TVR Parts Drop Links
Discussion
s3c chris said:
Andav469 said:
I went through this exact scenario 18 months ago, my car had completed 36k miles on the original billies, they weren't leaking and worked well, however, as I had replaced/upgraded all other joints and bushes, I wanted to do the same with the suspension.
I looked at all options and as my car is used on the road, I opted for the mk4 billies from Ben Lang, once fitted, the handling of my car is night and day different, so I suspect my old billies were way past their best, even though they weren't leaking.
The 3 height adjustability is a bonus too
Just out of curiosity, what height setting is the normal one to use with these new shocks? Mine are not fitted yet and they came set to the highest ride height, not sure what this will look like in reality?I looked at all options and as my car is used on the road, I opted for the mk4 billies from Ben Lang, once fitted, the handling of my car is night and day different, so I suspect my old billies were way past their best, even though they weren't leaking.
The 3 height adjustability is a bonus too
Regards Chris.
Oh and my 2p on the length whilst I'm pushing the trolley around tescos...
I don't think the length will effect the roll bar because the force from the link doesn't work in that way, it pushes straight down on the end of the bar, it doesn't lever it.
The only issues that I can think of with shorter ones is that the clearance will have changed and may cause interference with other components.. unlikely... And that the shorter linkss will be pulled at more of an angle when the bar is at full twist which may cause the top bushes to wear quicker or bent that crappy piece of metal that they bolt through. I can't see either of these being a real problem with 10mm difference though.
I don't think the length will effect the roll bar because the force from the link doesn't work in that way, it pushes straight down on the end of the bar, it doesn't lever it.
The only issues that I can think of with shorter ones is that the clearance will have changed and may cause interference with other components.. unlikely... And that the shorter linkss will be pulled at more of an angle when the bar is at full twist which may cause the top bushes to wear quicker or bent that crappy piece of metal that they bolt through. I can't see either of these being a real problem with 10mm difference though.
s p a c e m a n said:
Is that bolt long enough to go through the roll bar? Looks considerably shorter than the leven one...
Other than that I'm in
Basically the whole thing is roughly 10mm shorter, so if the distance between lower bush saddle (washer) and the centreline of the ball joint is also 10mm less once you've tightened the top nut to trap the two bushes between the wishbone bracket the 10mm overall reduction in length is of zero consequence.Other than that I'm in
What does change however it the distance from the ARB eyelet to which your bolting the ball joint end of the 200sx drop link and wishbone plate, this measurement is dictated by the distance between the lower bush saddle (washer) plus the thickness of the lower bush and the centre of the ball joint.
Increasing this critical distance will either increase the mechanical advantage (leverage) the wishbone has over the ARB (torsion bar), or decrease it if you shorten the distance ie instaled the 10mm shorter Nissan 200sx drop links I'm presenting here.
Reducing the mechanical advantage (leverage) the wishbone has over the ARB (torsion bar) will make it harder to twist, this in theory is exactly the same as sticking with standard length drop links but fitting a heavier (larger diameter) anti roll bar.
If you look as drop links fitted to race cars they are nearly always adjustable, just like a turnbuckle their length can be extended or reduced to alter the leverage the wishbone has over the anti roll bar. On a tight wet track you might choose to make the link longer because this will reduce the effects the ARB has and so aiding traction, conversely on a dry track you would shorten the drop link to reduce roll.
As such (if I'm correct) fitting these 10mm shorter Nissan 200sx drop links would reduce roll at the rear, this might actually be advantageous on 'Ol Gasbag' because she caries a touch more weight at the rear so can be prone to slight under steer in extreme circumstances.
In many ways the important element is the relationship between the front and rear, reducing roll at the rear is much the same as softening the front and softening the front roll in relation to the rear gives the front tyres better contact with the road surface and for longer, thus reducing my undesirable under steer characteristic.
Well that's how I see it, but I'm happy to be corrected.
s p a c e m a n said:
I don't think the length will effect the roll bar because the force from the link doesn't work in that way, it pushes straight down on the end of the bar, it doesn't lever it.
Look at the shape of an ARB, particularly the distance from the ends to the body line of the main bar and you'll soon see there is indeed leverage at play, also keep in mind an ARB is a torsion bar so it's spring effect is gained through twisting it.
