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Novasportc550

Steering problem

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hi, as most of you will know I have recently built a manta 400 rep. But having a problem with the steering, it's not returning to centre. It's a standard steering rack and has the Corsa b elc power steering.. Anyone else have this problem..

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That is normal with the Epas fitted

Because you are turning a couple of extra bearings and the electric motor internals the small amount of drag in the epas column is enough to stop the normal self centering from working as it did before. It mostly affects it when its only a little off center at lower speeds, and is very noticeable compared to a normal car. But you do get used to it quite quickly if you drive it a lot. Some of the first modern cars with EPAS have the same issue to a small degree but most manufacturers have changed the suspension geometry to get the feel back now.

The way to get the feel and self centering back is to increase the castor angle in the front suspension. (the castor angle is an imaginary line drawn through center of lower balljoint and upper balljoint on the upright) to increase castor you need to move the upper ball joint backwards.

You can get a small amount by moving the spacers on the upper wishbone bolt to the rear of the x-member, but that doesn't help much. For more you can cut the tube that goes through the x-member at the front and add spacers at the rear. Depends how far you want to go and what you are using the car for. Or even modify your upper wishbones/ build custom ones.

The works 400's ran a lot more castor but they had custom upper wishbones, and trick uprights to do that. Of course lots of camber makes the steering really heavy, which is ok with epas but without it its a pain. Spewy555 when he was running his 400 rally car was using a huge amount of castor 7.5 to 9 degrees with his Epas from memory.=

Oh one other thing the manta's had different amounts of castor as standard through their evolution. The early B's had least, then the face lifted 1.8's, with the GT/e having the most. I know the upper hole in the Upright is in a different position on some of them so presume it was all done by different uprights rather than different wishbones as well. So depends what upright you started with to what castor you start with.

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Would the lack of self centering be the reason the steering feels a bit vague, or could it be because I've got a quick rack as well as the epas?

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Depends what you mean by Vague.

You do loose a little of what you are used to in the way of feedback from the front wheels, As again there is extra drag in the system. Changing the castor will also bring that back. It should still be very precise with a quickrack on, if there is play or a loose dead spot in the steering it isn't because of the epas as it is a solid shaft through the middle.

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Would think that your wide 205 front tyres should return steering to centre everytime, its as easy to turn this system when working correctly, with car jacked up at the front, and turning the wheels in and out.

Either something is not right with the rack, or the ecu, motor or controller.

You have a sensitivity level controller fitted, right!

Edited by brady

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