Took the Bishtail to the weighbridge recently (after the TDi went in ) to try and sort out my springs.

Front axle came in at 1260kg

Rear axle 1040kg - (could add a bit to that as the tank was 1/4 full)

I want to run with a compressed front spring length of 12" which is a true 2" lift.
I would like a similar arrangement at the back too, but don't know the standard spring seat height.

Having recently done some rapid travel in Mark90's truck I was impressed with how smooth the ride was over ground that I would have been shaken about on in the RR (not that I drive that fast you understand ). I wondered if it was due to having Bilstein shocks which I know are heavily damped? (Mark has Procomps)

Anyhow, I have been through the tech archive and tried out all sorts of spring lengths (on paper) but can't find one that gives me the ride height without being stupidly stiff.

Anyone got any clever ideas? What sort of spring rate will give me the suppleness I want? Ideally I would like to use LR springs as I cannot afford OME or other expensive types.

Thankyouverymuch.

Have a peekybooboo at our own Forum Trev (LR90s) website, and his ickkle programme wot I used

Nige

When calcualting the compressed spring lengths you did subtract the unspung weight of the axles/tyres/etc didn't you?

Already had a go on that and [hangs head in shame] couldn't get to grips with it [/hanging head]

I'll give it another go with a lower concentration of wife beater.



Mark - no didn't even cross my mind. I was just measuring what I have now - 10" seat to seat with a 2" spacer. That gives more or less the right height, How much should I subtract for the axles and what spring rate should I aim for front and rear?

OK, so I've had another go and now I understand!

Based on Trev's guidance of 10" at the front and 11 - 12 at the back I can get this:



Which gives an approv 2" lift.

Forcing some articulation gives reasonably balanced movement (as you would expect withequal spring rates) but slightly more at the front than the back. (again, slightly more weight there). I have allowed 200kg at the front a 140 at the back for axle and wheel weight. a guess, but it's probably reasonable.

So is such a light spring rate a good idea? Will it bottom out all the time or be horrible on road?

HELP!!

For reference I have 170lb (red/white police spec rears )on the back and approx 220lb (calculated) on the front. I might change the fronts to 170lb red/whites too but it may be a bit too wallowy then.

Remember also that if you go for softer springs, the amount of travel you get for the same impulse force (going over a bump say) will increase pro rata.

If say you are moving from 200 lb/in to 170 lb/in, you also need to increase the length by 18% otherwise it is likely to bottom out!

This is one bit of the calculation most people forget!

Si

I found the red/whites, 170 lb, too soft on the front on-road, especially on roundabouts and twisty corners on b-roads where you are braking and transferring weight to the front. I would think that 150lb all round would not be good for handling.

Cheers

Steve

Got you r message Charles ………timing couldn’t have been better.....….. I am still trying to track down the stumpy one………. I’ll call you tomorrow



I use 764’s on the front (220lb) and 781’s on the rear (290lb) ……. Works for me


Ian

DSN is running police spec springs alround give the lift and articluation as required but ducks and dives a bot on the road as Steve says,

i am running procomp alround on mine + 20% on stock front and +15% stock on rear, and +2" alround. They were on it when i got it so dont know the free lenghts sorry.

dont forget too soft and side slopes also become worse! esp with Pugwash on the lower side as i found out at 7S.....