Further opportunity to alter the amount of mechanical advantage the wishbone has over the twisting the ARB is offered by the drop link, increasing the length of the drop link reduces the leverage and decreasing the length would increase it.
This is why race cars have adjustable drop links, if drop link length had no influence they wouldn't make adjustable ones
Personally I think these 10mm shorter Nissan 200sx drop links I've found would stiffen things up and reduce roll all at the rear, this may or may not be desirable of course depending on many variables, weight distribution differences being just one.
I'm not promoting these links, I'm merely measuring and presenting them for discussion.
I'm under the impression though that the leverage pressure would only be altered by changing the length of the part of the bar that you've marked 'leverage'. The length on the drop link applying pressure to the end of the bar shouldn't change the force applied to it, unless I'm missing something... which I normally am 
(I'm buying a pair anyway, they're a good find as far as I'm concerned)
(I'm buying a pair anyway, they're a good find as far as I'm concerned)
s p a c e m a n said:
I'm under the impression though that the leverage pressure would only be altered by changing the length of the part of the bar that you've marked 'leverage'. The length on the drop link applying pressure to the end of the bar shouldn't change the force applied to it, unless I'm missing something... which I normally am
(I'm buying a pair anyway, they're a good find as far as I'm concerned)
+1...(I'm buying a pair anyway, they're a good find as far as I'm concerned)
Phil
Are they genuine or after market drop links ? seen them on the Net from £10 to over £65
http://www.ebay.co.uk/itm/Hardrace-Front-Drop-Link...
http://www.ebay.co.uk/itm/nissan-200sx-180sx-front...
http://www.ebay.co.uk/itm/For-Nissan-200SX-S13-1-8...
http://www.ebay.co.uk/itm/Hardrace-Front-Drop-Link...
http://www.ebay.co.uk/itm/nissan-200sx-180sx-front...
http://www.ebay.co.uk/itm/For-Nissan-200SX-S13-1-8...
Bassfiendnoideawhathp said:
s p a c e m a n said:
I'm under the impression though that the leverage pressure would only be altered by changing the length of the part of the bar that you've marked 'leverage'. The length on the drop link applying pressure to the end of the bar shouldn't change the force applied to it, unless I'm missing something... which I normally am
(I'm buying a pair anyway, they're a good find as far as I'm concerned)
+1...(I'm buying a pair anyway, they're a good find as far as I'm concerned)
Phil
s3c chris said:
Just out of curiosity, what height setting is the normal one to use with these new shocks? Mine are not fitted yet and they came set to the highest ride height, not sure what this will look like in reality?
Regards Chris.
The highest setting is the standard height setting, all other settings are to lower the car, on the rear I have standard height setting and on the front, .I have one groove lower.Regards Chris.
I tried all the settings and for me on uk roads, this is perfect
s p a c e m a n said:
I'm under the impression though that the leverage pressure would only be altered by changing the length of the part of the bar that you've marked 'leverage'. The length on the drop link applying pressure to the end of the bar shouldn't change the force applied to it, unless I'm missing something... which I normally am
(I'm buying a pair anyway, they're a good find as far as I'm concerned)
Thanks, I'll be fitting mine too, the distance between the wishbone and the centre of the ball joint can easily be adjusted anyway just my altering the bush thickness. (I'm buying a pair anyway, they're a good find as far as I'm concerned)
Longer or shorter links will change the angle of the section/s of the ARB I've labelled leverage when at rest, this angle will have an impact on the amount of available mechanical advantage because the distance from the end of the lever to the fulcrum point changes with angle. If you've ever shifted your body position when levering something with a crow bar to get more power all you're doing is naturally changing the angle of pull/stroke. Another way to test this is when tightening a nut with a ratchet, when you get to the end of your stroke and the angle is reduced you'll find you have very little power over turning the nut, so you naturally ratchet back to take another stroke at which point you also find you immediately get more power.
Finally if angle had no impact on mechanical advantage we wouldn't need ignition timing, you need the full force of the expanding combustion gasses to act on the crown of the piston precisely when the con rod is at the optimum angle to make best use of them, this is how we achieve maximum power from an engine and will typically be around 90° after top dead centre (ATDC) on the power stroke of using the example of a single cylinder 4 stroke engine. The truth is 90°ATDC is where the combustion gas has the most leverage but not necessarily the most instantaneous angular velocity, hopefully however it helps you see angle and leverage are indeed unavoidably connected.
