Initial impressions: Nitron 46mm NTR Race 1-way shocks

[X.l.r.8]

I’m assuming it’s the k series as last time I looked the 46mm one way shocks are only for the k-series, for Toyota you need 3 way for 46mm or 40mm for one way. The intax shocks are 36mm so I don’t think the 40mm are much of a compromise

 

[hallvardr]

I’m assuming it’s the k series as last time I looked the 46mm one way shocks are only for the k-series, for Toyota you need 3 way for 46mm or 40mm for one way. The intax shocks are 36mm so I don’t think the 40mm are much of a compromise

I talked directly to Nitron in the UK and they said that the kit I bought is not a Lotus kit, but a custom Tesla Roadster kit. So everything should be correct. Looks awfully short though. I will have to measure when I finish this one side. Looks like I can just adjust the rideheigh myself without changing anything else. So then I can just lift it a bit. I wonder if they set it up like this to change the weight geometry on the car? I have to contact them and ask.

 

[X.l.r.8]

I hope you are right, there’s not much travel in the shock so in my head if you start 6 cm shorter you end up 6 cm shorter.

 

[hallvardr]

Installing Tesla Roadster NTR Fast Road kit.
The kit is similar to this: Lotus Elise S2/S (Toyota) (05- ) NTR Fast Road 40mm Suspension Kit
But made especially for the Roadster. It is not listed on their site, but can be ordered directly from them.

The packaging and build quality is amazing. The setup from Nitron was:
Springrate front 550 + helper 150 Combined rebound/comp -10
Springrate rear 700 + helper 150 Combined rebound/comp -10

Old and new rear shocks. Nitron are slightly shorter, but stiffer so it's about the same ride height (did not measure exactly)

The install was pretty easy. The bottom bolt was pretty hard to see since I do not have a lift, but the is a pass trough hole to get to the bolt, so it all went well. I also got new bolts that should stay rust free.

The front driver side old and new bracket with ABS holder plate. This is the big job, It need to be cut and fabricated to fit. I ended up doing pretty much exactly the same as this brilliant write up:
Remplacement des suspensions du Roadster – Environnement et développement durable
Only difference I did was to use aluminum instead of welded iron on the additional bracket helper on the right side.

This is how mine ended up looking. Works well.

The front dampers. Here the new one was 3cm!! shorter than the new one. According to Nitron it was supposed to be like this after feedback from Roadster owners, but I think it was an error.

Here is the front driver side all finished with the bracket and damper + new wheel bearing

This is how the car looked after installing the new damper without any adjustment. The front is about 2,5cm lower than original. I took it for a short test drive and the wheel hit the fenders on turning and the car bottomed out in my driveway. So it was unusable. I then adjusted the first side and moved the adjustment rings down 2,5cm. This compressed the black helper spring completely but got the car back up to pretty much exactly the original ride height. On the first side I used the adjustment tool that came with the set, and it was really fiddly and took forever to adjust. On the second spring I fount out I could just turn it with my hands and it took about 10% of the time. I have mailed with Nitron and they say that the helper spring is there just to make the car the right height, so it does not affect the suspension at all that it is completely compressed. And I can't say that I noticed any difference on the short drive I had, so I guess everything is as it should. I would recommend to order the damper the same length as the original though, just to have some more play on the springs.

This is how the car looked after my final setup. It's not 100%, but probably about 95%. The car is going in for an EU control and a full wheel alignment (+ brand new AD08RS rear tires) on this coming Monday. I did have a pretty good test for the suspension though. The day after I was done with the shocks I entered and autocross event.

I have to say the suspension felt really good, I even got the winner of the event (Porsche GT3 driver) to take drive in my car and the only thing he complained about was a bit to much understeer, so I guess it's pretty good.

 

[X.l.r.8]

the helper springs will act like spacers if a wheel goes to full extension but not a lot else. A longer spring would effectively decrease its stiffness and a shorter spring without the helper spring would rattle about if you went full extension and more importantly bottom out. I have oversized wheels/tires so going lower is not an option. I guess the shock will not bottom out at that amount of spring compression. Great write up and I think it helps with people trying to visualize the adapter needed. Do you feel the spring is overly soft? or is the shorter spring effectively making up for the lower rating?

