37 Ford Build...........Continuation

[kwhizz]

This has got nothing to do with any of the Muscle cars talked about on this site........But....Just in case you ever become exposed to these issues this will help in the Knowledge Base.....There is a link at the bottom of the page to the original build for the "New" guy's here.......

Just for what it's worth to anyone else doing this type of a swap in a Street Rod or other with a Mustang II type suspension........I had a issue that it seemed to be VooDoo magic that nobody (Suspension manufacturers included) seemed to be able to address correctly and really understand.........Now.....these guys....Heidt's, TCI etc all sell their kits with the option of Power Steering.........Now......The problem comes in with the GM pumps putting out way too much flow and pressure for the Mustang II racks....The II rack uses 2 GPM and 900 PSI.........the GM pumps (depending upon which one you have) flow from 2-3.5 GPM and 1100 - 1800 PSI.........so.....There is a major mismatch and the car are way too "Twitchy" at highway speed.....so....when you call and ask what to do they recommend the Heidt's bleed off valve or a flow restrictor out of the pump.......these Band-aid fixes basically take the sharp edge off the problem but don't really solve it.........
With that said......I did the Band-aid fix and was able to drive the car many miles, but......at Highway speed you had to be aware to the "Quick" steering sensitivity of the car.......so....The comfort level of driving the car was O.K......But it really wasn't O.K....
The car was so perfect in every other aspect that I just couldn't leave it alone and I had to educate myself to get into the world of this VooDoo magic to resolve this issue...
Now.....I've got the GTO Power Steering pump on my car which has the 2-2.5 GPM flow and 1100 PSI.......The normal Mustang II Power Steering rack is 2 1/2 turns lock to lock......after researching a little bit I found out that the 84-86 Ford Thunderbird Rack is a bolt in replacement for the II....and it is built to operate at the GM pump pressure and it's 3 turns lock to lock..........
I just swaped the racks out and went out for a test ride.........absolutely "Perfect"....I don't understand why these guy's that sell this stuff don't have this knowledge at their fingertips.....or supply the T-Bird racks with their kits....Now....If I was building a Auto cross car the T-Bird rack might be a little slow.....But...for the normal street driven car the steering is just too quick.....

















http://ls1tech.com/forums/conversion...2-install.html

[Canuck]

Ken
It takes a smart and determined guy like you to sort out what others can't.
The others work on theory and probably don't drive a vehicle 4-5000 real miles to find out theory doesn't always work.

Nice work.

Paul

[Dicky]

Ken, thats a Beautiful Build, &amp; real ADULT money. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] It looks so good. Thanks for the tip on the Ford Vs. GM pumps &amp; racks, that will help alot of builders.

DH [img]<<GRAEMLIN_URL>>/flag.gif[/img]

[MrsBillyBobcat]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Canuck</div><div class="ubbcode-body">Ken
It takes a smart and determined guy like you to sort out what others can't.
The others work on theory and probably don't drive a vehicle 4-5000 real miles to find out theory doesn't always work.

Nice work.

Paul </div></div>

[img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] [img]<<GRAEMLIN_URL>>/worship.gif[/img]

[markjohnson]

Ken, that's very interesting and thanks for taking the time to share . . . . like you always do. Hey, let me just ask if a larger Power Steering pulley would slow down the pump enough to be usable? Thanks..

[kwhizz]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: markjohnson</div><div class="ubbcode-body">Ken, that's very interesting and thanks for taking the time to share . . . . like you always do. Hey, let me just ask if a larger Power Steering pulley would slow down the pump enough to be usable? Thanks.. </div></div>


Mark......You would reduce flow (slightly) but not Pressure........And there are about 10 different GM LS pumps that all put out differnt GPM and pressure.....Gets real complicated real quick.....

Ken

[PxTx]

Interesting to read that Ken. When I did my AAN S4 5 cyl turbo swap in my old 1987 Audi 4000 I had concerns about power steering compatibility. I was lucky and it all worked out. Dawing from my experence and yours, I think the real issue is probably flow, which prior to your post, I had not considered.

My original PS rack had a pump on it that was rated at 75 bar (which is about 1100 psi). When I swapped the AAN motor, the S4 had hydroboost brakes since it was a turbo car. I did not want to go hydroboost, so I kept my OE brake system. My original PS pump was too different to swap on, but I was able to grab a pump use in the later A6 that physically was the same, sans the extra pump segment for the brakes. The A6 pump is labled 120 bar (about 1800 psi).

My car drives great, but I am cautious not to stay on the steering lock when in tight turns. I've compared my car to stock cars and the steering is no different. I always wondered how the increase in pressure seemed to have zero influence on the steering responce and feel (doesn't feel any lighter than stock). After reading your post, I think it is probably due to wither having the same, or lower flow as the stock pump.

If that is the case, Mark's question really is interesting, as a possible solution. Thanks for sharing!

[Xplantdad]

Great stuff Ken...as always!