In the case of the ARB this angle will always be equal both ends as long as the ride height from side to side and the length of both drop links are identical, but longer and shorter drop links still change the angle and that will alter the amount of mechanical advantage the wishbone has over the resistance in the ARB.
The length of the drop link is especially important if you're altering the car's ride height, if you're not altering the ride height then you should really retain the length of the standard drop link. If you lower the car you are shortening the gap between the point the drop link attaches to the wishbone and the point it attaches to the ARB so you'd need to compensate by adjusting the length of the drop link.
When the car is stationary and the ride height is the same on both sides then theoretically there isn't any preload on the ARB, it only becomes loaded when the ride height differs from one side to the other which is typically under cornering loads.
The key reasons race cars use adjustable ARB links are.
1. To 100% ensure that there's no pre-load on the bar when the car is sat at it's natural ride height (no roll)
2. To ensure the bar doesn't foul on the body/chassis if the vehicle is lowered
3. To make sure you don't run out of joint angle when running different ride heights/suspension travel
4. To maintain the optimum angle of the of the section/s of the ARB I've labelled leverage
The truth is I doubt 10mm will make much difference on our cars but there's a reason why TVR chose the drop link length they did and why this length is exactly the same on the Leven links I was using. Of course by simply adding a 10mm thick rubber washer under the lower bush you can solve the problem in a stroke, but it may mean you run out of thread at the top unless you then reduce the top bush thickness by the same 10mm.
This in essence is exactly what I plan to do
Discopotatoes said:
Bassfiendnoideawhathp said:
s p a c e m a n said:
I'm under the impression though that the leverage pressure would only be altered by changing the length of the part of the bar that you've marked 'leverage'. The length on the drop link applying pressure to the end of the bar shouldn't change the force applied to it, unless I'm missing something... which I normally am
(I'm buying a pair anyway, they're a good find as far as I'm concerned)
+1...(I'm buying a pair anyway, they're a good find as far as I'm concerned)
Phil
Phil
ChimpOnGas said:
<<SNIP>>
The truth is I doubt 10mm will make much difference on our cars...
Absolutely ... The truth is I doubt 10mm will make much difference on our cars...
The point is that if you're *THAT* bothered about a 10mm change in the height of the ends of your rear ARB making some difference that's going to upset the vehicle then don't try to save £80 and get the parts that fit right.
If the "leverage" part of the ARB is - say - 30 cm long (at 90 degrees to the main ARB shaft) then it describes a circle of 188.5cm circumference. A 10mm change in tip height would in that case be less than 2 degrees of change in the angle of the lever which would come out as (using good old SOHCAHTOA)as changing the effective lever length by about 3mm (1%) which is going to make bugger all squared difference as both sides will be equally affected and will simply make your ARB seem very slightly stiffer.
...and the example about ignition advance is irrelevant to this discussion on the change in leverage on ARBs - ignition advance / retard is there to address a number of other factors instead such as managing preignition (detonation) with regard to engine load, engine speed and flame propagation times due to compression pressure and fuel flammability / octane rating and is related to a fixed point (TDC). An anti roll bar is not fixed rotationally other than to the opposite side wishbone (the ARB brackets on the chassis do not lock the ARB rotation) which would also have had the link changed and so would 'match' - the ARB would still be working within its normal range however with the suspension unloaded (for example with both rear wheels lifted) then the ARB will be rotated very slightly further however under all normal uses the ARB will still be within its normal operating angles of rotation and as long as the drop link physically fits and nothing binds up mechanically then the change to the roll characteristics will be unnoticable.
Phil
Leverage is leverage, and angles is angles.
Degrees of crank rotation is the same as con rod angle... and that will always influence the point of maximum leverage, just the same as the level of droop on the handle on your bathroom door will effect how hard you need to lean on it next time you need a pish.
The same rules of physics apply, because rules is rules
The fact is lengthening or shortening your drop links will change the angle of the lever part of the ARB, and that will alter the mechanical advantage the wishbone will have over the torsional resistance of the ARB.
