shocks too low,sitting too high?

[boris77]

I finally fitted a set of protech shocks to replace the tired spax ones. I'm wondering if I've got a ride height issue, I'm sitting slightly higher at the rear than I previously was. I've set the rear to 6 1/2 inches, I'm wary of going lower as:

a) The spring is lose when the shock is fully open. About half to 1cm of slack at the top

b) There only appears to be about 4 possibly 5cm of shock left "to play with" before hitting the rubber stop.

Is this ok?

I've got the original build manual, it says rear height set to 6 1/4" +1" to -2" and front 5 3/4" +1" to -2"

The shocks are 12.5" front, 14" rear (same as the spax they replaced).

One other question,am I right in saying there should be about half an inch difference in height between the front and rear?

Any advice/comments gratefully receieved, thanks.

[Darren B]

Did you get new springs from Protech as well?  I fitted Protechs to mine over the winter and the one thing I noticed was that the 2 new front springs that I bought with them were 7.5" rather than the 8" ones I had on before.  This caused initial problems with setting the front ride height high enough for road use without running out of platform adjustment thread.  I ended up buying longer springs all round in order to not have the platforms too high up the thread.

[Jenko]

Hi,

I've just fitted some protech shocks and springs, and didn't have his issue...I'm assuming you have an SEiW.

I measured my old spax before ordering, I was using 14" rear, and 12.5" front.

Springs were 300lbs front, and 175lbs rear....For ride height, the settings I used was 145mm rear, and 125mm front.

Now then, what I don't know is spring length....I'm wondering if you have the correct length...

Basically, on the rear I ended up with about 12 threards showing from the underside of the adjustment nut. this gave me my 145mm ride height.....

What spring rates are you using....I must admit, mine do not have any slack when fully open (i.e. rear wheels jacked up), although I can still just about turn the ride height adjust nut by hand....

My guess is spring length may not me optimum....But if you the car feels ok when driving and doesn't hit the bump stops on normal road surface, then I wouldn't worry too much......

[Blatman]

a) The spring is lose when the shock is fully open. About half to 1cm of slack at the top

So wind up the spring platform so that the slack is removed.

b) There only appears to be about 4 possibly 5cm of shock left "to play with" before hitting the rubber stop.

Sounds just about OK, BUT...

What year chassis is it? The rear upper shock mounts have occupied different areas of the chassis over the years, such that different length shocks are needed depending on when the chassis was manufactured. It may be that the 14" shocks are simply too long. Combined with springs that may be a little too short, it'll cause problems..

[Muttleys V8]

My shocks are both 12 inch !!!!!!! front and rear!

Not many cars have this set up.

Steve

[Blatman]

Only every car built after about 1998 (or thereabouts, IIRC)...

[Peter M]

My car is 05 chassis with longer shocks on rear and i have the same probs as boris77 and the only way i can get any near rear ride height is to wind spring platforms down so there is slack in springs.

[Phil. S]

Sorry in advance if this is really stupid, but don't you wind the platform up, ie, compress the spring more, to get more ground clearance?  

I'd better get at least this right, as I'll be fitting my protechs in the next few days.

[Peter M]

Correct but we need to get less ground clearance sitting too high on rear at moment.

[Blatman]

My car is 05 chassis with longer shocks on rear and i have the same probs as boris77 and the only way i can get any near rear ride height is to wind spring platforms down so there is slack in springs.

Which means your shock is probably too long...

[Peter M]

But these were supplied by westfield and have spoken to mark and he says they are correct.The build manual even says the rear shocks are longer.

[Mark B]

a) The spring is lose when the shock is fully open. About half to 1cm of slack at the top

So wind up the spring platform so that the slack is removed.

b)

Yeah but if he does that he'll end up with a ridiculously high rear ride height....

[Blatman]

Where are the shock mounts on the chassis? If they are adjacent to the roll bar mounts, then 14" shocks are, IMHO, too long.

As for "Westfield say it's right", well yes, they may, but that doesn't mean it can't be improved upon. I've had *lots* of bits over the years that have been "factory supplied", and the only things that have been 100% perfect out of the box were the rear uprights, and a battery tray. *Everything* else has required some sort of attention.

As for the problem of loose springs, there is no reason why they should be loose, as long as the shock is the right length, and you buy a spring to suit. None of the 8 springs on my 2 Westfields are as long as supplied by the factory, but none of them are loose, even at full droop...

[Blatman]

a) The spring is lose when the shock is fully open. About half to 1cm of slack at the top

So wind up the spring platform so that the slack is removed.

b)

Yeah but if he does that he'll end up with a ridiculously high rear ride height....

Only if the spring is also too long. Don't wind it up all the way, just enough to tension the spring...

I do mine this way.

Buy a shock of the right length. This may or may not be the length that the factory say is right...

Once it has arrived, wind the spring platform down to it's lowest setting.

Measure the gap between the upper and lower spring platforms.

Buy a spring that length, or as close to but slightly shorter.

If you have enough adjustment on the shock (and most will have plenty), simply placing the spring under enough tension that it won't fall out on full droop will make no difference when it comes to adjusting ride height.

I've recently re-specced all the shocks and springs on the sprint car this way, and I have enough ride height adjustment available without adversely affecting the function of the suspension, or worrying about the springs falling out. And yes, I can adjust it up plenty high enough for road use, and low enough for it to be too low to pass scrutineering

[nikpro]

I thought factory supplied rear shocks were 13" and fronts 12"

Maybe the wrong springs are fitted to the rear; try softer springs as this will lower the rear ride height as well.

I believe that the factory standard rear springs are white; there is always a chance that they could have painted the wrong poundage spring?

I think 160lb rear springs are standard on CEC's

Also it is worth checking that there is no pre-load in the bushes on the rear wishbones as this will not only destroy the bushes but adds to the effective spring rate.

remember the car will settle over time; I think my ride hieght dropped by about 5mm over the first 500 miles.