533 replies to this topic

[Scuffers]

Isnt it probably accurate to say that these companies got the standard shocks which came off the car, measured them and replicated the lengths? If the standard shocks were wrong (there has been evidence of standard shocks allowing wishbone to chassis contact) then these companies just copied what they had it was never ever going to be right.

if that's correct, then it's quite scary on several levels.... 

[Matthew Bentley Racing Ltd]

Thought I should post as Chris has just so people know where I stand. I have no issue with running any make of damper, I say that because damper choice is never black and white and budget nearly always plays a big part. I want to give nick (or anyone else) the best I can within his budget). Nick brought his car to me for a full geo setup. He also asked me to let him know if I found anything that could be improved. On initial measuments I found the a couple of things that could be improved. One of these was his rear droop length. I know that this thread has got a bit wild. But from my end it is far less 'dramatic'. I have sent the dampers back to nitron and they are converting them to the later spec damper (I add for a lot less than I thought they were going to charge) and Chris has offered to deal with them to resolve the issue. When all is sorted Nick will have a better handling car than when he started. And that for me is always the goal when a customer brings their car to me. Hope that sounds sensible :-).

[Mike (Cliffie)]

Sorry, to clarfy:

 

Hoffmanns spec on Sticky's was just the valving and not the length; that was standard Nitron issue.

 

Yes, standard Billies did allow chassis contact so possibly Chris, they did.

 

My Quantums are off the shelf stroke lengths with a change of end piece.

 

 

[chris_uk]

End of the day.. These companies didnt supply anything unfit for purpose or anything dodgy which was going to kill you, so nothing wrong with previous itterations of shockers just not as good as some (its like comparing valving between makes) Now we are armed with this info we can ask when buying new shockers if we feel the need or to check. From all you professionals what kind of droop length/distance is deemed acceptable? For example between 50-100mm droop (numbers used purely fictional do not burn me at the stake) Or.. A usable total length? For example minimum distance (danper closed) minumum 400mm, damper open 500mm - 600mm (or whatever the acceptable droop equates to) Im starting to find it difficult to understand why this is such a big deal.(i know why its important to have adequate droop, i was talking about how the thread has progressed into a quantum vs nitron bashing thread)

[Mike (Cliffie)]

Easy to explain Chris: you know when we went out in Max's car at Snetterton and I lit that pax rear wheel up for a good length of the back straight? That was because the rear wheel was not in full contact with the tarmac and unloaded as the rear shock had run out of droop and we were at maximum open length of that rear pax shock.

 

The LSD does really well to mask that issue BTW.

[chris_uk]

As i said above, i understand the need and the implications of having enough / not enough droop, i was refering to the thread as a whole..

Edited by chris_uk, 28 June 2013 - 10:04 AM.

[cnrandall]

End of the day.. These companies didnt supply anything unfit for purpose or anything dodgy which was going to kill you, so nothing wrong with previous itterations of shockers just not as good as some (its like comparing valving between makes) Now we are armed with this info we can ask when buying new shockers if we feel the need or to check. From all you professionals what kind of droop length/distance is deemed acceptable? For example between 50-100mm droop (numbers used purely fictional do not burn me at the stake) Or.. A usable total length? For example minimum distance (danper closed) minumum 400mm, damper open 500mm - 600mm (or whatever the acceptable droop equates to) Im starting to find it difficult to understand why this is such a big deal.(i know why its important to have adequate droop, i was talking about how the thread has progressed into a quantum vs nitron bashing thread)

 

The optimum level of droop really is a moving goal post and the real answer is; enough so that you never run out of travel at the back.  If your car is very stiffly sprung then you will have less roll and use less travel under most circumstances, if you have very sticky tyres and use the car on track you are going to get more extreme roll angles etc etc.  On a VX you are in the fortunate position to be able to accommodate a nice long damper so you may as well make the most of it and get plenty of travel in there.  If you have 100mm of stroke and, say 400/550lb spring I would suggest something in the order of 40-45mm of the stroke in bump and the balance ion droop.

[siztenboots]

the issue I had with my 46's was I believe too much droop ( probably wrong term ) , but the open length caused the upper wishbone , lower surface to touch the chassis.

