Power Steering questions
 

I was wondering what anyone is running fro power steering on a 2nd gen race car. We have a 13B P Port with a 51 Weber, we have no computer etc. The car is quite hard to steer and has been for years, as I get older putting power steering back in would be nice. The factory pump is computer assisted and only designed to run to a max of 7,000rpm and we run between 7,000 - 10,000rpm. Anyone have any proven idea's??

Are you running a de-powered rack, or a rack that's just got the lines looped? Is the yoke plug/nut overly tight or have you tried loosening it?

We are running a de-powered rack right now.

you have options!

the S5/high option S5 dual line vehicle speed assist rack uses a computer, but if you unplug it, it gives you 50% assist all the time. if you plug it in, the ONLY input that the thing uses is vehicle speed, which comes off the stock speedo. or you could build a box i think its a 0-5v signal.

the other option is the S5 base model system. its just a normal PS system, no computer. the rack is a bit slower 17:1 instead of 15:1, but IMO it feels more natural.

you will need a bigger pulley to drop the pump speed in either case, but that isn't a huge problem either

Not sure if you are into fab work or anything...but I run a late 70's chevy car PS pump with a stock billet aluminum pulley on a 3 port rack. I made a simple bracket that bolts to an A/C only bracket. i can use the factory tensioner with a slightly longer belt and it doesn't interfere with anything.

I spliced the returns together. It's excellent. No complaints. Dry steering is easy and I rev my engine to 8500 with no cavitation, boiling or spills.

The PS pump would be happier with a trany oil cooler tho.

Thanks for all your input! The S5 base unit seems like the way to go, I wonder if it will work with the quicker rack?

Of the suggestions above, is anyone actively road racing with your set up and turning over 7,000rpm consistently?

I'm running the s5 base model PS setup and shifting at 9000. The unit has become noisy lately while parking / slow speed, but seems to function ok.

i think a smaller pulley would really be a good idea

Is that in a street/track car or strictly track??

^ road racing and track days. I only notice the noise in the paddock.

i meant under drive! i think that would actually make the pulley bigger

My setup sees no less than 4K rpm unless in the pits warming up/cooling off.

I shift at 8500rpm and most my road racing is in the 6-8500 range.

The car is strictly race. It is not street legal and is a battered track mule! :lol:

The the stock SBC pulley is quite large and under drives it perfectly when using the stock A/C pulley on the crank. No bubbles in the fluid after a hard race nor is there any complaints from the pump. It doesn't get hot either.

My bracket is just the stock SBC base bracket with a small plate welded to make a "t" with 2 holes to line up with the upper A/C mounts. Very simple. Was litterally done in 15min start to finish!

Good luck with any route you take!

You were right the first time. Larger pulley on the pump, smaller drive pulley (aka under drive).

If you can post a pic sometime that would be great!

Have you looked into using a proper manual rack? While the ratio maybe high it will certainly be easier than reinstalling the PS system. Simpler and lighter also.

I have one and never had any issues nor thought of it as heavy.

-bill

1st: Is the dog in your picture a Great White Pyrenees?
2nd: Tried the manual rack and it was so slow it was hard to correct oversteer with it. It wasnt much easier than the converted power rack we have in now.

With a smaller diameter steering wheel, it does become a bit heavy in the paddock and slow, tight corners, IMHO

Ask and ye shall receive. Hope this gives you what you are looking for. Hard to get pics as my engine bay is really cramped.

There isn't really anything special about it. The factory FC feed hard line was re-flared to accept the GM pump fitting. The 2nd and 3rd port are tee'd together to the single return on the gm pump. Mazda bends in the hard lines stay the same.

Parts:

RX7 AC only bracket
Brand new GM pump $55 @ most parts stores! (From late 70's mid/full size cars)
Billet Aluminum pulley $25 @ Fleabay
low driver's position bottom bracket $5 @ wrecker
4" piece of flat stock (Scrap Pile)

The best part is, if you blow the pump, you can get a new one almost anywhere. This is why I also run a SBC alternator. 125 amps of cheap replaceable goodness in the stock location! Also, with no clearance issues!

http://i56.photobucket.com/albums/g1...B/P3070012.jpg

http://i56.photobucket.com/albums/g1...B/DSCF0188.jpg

http://i56.photobucket.com/albums/g1...B/DSCF0191.jpg

http://i56.photobucket.com/albums/g1...B/DSCF0189.jpg

http://i56.photobucket.com/albums/g1...B/DSCF0192.jpg

Let me know if you need anything more specific.

Cheers!

Thank you for the pic!!

Good catch - my wife and I work with the breed rescue so we have two or three around the house at any time. :-)

-bill