I am looking at adding power steering to my manual steering car. I am adding performance upper and lower control arms, KYB's and New rear leafs. I am looking at a box that has A 2.5:1 there is also some other type of ratio numbers that dont mention turns but has to do with the qickness of the reaction of the steering box. Can anybody shed some light on this for me?? Educate me??
Thanks

I'm no expert either but I will try to explain a bit of what I have learned. The number of turns lock to lock is usuallly a pretty good indicator as to how quick of a box it is although it really has as much to do with the internal stops and the resulting turning radius also. If the stops are closer to the center then your radius is bigger because you can't crank the wheel as far and of course the LtoL is less. Some boxes have more effort incorporated into the box by virtue of different valving which gives you a better road feel. Also there are different ratios like 12:1, 16:1. Variable ratio boxes run one ratio near the center and then change the further you turn the wheel. I'm not all that clear on how this affects your steering. When I changed my box out I boiled it down to effort and radius(and availability). I went with a 98 Grand Cherokee box. I'm happy with the results. I could use a bit more effort but it's basically a street car so I'm good with it.

How did you come about the Cherokee box?

Thanks for the info Firebob!! Was it a dififcult installation?? I am trying to achieve handsling and enjoy a little road feel. I am trying to get away from what I call the Pontiac "float" Other Pontiacs I have had feel like you are floating around the road rather than driving it!

Good shocks with decent front and rear sway bars helps a lot.

TOHCan
That is part of the plan. KYB's for shocks. Getting sway bars, new leafs, control arms etc

I think you have a typo there. Did you mean 12.5:1 instead of 2.5:1?

Very helpfull. http://lee-powersteering.com/steering-gears.htm

Thanks for the info. What I meant was 2.5 revolutions of the steering wheel from lock to lock

I picked up the Jeep box at the wrecking yard. I went after the IROC box but this was way easier to come by and the turning radius is exactly the same as a stock 1st gen box.
You also need a different rag joint but one of those can be sourced from a GMC pickup of a peticular set of years(I have it writen down somewhere) and since it's a metric box you also need adapter fittings for the hoses. Sounds complicated but it's not really. I think I was at the wrecking yard about an hour and was walking out with everything I needed, except for the fittings, for $50. You can get the fittings from Speedway cheap. Installation was a breeze. Easy swap. Nice upgrade.

Pozzi Racing Has more info than you might want on first gen f body steering swap, but he details everything pretty well.
He advocates the 12:1 ratio box, but is interested in race prepping his camaro. I went with the 14:1 reman box and am super happy with it. Lots more feedback and 2.5 turns lock to lock. I had driven a pro touring 'maro with the fast box and 18" wheels, way too twitchy for me. I also had a new high pressure hose made at a local hydraulics shop instead of using the adapters.

I will check them out in the am but did talk to glider's recomendation of LEE Power steering. They recomend a Delphi 670 for what I am doing which is more of a road racer /. pro touring. better road feel and if you send in the pump they will rebuiuld it and calibrate the units together. was very impressed with what I learned from them

I had Lee Steering rebuild my factory box, excellent work.

Lee is definitely the way to go if you have the extra dough to lay out for it. They say they will custom make the box any way you want. Any pressure, any valving, any ratio. Know what you want before you order.


I would like to get a set of those SSbraided lines for mine. I think it cleans things up nicely.

A good ratio box is a great start but I am waiting for someone to install a ididit column and report back with the before and after results.

I have the late model Iroc box. It works great but did have to go with a new rag joint & fittings on the box to convert the hoses from metric to standard on the new box. Like Firebob I wish it had a little more resistance on the steering but a huge improvement from the stock box.

If you go with the Lee box you won't be disappointed.

glad to hear all the good words about Lee. I will pass it on to them. They will even calibrate the pump with the drive unit if you send yours in or buy one from them

The pump is $545 or $645, dont remember right now

I spoke to the folks who built mine for me. They have brand new steering gears they can build with whatever ratio you want or need. If you have any questions, speak to Lance. They know their steering!

http://www.pscmotorsports.com/

I got mine from the local NAPA store. They offered a standard and a quick ratio. I choose the quick and it bolted right in and works great.

Best links for steering Box info. Go to the bottom of the page.
http://jimshea.corvettefaq.com/?cat=4

This link has the Camaro steering box specs.
http://jimshea.corvettefaq.com/?p=554#attachments

This link for the Jeep steering box specs
http://jimshea.corvettefaq.com/?p=566#attachments

This CC article even points back to Jim Shea's links above.
http://www.carcraft.com/techarticles/ccrp_0901_gm_steering_box_upgrade/index.html

PY link
http://forums.performanceyears.com/forums/showthread.php?t=643091&highlight=steering

I had my box rebuilt with by Lee the first time around. I liked the idea of keeping my original box. I didn't have to worry about adapters. When I got the car running I hated the feel even thought it had the quick ratio. I could turn the wheel with my pinky. Came to find out that the torsion bar is really what gives the feed back or resistance to turning. I sent the box to AGR the sencond time. I talked with them about it and he took a bunch of info on the size of the wheel, tire size, weight of car and such. I had a AGR pump that wasn't working so I sent it all to them to get worked out. I set mine up a bit on the heavy side but I'm happy with it.

What do you mean "the torion bar is what really gives the feedback"? Only Mopars were built with a torsion bar suspension as far as I know.

I will give them a call just to check as i have not yet ordered the one from LEE. I am still looking at the Delphi 670 they have it with a 12.7:1 ratio. Then going with their pump, calibrated to the unit. After talking to Gail over their a few times now, I am very impressed with their knowledge. They go back to the 70's as far as experience goes
They literally will test and calibrate the pump with the gear box before sending it out. The price of the 670 from them is about $50 to $60 more but that is worth the extra labor they seem to put into it.

To get the power steering assist, a spool valve has to allow hydraulic pressure from the pump to push on the appropriate side of the arm with the appropriate amount of force. The shaft that runs through the box is a fairly small diameter and as a result twists when steering force is applied to it. The spool valve is attached to this shaft.

When you turn the steering wheel at highway speed, there isn't much force involved so the shaft doesn't twist very much, and the spool valve doesn't open very much either, with the result that not very much assist is applied. When you're turning the wheel while parking, the shaft twists quite a bit, allowing the spool valve to open more fully and increase the amount of assist.

That is how the amount of steering effort is tailored; a thicker shaft twists less and generates less assist for the same amount of steering force applied by the driver. That makes for higher effort and more direct feedback. A thin one gives that '60's Mopar novocaine feel, where you can flip the wheel with one finger and have it turn a complete turn on inertia alone!

You can test the amount of torsional resistance your steering box has by turning the steering wheel with the engine off. The shaft will twist a certain amount before hitting the internal stops that prevent damage to that shaft; you'll feel those stops as they take the load and make a direct connection between the steering wheel and the front tires once the shaft has reached its maximum allowed twist. The size of the shaft affects how much force is needed to twist the shaft before it hits the stops. If you know how your steering feels or even better if you have a spring scale, you can test other boxes at the boneyard to see how they compare.

If you have a manual steering equipped car and one with ps, you'll easily be able to feel the difference; the manual box is a solid shaft as opposed to the ps box's twistable one.

It's all in the article that was linked to earlier:
http://www.carcraft.com/techarticles/ccrp_0901_gm_steering_box_upgrade/viewall.html

I notice that they didn't include the numbers from what used to be the good box, which was the WS6 Trans Am box. I've used both and the Monte Carlo SS box is pretty close but is metric.