, 2014 2:59 pm

Phil

I used Rohans, method easy to do and works fine
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PostPost by: englishmaninwales » Thu Oct 30, 2014 3:29 pm

+3
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PostPost by: l10tus » Thu Oct 30, 2014 8:08 pm

Guys,

First, Thanks for the replies!

Second, standard shocks, springs, rubber metalastic bushes., original OEM setup.

When you say jack up one wheel at a time to normal ride height, is that as the manual recommends ? (6.5 inches to the each datum position, on the front ?) etc.

Because that must be a bit awkward to guess, unless you've used weights previously and noted where the body sits, whilst on all four legs ? - I'm trying to establish the correct ride height, after a long rebuild, having never driven the car.

Sorry to be a muppet, but Rohan / Hawksfield / Englishman, can you be a bit more specific, or am I missing the point a little?

John, What advantage is the original metalastic type bushes, over the "loose fitting" Polybushed version? ( didn't the torque effect of the original rubber ones make a contribution to the general feel and renowned handling?)

Should you uprate the springs to assist with the poly bushes, as compared with standard?

I would have thought that poly would only be really suitable for vehicles that didn't rely on the torque in the rubber bush assisting - or doesn't that count / I'm wrong ?

Please educate me what the Polybushed version is all about, is it longevity and ease of fitting, etc, or just 'go faster appeal' ?

Do you gain any better ride / handling or suspension feel?

RSVP,

Regards,

Phil.
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PostPost by: l10tus » Thu Oct 30, 2014 8:16 pm

John,

I just realised you must be using adjustable spring platforms all round ?

So you obviously set the ride height with the springs perches?

But doesn't the fact that the bushes are not really clamped up make for having to re- tightening the suspension pivot bolts more often and a 'general slack' feel when you hit UK potholes, etc ?

Just can't help thinking that some of the built in damping and rigidity will be lost, when using Polybushes that's all?

Regards,

Phil.
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PostPost by: rgh0 » Thu Oct 30, 2014 9:05 pm

You don't need to be to precise about it. I just aim for the lower wishbones or A frame to be near horizontal. The manual drawings gives some suspension dimensions for normal ride height also.

Tightening the bushes at normal ride height is about maximising the bushes life by centring the bush clamped point and thus minimizing the rubber deflection as the suspension deflects up and down from the clamped position.

The actual spring rate of the bushes is small and not really significant compared to the springs so I don't think they contribute much to the ride or handling quality. Poly bushes generally hold the suspension better so you get less unwanted deflection under load that affects suspension geometry.

cheers
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PostPost by: AHM » Thu Oct 30, 2014 10:56 pm

Again I agree with Rohan - I use the underside of the crossmember as a datum and a straight edge. - It just isn't critical.

Rubber has nonlinear elasticity, and is better at not transmitting vibration.

A standard elan is a remarkably smooth and comfortable means of conveyance. As you "Improve" things it becomes harsher and noisier
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