Ride Height Adjustment - Nitrons

[whaleys]

Hi all,

Does anyone have any advice for adjusting the ride height of the Elise? I have Nitrons fitted and the car is a bit too low, I can't get over most speed bumps or in any car parks and its now driving me nuts. So I was going to raise it by 20mm or so, does that sound extreme? At the moment you cant really fit your fingers in between the tyre and the wheel arch so I figure its fairly low. Is there anything I should be aware of?

Also I don't have the spannery tool thing (technical term) for adjusting it, does anyone know where I can get/buy one?

Finally I may be changing the springs to Eibach ones (thanks to Jen) is any one aware of any good spring compressor tools that are good for coilovers? I have a set but the are for larger more standard springs on a "normal" car.

Thanks,
Graeme

[woody]

You won't need spring compressors, just back off the threaded spring seat.

Think Nitron will be able to supply you with a tool, but there's not a lot of access to use it on the car anyway. A 6mm drill bit (I've used hole cutters for wood in the past; 6mm drive but fairly long) will do the trick.

To determine what height the car is at just now, park it on a flat surface (you can add ballast to represent the driver & pax if you wish) and measure from the chassis just behind each front wheel to the ground, and from the chassis just in front of the rear wheel to the ground. Generally the cars are set up to be 10 mm lower at the front. There's a ratio of distance the spring seat is moved on the threads to height adjustment seen on the car. 7mm on the ythreads for 10mm in ride height at the rear rings a bell, should be on the seloc tech wiki.

If you do increase ride by 20mm, get the car geo'd again; camber & toe at both ends will have changed.

[Shug]

Woodys advice is spot on. Only thing I'll add is be careful you're not winding the dampers up too much. Nitrons in most standard configurations don't have much droop travel and you don't want to drive with them nearly topped out (wheels will constantly be leaving the deck on rough roads) It may require a change of mounts if the springs are already reasonably compressed at the ride height you're running.

[mckeann]

what spec nitrons do you have fitted (what age, spring rates, who supplied them etc et) and what ride height are you at currently??

[roadboy]

Yeah, what Shug says is important.

As a rule of thumb the collars should just be touching the spring on full droop with no preload. (If they're all like this the ride heights should be near optimum)

If they have considerable preload on already then raising the ride height will remove any droop travel you may have and make the ride very crashy.

Dan

[whaleys]

Ok I may give some useless responses here but bare with me, I'm just now starting to learn a bit about this.

The Nitrons were on the car when I bought them. I'm fairly sure hey are the NTR Fast Road 1 way adjustable and just found out that the spring rates are 400lbs front and 475lbs rear. They were fitted late 2007. I don't know the current ride height but I will try and measure using the advice woody gave, but when I've seen mine next to standard height I would say its a good 40mm, maybe 50mm lower, that might be a lot of rubbish but its what I would guage.

What is suspension droop?

The springs that Jen is selling are 325 and 400, that is less that what is currently fitted, how will that compare and is it a bad thing? It's currently a very harsh ride and I rarely track it.

Thanks,
Graeme

[woody]

Droop is the amount of downward travel from the static position a wheel can travel. I've always worked towards a minimum 80mm droop when setting up the rear of an elise, where it can be limited (Had intended to mention this in the first reply but work got the better of me).

To measure it, measure from the center cap on the wheel to a point directly above on the wheel arch lip (you may want to mark the point). Then jack up the car so the rear wheel is completely off of the ground (i.e. the wheel & suspension are at full droop) and re-measure from the center cap to the same point directly above on the arch. The difference is the amount of droop the car has at that wheel.

Given what you've said about your Nitrons, they may be in need/benefit from an overhaul depending on how old they are/were last overhauled and the miles they've covered. Having Nitron overhaul them will give you far more options WRT to setting up the damper as Nitron's base settings have changed over the last 12-18 months. They could also advise you on the springs and fit the eibachs if required at the same time.

[mckeann]

the springs Jen is selling are PROBABLY for an S1 nitron, so are a different length than what the S2 needs. Make sure of this before you buy them.

You need to measure your ride height just now, before you go changing it. Measure from the ground to the chassis at the front and rear, dont use any parts of bodywork, also make sure its on flat ground.

[whaleys]

To measure it, measure from the center cap on the wheel to a point directly above on the wheel arch lip (you may want to mark the point). Then jack up the car so the rear wheel is completely off of the ground (i.e. the wheel & suspension are at full droop) and re-measure from the center cap to the same point directly above on the arch. The difference is the amount of droop the car has at that wheel.

