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Discussion Starter #1
Hello all,
I am installing a Nitron road coilover set these days on my 1990 Turbo SE, and I want to lower it slightly without compromising steering and other driving abilities.
Chassis height is completely standard and so is susension before commencing any work, though dampers and springs have been changed for new original Lotus items years ago (so second set). They work and have no abvious defects.
So, before touching anything I measured the standard suspension height to vary 3mm from left side of car to right side of car.
After installing the rears of the Nitron set (long story, longs hours of adaptation), I could measure the same 3mm variation in ground to wheel arch, being on flat level garage floor or outside - it was the same.
The same 3m also showed no matter if I kept the ride height standard (170mm front and rear) or lowered the car.
The Nitron coilovers were set to the exact same height.
Fronts will be commenced later this week hopefully, as it seems there is fairly much adaptation to make this "bespoke" set of Nitron coilovers actually fit... (I'll report back on that topic another day).
I did drive the car a little bit to settle the suspension.

My questions are these:

1/: Does it matter?
2/: should I adjust one side slightly to be able to measure the same ground to arch height?
3/: I won't be able to have corner weights untill later this year, possibly next Winter.

Thanks for your interest in this matter.
Cheers,
Redfox

ps: here's a picture of the rears lowered 23mm from standard height as a test to see if it did affect the differences side to side - it didn't. Surely looks mean, but that's another discussion ;) So never mind the "high" front end.

1258371
 

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Have you tried measuring ground to frame? These bodies are fiberglass - they are not precise side to side.
 
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Here is what I always did on my old 911s. They have very light front ends and I felt like I had good results as far as feel and even lock up of the front tires under extreme braking.

I placed my weight in the drivers seat (bags of horse feed work well for this if you happen to have horses).

Use spring perches to get ride height close to where you want it all around, maybe a skosh lower than stock.

Remove front wheels and place jack in the center of the car between front axles - on a piece of pipe is ideal so it can roll freely.

Lower front end to approximately stock ride height.

So now you have a tri pod.

Adjust threaded perches on rear so the height of frame from ground is the same on both sides.

(obviously lots of wheels on and off and back and forth - its a PITA)

Repeat for the front end with rear jacked up on tri pod.

Remember to settle the suspension each time you take the weight off a tire.

Was the result as good as setting cross weights with scales? absolutley not. But not bad for garage DIY work and scales are $$$

I read about the technique on the Porsche forums and I found it seemed to work well. I wish I had a chance to check the scale corner weights after the "Tri Pod method". I think some one on the forums did check it and it was pretty close.

I have had race car set up guys argue that it will not work but I am not sure they understand the technique.

Your Esprit is going to be the baddest on the planet. Lovely choices.
 

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Yeah I would be wary measuring from the body unless you are just going back to where you were before. Even steel fenders can be off by half an inch or more.
 

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Discussion Starter #5
Thanks Erik. Good points made. I get the point in your method, with the two front wheels out of the equation. Yes, they are handbuilt, despite VARI method bodies, and ageing as well.
Actually, I do happen to have some horses and 1 donkey plus a barn full of horsefeed ;) If the mice have eaten all the horsefeed, then I'll just use two of the Shetland ponies as passengers.
Hmm... Must add that as a standard horse suspension procedure to my Lotus Service Notes.
I will first redo the loading in the car + fuel, then loosen all bolts and retorque and see if it does anything. Then follow your procedure.
I also think that to be certain, I will have to do the whole front as well - dampers, bushings etc, but it may take a while, as I also want to resurface the front track arms.

Cheers,
Redfox.
 

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Some one brought disconnecting the sway bars in a thread couple of months ago. I have not had a need to corner weight my car yet (soon hopefully installing adjustable susension) so Ihave not looked at how I might disconnect them. Do you have any thoughts on that?

Looks like it is not straight forward on the Esprit.
 

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Wingless Wonder
1988 Esprit Turbo
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What @mike.griese said has been documented over and over: DO NOT measure to the body.

