i know GM sucks, but they do that thing where one bank of cylinders turn off on their v8s and v6s. Would it be possible to do that with an rx7? especially for highway cruising?

i want to see discussion, practicality and possible approaches

 

every tried to drive on one rotor? no power for even cruising.

 

Its been discussed before and as Murray said-- driving with one rotor sucks. Id imagine you would have to keep the oil injection going too so imagine the puff of smoke you would get when you put your foot down.

 

there was a huge thread on this already
give a search for it

 

and running on one rotor is less efficient that 2 rotors. give the debate a rest..

 

Yea, driving on 1 rotor blows. I blew my rear rotor 100miles away from home. I drove it back. I had it to keep it in 3rd or 4th the whole way cruising 60mph. No power at all.

 

Im not sure how gm's systems work, but I would think for this to work well you'd need a valve that opens the chamber not being used and allows compression to vent. This would reduce the losses on the rest of the engine, just like an engine with the sparkplugs out spins a lot faster and easier than one with the sparkplugs in. IF you wanted to kill the entire rotor on a rotary engine, you could use such a valve to help reduce pumping loss.

This can work pretty well on a big v6 or v8 engine, because you still have plenty of other cylinders "working" at the same time, so the loss of 2 or 4 isn't such a big deal. With a rotary, you only have 2 chambers, so the loss of one is going to be a problem.

What would be interesting to see in a rotary, would be cutting fuel injection every other face on opposing rotors when in cruise mode. For instance, if the front rotor has faces 1-3 and the rear has 4-6, and the system would normally fire fuel to each face sequentially 1-4-2-5-3-6 every time. Then the system might kick in and inject fuel only for 1-2-5-6, then 4-2-3-6, then 1-4-5-3, and repeat the pattern as long as the cruise mode is engaged (or some similar pattern). This way you'd still be "using" both rotors, you'd have no excess oil buildup or plug fouling, no differential in heat or friction generation, no vibration or severe sudden dropoff in power, yet you still get the benefit of lower fuel requirement.

IF you could come up with a fast-enough-reacting valve to relieve compression/pumping loss as mentioned above, this rotary fuel injection cut would work better still. But at a normal highway pace of 3000 rpm, each face of each rotor clicks by in about 1/16th of a second, so it's unlikely you could come up with a valve that would work fast enough and well enough to vent only one face at a time, instead of an entire chamber for a longer period of time (like killing one cylinder in a piston engine).

 

Short answer: NO.

GM (and Mercedes Benz) spent millions of dollars figuring this out.
I'd recommend getting a more fuel efficient daily driver - or just get rid of your rotary vehicle if you're worried about gas mileage.
We don't own these cars to brag about gas mileage.


-Ted