I am swapping and will keep data as I go along. Some of you might think this is stupid, but I really enjoy experimenting and collecting data along the way. I just took the PS pump and ram off and still have the rest of the PS system hooked up. I will "try" to drive it tomorrow. Then I will pull back into the driveway and use a torque wrench to measure how hard it REALLY is to turn without the power assist parts. Then I will put in a full manual system with the PS gear box, measure with a torque wrench, and then put in he Manual box and measure. So, hopefully, we will not discuss how it is "a bit harder to steer" and will have real numbers to toss around. Only problem is I forgot to measure the torque with the power system hooked up. If someone has a power system and 215 tires, and has the time or interest to do so, I would like the torque numbers... If not (most likely) then I will still do the experiment with the other configurations.
Rando76 did this swap. reference thread:http://mmb.maverick.to/showthread.php?t=16189&highlight=steering Rando, do you have any feedback? edit: Looks like Frank (71Gold) did this also. Frank? Feedback?
I am going to just experiment with it along the way. Today, I will blow all the fluid out of the power valve (still installed) and tighten the adjustment screw all the way, hoping it will take out some of that play. Then attempt to drive it (only in and out of the driveway, maybe around the block), using the dry valve as a makeshift Manual Adapter. Not sure if tightening the adjustment screw all the way will do anything, but figured it couldn't hurt. I was late getting my money order in the mail for my manual setup, so probably won't get a chance to install it until next weekend, maybe the weekend after.
OK, drove it with PS box in, as well as the valve, but the adjust screw is tightened as tight as I could get it. I have a 13.5" steering wheel, and it would turn with only moderate strength needed, preferably with both hands, for wide radius turns. To make a right or left hand turn from a stop and at low speed, it took both hands and quite a grunt to turn. On the epoxied garage floor, 35psi in both front tires, 215/60r15, it took 33 ft/lbs to turn the wheels (measured from the big nut in the steering wheel). I will try it again with PS box and all manual setup, and again with MS box and manual setup. It will take a week or two before I can do this.
Anyone have any idea how much HP I freed up by losing he power? I didn't even think about it until now...
I wouldn't be amazed if it was a very small amount. I was guessing 5-ish. Just a little less rotating mass and wasted torque, and my traction should be improved, now that there isn't a fine spray of steering fluid across my back tires
I took it out on the highway and took it for a short spin. I still don't trust that little ball joint at the top of the valve. It still has that 1/2" play that it had when it was power assisted, but instead of reactivating the other side and then making the car weave that way, back and forth, the car stayed straight and I had to make minor adjustments back and forth to keep it there. BUT, the steering is MUCH more sensitive. You can feel every little bump and dip in the road. I like that. I bet it will be even better when i get the entire system up and tight.
Since I had the car off the ground for another project, I decided to slowly drop it to the ground until I could steer and it felt about like how it felt with the power steering, just so I could measure (approximately) the torque needed to turn the wheel with the PS system installed. Well, when I got it just about right, I put the torque wrench on it and no matter how low I went, it still turned without "clicking" the wrench. So, I guess it is safe to say the baseline torque with power steering installed is close 0 ft/lbs, I will estimate 1-3 ft/lbs. I don't have the means to measure in/lbs.
The only difference between the boxes is the number of turns of the wheel from 'lock to lock' they call it. That is the number of turns it takes to get your wheel from hard left to hard right. The PS box does it in fewer turns. The manual box has more turns so it is easier, but the steering is not as responsive. It's all in the gears... think of PS as having 4.11 gears for quick turning, while the manual might be like 3.00 rear gears for ease of use, but is not as quick. My 75 had PS when I got it. I took the pump and hoses off and drove it for years. It took a little getting used to when not moving, or going very slow. Like when trying to turn into a tight parking space. It isn't bad after you get used to it... My 72 has manual from the factory and I don't like it. You have to turn the wheel too much, and the effort is not that much better. When you are still or going slow, it still takes plenty of effort. I was told, after the car was parked, that all I had to do to make the steering easier on my 75, if I wanted, was to take off the slave cylinder. The reasoning is that part of the effort required was overcoming the resistance of the piston in the slave. I never thought about it, like I said, a day or two with the pump off and I was used to it. I don't know about Maverick guys, but Stang guys like putting the PS box on their MS cars to get quicker steering. It is considered a performance upgrade, and I agree. Dave
I have a small steering wheel, and the power box on the manual system (actually, just the power system minus the pump and power ram) was quite difficult to steer with 215 wide tires. I was afraid I was going to bust the little arm off the power valve before too long, so I quit driving it until I got the manual system set up.
Little arm on the power valve? I don't know what you mean... My 75 has a 13" Grant wheel. I took off the pump and hoses, that was it. I left the ram on the steering linkage. Just too lazy to take it off. I am sure the piston in the ram added plenty of resistance to mine. Especially running dry for years. It is still on there, 16 years later. However, it hasn't driven under it's own power in 8 years. Anyway, 13" wheel and 215/70s the entire time I have owned it. It was noticably harder to steer with the 351c installed, but it is quite a bit heavier than a 302.
