Power Steering delete for fuel economy gain - anyone done it? - Page 4 - Fuel Economy, Hypermiling, EcoModding News and Forum

arb · 08-07-2009, 02:03 PM

Quote:

Originally Posted by bgd73

the delete does work. The power needed in tight spaces is worth the extra fuel, and i did learn there is a draw even in a straight line. A manual steering version of the same car, revealed the difference.

I didn't think you be happy with the drag of the ps unit w/o the fluid under pressure, plus the wrong gear ratio - kind of like trying to start from a light in second gear - yes, it will work but not feel very good.

You might find a manual rack & pinion for your car :-)

busypaws · 08-07-2009, 08:38 PM

Pulled the pump/belt/expansion bottle etc. Took one of the rubber hoses and just looped the input to the output of the rack (about 2 feet of tube/hoses). Put enough fluid in to keep it flowing but left enough air in the hoses for expansion. Parking in the grocery store is a workout but up to 40mgg.
97 Mazda Protege.

bluetwo · 08-07-2009, 08:42 PM

Cool. I guess what I'm missing is..... ...how the heck does it flow when you remove the belt?

I get leaving fluid in it, so it doesn't get ugly inside, just.... what am I missing?

busypaws · 08-07-2009, 08:48 PM

I just turned my power steering into a manual steering box. The act of turning the wheels forces the fluid out/back. That is how the pump was helping you turn. Now that you supply the turning force you are pushing some of that fluid out the outlet and back through the inlet. It is how the power steering assist is setup inside the rack. Reading this site and others it mostly states to make sure you have some loop from the output of the rack (input to the pump) back to the input side of the rack (output of pump). If you just cap off the rack then you really have to work harder to turn the wheel.

bluetwo · 08-07-2009, 09:01 PM

Quote:

Originally Posted by busypaws

I just turned my power steering into a manual steering box. The act of turning the wheels forces the fluid out/back. That is how the pump was helping you turn. Now that you supply the turning force you are pushing some of that fluid out the outlet and back through the inlet. It is how the power steering assist is setup inside the rack. Reading this site and others it mostly states to make sure you have some loop from the output of the rack (input to the pump) back to the input side of the rack (output of pump). If you just cap off the rack then you really have to work harder to turn the wheel.

So just disconnecting the belt doesn't mean you have free turning steering with no interference from the pump? The pump is no longer getting it's energy so it's much like the engine is off and you're pushing against the same kind of resistance? That seems insane to me because without considerable motion power steering systems with no pumping action are WAY hard to turn. It's not even close to being safe to operate a vehicle that way.

What you're proposing is that someone could remove the interference from the pump by simply bypassing it (whether that involved removing the whole power steering system or not) by just creating a loop of sorts with a long piece of hose, wherein power steering fluid would flow slowly or moderately through what is left of the power steering system. Or have I still missed something?

busypaws · 08-11-2009, 06:37 PM

Yes,
I pulled the belt first. I drove for a month or two before I removed the pump and did the loopback. It got a lot harder to steer when I pulled the belt. I can not really say that it got that much easier when I did the loopback (Removing pump and resovior). However my PU truck does not have power steering and It doesn't feel any harder to steer the Protege then the PU.

bluetwo · 08-11-2009, 09:13 PM

Seems like it's almost not worth it then.... I may just have to try it and see just how the steering feels. It's been a while since I felt what it was like with the engine off. :-)

busypaws · 08-11-2009, 09:37 PM

You can always put the belt back on if you don't like the feel.

This is just my thinking: (Only been at this for 6 months so----)
1) I have a 5.5 mile commute with 12 stoplights. I don't get above 35 miles per hour.
2) For me to hypermile it will not buy me much to do aero stuff since I never travel fast.
3) I need to work on weight loss for the car. Remember physics inertia is mass times velocity. I need to loose mass to make it easier to accelerate.
4) Rotating mass is worth about 10 times regular vehicle weight. (my rule of thumb)
5) The PS pump weighs about 15 pounds, maybe 5 pounds is rotating. So pulling out the PS pump/hoses saved me 10lbs non-rotating and 5 rotating (equivalent to 50lbs). So in my mind I removed 60 lbs of inertia from the vehicle.
Now I do the AC, lightweight crankshaft pulley, lightweight rims/tires, smallest alternator and I hope to start really affecting the gas mileage in city driving.

arb · 09-11-2009, 11:09 AM

Next to the power train, the largest concentration of mass on your car is the glass. If you could get away withthin plastic sheeting like Jeep uses for the side/rear windows on the entry level, you'll save a ton of weight. The windshield is another story - you want it.

Christ · 09-11-2009, 03:12 PM

Quote:

Originally Posted by busypaws

You can always put the belt back on if you don't like the feel.

This is just my thinking: (Only been at this for 6 months so----)
1) I have a 5.5 mile commute with 12 stoplights. I don't get above 35 miles per hour.
2) For me to hypermile it will not buy me much to do aero stuff since I never travel fast.
3) I need to work on weight loss for the car. Remember physics inertia is mass times velocity. I need to loose mass to make it easier to accelerate.
4) Rotating mass is worth about 10 times regular vehicle weight. (my rule of thumb)
5) The PS pump weighs about 15 pounds, maybe 5 pounds is rotating. So pulling out the PS pump/hoses saved me 10lbs non-rotating and 5 rotating (equivalent to 50lbs). So in my mind I removed 60 lbs of inertia from the vehicle.
Now I do the AC, lightweight crankshaft pulley, lightweight rims/tires, smallest alternator and I hope to start really affecting the gas mileage in city driving.

There are two formulae for calculating rotating weight. There is one for vehicle weight, and one for engine/accessory weight.

I believe vehicle weight (rims, tires, etc.) is 7:1... engine weight is significantly less, because of the way that engines rev up and down. It's something like 5:1, IIRC.

Don't quote me on those numbers, though. Calling it 10:1 is very optimistic.