Scott Russell linkage modification for lowered cars. Discuss.

[edk]

There's a small part that's being sold on b15sentra.net that modifies the geometry of the Scott Russell linkage. The theory is that it doesnt work quite correctly and throws off alignment once a car has been lowered, and this part corrects this.

I'd be interested to know what people's thoughts are on this. Keep it technical if you can please . Clearer shots of what this is and where it goes can be seen in the link at the bottom of the quote.

Here's the details:

QT Adjustable Link

QT link, what is QT link? I am pretty sure a lot of yall might have not heard about Scott Russel Link(SCL). Basically this link is locate on your rear axle(beam). There is a small piece of link connects between this big chunk arm( whatever u want to call) with rear axle(beam).
This small piece of metal actually is pretty useful, and believe me or not
this link has been used on B15/B14/N16/N15/P11/A32/A33/A34
It designed for the cars that have been lowered.

So let me explain how this link work out on our car after lowering

1. Why QT displace after lowering the car?
2. The movement of QT Principle and the usage of V line.
3. How does QT principle movement prevent the car incline?

1.
1.Why QT displace after lowering the car?

If you lower your car, the entire rear axles will extend out to the right hand side.
If we look at pic here, red line shows stock high, yellow line shows after lowering position.
So we use QT adjustable link to replace our SCL to extend out to left hand a little more.
Now it balance on both side.
Red shows stock high, Yellow shoes lowering positing

2.
See the red line here, it shows a V line. When the car is braking or driving on uneven road& turning, the Green arrows will lift the car up.
By now V line will be flared-out, the2 side pivots fix; therefore have the upward resistance so the v line will line up equal. (before lowering)

3.
From this pic you can see when the car makes right turn, body inclines because of the centrifugal force. The reverse strength( red arrows+blue arrows). This is how Nissan makes our car balance, and reduce the chances of inclining.

This QT adjustable link idea is alignment purpose+reduce rear axle jumping so much.
It is all depending on driver, and can be necessary or unnecessary mod.

The following pics show our rear axle(beam) extends out after we lower our car
Here is some measurement to adjust our car

Here is the guy's original post, http://tw.myblog.yahoo.com/b14-ser/article?mid=4026&prev=5441&next=1413&l=f&fid=7

If anyone of you guy still have no clue, or wonder what hell my English doesn't make any sense let me know. I will do the best I can to help out.

 

[Raceworx]

same as an adjustable panard rod on micras dude.. but with our linkage the difference isnt as bad.. my car was a few mm out when compairing arch to tyre.. also would be a right ball ache to install

perhaps one for the more track orientated

 

[Sam]

I did note on my gti when it was low on the coilys that the arch to wheels gaps were different but my gap was larger on the other side..........?

 

[Truganini]

Maybe I am being a little slow here but I dont see how that whole linkage works.

As I see it from the pics on edk's post and from the pics on the guy's original blog, one end of the arm is bolted to a bracket, which is central under the car tucked up by the fuel tank. The other end is bolted to a bracket that is welded to the axle.

Now I understand the principle's of leverage and how the end of the link would follow an arc and therefore would indeed move to one side when the car is lowered, but I am totally missing how that little adjustable piece in the middle can move the axle back again when the two fixed points at either end of the link are still in the same place.

Help me out here guys, can anyone give me a Dummy's Guide To . . . . .

Is it moving just on the deflection in the bushing on the end bolted to the axle and if so, isnt 8mm a huge movement for a bush like that?

Trug

 

[shaggy_master]

Trug you extend this bracket to a slightly longer length than the stock one so the axle remains in the centre after lowering basically..
Its length-adjustable
I actually think it works, in principle.
Joe