You have the rear springs set to the same height. Rest assured that all is right with your car. (I've messed with the springs on both my own '88 and a '95 with the same outcome.)
 

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Another way to set the heights is with scales under each wheel and try to get the weights on each wheel the same, ie, both fronts and both rears set equally side-to-side (not front to back). That may take setting the heights slightly differently.
David Teitelbaum
 

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Discussion Starter #10
Thanks for the replies.

Yes, I brought up the corner weighing on the Esprit with regards to th e possibility of making adjustable front arb setting.
Som just to make it clear: I will not adjust the springs measured on "ground to arch height". I know there are plenty of possibilities for all sorts of differences from that perspective.
I will measure it on chassis height, as I normally do. I have an easy tool for that.
I am interested in cornerweighing to make it more accurate. But I don't have any.
Just for the fun of it, I meaured the ground to arch height on all corners, before installing new suspension. And it turns out to be the same as before: 3mm difference left to tigh, with left side being 3 mm. lower; that would be my driving side.
I'll take not of Eriks method and try to meaure it out on my car and see how things turn out.
I will also before and after that measure the speing perch on the chassis points to ground height on both sides.
I am also interested in how the body sits on the chassis and any twisting in the bodyshell.

Cheers,
Redfox
 

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Hey Redfox,
I am definitely interested in your experience with using Nitron suspension as I was thinking of using them to update my suspension.
I definitely would appreciate any first hand experience.
Jason
Esprit S4
 

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Ima gonna crash this party with a 87 Giugiaro Esprit that just got updated to Gazmatic shocks (they have part number for the shocks specific to Giugiaro) but their 'recommended' springs were far too hard (they appear to be Stevens ratings). I stayed with factory OEM springs (to the point of getting New Old Stock front 87 springs from SJS - the originals were rusty; mechanic recommended replacement, but after seeing the springs, the rust seemed to not be structurally bad).

Like Redfox's experience, the front shocks didn't fit correctly for the OEM springs - the lower perch needed to be 4" diameter, not 3" and Gazmatic didn't have 4" perch. I had a shop in Nevada custom-machine a 4" plate to sit on the Gazmatic threaded 3" perch.

I wanted to have same OEM compressed spring height, but the front didn't have the proper room - it was compressed a bit lower (and car sits lower too).The rears were adjusted to match height.
Not sure if adjusting to OEM body height would help if the Nitrons are completely different spring rates and compressed heights.

The car sits about 3/4" lower - I'm normally not a fan of lowering a car for cosmetic reasons - I prefer longest wheel travel at expense of looking like an 4 wheel drive truck. However, this modification looks cool and car rides a bit harder than before. Will adjust the valving to see if a softer setting will be preferable.

I also had all the bushing changed from aftermarket polyurethane to rubber bushings from SJS and JAE. One bushing on left rear driver side upper link near exhaust manifold was melted and the same side OEM shock was empty of oil. Suffice to say with new bushings and shocks, the car is amazingly much better. I also had them put weights gym set weights, not horse feed bags) in driver seat (1/2 tank gas) and do the alignment accordingly. It tracks straight so much better; the rear camber is still a bit off and I have adjustable upper links from JAE for next go around.

The corner weighting - I passed on that as mechanic said not really necessary for a street cruiser like me.

The Lotac Bilstein package was considered, but I just could not justify the cost given I don't really push the car that hard. So the compromise was existing springs, new bushings, and Gazmatic shocks that have individual dyno charts. The rumor is they dynoed the Lotac Bilstein shocks and set up their version accordingly.

I looked briefly at the Nitron kit - it's pricey and frankly I didn't know anything about the 'tuning' parameters used to create them. However, many non-Esprit owners seem to like them.
 

