Sumo Bumpsteer etc. etc.......

[stu e]

Cortina rack mount nearside.
Sorry it's not a good picture but you should be able to get the idea.

[Sidecarbod]

Originally Posted by stu e

Cortina rack mount nearside.
Sorry it's not a good picture but you should be able to get the idea.

Cheers for the picture.

That does not like an easy rack to modify

Pete.

[Sidecarbod]

Originally Posted by Sidecarbod

Your sort of assuming that you have bumpsteer problems!

Although the grip of death on the steering wheel would suggest that you do!

Support the car at ride height on bricks on one front side of the car only, have both front wheels on the ground, one will be under the weight of the car the other will not.

Attach a long stick to the wheel so that its horizontal and pointing forward. Jack the wheel up under the wish bone and watch what happens to the end of the stick. It should move upwards, if it moves up and outwards (or inwards) then you have bumpsteer. (In fact it should move outwards a tiny fracttion as the wheel itself is also moving outwards as it goes up....maybe 5mm outwards).

If the stick was say 4 metres long (a laser beam stick) then the end of it would move out 100mm even though the wheel and only moved out 5mm.

The longer the stick the easier it is to see the error.

Have the steering pointing striaght ahead during the test.

Pete

Just had a thought!

You will have to slacken off the the shock spring so that you can jack the wheel up from its ride height up to the shocks' bumpstop. Doing this will show you the bumpsteer from normal ride height up to the full shock compression.

You could measure from full droop to normal ride height by jacking the car right up. Stick a brick under the wheel that you are NOT measuring so that the rack has something to push against. You can then measure the bumpsteer from full droop to normal ride height. (The point at which the jack starts to lift the car of the supporting bricks). If the shock spring is slackened off you can go from full droop to full compression.

This all sounds hard but believe me its not, you only need some bricks, a jack and a bamboo stick!

Pete

[Noel]

The Mk3 with Chevy lump uses a Ford P100 rack. I'm sure that if you fitted a RV8 then the rack was different. I measured the difference between the two at Pilgrim and it was the 8mm difference that was cut off the RV8 rack. This is why I delayed the mod, as at the time the mods were being done to RV8 installations.

Looks like the Mk2 is different again?