174 replies to this topic

[JimmyJamJerusalem]

OK so thanks to Scuffer's tests we have found there are some issues with a number of VX220 Nitrons.

 

It seems that Nitrons NTR 40mm's that were supplied in the TMS spec, some pre 2009 Nitrons and some custom builds are quite short (open length of 395mm).

 

Nitron 46mm shocks are not effected by this issue

 

There is no safety issue and the shocks perform very well however the stroke window does not match the fairly tight articulation window of the wishbones.  Some shocks are too short.  Bump rubbers were introduced to limit this to prevent the short closed length causing interferance between the wishbone and subframe but there is stroke wasted here which is then also lost in rebound as the short open length of the shock limits the rebound.  Alexb's pic illustrates this well.

 

 

Many people have had these shocks for years without noticing and there has not been any actual complaints for this issue but it is a good idea to try and optimise this to unlock the full potential of the Nitron shocks which remain very good.

 

Ok so doing some calculations

 

Overall wishbone articulation = 435 open 325 closed.

 

So dead centre of the articualtion stroke = 380mm

 

Most people drop the ride height by about 15mm so damper to wheel ratio of 1.35 means you'll take 11.11mm from the damper.

 

So your damper would be set at 368.9mm to achieve around -15mm ride height.  Split the 80mm stroke 60:40 (rebound/bump) and the shock limits are ideally 416.9mm and 336.9mm (for this stroke length).

 

Current spec actual length

 

NTR40's

 

Open length = 411.5mm

Closed with bump stop compressed = 331.9mm

 

NSS

 

Open length = 415.3mm

Closed with bump stop compressed = 331.9mm

 

Now to be 100% perfect the Nitron NTR shock would have it's rebound/bump window shifted a further 5-10mm or so (longer) but this just pure optimisation and not actually necassary.  I will pass this on to Nitron though once I confirm the figures and request that they change the spec of VX220 dampers to reflect this research.

 

 

 

The problem seems exists in earlier spec shocks which were supplied by tuning companies around 2009.  These seem to have a short open length of 395mm and a closed length of around 310mm.  This closed length has been limited with rubbers so the actual available stroke is now very short and the lower the car's ride height is set the less bump is available before wishbone contact.  Additionally there is not alot of actual rebound either (35-40mm at the wheels at around -15mm ride height).

 

Now we are looking to judge the demand for an engineering solution for this. 

 

If you want to argue about this go back to the original thread, if you think you might have problem then please measure the open length of your shock and post up your details if you are around the 395mm mark.

 

Here's what to do -

 

Jack the car up

remove rear wheel

Remove two shock mount bolts

Measure as shown below

 

 

Then if you think you are effected and want to look into an engineering solution then add your name to the list with the details of the shocks

 

1.  FLD  395mm TMS 2-ways

2.  Alexb  395mm 3-ways

3.  JohnTurbo  395mm, Elise shocks

4.  Rossco, 402mm CF 1 ways

5.  JG 407mm, CF 1 ways

6.

7.

 

 

 

[2-20]

1.  FLD  395mm TMS 2-ways

2.  Alexb  395mm 3-ways

3.  JohnTurbo  395mm, Elise shocks

4.  Rossco, 402mm CF 1 ways

5.  JG 407mm, CF 1 ways

6.  2-20 395mm  2 ways  (sold by TMS)

7.

 

Edited by 2-20, 26 July 2013 - 08:52 AM.

[techieboy]

1.  FLD  395mm TMS 2-ways 2.  Alexb  395mm 3-ways 3.  JohnTurbo  395mm, Elise shocks 4.  Rossco, 402mm CF 1 ways 5.  JG 407mm, CF 1 ways 6.  2-20 395mm  2 ways  (sold by TMS) 7. Techieboy 395mm 40mm NTR 1-way single bumpstop (TMS VX spec circa 2006)

[Zoobeef]

1.  FLD  395mm TMS 2-ways 2.  Alexb  395mm 3-ways 3.  JohnTurbo  395mm, Elise shocks 4.  Rossco, 402mm CF 1 ways 5.  JG 407mm, CF 1 ways 6.  2-20 395mm  2 ways  (sold by TMS) 7. Techieboy 395mm 40mm NTR 1-way single bumpstop (TMS VX spec circa 2006)

8. Zoobeef 395mm 1 bumpstop.

[Dave E]

1. FLD 395mm TMS 2-ways 2. Alexb 395mm 3-ways 3. JohnTurbo 395mm, Elise shocks 4. Rossco, 402mm CF 1 ways 5. JG 407mm, CF 1 ways 6. 2-20 395mm 2 ways (sold by TMS) 7. Techieboy 395mm 40mm NTR 1-way single bumpstop (TMS VX spec circa 2006)

8. Zoobeef 395mm 1 bumpstop. 9. Dave E 390mm 40mm 1ways with single bumpstop, bought from a groupbuy on here early 2008.

[PaulCP]

1. FLD 395mm TMS 2-ways 2. Alexb 395mm 3-ways 3. JohnTurbo 395mm, Elise shocks 4. Rossco, 402mm CF 1 ways 5. JG 407mm, CF 1 ways 6. 2-20 395mm 2 ways (sold by TMS) 7. Techieboy 395mm 40mm NTR 1-way single bumpstop (TMS VX spec circa 2006)

8. Zoobeef 395mm 1 bumpstop. 9. Dave E 390mm 40mm 1ways with single bumpstop, bought from a groupbuy on here early 2008. 10. Paulcp 395mm 40mm 1way, single bumpstop bought direct from Nitron via Plans 2006

[Darcini]