Thanks for the info, will do that as well and get back to you.

the springs Jen is selling are PROBABLY for an S1 nitron, so are a different length than what the S2 needs. Make sure of this before you buy them.

You need to measure your ride height just now, before you go changing it. Measure from the ground to the chassis at the front and rear, dont use any parts of bodywork, also make sure its on flat ground.

Will do, does that apply to S2 K-series as well?

[roadboy]

S2s (K series) run 7" springs all round where as S1s run 7" and 8".

Woody, how much droop travel you should have will depend on a number of factors such as damper length, static ride height desired, spring rates, etc.

On my Dynamics 2-ways I cannot achieve more than 30mm of droop travel and the ride height is already very low but the spring rates are very high.

Dan

[ikarl]

I don't have an elise, so just trying to be helpful....

would you not consider swapping with another member for suspension that meets your needs better and with someone who might want something more orientated towards track use? there's normally a deal that can be done on SE

[robin]

On the subject of bump/droop:

I run pretty hard springs (Neil, can you remember the actual spring rates, pretty sure it's 600+ at the rear anyway) and a conservative ride height of 120/125 and I get tons of droop at the rear and almost none at the front, which is good because it gives better drive out of the corners where it lifts the inside front but keeps the inside rear planted.

In an ideal world your droop and bump travel would be more or less the same - if your springs and dampers need 100mm of bump it's unlikely that 25mm of droop will be adequate; droop and bump aren't always symmetric of course as the dampers react differently to the two. Even so I would suggest that a 60/40 ratio between the two would be as far away from 50:50 as you would want to go at the rear. At the front I don't believe you really need a huge amount of droop travel so you could easily go to 25:75 and get away with it.

All IMHO of course - racing drivers and their engineers will tell you differently.

On the subject of how your mostly road oriented S2 should be setup, 130/140 would be absolutely fine and should allow you to clear most hurdles they put on the roads. It's easy to wind up the spring platforms and raise the ride height, but you will need to get a geo afterwards, though it won't be terrible, the raise in ride height will affect front and rear toe angles a bit.

Once you've raised the ride height (and before you get a geo) you'll want to play with the damper settings to make sure it's not too stiff or too bouncy. A B road you like will help here.

I don't think 400/475 should be so bad, perhaps the damping is just too stiff - I would turn the dampers to full hard (that's the adjusters clicked as far round to the + as they'll go) then wind them off to full soft counting the clicks, then wind them back up to 1/3 from full soft, approx, with the rears being 2 clicks harder than the front. So if there are 16 clicks top to bottom then you want 11 from hard at the front and 9 from hard at the rear, say. Now go for a spirited drive, but don't go mad! If the car feels confidence inspiring your job is done. If it bounces like mad and doesn't settle cleanly into the corners then you need to turn the front/rear dampers up 2 more clicks. Repeat until it feels stable and leave it at that setting forever Now get a geo.

If you cannot get a good setting then if they've seen a lot of miles then chances are they need a rebuild. You could at that point switch to lower spring rates. Repeat the "setup" procedure and then get a geo.

Cheers,
Robin

[mckeann]

On the subject of bump/droop:

I run pretty hard springs (Neil, can you remember the actual spring rates, pretty sure it's 600+ at the rear anyway) and a conservative ride height of 120/125 and I get tons of droop at the rear and almost none at the front,

Even so I would suggest that a 60/40 ratio between the two would be as far away from 50:50 as you would want to go at the rear.

On the subject of how your mostly road oriented S2 should be setup, 130/140 would be absolutely fine and should allow you to clear most hurdles they put on the roads.
Cheers,
Robin

we had 450/600 on ours, but our dampers are much longer than the standard S2 nitrons of a few years ago. For ours, it was no problem to raise the ride height and still have plenty droop (infact initially i had something like 25mm bump, and 75mm droop until we changed the brackets)

Phil Smoker had the original S2 nitrons before changing to our spec, and he used to struggle for droop at anything above 120mm.

[whaleys]

Ok I got home a little late tonight so didnt get a chance to measure the droop but I did manage to measure the ride height as per Woodys instructions. It's 105mm at the front and 115mm at the rear, I'm not sure how that relates to a standard setup. Do we need to know the droop before we can gauge how much it can raised by?

Thanks for the info Robin, that's a big help.

Graeme

[mckeann]

Do we need to know the droop before we can gauge how much it can raised by?

Graeme

yes, definitely