82-T/A

Hey guys,

Not to steal the thunder of the other manual steering post below mine, but I was curious what the benefits are to having a manual steering rack over a power steering rack. I've been working on my Porsche since I got it, so I haven't really had much time behind the seat (partly because it was attached with drywall screws into the floorboard).

How difficult is it to steer? All the Pontiac Fieros that I've owned have had manual steering and it's really no big deal, and the steering / response is absolutely awesome. It feels like I'm one with the road. However, I'd like to let my wife drive the 944 and I want to make sure it won't be too much for her to handle. What kind of steering effort is required? At speeds I'm sure it's normal, but making U-turns and pulling out of parking spots, can a fairly small girl be able to handle it?

Second question is, will the engine benefit from any reduced drag on the motor? I'm focusing on the interior right now before I clean up and do the maintenance on the engine bay... is the steering pump driven by a timing belt, or an accessory belt?

Last question is, what kind of steering do our 944s have now? In most of the newer cars I've driven (everything from a lowly 96 Grand Am to an 06 Solstice) the power steering is speed variable. Basically, it gives you more boost in the lower rpms, but none at all while on the highway (to give it a more stable driving experience). Can I expect the Porsche to be like that as well?



Thanks!!!


Todd,
2006 Pontiac Solstice
2002 Ford Crown Victoria LX-P74
1987 Pontiac Fiero SE/V6
1984 Porsche 944
1981 Pontiac TransAm WS6
1973 Volkswagen Type-2 Transporter

Airflite40

The main advantage is no leaks.

I don't know what the power steering rack in a 944 feels like, since mine had no pump and no fluid left in the rack when I bought it, but I can tell you the manual I rack I put in feels great.

The hardest part is parallel parking and low speed manuevers, like doing a 3 point turnaround in an alley or something.

I don't mind the steering effort since I put the rack in and I knew what I was getting, but I would expect my GF to be annoyed by it and struggle with it....if she could drive a 5spd that is!

sharky47

No leaks

More room in engine bay (no fluid tank)

Less weight

Less rotational mass on engine (small amount, but still)

Less parasite drag on engine

More feedback from road


I have two manual steering cars and three power cars and I like the manual ones better. The ONLY time it is more work is in a parking lot and even then it really isn't that noticable. I am getting ready to convert my daily '87 to manual........

UncleMaz

Along with no leaks, the other benefit is forearm strengthening. I wouldn't have it any other way in a sports car.

V2Rocket

I have a power rack that blew its seals and leaked out all the fluid, so I assume that could be considered a semi-manual rack. I really have no problems with it, even at very low speed (U-turn), I'm just used to the small gear on the end of my steering shaft. Of course, I'm bigger than the average person (6'5"), so that might be contributing to my driving ease as well

Mike C.

I swapped in my spare (manual) rack when I was having my power one rebuilt and after 3 weeks I was happy to put the power steering back in. The manual might be better on the track but for a daily driver I found it a pain in the *** for any low speed manuvering. Also, the manual rack has a slower gear ratio so you have to turn the steering wheel more to achieve results. YMMV....

Mike C.

I also have a 1990 Mazda Miata with manual steering and on that car it's great. The 944 has more weight on the front wheels and a larger tire contact patch than the Miata...

pjburges

I have a manual rack in my car and it's not nearly as bad as some of the manual racks I have driven in other cars.

The manual rack gives a lower ratio than the power rack which decreases steering wheel torque.

On the power rack, no variable valving is used, you have a constant amount of assist at any speed, although one might argue with increased RPMS the increased pressure might make the rack slightly easier to turn.

If you drive your car on the edge (the legal way), you will find alot of benifit in the manual rack because you can drive your car closer to the tire's and vehicle's limit.

This is becuase as you go into a corner your combined mechanical and particuarly pneumatic trail (tire contact patch shape) begin to change. This change in the contact patch shape via the pneumatic trail changes the amount of torque "feedback" going to the wheel. The tires will gradually start to break away and the torque induced on the steering wheel will start to lessen as well. That change in resistance in the steering wheel is because the lateral force across the tread patch is decreasing and moving toward a breakaway (slide) (Milliken, 1995)

Its kind of like that movie in the 944T forum of the crashed Ferrari Enzo. If only the guy knew how to drive, or had a tightly geared manual rack like the 944's he wouldnt have continued to laterally load his tires b/c he would have felt that decrease in resistance in the steering wheel and backed off before he started sliding out of control. In summary I think the 944 manual rack kicks butt. However, it is harder to deal with in a grocery parking lot - but then again who buys a Porsche to go grocery shopping with, maybe someone with a Cayenne I suppose. Ok im off my soap box for the day

82-T/A

Thanks, I appreciate it. I kind of agree... I just know my wife will want to drive it, and I want to make sure she'll be able to. She'll just have to start working out her foreams I suppose!

M758

Benefits
1) Better feedback throught steering wheel allowing you a better feeling of what the front wheels are doing in the track surface.

2) Less weight. Manual rack is lighter than power and has no powersteering pump.

3) Less crap to break/leak. No leaking powersteering anywhere and no adjuster rod to break.

4) More room for 951 oil cooler.

Downsides
1) Hard to turn at low speeds like in a parking lot

2) requires strong arms in an autocross. Those not preppared can easily get "behind" and simply not turn the car fast enough for certain corners.

3) Could induce fatigue if usings big front tires on the track


I have run all 3 configuraitions. Power steering, power rack with the pump removed and manual rack.

My preference is as follows
Track car = Manual Rack
Street car = PowerSteering
Autocross = Powersteering- never use unpowered powerrack as you can't turn enough. Manual is ok, but requries lots of work.
Track car with massive front tires = Powersteering

pjburges

Yeah, I was just blasting Cayennes really. It is a bit of a pain in tight spaces but certainly not impossible. Be careful though b/c your wife could get tough like Arnold Schwarznegger cranking that wheel around and be like - Ruun get back to the choppa!! ayeeehaa!

did you know that the steering intermediate shaft has "Germany WWII PNZR" engraved on it? Its made out of cast steel and weighs about 30lbs. It probably came out of a panzer tank.

Jay Gratton

Growing up my Dad had a '83 944 without power steering and my Mom (who is a little women) had no problem driving the car as long as the car wasn't sitting still. She would always have to be rolling juuuuuuuuuuuuuust a little to get it to turn. Other wise she loved the car!

theedge

Harder to turn, more so if you leave the pump, lines and fluid in....

But a 5' 4" female friend of mine did just fine in parking lot type driving while I taught her to drive 5 speed.

500

That is a good summary. What would you consider to be the widest front tire you'd still prefer the manual rack with?

M758

Don't know as have never run with anything wider than a 225 (in my race car or 944 turbo). Me thinks 10" wide slicks would qualify.