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Discussion Starter #13 (Edited)
So yesterday I did the rears and today I adjusted the camber angle on the rear wheels. Just a test, not hoing to settle for such a low car. After adjusting the upper rear track arms, the suspension looked a bit higher, just about right being slightly lowered. I don't want a 4wd look and don't want a slammed crawler as well. The coilovers from Nitron seems firm at the rear and a bit softer for the front. Springrate are the same - 50N/mm. Didn't have a chance to testdrive as we had a nasty hurricane coming in. I chose to buy new top mounts for the front, as I didn't have to take the original suspension with it's hard spring preload, apart.
I also used a couple of polyurethane siolators on top of the springs to isolate for road noise.
Here's a pic with standard suspension and standard ride height. Looks totally silly, but that's it.
1258639


And here's a pic with the slammed installment of the kit:
1258640

But on this stage, the rear wheels had a very old bmw camber look to them, so had to adjust to 10,35mm tilt inwards, which raised the rear somewhat, looking like this:

1258644

Couldn't take a better photo than this, as the hurricane began to hit us, and I had to stay indoor. Suspension will settle a few milimeters lower than shown here on the rear.
I'll go for the slightly lowered height. Next up is redoing all front track arms etc.
I managed to combine new old stock original top bushing on the damper rods with red poly bushings, which just happens to be made by Avo.
How it drives and how stiction etc. are, I cannot comment on at this stage. Will have to make a full geo and take the car out when Springtime comes closer.
Nitron's road kit seems fairly well made, apart from a few small niggles, like on the exhaust side at the rear, the edge of the inner wheelarch have to be ever so slightly filed down, or eased, to make room for installation of the adjusting knob of the Nitron damper.
The rear dampers cannot be installed on the 1990 Turbo SE chassis, so Vulcan Grey kindly sent me a drawing of his own making for two adators to suit, which I had made and anodised. They had to be slightly modified though, to allow the bushing and special washers to fit. The heat shield over the rear left top bushing also will not fit correctly with the Nitron kit, so I found a way to hopefully make it sit tight and protect.

To sum it up, this Nitron kit is not complete and ready to be installed out of the box. Depending of model of Esprit, one have to adapt the kit to suit. Be prepared to do so, and you can enjoy a more modern approach to suspension on the Esprit, compared to old style non-adjustable dampers and springs. Price is a bit heavy, but still cheaper than the Bilstein/Eibach Lotac kit that Lotus offers, and which in my humble view is too soft and offers no adjustment possibilities, and even though the owner install per procedure, using the lower of the two positions of the lock ring, balasting the car and tightening the bushings afterwards, it still sits too high. I've tried an Esprit like my own with the Lotac kit, and honestly I don't like it. Each to his own of course. I think time has moved on suspension-wise.
I feel the kit is a bit expensive and should have been more ready to be installed for the price. I called Nitron to suggest this, and they responded that this will not be an option, nor will they deliver a document that shows international approvement for MOT. They do offer the possibility of writing a letter stating that their kit is special made for this and this car, which I will have to show at the next MOT, so it will be aded into the States central database of my car. Nitron recently raised the price of their Esprit kit some 125 usd.
I should add that Nitron says they offer full rebuildable actions to the kit and suggests this every 10-15 hours of race/track time, or every 20.000 - 30.000 kilometers. I'd be doing that before that milage, because of age. Adjustment of height is infinite, and is done with a small tool that comes with the kit. It can also be bought seperately if need be. The lock rings are aluminium and may be a bit soft in material, so be carefulll when using the tool to adjust. Thread is fine and there are plenty of thread to go both up and down if one so wishes. An ordinary "C-spanner" cannot be used it seems. The aluminium parts are fairly well protected in grey anodising of, I guess, around 30 micron, so should last fairly long. Other bits are stainless and aluminium and then a few nuts and washers of normal type.Springs are light blue and powdercoated and looks good and solidly done. Lettering is white and data are printed on all springs for easy read out. Helper springs on the rear are black and says 15 N/mm. Each damper is numbered individually, for future reference.
I'll report back how it fares, once on the road. So far, so good.
Cheers,
Redfox
1258645

A front samper assembled with new top mount, yellow road noise insulator and red Avo coilover damper rod bushings (2).
 
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