 

[hallvardr]

the helper springs will act like spacers if a wheel goes to full extension but not a lot else. A longer spring would effectively decrease its stiffness and a shorter spring without the helper spring would rattle about if you went full extension and more importantly bottom out. I have oversized wheels/tires so going lower is not an option. I guess the shock will not bottom out at that amount of spring compression. Great write up and I think it helps with people trying to visualize the adapter needed. Do you feel the spring is overly soft? or is the shorter spring effectively making up for the lower rating?

The entire setup feels very good I have to say. More comfortable than the old on first impact, and still feels firmer and makes the car hug the road a LOT better. Regarding the spring rating, this is the answer I got:
You have a total of 850lbs in the rear but it is the main spring which is taken into consideration, your friends main spring is 600lb and yours is 700lb meaning you have a stiffer setup. The helper springs do not having a bearing on the main spring rate for the car.

 

[hallvardr]

Mayday mayday!
Had the car in for an EU control today, and since the shocks that are on the car now are not original they demanded TÜV documents to approve the car. But Nitron does not have those documents apparently, so now I might have a pretty big problem. How did the other two? European Roadsters with Nitron do that?

 

[X.l.r.8]

Not ideal but can you throw the original shocks on while you sort it out

 

[hallvardr]

Not ideal but can you throw the original shocks on while you sort it out

I can, but I do not think I will be approved since the rear driver side has a small leak... I really hope Nitron will be able to provide the papers.

 

[hallvardr]

It is impossible to get the car approved in Norway without the papers.
NITRON refuses to make the papers needed and now also refuses to take back the kit.
So this is a pretty horrid situation, and I am extremely disappointed by how Nitron is handling this...

 

[Rolf68]

What a horrible situation... How can they refuse to give required paper for a product they sell in EU ??

And how are we supposed to maintain our costly cars if we're unable to get original replacement pieces from Bildstein ? This is becoming crazy !

I was never told I could end up in such a situation here... Hope it won't be an issue in France

 

[Stefan T]

It is impossible to get the car approved in Norway without the papers.
NITRON refuses to make the papers needed and now also refuses to take back the kit.
So this is a pretty horrid situation, and I am extremely disappointed by how Nitron is handling this...

Repaint them to yellow and blue and go to an other station an don't say any thing

 

[hallvardr]

What a horrible situation... How can they refuse to give required paper for a product they sell in EU ??

And how are we supposed to maintain our costly cars if we're unable to get original replacement pieces from Bildstein ? This is becoming crazy !

I was never told I could end up in such a situation here... Hope it won't be an issue in France

I hope so too. I have read the rules here in Norway more careful now and I still have a slight hope that they can be approved. But I need them to write a document confirming that the shocks are made to the specifications of the Tesla Roadster. But Nitron has now not answered any mails the last days... I found out that I might be able to use the credit card customer service and get the money back via them since I did not get the goods as described. So that can be an option in worst case.

Do anyone here know the spring rates of the original suspension?

I am wondering if the Nitron one have high enough rates to cope with the 450 extra kilos of the Roadster.
Looks like Mine has 550 front and 700 rear which is the same as a race shock for the elise. While the road shock for elise has 450 front and 600 rear. I have a feeling that the Roadster needs even more?

 

[X.l.r.8]

The 2 places I have seen both state 900 for rear and one says 600 for front and the other 700. One could have been adjustable shocks though. I’m not sure

 

[X.l.r.8]

Also remember the roadster spring is a lot longer effectively making your 700 spring stiffer. I don’t remember the equation but I know it’s in Herb Adams chassis design book that was once my bible back before books came before internet. I assume any chassis design book will give you the calculations thought. The helper spring compresses making the 700lb spring 25% shorter than the 900. I bet it’s close. The Nitrons obvious ability is the valving that controls the spring, not the other way around.

 

[hallvardr]

Also remember the roadster spring is a lot longer effectively making your 700 spring stiffer. I don’t remember the equation but I know it’s in Herb Adams chassis design book that was once my bible back before books came before internet. I assume any chassis design book will give you the calculations thought. The helper spring compresses making the 700lb spring 25% shorter than the 900. I bet it’s close. The Nitrons obvious ability is the valving that controls the spring, not the other way around.

So you actually think the Nitron are strong enough?