[chris_uk]

So ideally you need to specify to the company making your shockers what your requirements are. So going back a couple of pages to what i said earlier, if the off the shelf shockers dont meet your requirements then you need to get a custom set made which would be an extra cost. Aslong as they dont go below a minimum length (as to not foul the wishbone/chassis) in reality they are not selling anything 'wrong' or 'unfit for purpose' so its down to the buyer to either trust the seller or specify exacts at an aditional cost.

[siztenboots]

So ideally you need to specify to the company making your shockers what your requirements are. So going back a couple of pages to what i said earlier, if the off the shelf shockers dont meet your requirements then you need to get a custom set made which would be an extra cost. Aslong as they dont go below a minimum length (as to not foul the wishbone/chassis) in reality they are not selling anything 'wrong' or 'unfit for purpose' so its down to the buyer to either trust the seller or specify exacts at an aditional cost.

 

or maximum length , this was much more noticeable as in normal road use , it was banging . the bump stop issue for minimum length would be much harder to replicate

[chris_uk]

You get my drift tho.

[siztenboots]

You get my drift tho.

 

totally , as annoying as it was at the time, I learnt a lot from the experience

[Mike (Cliffie)]

the issue I had with my 46's was I believe too much droop ( probably wrong term ) , but the open length caused the upper wishbone , lower surface to touch the chassis.

A proper length damper should not allow wishbone/chassis contact on either full compression or full droop.

 

On the whole (and I know some companies have used the bump stop as part of the springing) the bump stop is there to dampen the travel as it reaches maximum compression not to stop the chassis contact. As Randy said earlier, the larger bumpstops fitted a few years ago to try to stop the contact was a stop gap measure only.

[siztenboots]

mike it would be good to get some video footage of the wishbones on your car with a big aero load , to see if you can notice the difference at high speed

[cnrandall]

On my car I can watch the wheel move reletive to the body in the wing mirror as you travel down the straight... Moves quite considerably

[chris_uk]

You cant see that on the vx. Infact this is pretty much what you can see.

[siztenboots]

I was thinking a small keyring camera in the wheel arch, plus a small light source

[JimmyJamJerusalem]

the fact that nitrons VX dampers seem to be speced too short (as in to the point of having sod all droop)

So to go back to page 1 where Simon kicked off this little bun fight with his poison. This is just his opinion and not reflective of any long term or on going fault with standard Nitrons. Now there's a surprise! Mike - additionally MAXR's car has tons of droop as he has the same spec as mine which ive measures and he has full rear tenders. The wheel was still unweighted by the dynamic of the weight distribution on that corner though so the pikey std diff would spin the inside wheel. This like you said is where an LSD comes to the party cheers for bringing some clarity back to things, I was going round in circles with Scuffers.

[Mike (Cliffie)]

mike it would be good to get some video footage of the wishbones on your car with a big aero load , to see if you can notice the difference at high speed

I can get a camera in there but don't ask me to notice differences, I only drive the ruddy thing.

 

What I can tell you is that we are seeing speeds in excess of 105mph round Coram this year compared to high 80s last year

[alexb]

Congratulations!!! (7 pages and still going strong)

 

I'm the happy owner of old spec Nitrons and did some measuring and calculating before and after fitting, so I feel I can add to the confusion with some confidence. If the wishbone articulation from top to bottom is really 435 to 325 mm (I have no reason to doubt this, but will measure it this weekend) and you design a shock with about 90 mm useable travel, it does stand to reason that all that travel should be within the articulation limits of the wishbones. My Nitron's go from 395 mm open length to about 305 closed (that includes 2mm bumpstop compression). At the closed end, that's outside the wishbone articulation limits. There is still more than room enough at the full open end. I call that a specification or a design error, as you can not use the full travel of the shock and there is no reason not to. All you have to do is make the body 20-25mm longer. And this is regardless of everything else that comes to play. I'm very willing to listen to anything that says this statement is BS, but with the measured values, that's all I can make of it.

 

And now for something entirely different: the amount of travel of the shock that you actually use may very well be within the limits even set by a shock that is not using the optimum in wishbone articulation. That will depend on spring rating and damping settings of the shocks, but in most cases I guess it will be given that most owners of such shocks are quite happy with them. Me amongst them. Although I have to say that I would prefer my shocks to be 20-25 mm longer, as this would give me more freedom to play with settings.