Case Studies

Nitron Dampers

“I went in a car with 550/700 On Randy’s new ones and they were more compliant than my old 400/550 on regular Nitrons…” –

Alex A from SELOC

“From what I understand, the valving on the Hofmann’s spec Nitrons is different to standard. My Hofmann’s Nitrons run 550/700, plus helpers, and they are really comfortable – even my wife doesn’t find them too harsh on country roads; whereas I have been in a standard Nitron’d car, with much softer springs that felt a lot harsher.”

Harwood from SELOC

Two thumbs up to Hofmann’s and Nitron

A week ago yesterday, my NSR Bilstein gave up the ghost (along with its oil). On Tuesday morning I rang round to try and find a set of Nitrons to fit, and having spoken about costs and timescales, decided on Hofmann spec Nitrons. Quoted lead time was 10 days (wherever I could get them from) and Hofmann’s offered to lend me some dampers to get me mobile in the event that my dampers hadn’t arrived in time for tomorrow’s Activity day. I placed the order early afternoon of Tuesday, after Randy called to discuss the use I intended to put the car to.

Ben at Nitron really pulled the bung out and on Friday morning the dampers arrived at home! Hofmann’s fitted me into the workshop for a full cornerweight/Geo, including bumpsteer adjustment today at three days notice. I put the dampers on myself, after a call from Randy to explain the spacers/”O” rings etc.

Got back from Hofmann’s earlier today after my requirements were discussed in depth and a GEO spec agreed between Randy, Me and Matt. The GEO was finished bang on time, at the quoted cost, despite a couple of seized bolts/sleeves and the additional bumpsteer adjustment, which were unexpected. All the while, I was supplied with Coffee and WiFi access so the four hour wait flew by (the workshop is a real Aladdin’s cave for sports and vintage fans as well).

The car is transformed – compliant but taut, utterly stable at any speed and noticeably better transient turn in and mid corner performance.

Very many thanks to Randy, Steve, Duncan and Matt at Hofmann’s and Ben at Nitron for fantastic service, you really dug me out of a hole and I’m very grateful to you all” – Flying Banana from SELOC

“When I took the car to Donnington I gave up far before the car let go but I’m a whimp!

It did break away a couple of times but it was very controlled and gradual so it was easy to catch. I do have about 300hp and toyo 888s but the shocks coped very very well. One guy it took for a spin declared it the best set up Elise he’d ever been in. A very big compliment about an S2 from the owner of an S1 I think”

Dr H from SELOC

I’ve got some of Randy’s Nitrons on mine with 550/750 springs and helpers and they are seriously good on track.

Not as bad as you’d think on the road either, even on their track settings. Roll on Summer when I can get the most out of them.” –

Jamwill79 from SELOC

Ok, this is going to turn into a mini Nitron review as I have just returned from Hofmann’s tonight with a big smile on my face.

I can only confirm what Harwood says. I was looking for better track performance and hoping road use wouldn’t suffer too much.. Despite a new geo, when the car on track it felt like a bit of a hippo wallowing around. Ride on local roads was ok but not what you’d call refined. I’d had a ride or two of normal nitron exiges on track days and was impressed. Did the usual research, called Hofmann’s, spoke to Chris. Frankly, I don’t know my track rod ends from my lower wishbones, so I was in his hands. All I knew was no-one had a bad word to say about his kit, and his results spoke for themselves. Also booked in for the Hofmanns ARB. Chris suggested 650 on the rears and (I think) 525 on the fronts.

Sooooo… day off today, set off at 5am from ooop north (J39 M1) and was in Henley for 8am. Dropped car off at 8.30, after eventually finding Hofmann’s. Bit surreal, they have a very large unit, mainly full of Lotuses and old Rollers… left them to it whilst I discovered the delights of Henley-on -Thames. Killing time, went into WHSmith and flicked thru EVO magazine and the S2 Exige buying guide. I’d forgotten that my car was one of the original press cars (for better or worse.. I was spun the line by the previous owner that Lotus would have been desperate for the press car not to break down so it would have been well looked after.. It didn’t stop me buying it….) and there was a picture of my motor going sideways!

Anyway, several coffees/bacon butties later and I returned to find that all my suspension parts were seized and they were have a great time dismantling my old set up before the Nitrons could be fitted. I was surprised at how sexy a set of dampers can look when you see them being taken out of the box..

Eventually fitted/ride height sorted (I think this is the 1st Exige S2 they have set up) then onto the corner weighting scales. Oh dear. . I’m 6ft and pretty solid. And the car had a brimmed tank of petrol. 1008kg. Eeek!. remove my weight and (?40kg fuel) and you have 880kg. Bit lardy.

