Rack and Pinion conversion

[bygrace]

Rack specs

Wow Mike, youre a real specs guy. I just went ahead and put 'er in. I'd say the specs are pretty equivalent. Yer right, any tilt to assist in aligning to the steering column has to be built into the mounts. Esp the left, since the right rubber is round. I just made their angles match for looks, as you will see. So is your address on this site or what?
Mike S.

[Derbird]

I am using a pump off of a 1987 sunbird, it is small with a remote resivor and not very expensive.

[bygrace]

Sounds like a nice pump. Let us know how it works. Lately, I've been looking at the electric power steering that simply replaces the middle of the steering column. Servomotor, controller and all in one place, under the dash.

[Brushwolf]

Wow Mike, youre a real specs guy. I just went ahead and put 'er in. I'd say the specs are pretty equivalent. Yer right, any tilt to assist in aligning to the steering column has to be built into the mounts. Esp the left, since the right rubber is round. I just made their angles match for looks, as you will see. So is your address on this site or what?
Mike S.

PM has been sent..

[Brushwolf]

PS pumps for R&P conversion

I am using a pump off of a 1987 sunbird, it is small with a remote resivor and not very expensive.

Yeah, rather than mess around trying to get pump pressure ratings to match the rack it would seem simplest to just get a pump that matches the rack, fittings and all.

Sunbird is likely similar to Cavalier and Corsica pump though they list different pumps for different 4 & 6 cylinder motors (and racks). Rebuilt Cavalier pump for V6 rack is only about $40, then figure out a pulley and mounts to fit motor...

For anyone that cares, it looks like Ford used an Eaton pump until about 1965, then went to a Thompson pump into the 70's - although I have a (74?) Lincoln 460 with what appears to be a Saginaw factory pump too. Other pumps used by Ford too. Too many to mess with.

Near as I can figure, these changes were all made because of progressively greater pump pressure output requirements.

Up until the ram type PS went away in favor of the integrated steering boxes, the pump pressures were as low as 620-740 PSI. Some of these pumps can be modified to increase pressure though, along the lines of modifying an oil pump for higher pressure though it appears.

Back in the day, the problem has usually been the opposite as seen in street rods (GM pump in the 1970's put out about 1000 PSI and MII rack can only handle about 800 PSI). Too much pressure...

So, you can get pressure reduction valves to knock the pump output down and use the GM Oldie PS pump with MII rack. That would seem to indicate the old GM pumps are close to later GM R&P pressure requirements.

Tuff Stuff aftermarket pumps (GM Saginaw style) put out about 1200 PSI. (And sell a pressure reducer to use with it if you have a MII rack).

1988 Mustang 5.0 pump puts out 950-1230 PSI (I have one here). Apparently 85-88 TBird (R&P) uses a higher pressure pump compared to MII rack of around 1000 PSI, so if you swap a TBird rack in to replace a MII rack (same dimensions) you can eliminate the pressure reduction issue and TBird rack works with GM pump with no pressure variance issues.

Which is a backwards way of saying that it then appears that the 85-88 TBird pump puts out roughly the same pressure as a late 80's early 90's Mustang pump, kind of like you would expect. I have a couple of those TBird pumps with V pulleys too, but off 2.3 Turbo Coupes..

But the pump that was originally used with the rack only leaves you with mounts and pulley differences, so that would seem to be the easiest route and let the engineers figure out what the output of the numerous older pumps might be..

Thanks, Mike

[bygrace]

pump and rack specs

Amid all the pump and rack specs, I would be interested in checking for the proper range of travel for the moving center on these various racks. For full right-to-left turning ability, that is. The one I used comes up short in this department.

[Brushwolf]

Yeah, that would be good to know.. They don't publish that on the websites I have looked at racks. What rack did you use again?

Thanks, Mike

[Brushwolf]

Oh yeah, Corsica.. Thought you were two different people, but I guess not...

[Brushwolf]

Have a Cavalier rack here maybe I can check when I get the car back from western MN. Going to pick it up now and will be gone a couple days probably. Prefer to get out there by dark.

I can live with a little shorter turning radius though, I think. Automatic and PS in the event it takes a 2nd try isn't too tough..

Thanks, Mike

[bygrace]

rack travel

I guess you'd have to compare it to the ball-stud travel on the original setup. Or any fixed point on the center link. Kinda late for that if everything is taken out (I think I saw pix with no motor, etc.) Original travel mashes the spindle casting into the control arm.
Um. I might have you guys mixed up too. Too many Mike's.
Hey did brushwolf get the mount pivtures i emailed?
Mike S.
The old guy with an S... Not just plain Mike.