Go for a ride on your bicycle and tell me I'm wrong, your leg muscles will soon tell you everything you need to know about leverage and how the angle of a lever alters mechanical advantage. Now try riding the same bicycle in the same gear on the same flat road but this time without shoes, your leg is now only 1cm shorter without a shoe but assuming the seat post position remains unaltered (just like shortening a drop link) you'll immediately discover how angle alters leverage.
My point is shortening or lengthening your drop links will have an effect, shortening your drop links as in the case of the Nissan 200sx ones will provide less mechanical advantage the wishbone has over over the ARB (torsion bar), and that is more or less the same as fitting a stronger/larger diameter ARB. I say more or less because the amount of available travel will be reduced too, the real question is how will this translate to what you feel & experience on the road?
You can do all the calculations you like, but only real world experimentation will reveal the answer to that question which is why I plan just such experiments.The thing is if you sit down and work out all the possible permeations there are lots, so it would take a very patient man to find the best combination, and you may just find the difference between best & worse is so small it almost becomes a pointless exercise.
But I will...on behalf of the PistonHeaads massive, have a crack at it
Degrees of crank rotation is the same as con rod angle... and that will always influence the point of maximum leverage, just the same as the level of droop on the handle on your bathroom door will effect how hard you need to lean on it next time you need a pish.
The same rules of physics apply, because rules is rules
The fact is lengthening or shortening your drop links will change the angle of the lever part of the ARB, and that will alter the mechanical advantage the wishbone will have over the torsional resistance of the ARB.
Go for a ride on your bicycle and tell me I'm wrong, your leg muscles will soon tell you everything you need to know about leverage and how the angle of a lever alters mechanical advantage. Now try riding the same bicycle in the same gear on the same flat road but this time without shoes, your leg is now only 1cm shorter without a shoe but assuming the seat post position remains unaltered (just like shortening a drop link) you'll immediately discover how angle alters leverage.
My point is shortening or lengthening your drop links will have an effect, shortening your drop links as in the case of the Nissan 200sx ones will provide less mechanical advantage the wishbone has over over the ARB (torsion bar), and that is more or less the same as fitting a stronger/larger diameter ARB. I say more or less because the amount of available travel will be reduced too, the real question is how will this translate to what you feel & experience on the road?
You can do all the calculations you like, but only real world experimentation will reveal the answer to that question which is why I plan just such experiments.The thing is if you sit down and work out all the possible permeations there are lots, so it would take a very patient man to find the best combination, and you may just find the difference between best & worse is so small it almost becomes a pointless exercise.
But I will...on behalf of the PistonHeaads massive, have a crack at it
SILICONEKID345HP said:
Are they genuine or after market drop links ? seen them on the Net from £10 to over £65
http://www.ebay.co.uk/itm/Hardrace-Front-Drop-Link...
http://www.ebay.co.uk/itm/nissan-200sx-180sx-front...
http://www.ebay.co.uk/itm/For-Nissan-200SX-S13-1-8...
I wouldn't waste your money on those expensive uprated ones, just buy the well respected German Febi Bilstein brand for £12.41 each delivered to your door.http://www.ebay.co.uk/itm/Hardrace-Front-Drop-Link...
http://www.ebay.co.uk/itm/nissan-200sx-180sx-front...
http://www.ebay.co.uk/itm/For-Nissan-200SX-S13-1-8...
http://www.ebay.co.uk/itm/391329037606
My guess is even these quality brand drop links will have a relatively short life, but I also wouldn't mind betting they will last quite a bit longer than the Triumph TR6 vulcanised rubber in a ball socket type TVR fitted to the car from new.
These sealed ball joint links should prove quieter, but the real advantage of using Honda & Nissan links is unlike the originals, Leven or the so called "uprated" TVR parts specialist ones... is you can afford to replace them much more frequently.
A pair of Febi Bilstein Nissaan 200sx links is £24.82 and a pair of Febi Bilstein Honda Accord links only cost £18.72, so a full set of quality new type sealed ball joint drop links will set you back £43.54 where the same offering from Racetech Direct they're calling "uprated" is going to be close on £140.00 once you've added the VAT and carriage.
Basically you get the same thing and save yourself £100, this is the same £100 Racetech enjoys as profit, it's a nice margin I would kill for in my game but I guess it's up to you if giving them 100 of your hard earned quids appeals?
Personally I'll be putting the £100 I've saved towards my new Billies
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