1. FLD 395mm TMS 2-ways 2. Alexb 395mm 3-ways 3. JohnTurbo 395mm, Elise shocks 4. Rossco, 402mm CF 1 ways 5. JG 407mm, CF 1 ways 6. 2-20 395mm 2 ways (sold by TMS) 7. Techieboy 395mm 40mm NTR 1-way single bumpstop (TMS VX spec circa 2006) 8. Zoobeef 395mm 1 bumpstop. 9. Dave E 390mm 40mm 1ways with single bumpstop, bought from a groupbuy on here early 2008. 10. Paulcp 395mm 40mm 1way, single bumpstop bought direct from Nitron via Plans 2006 11. Darcini 392mm 1way, single bumpstop TMS from approx 2009

[JimmyJamJerusalem]

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]OK so we've been working with Nitron on optimising the current NTR spec shock and we're happy now that the standard spec VX220 NTR 40's has been improved.  They will have a more robust solution to the closed length issue which has now been limited to an absolute closed length of 325mm which will ensure no contact wth subframe at maximum bump.  A bump rubber will remain in place.[/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"] [/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]As for the open length this too will be increased slightly to around 417mm which (from typical ride heights) will offer more droop than Lotus designed the standard shocks with.  Exact figures not to hand but looking at around 70-75mm which is plenty (even for a road car).[/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"] [/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]All damping is within the articulation of the shocks.  Only concern currently is springs as this may render the requirement for a helper spring to be used which will inflate the cost of this kit....[/font]

 

 

 

With regards to the old spec 395's etc.....  I would like to know your thoughts on these suggested solutions....

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]You have a few options available so contact me if you want to go ahead with any of the options below.....[/font]

 

 

1,  We can return your shocks to Nitron who will modify your shocks to put them in line with current spec shocks.  This will move the stroke window to within the wishbone articualtion window and improve your droop significantly.  This will cost £50 +vat

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]2.  We can book your shocks in to Nitron for a full refurb (£65 per corner + vat) during which the shocks length will be modified free of charge.  They will be updated with the current 2013 spec internals and will come back in 'as new' condition.[/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]3.  (Just for PCooper) If you have had your shocks refurbed within the last 12 months then return your shocks to Nitron and they will also be updated free of charge.[/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"] [/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]Nitron will not pay for carriage of shocks.[/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"] [/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"]I think that's pretty fair to be honest so please if you'd like to pursue any of the options above drop me a pm [/font]

 

[font="Arial, 'sans-serif';color:#222222;font-size:10.5pt;"] [/font]

 

 

[FLD]

Top Job Jimmy, these are seriously good prices!

I'd be after an option 1. I have 2 shocks that don't 'click' round on the adjusters so could I get that addressed?  Not sure they need a full refurb really.

 

Could we investigate the potential cost in the helpers too please.

 

ETA:

sorry, missed the via PM bit

Edited by FLD, 31 July 2013 - 04:09 PM.

[Darcini]

So just to clarify Jimmy,

option 1 is £50 for both shocks to be modified or £50 each ie total £100?

Then plus return carriage and vat?

[JimmyJamJerusalem]

These are just a suggestion so far as we've still got to finish design and get accurate costing but we think it can be done for around £50 plus vat total. Please guys I'm looking for your reactions as to whether you think this is a fair solution rather than sorting it this second as we've a bit to go yet before we can take shocks in Personally I think given the age of the shocks in question then a refurb is probably overdue anyway in which you get sorted for free.

[JimmyJamJerusalem]

I hate using iPhones on here

[Dave E]

Jimmy is there a time limit to this offer, I've already wasted 6 months of this year sorting the thing out so would far rather do it over the winter. Personally I'll be going for option 2, they've been on the car for 5 1/2 years and never been touched so could probably do with a refurb and also at that price it's a no brainer.

[Exmantaa]

Think this is very good. Open/closed lengths also seem good to me, as too long rears will give more need for helper springs.

Is there also some offer on helper set if bought together with the shock update?

[JimmyJamJerusalem]

they've been on the car for 5 1/2 years and never been touched so could probably do with a refurb.

probably ha ha. You animal!! It's not like you drive them soft either Can't see there being a time limit on it but as I said watch this space

[JimmyJamJerusalem]

Think this is very good. Open/closed lengths also seem good to me, as too long rears will give more need for helper springs.

Is there also some offer on helper set if bought together with the shock update?

 

Off the top of my head I think they're £50 per corner plus vat for the additional platform and a 150lb Eibach spring.

[Dave E]

Ok Jimmy and would just like to say much I appreciate your time in sorting this out, you could just as easily pointed us in the direction of Nitron and say there you go because in reality it has nothing to do with you. So cheers mate

[Darcini]

Yes, good point that, cheers JJJ

[CocoPops]

Ok Jimmy and would just like to say much I appreciate your time in sorting this out, you could just as easily pointed us in the direction of Nitron and say there you go because in reality it has nothing to do with you. So cheers mate

I also, think it's not Jimmy that should have sorted this. Nitron could (and should imho) have given a public response, rather than going through Jimmy, who has more than enough on his plate. So to Jimmy for staying on it and to Nitron for being not quite as helpful as they could have been (imho of course).

[PaulCP]

Ok Jimmy and would just like to say much I appreciate your time in sorting this out, you could just as easily pointed us in the direction of Nitron and say there you go because in reality it has nothing to do with you. So cheers mate

I also, think it's not Jimmy that should have sorted this. Nitron could (and should imho) have given a public response, rather than going through Jimmy, who has more than enough on his plate. So to Jimmy for staying on it and to Nitron for being not quite as helpful as they could have been (imho of course).

Couldn't agree more. An excellent result all round, thanks Jimmy