Hello. I found this forum by chance the other day and I have to say I'm very impressed with the level of knowledge and experimentation. I hope to learn a lot from everyone here. After losing the PS belt on my old volvo the other night, I had an idea for switchable power steering. The PS pump in this car runs off a V belt from the crank. When the PS belt let go, I couldn't tell any difference in the amount of steering effort at anything above 20mph. The pump has a built in bypass for just such an event. But at a standstill its almost impossible to turn the wheel.
This gave me the idea to use a electric clutch type pulley from an AC compressor on the PS pump hooked up to a switch in the dash. This would allow me to turn off the parasitic drag from PS pump when cruising on the highway or any other long stretch of road, then switch it back on when I get into low speed city traffic or maneuvering around a parking lot. I could swap in a complete manual rack from an older volvo but I really don't like the 4.5 turns lock to lock with the giant steering wheel. My 95 dodge neon has manual steering with 4.0 turns which I don't mind so much because its a much lighter car. The PS rack in the Volvo 240 on the other hand is only 3.0 turns lock to lock with very precise and weighty feel.
A couple of articles I read on electric power steering all claim 5% improvement in fuel economy over conventional hydraulic PS. I think this modification could accomplish the same thing. What do you think? Has anybody else tried this?
This volvo 240 has been converted from a fixed fan to electric cooling fan, a large rear belly pan and all synthetic fluids. It currently gets between 20 to 26mpg with a 4 speed automatic (non lock up torque converter). EPA rates the car at 18/23 with automatic transmission. As soon as the weather warms up I'll be installing a 5 speed manual transmission I have sitting in the back yard and swapping the 3.73 differential for a taller 3.31 ratio. If i can get the volvo to 25 city, 30 highway I'll be very very happy. Anything more will be icing on the cake. I'm also considering a light pressure turbo since the parts already exist for this 4 cyl engine all over the junk yards. The stock 2.3 litre NA red block engine makes a pathetic 114hp with very healthy low end torque.
I already have base 95 neon with no PS or AC which routinely returns 35-40mpg so I don't need to get too crazy with the volvo.
The 2 speed electric cooling fan came from a later volvo with relays and temp switch in the lower radiator hose. Its an extremely reliable and quiet system.
On the right you can see the PS pump pulley in question. The AC compressor pulley is just below. I removed the AC belt because the system is leaking. The old viscous clutch type fan was mounted directly on the water pump pulley.
Volvo started using aerodynamic (sort of) belly pans under the engine over 30 years ago. This design could be substantially improved with a completely flat sheet of aluminum from the air dam back to the front cross member.
I fabricated this rear belly pan out of an old plastic floor mat, the kind you under wheeled office desk chairs. Its ugly but effective. On my volvo 960 wagon it increased mileage from 25 to 28 highway tested over many many long road trips at my usual 70mph cruising speed. Very effective and cheap. Despite being a 3500lb, 6cyl 200hp,automatic, the 960 is blessed from the factory with 3.31 locking differential, lock up torque converter and a 10.7:1 compression ratio on 87 octane. The engine runs 2000rpm at 60mph. City mileage can fall as low as 17 mpg when I really step on it.
Junk yard 5speed ready to go into the 240. Total cost with pedals, driveshaft, flywheel, new clutch and other ods and ends = $250.