Frankly, I fully expect it to be superb on track; at Oulton next friday so will see then. What I wasn’t prepared for was the on road transformation. It feels firmer (as you’d expect) yet miles more compliant and supple. It shrugs off small imperfections/expansion joints in a way the standard set up never could; even large defects are handled far better. Turn in is telepathic-can’t wait for the track. Overall, a complete revelation over the standard set up (which frankly now looks very, very compromised if not poor) and it has totally transformed the car.

So to the OP; It seems you can have the best of both worlds. On the basis of my experience, there seems little point in going for the softer spring rates, but I clearly can’t comment on a standard Nitron setup; I have no idea how much this differs from the Hofmann setup.

Quick question for Nitron owners. The car now feels frighteningly well planted as though you could push it sooo much further. I got used to the standard cars limitations and when it was going to break away (on track). I’ll clearly be able to carry a lot more speed through the corners – will the limit be progressive or am I more likely to get caught out? Oulton will be my test bed and it’s not the most forgiving circuit if you get it wrong….

As a regular contributor on here has as his tag line…. don’t be gay, get Nitrons.” –

Stavros from SELOC

Randy’s Nitron roadtest

Posted for the French community who doesn’t know this product yet, but I felt I should post in English as well (mean my poor “Frenglish”). Good luck reading it (quite long, but I hope useful to some).

After some long questioning and testing, I decided to renew my suspension. My car is a 180HP S1, with 048M tires, used 70% on the road and 30% on track in terms of mileage. My wife and I are quite sensitive to comfort as we drive often on French C- roads. For this reason, and the fact I believe a suspension is made to work (has to be as soft as acceptable without compromising geo and body motion, to provide best grip), I had until now 325/400 standard Nitrons on it, a nice choice so far. Why bother then? First because the 048M have really more grip than the 038LTS, outlining some (non critical) limits on fast dry tracks, second because some recent tests with various spring rate indicated there could be a way to improve things a bit without compromising the ride on the road. As Chris had developed some ideas that seem to match my small understanding of what should be done, and after some rave comments, I decided to take contact with him. First of all Chris is really a great guy who knows quite a bit about suspensions (and not just about racing), also extremely friendly enough to spend a lot of time explaining all the points per phone to who was then not even a prospect (me !). His advices are so good I would really encourage anyone to take contact with him before purchasing any suspension for a sport car, and eventually follow his recommendations to have a tailored suspension matching your needs and tastes.

After some basic calculation, I figured the max I could go springwise with his set up would be 450/600, but Chris convinced me (based on my needs) to go for 400/550, probably enough baring in mind that 50 difference would anyway not really change a lot on the track behavior. So here we go, road report with Randy’s Nitron, 400/550 Eibach springs plus additional helpers on the rear only. Note there are various combos available with up to 550/750 springs with helpers front and rear.

First of all the kit operates really well. No issue with the stiff spring rates, no NVH issue, to instability due to the « double springs » at the rear, no issue with road vibration transmissions, no issue with odd transitions or noise due to the 2 rear springs etc. Works well, feels simple and straightforward while driving.

I guess it is worth going into some technical details at this point. The front springs are conventional as with this (conservative) spring rate there is no need to go another route. Note front/rear spring stiffness ratio is in line with what Lotus proposed and also more consistent with the weight distribution than say 400/475. It makes also sense in terms of roll stiffness (no BAR at the rear). The rear springs are quite stiff, 550, but that doesn’t mean a lot in isolation to the associated damping hydraulic. The additional springs are not tenders, as I initially suspected and posted (with a wrong equivalent spring rate, as no equivalent in fact), but pure helpers. The helpers are completely compressed when the car is stationary , and also compressed on bump. Basically, in these cases the best they can do is behave as non existent. Why do we need them for then? On rebound, to help traction / grip. With high spring rates at the rear one could possibly have little downforce (eg grip) on the inner wheel in a corner. Same after a speed bump, road camber change etc., where on rebound grip could be lots and car reaction become sharp. The helpers press the wheel on the road keeping some grip. If you don’t have any LSD, and I don’t like them on an Elise, then traction tuning is key on track.

The key here is Chris’ development work. On one side stiffer springs to get closer to the natural spring requirements for the Elise. On my road & track S1, they seem to be a golden number around 400 or 500 as previous tests on conventional suspensions showed. The main body control is then achieved on stiffer springs, with then normal (eg softer rather than harder) damping laws to control oscillations. In return, the softer damping laws counteract the stiffer springs and the sum of both is supposed to give an acceptable ride and grip (despite the fact harder springs require quite hard dampers to control their energy, all a matter of compromise !). Comfort and grip are mainly a function of rebound (of course of bump and spring rate, tire stiffness and pressure etc. as well, but rebound is really what you feel more than springs to a certain point, except maybe at pedestrian speeds). For this reason (guess grip for track, comfort for the road), Chris developed for sure very specific bump and rebound laws (quite different as one can feel from standard Nitrons), but also a different bump/rebound relation (guess rebound being closer than bump than usual, eg smoother rebound law for a given bump law counterpart). But the hydraulic subtleties of the curve shape (the « S ») seem also to differ from the normal parts. All this to say that this set up works in a quite different way than my classical Nitrons, making any spring rate comparison or any click setting between both useless. And outlining quite a lot of development work.

