Thread: What is actual wheelbase of 110"?

Maybe have higher tyre pressure in the LHS to compensate! (That's just being silly.)

There is likely a good engineering reason for this, as it was a comment about the RRc back in the 1970's that one side is shorter than the other.

I'm no engineer, but if you consider a skate board as they lean the trucks underneath turn inwards. In the coil sprung Land Rovers the different wheelbase may be to compensate for the rotational effects of the engine/drivetrain and keep the vehicle heading straight ahead!

Originally Posted by Lotz-A-Landies

I'm no engineer, but if you consider a skate board as they lean the trucks underneath turn inwards. In the coil sprung Land Rovers the different wheelbase may be to compensate for the rotational effects of the engine/drivetrain and keep the vehicle heading straight ahead!

depending on how the links are set up can change the hole "skateboard" effect....the Original RR, which is what the link design for all defenders, disco 1's and RR classics are based on, had about 0 degrees roll over steer in the front and approx 3-4 degrees roll over steer in the rear. The Rear roll center height is higher than the front. What this means is when turning in a corner the body roll will make the axles steer more "into" the corner (roll OVER steer) the rear will steer more than the front.

having a higher roll center in the rear will mean that the rear end should loose traction first when pushed to hard into a turn...

regarding the rotation of engine effect....this is not constant so I doubt it is designed that way....

one thing LR could have done to improve the rear link set up, IMO, is to push the axle end of the trailing arms (lower links) out as far as they could go.

cheers,
Serg

Originally Posted by Lotz-A-Landies

Maybe have higher tyre pressure in the LHS to compensate! (That's just being silly.)

There is likely a good engineering reason for this, as it was a comment about the RRc back in the 1970's that one side is shorter than the other.

I'm no engineer, but if you consider a skate board as they lean the trucks underneath turn inwards. In the coil sprung Land Rovers the different wheelbase may be to compensate for the rotational effects of the engine/drivetrain and keep the vehicle heading straight ahead!

Nope, no good engineering reason AFAIK, just bad/loose tolerances

Unlike an oval we turn left and right in the real world

Originally Posted by rick130

Nope, no good engineering reason AFAIK, just bad/loose tolerances

Unlike an oval we turn left and right in the real world

May well be loose tolerances but 0.88" seems a lot of tolerance!

Yes I know that we turn both left and right in the real world, however if we were travelling on a perfectly flat and straight road, would not the fact that the engine is rotating cause increased downward pressure on one side and reduced downward pressure on the other. The gyroscopic effect definately affects aircraft, as was found in WWI with the Stopwith Camel.

In our Land Rovers, the downward pressure on the LHS would cause the suspension on that side to depress a little therefore lengthening the wheelbase and vice a versa the RHS shortening the wheelbase slightly with a resulting effect that you steer straight ahead and not ever-so-slightly right.

Just to highlight the issue, who hasn't been watching one of our coil sprung Land Rovers, particularly the V8 RRc, when someone revvs the engine with the vehicle stationary, there is a noticable body roll. What must it be like when travelling at 100 clicks?

There must be some engineers or physicists on this forum?

There is very little inertia at cruising speed, so torque roll forces would be negligable.
Engine revolves in an anti clockwise direction, so any engine torque roll forces, which can be considerable and multiplied by the gearbox transfercase ratios in low gear climbing a steep offcamber gradient will apply a downward force to the right hand side (equal and opposite reaction). I have used this torque roll to advantage at times to keep the vehicle from rolling over on steep ugly climbs by attacking the gradient at a slightly oblique angle with the vehicle leaning slightly to the left. This technique however only works until wheelspin occurrs, whereby torque roll ceases. It's subtle but traction is also improved slightly compared to attacking the grade square on because torque roll is less likely to unload the left hand side wheels.
Wagoo.

Actually, lengthening the wheel base on the LHS does reduce the tendency for a beam axle vehicle to pull to the left on a cambered road. (driving on the left)

Super Pro do this with some clever bushes for the front LH radius arms.
Personally I'd stagger the castor (slightly more on the LHS) but that's a lot harder to achieve.

Originally Posted by rick130

Actually, lengthening the wheel base on the LHS does reduce the tendency for a beam axle vehicle to pull to the left on a cambered road. (driving on the left)

Super Pro do this with some clever bushes for the front LH radius arms.
Personally I'd stagger the castor (slightly more on the LHS) but that's a lot harder to achieve.

And was part of ford and holdens chassis and suspension design a while back.
Seen (and had) several vehicles with longer lhs wheelbase.

Originally Posted by Lotz-A-Landies

May well be loose tolerances but 0.88" seems a lot of tolerance!

Yes I know that we turn both left and right in the real world, however if we were travelling on a perfectly flat and straight road, would not the fact that the engine is rotating cause increased downward pressure on one side and reduced downward pressure on the other. The gyroscopic effect definately affects aircraft, as was found in WWI with the Stopwith Camel.

The gyroscopic effect only exists when the vehicle or engine is accelerated (including turns). In the case of the Sopwith Camel (and other aircraft as well, but exacerbated by the camel's short length and the high power and high rotating mass of the rotary engine). This was noticeable with my Cessna 180, which exhibited a strong tendency to turn left if the throttle was opened or the tail lifted suddenly at low speed, and it had about the same power as the Camel, but much lower rotating mass and a much longer lever arm for the vertical fin. I would have hated to have flown a Camel!

In our Land Rovers, the downward pressure on the LHS would cause the suspension on that side to depress a little therefore lengthening the wheelbase and vice a versa the RHS shortening the wheelbase slightly with a resulting effect that you steer straight ahead and not ever-so-slightly right.

Just to highlight the issue, who hasn't been watching one of our coil sprung Land Rovers, particularly the V8 RRc, when someone revvs the engine with the vehicle stationary, there is a noticable body roll. What must it be like when travelling at 100 clicks?

This effect is the result of the inertial force on the vehicle resulting from accelerating the rotating mass of the engine. At a steady 100kph, as there is no acceleration, there is no force.

There must be some engineers or physicists on this forum?

The engine rotating produces no downward force on either side. There will be a force when the engine is accelerated or decelerated, but not at steady speeds, and because the vehicle is relatively heavy and low powered, this effect will be very small compared to other forces acting on the suspension. The situation will be very different with drag racers which have very high power weight ratio and are as light as possible, and in use are continually accelerating.

It is much more noticeable on aircraft, which, even on the ground, are much less constrained in movement than road vehicles.

John