Panhard Rod

[yohan18]

hey guys

i was looking around and i seen that they said its nessasary to have a adjustable panhard rod, can anyone tell me why this is so? as i have lowerd my ke70 and i cannot find any info on this.

 

thanks matt

[ke70dave]

panhard rod keeps the diff in the centre of the car.

 

when you lower the car, the geometry of the rear supension forces the diff to move to one side.

 

if you have lowered your car, go and compare the distance between your rear wheels to the guard. you will find that diff is offset towards the passenger side, so the

 

you don't exactly need a panhard rod if your tyres aren't scrubbing...but i would highly advise it, as it straightens everything up. and you new bushes with the panhard rod, so your rear suspension feels a bit tighter too.

 

i suggest whiteline, nice and cheap, i got mine for about $140 delivered i think. ebay go!

 

i cannot find any info on this.

 

ohhh really?

 

http://www.rollaclub.com/board/topic/19309-ke70-panhard-rod/

http://www.rollaclub.com/board/topic/46210-ke70-adjustable-panhard-rod/

Edited July 27, 2011 by ke70dave

[GJM85]

panhard rod keeps the diff in the centre of the car.

 

Why, specifically, to the passengerside?

I've noticed the rear end of my 20 sits about 10mm out on the passenger side since I installed 50mm lowering blocks and the ke55 shocks...

Edited July 27, 2011 by GJM85

[ke70dave]

the panhard rod is a single rod between the chassis and the diff, thus the mount on the diff moves in an arc so the diff moves literally as it moves up and down. Have a look at a ke70 rest.end and you will see why it moves the way it does. Your ke20 is a completely different rear end to a ke70.

[GJM85]

Your ke20 is a completely different rear end to a ke70.

 

Tell me about it. I'd have fixed off the ke55 sway bar if the chassis didn't run on the inside of the floor pan in the rear end... That would have held the diff centre.

[altezzaclub]

Gav your diff doesn't move sideways as that is working against the wide width of the springs. They resist sideways forces very well and only the spring hangars twist. They're prone to windup under acceleration and braking, so they axle tramp easier.

 

The Ke70 has coils, so there is nothing to stop sideways movement except that panhard rod. You can stop the diff moving from side to side in its arc as it moves up and down by swapping the panhard rod for a Watts linkage. mitch-12 has one fitted.

[B.L.Z.BUB]

As the chassis (blue) lowers, the panhard pushes the pivot point on the diff out. (red)

Forcing the diff out of center (green)

 

[ke70dave]

brilliant diagram!

[yohan18]

So in light of all that, is that why lowered cars with non adjustable panhard rods like to spin/flick out of control in the rear end? Cause the diff is no longer in the centre of the car?

[GJM85]

I c said the flee. Maybe it's just my eyes or the body. Everything seems to measure up. With the exception of measuring the gaurd to the outer edge of the tyre. That't where the difference is.

[B.L.Z.BUB]

So in light of all that, is that why lowered cars with non adjustable panhard rods like to spin/flick out of control in the rear end? Cause the diff is no longer in the centre of the car?

 

It wont cause handling issues. The amount it moves is negligible. I only got an adjustable as it was dirt cheap and I needed to do my bushes anyway.

[altezzaclub]

is that why lowered cars with non adjustable panhard rods like to spin/flick out of control in the rear end?

 

More to do with bad setups I'd say- I don't see V8supercars spinning out of control unless someone hits the 600bhp pedal!

 

Lowering a car is actually very complex, seeing manufacturers spend millions paying engineers to set it up correctly in the first place. Some great stuff on the web however, start with centre of gravity & roll center, and read how to prepare an autocross or gymkhana car.

[philbey]

Remember though that they spend millions to engineer the parameters for the car and it's target market.

 

Corolla stock setup were likely to meet the safe yet comofortable requirement and not the handling requirement.

 

The science is straightforward, like altezzaclub said, there's a lot of info out there and simple performance mods can be done easily and effectively, if you read up first!