 

[hallvardr]

After much back and forwards I finally got Nitron to make me a paper that I hope will get my car approved with the dampers. They claim that the 3cm shorter front shocks is the same as the Elise S2 and the correct length? Which does not make sense to me, and I fear that this will add more stress on the other parts in the suspension + need a camber adjustment.
They also claim that their 550 front and 700 rear springs are the correct spring rate for the car, which absolutely does not make sense to me since they use the same for the Elise which is 450kg lighter.
My dilemma now is. Should I hope that the Nitron are better and will hold up better, or should I use my insurance and get a refund. My other alternative is to send in my old Bilsteins to a place I found and get the rebuilt for half the price of the Nitrons...

 

[hallvardr]

Update. I just wasted 4 months on Nitron and they have horrible customer service!

-It is impossible to get the Nitron shocks approved in Norway since they do not come with any documents.
-Nitron sent me the shortest size dampers they make, even though the Roadster should have the longest. It was barely possible to use it, and I needed to compress the helper completely and the normal spring half way + getting shims to correct the camber.
-Nitron claimed that they sent the correct spring rates, but after looking into it they are lying.

Lotus Elise S2: 860kg
Lotue Exige V6: 1176kg
Tesla Roadster: 1260kg

Tesla weigh 31,7% more than the S2
Tesla weigh 6,7% more than the V6

Nitron Lotus Elise S2 spring rate: 425lbs f, 550lbs r
Nitron Lotue Exige V6: spring rate: 550lbs f, 1100lbs r
Nitron Tesla Roadster: spring rate: 550lbs f, 700lbs r

Tesla has 22,7% more springrate f and 21,4% more springrate in the r than S2
Tesla has 0% more springrate f and 36,3% more springrate in the r than V6

Looking at Nitron calculations the Tesla Roadster should have:
Tesla Roadster: spring rate: 600lbs f, 1200lbs r

What I have heard the original Tesla Roadster has:
Tesla Roadster: original spring rate: 600lbs f, 900lbs r

Even though the shocks they sent me had all these errors Nitron refused to return them and were just making excuses. They just said that they heard other customers had given positive comments about the spring rate, even though they can see that the calculations are all wrong. They also that I should expect a lower car in the front when buying racing shocks. And that is even though the shocks are called fast road shocks and they do make longer ones. Truly horrible service!! They did not seem at all interested in giving correct shocks for the car. I therefor wanted to return them which they also refused. Luckily I payed for the shocks with my credit card, giving me insurance which I used to make a complaint. Nitron acted very cocky about this saying that they were sure that the insurance would agree with them, but I got a quick reply from the credit card company saying that the money was returned and a confirming that everything was settled. Nitron on the other hand claims that it is still not settled and are still refusing to give me return info. Nitron could have handles this with a simple return in June, and now it's October and they are still trying to be as difficult as possible, with the exact same outcome...

What I ended up doing to actually get working shocks on the car was to ship my old shocks to Bilstein in the UK, they refurbished all of them and sent them back for less money than one of the Nitron dampers, and now the car feels perfect again, much better than it did with the Nitron on the car. I off course also had to weld back the ABS bracket I cut in half to fit the Nitron shocks. Refurbishing the Bilsteins was my original plan in the first place but I never got answers on the mails I sent to Bilstein UK, and after reading positive comments on several posts here I ended up going for the Nitron. (big mistake) After getting some tips from the Facebook group I ended up calling Bilstein UK and then everything finally got sorted out.

Refurbished Bilstein + new bolts and drop links are now on the car.

 

[X.l.r.8]

wow, quite the journey, they obviously are thinking the lotus Elise with the shorter shocks are what’s used on the roadster. Not the longer ones. If that’s the fundamental belief they are using then no one will get the correct shocks from here on in. That’s commercial suicide in my book.

 

[hallvardr]

wow, quite the journey, they obviously are thinking the lotus Elise with the shorter shocks are what’s used on the roadster. Not the longer ones. If that’s the fundamental belief they are using then no one will get the correct shocks from here on in. That’s commercial suicide in my book.

With all the info I gave them, they can easily make a kit that would fit and work very well, but they were totally uninterested in every way to make something that would actually work I hope the customer service guy I talked to gets fired or find something better to do. Their product seems good, but their lack of interest to find the best product for the customer ruins everything.