Thread: R&P and bump steer

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What are the correct angles to prevent bump steer on a mustang R&P for street use?.I would be installing it on a 1989 Astro van.I know of two that where done.Just looking for additional input.On Astro vans it eliminates the constant replacement of idler arms which is one of the downfalls of the steer design of the vans.

Please and Thank You.

did you see the thread " pinto front suspension angles " ?

This Woodard steering tech article is geared more towards race cars and is a little lenghthy,but very good info.
http://www.woodwardsteering.com/imag...df%2064-79.pdf

Thanks guys.I'll check those ref''s out.

The short version is to get the rack at same height as the tyerod attachment point, thta way they rise and fall at the same 'rate'. A few different ways to get this done.
If the attachment point is higher or lower than the rack centerline then the arc travel will run 'uphill or downhill' and toe the tires in or out as it goes over a bump. The worst case is when the angle is uphill and when the tire falls it will toe 'out' and that is when the car will change direction, esp when cresting a small hillock. If id is downhill then it will toe in, you'll have tire scrub but the car will go straight.

i have question about rack and pinion i have a 1954 chevy truck is there a r&p that i can pull out of the salvage yard and make a mounting plate for it thanks

PM Smiliesafari.He installed a Mustang R&P in his Safari van.In fact,I would be getting the attaching points from him should I do a R&P conversion on my van.

The rack and pinion steering conversion is a lot less complicated than some people would have you believe. I did the first sucessful (that I know of) r&p conversion, in this kind of vehicle, on my 1996 Safari van. This conversion has been in the van for several years now and has worked perfectly. The reason I did the r&p was to replace the sorry drag link type steering that these vans come with. The drag link is hung on two idler arms that for some design flaw wear out in as little time as two years. And I'm not talking about cheap chinese junk parts. I use Moog suspension and steering parts. Some things to consider: The rack must come from a vehicle that has the same steering location as the vehicle that it's going to be used in. By that I mean front steer or rear steer. Is the steering in front of or behind the axle centerline? The rack should have enough travel that the spindle stops can be reached. It should be located in a vertical and horizontal position as near as possible to a straight line with the steering knuckle tierod attachment points. It should be from a vehicle of the same weight as the one that it is going to used in. If it is a power rack then almost any modern power steering pump will work. You will most likely have to modify or have custom hoses made.

Originally Posted by 54 chevy guy

i have question about rack and pinion i have a 1954 chevy truck is there a r&p that i can pull out of the salvage yard and make a mounting plate for it thanks

The 54 Chevy truck has a solid front axle, so replacing the steering with a R&P unit is going to be difficult without inducing bump steer. The only way this is possible is to attach the R&P unit directly to the axle, but then you have the problem of providing a flexible steering shaft from the steering shaft to the unit. It also greatly increases unsprung weight which adversley affects handling and ride.
Of course, you could install a Unsteer R&P unit to replace your steering box, but this is not something you are going to find in a salvage yard. I have never heard of anyone building a Unisteer type unit from a salvage yard R&P, but I suppose it is possible if you have the machining capabilities.