Now, how does it feel on the road ? My baseline is my well known 325/400 suspension on +16clicks (from full hard), the same setting with 400/475 as an alternative (see previous report). Tester is me… and my wife (no technical influence on her, she is only interested by the result on the road !) . After some extensive testing (270km) on various well known test roads, I found the road comfort to be acceptable between +16 and +20 clicks all round. Don’t bother about the high click figures. First I like it soft, indeed, but the car doesn’t feel like a muscle car and is still under control. Second these dampers are I suspect designed for harder (track) springs at the middle setting, no surprise the click figures are « offset », as by no mean they felt too soft from an hydraulic POV (but after 21 clicks). I finally decided my very own best compromise was at +19 for the (wet) road, noting that every click felt different but also the steps in between were fine enough to allow a proper adjustment. I noticed also that having 2 click difference front and rear could introduce some annoying Front/Rear oscillations on certain road undulations, which I didn’t like. So I kept clicks constant all round.

To the findings. On +20 clicks, the car felt as soft and as comfy as my previous Nitrons, which is amazing given the stiff springs. On +18 clicks, the car still felt comfy, but less soft, less rebound and with better body control and some positive feel. Firmer, different, but not less comfortable, quite the same league as classical 400/475. So the basics are Chris’ 400/550 combo is roughly in the same league as the standard Nitrons in term of road comfort. But that’s not all.

On some occasions, the new set up worked really better, both in terms of comfort (!) as in terms of grip. Legal (eg soft and long) speed bumps were taken at high speed, as in my latest Mondeo, without really noticing them (much better than in a normal car or with standard Nitrons). That was very surprising, also the way when coming off the bumps the car had no odd rebound movement (despite soft damper setting) and so absolutely no loss of grip. It was like sticking perfectly to the contour, both on compression and on rebound. My wife & I liked it very much ! The standard Nitrons can’t offer on that exercise that level of comfort, absorption /compliance and grip, only some VG 2 or 3 way dampers can (if properly set up for that !).

On a paved road (Chantilly for those from LOT–)) , Chris’ set up felt much better than the normal Nitrons, much more compliant and less crashy. In fact, the limit of the hard springs came only to play on high frequency high bumps (big pavestones looking really out at very low speed, big speed traps on French highways before péages at … higher speeds). On these occasions the new suspension didn’t perform really any better than the old one (but not really worst under any circumstance, just different and at the limit – for sure the car’s wheelbase comes here to play).

Another unseen performance came from road with big camber changes or when two concretes come together with a step to make the road. Grip was excellent, the car very composed and never nervous, while still very good on feedback (you could feel what was going on without being upset). The only surprise came when my wife and I expected the car to over react with force or even to slide on one occasion… and in fact in reacted by being on rails (and building lot of grips and unexpected high lat G).

Last but not least, not being able to bring it on a track, I did some basic performance tests on skid pads etc. It is difficult to say if there is more grip or not (you need a track for a proper real life evaluation), but for sure there is lot of grip and not less than before on the dry and on the wet, the latest being a good surprise (my guess is damper +springs are more compliant for better grip in the wet, same + better tire contact patch in the dry). In fact there even could be more grip in the dry… and a better control in the wet because the car is more planted and body reactions better controlled (TBC on track in anger !). Worth noting, the new set up kept the same excellent front/rear balance on the skid pad, the car being perfect. When going to the limit, the car is still as reactive to « throttle lifting » and « too much power », becoming as expected over and understeering, but again in a more composed way. It reacts, it is sharp, but it is even more controllable and doesn’t overdo or exaggerate the reactions. The reactions feel very linear and that helps a lot if you are a novice to feel the limit, same case when it comes to catching the car back or having a sudden line change : it won’t do miracles with the law of physics but it will feel more under control and predictable , you will be much more confident.

All in all a very good set up, IMHO even a bit more comfortable than the usual Nitrons due the better body control (less amplitude, less oscillations, less rebound reactions- the long oscillations in time or the hard when short input). It is difficult to say what harder springs would bring (or take away), but somewhere it feels (due to the perceptive positiveness)) much stiffer wouldn’t be suitable for a road use (but I have been wrong in the past on that with standard Nitrons, so a test would help there to confirm). If you use your car on the road only, then of course it would be nonsense to swap your existing Nitrons just for these. But, if you don’t have any Nitrons yet, or if you are attending trackdays or using soft tires, I would strongly suggest you take contact with Chris Randal prior to any suspension upgrade.

Now, I bought these parts for 70% road… but also for 30% track, and that’s where I expect them to score really (and mainly the reason I went for them). Let’s find out soon !

Claude

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