Spring Help please .....

[Anderzander]

I'm here to parade my ignorance again ..... The ride on my 90 could do with firming up: its lovely at tickover over rocks - but on the road requires a good progressive acceleration through any bend to stop it tipping me out of the side window. Its also leaning a little down on the passenger side (maybe I put the wrong sides back in?).

I want to keep some suppleness, I want to keep a standard height, but I think it would be better a little firmer.

I'm pondering what gains could be made in balancing the travel front / back too - but for now I can't really even understand the spring calculator....

So:

I took it on a weigh bridge and got 1080 on the front and 870 on the rear.

I have a 3 link front - so a little work to do on working out the unsprung weight. But as a guide - copying from here: http://forums.lr4x4.com/index.php?showtopic=85288

Front Axle 120kg

HD Track rod 10Kg

Half the HD drag link 5Kg

Ball joints 0.6Kg

Some of the steering damper 1Kg

3 link arms 15Kg + track rod guard ?

Rims and tyres (10 Kg + 20 Kg) x 2

Half the springs (4Kg)

Half the dampers (4Kg)

Total: 219.6 Kg

And the rear:

Rear Axle 100Kg

Half the trailing arms (10Kg)

Half the a-frame (10Kg)

Half the springs (4Kg) + X-Spings ?

Half the dampers (4Kg)

Rims and tyres (10 Kg + 20Kg) x 2

Total: 188 Kg

Thus on this guess-timation:

1080 - 219.6 = 860.4Kg for the front unsprung weight

870 - 188 = 682kg for the rear unsprung weight.

Now I have the calculator link: http://www.lr90.com/calculator.html

and the bible: http://www.red90.ca/rovers/springinfo.html

But what do I do next ? What's Obs on the calculator ?

I think the standard Td5 90 springs are:

rear springs

NRC 9462

NRC 9463

front springs

NRC9446
NRC9447

Any help greatly appreciated !

[discomark10]

the tipping over could be down to poor 3 link design causing a high COG.

So you want better road handling?

[Anderzander]

It's the safari gard 3 link and from memory the roll was about the same as the radius arms once I'd removed the roll bars.

[landroversforever]

What shocks are you running? My old Pro Comps were like that until I swapped them for OME. I've got Yellow/Whites on the front and Blue/Reds on the back.

[Aragorn]

The 110 front springs are progressively rated, maybe they'd be a sensible swap for the front end, and should result in a fairly stock height?

Factory 90 rears are already pretty stiff if you use the car unloaded lots AFAIK.

[landroversforever]

Need to be careful here as different springs were fitted at different times. The Blue/Reds I have on the rear are quite soft and are a standard 90 rear spring. (originally for one side I think).

[Aragorn]

AFAIK the stock fronts are 170lb and the stock rears are 225lb.

Which gives a pretty stiff rear end compared with the front when your F:R weight is 1000:800

[Anderzander]

I'm at work so can't check springs - but shock wise I have OME. Which are great - the damping is smooth it's just the spring is very soft.

[Daan]

AFAIK the stock fronts are 170lb and the stock rears are 225lb.

Which gives a pretty stiff rear end compared with the front when your F:R weight is 1000:800

I would swap them back to front to give good balance in articulation. It is close to what I run, although I have radius arms at both ends.

Certainly, if you run it like that, it is a very well sorted setup, except for high loads.

Daan

[tacr2man]

My 110 is very rolly , if thats what you mean by tipping you out the side window, but have found that the axles still stay flat on the road, to the point that you can drift it quite controllably as long as you dont get sea sick by the rolling of the body . Its a price i was prepared to pay to enable fast travel over corrugated tracks without shaking the fillings out my teeth. The anti roll bars are still on and koni shocks . its the springs that make the big difference. HTSH

[Retroanaconda]

I have 110 CSW fronts on the front of my 90 (154lbs/in) and 90 fronts on the rear (177lbs/in).

It may be because the set of springs I've got on the rear are very old and worn out but my car now sits slightly arse-down. Was thinking of perhaps going for a set of Disco 1 rears (200lbs/in if I recall correctly) as that's in-between the current ones and the factory 90 rear (225lbs).

[Anderzander]

Alas - Ive waxoyled my springs, so no colours until I take the white spirits to them.

The ride is defintiely down to spring rates - not damping or the 3 link. The roll is only the body - and I can drive round it, but I think the thing would benefit from a bit more resistance.

Swapping springs front to back isn't something I'd considered - though the articulation is prettily balanced as it stands. A bit more travel at the back, which I had put that down to the shock position.

When it moves over rocks the body sits level whilst the wheels articulate to similar degrees.

So, to my original post: is anyone familiar with the spring calculator ? And could you explain it's use to me ? I'm still non the wiser.

I did try some harder springs in the front ages ago and they were hideous. Gave a lift and rock solid front end - so I pulled them out and went back to standard.

Perhaps I could dig those out and find their colour to set a limit for how hard on the front.

[Paul Woodward]

The spring calculator divides the load on the spring by the spring rate to give the fitted length of the spring.

You can pick a spring from the list or input your values manually. Change the figure in the axle load box to your own figures.

I've no idea what the Obs box is for either!

I'm still number crunching trying to find a suitable combination for mine.

[Anderzander]

Thanks that's helpful !

I've found of a photo of the springs that I found too hard - and they were blue and red marked - so std. rears at 225.

I also found this list for the Td5 springs:

90 (2400 Kg)

Part No.

Colour Code

Front - Driver’s side

NRC 9446

Blue/green

Front - Passenger side

NRC 9447

Blue/yellow

Rear - Driver’s side

NRC 9448

Blue/red

Rear - Passenger side

NRC 9449

Yellow/white

90 (2550 Kg)
Front - Driver’s side

NRC 9446

Blue/green

Front - passenger side

NRC 9447

Blue/yellow

Rear - Driver’s side

NRC 9462

Green/yellow/red

Rear - Passenger side

NRC 9463

Green/yellow/white

Once I work through the spring list at spring rates greater than the 175 front fitted - the issue seems to be that the springs all are a fair bit longer, until I get to Disco / Td5 110 front spring NRC8045 - a progressive spring listed as 210 pounds and giving almost the same ride height I have now if fitted all round.

This looks interesting as it would firm the front up - and should help with that front end dive into corners - but would soften the back up a little which bumps a bit harshly on speed bumps and the like.

Any thoughts folks ?

One other thing: With a central tank on a td5 the springs are still 'handed' is that to accommodate the offset transfer box etc ? I'm presuming so as the longer spring length on the pairing seems to be on the right side of the vehicle......

..... though on the 110 Td5 the NRC8045 was fitted to both sides.

[Anderzander]

Looking on here: http://www.red90.ca/rovers/springinfo.html

Those NRC8045 springs are listed as 155 > 215 ...... presumably the progressive spring rate range.

[discomark10]

why not get X-deflex, would be better all round

http://www.x-eng.co.uk/StoreDisplay.asp?SL=73

[Anderzander]

It doesn't fit the td5, I think I'd still get that initial dive in the front corner, and it's expensive for me at the moment (saving to buy a new garage!).

[landroversforever]

Have a chat with Simon, I thought it did fit them with a spacer?

[Anderzander]

I just went off his web site. Cost is still an issue though too.

I'm thinking of giving a pair of those springs a go .......