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do rotaries consume less fuel at high revs?

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Old May 21, 2004 | 10:47 PM
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do rotaries consume less fuel at high revs?

Just a question, a friend told me that rotaries consume less fuel at high revs - is this true?
He also told me that they consume alot of fuel while idling, which makes sense to me because of the small amount of time the inlet and exhaust ports are lined up during the rotation of the rotors, so that makes sense, but i tell you what, my s5 turbo seems to burn HEAPS of fuel at high revs. So i think my friend may be wrong about that point... It doesn't seem logical to me either.
Is there a point in the rev range where fuel consumption is the most efficient.
Also i found out my fc is ported, mild extend port. I had it dynoed, and the best we could get before the clutch started slipping was 132 kw at the wheels on minimum boost. They also think the turbo is hi-flowed or aftermarket, havn't actually taken the heat shield off to look at it yet.

Dan.
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Old May 21, 2004 | 10:52 PM
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Your friend is wrong.

If I drive conservatively, my old '88 NA got roughly 15-17mpg in city. On the gas, and redlining it every few often, I can get as low 11-13mpg if I wanted.
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Old May 21, 2004 | 10:58 PM
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I put 67 dollars (about 64 litres) of BP ultimate into it the other day. I got 280 kms from 3/4's of that tank (i didn't reset the kms on the odo until 3/4 coz i forgot). It burns heaps and heaps of fuel. It's running rich as ****, but that's not going to change coz the dynotuning guy said rotors love that, and that it's been tuned for lots more power, but we can't really tweak it yet coz of the clutch slipping.

Dan.
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Old May 21, 2004 | 11:39 PM
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running rich is bad. rotaries dont love to run rich, they love to not detonate. given, you dont wanna tune the car as you would an n/a, but that has nothing to do with rich and lean.
max fuel efficiency is where your torque peaks i believe.
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Old May 21, 2004 | 11:49 PM
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the thing is with running rich you end up taking heat from the combustion proccess which means less power

running more fuel then there is air to burn means wasted space wasted power

running rich also means more unburnt fuel leading to depostis


less gas mileage



soo all in all only good thing about running rich is it can in the short term prevent detonation


but it isn't proper tuning
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Old May 22, 2004 | 12:17 AM
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Originally posted by Blind Freddie
a friend told me that rotaries consume less fuel at high revs - is this true?
Less fuel than what? Less fuel than a similarly powerful piston engine at high revs or less fuel that it does at low revs? Both would be wrong anyway, but your question isn't very clear.
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Old May 22, 2004 | 01:02 AM
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my s4 turbo will get around 380km's (Mostly Highway driving) from about 51 Litres if I do a tank full of short trips it will get down as low as 250km's a tank depending how heavy on the gas you are and I do like to give it a bit. I pretty much always use Shell Optimax. That was also before I just had my exhaust hole fixed so hopefully that might help alittle though with the new dump pipe it is running alittle more boost then it was.
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Old May 22, 2004 | 01:46 AM
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lol rotars love to run rich, what in the world.
Well, I would rather run too rich and waste fule, than too lean and ping my motor
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Old May 22, 2004 | 01:51 AM
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Originally posted by DEZERTE
lol rotars love to run rich, what in the world.
Well, I would rather run too rich and waste fule, than too lean and ping my motor
:
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Old May 22, 2004 | 06:07 AM
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no pistons... no problem
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mine consumes less fuel at lower revs, i get 4mpg at low revs, about 3mpg at full rev
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Old May 22, 2004 | 06:08 AM
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]v[akaveli's Avatar
no pistons... no problem
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but then again, maybe ur friend was talking about wasting less gas at higher speeds when the o2 sensor kicks in
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Old May 22, 2004 | 06:47 AM
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In terms of the question being unclear, i meant 'do rotors use less fuel at high revs than at low revs?'

Same engine, not comparing to a piston or any different engine.
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Old May 22, 2004 | 07:57 AM
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Originally posted by Blind Freddie
In terms of the question being unclear, i meant 'do rotors use less fuel at high revs than at low revs?'

Same engine, not comparing to a piston or any different engine.
Yes indeedy! Keep your foot in it and get there sooner so the engine won't be running as long. Engine not running = no fuel being used.
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Old May 22, 2004 | 11:18 AM
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Just a question, a friend told me that rotaries consume less fuel at high revs - is this true?
How can this be true? The higher the RPM the higher the rotors are spinning which means more combustion, and more combustion means more fuel. So theres no way in hell you can use less fuel at higher rpm's in any type of engine simply becasue getting to higher rpm's means more fuel.

Just move the exaust port to the side to eliminate overlap and youll have your self a lot better gas milage and more efficient combustion...kinda like what the RENESIS does . Or go stand alone and take complete control of your engine. This is the best way ive heard of so far

Last edited by RylAssassin; May 22, 2004 at 11:21 AM.
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Old May 22, 2004 | 11:22 AM
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at 3-4k rpm in 5th on the highway, I got about 30 MPG

city, 16-17 hitting 6 k rpm every once in a while.
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Old May 22, 2004 | 04:32 PM
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molotov, that's about what I get, when it's running :cry:

a little better city, No one believes me though.
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Old May 22, 2004 | 04:40 PM
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Its TRUE. Go N/A!
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