J
CTsupra
Supramania Contributor
Are you speaking in general, or referring to your car?
I see that you have a "built" motor and an AFC; runnimg 14psi. You should be fine to atleast 20. Consequently, you can detonate and fuel-cut non-interference motors all day if you like. It's not recommended, though.
I see that you have a "built" motor and an AFC; runnimg 14psi. You should be fine to atleast 20. Consequently, you can detonate and fuel-cut non-interference motors all day if you like. It's not recommended, though.
J
JerzeySlowpra
Guest
speaking for both, in general and my car, it usually holds boost pretty good it was cold out last night though and i would hit fuel cut every 2>3 shift just wondering if "fuel cut" damages anything with an non-interferance motor, which i thought it didnt
CTsupra
Supramania Contributor
You sure it was fuel-cut and not a back-fire from running alittle rich? If it was "bucking", then ya, you probably just spiked alittle bit from it being cold out. Nothing to worry about.
J
JerzeySlowpra
Guest
it was a buck and check engine flickered on real fast it was def fuel cut i think i just spiked from being cold
In general, on our engines, fuel cut doesn't hurt much other than on your swelling pride as the person you are racing flys past you.
J
JerzeySlowpra
Guest
Guys, only reason cutting off fuel from a rotary damages them is due to the fact that they put fuel and oil in together, injected. I do not fully understand it, but it is similiar to how a 2 stroke works, except rotaries have oil and fuel stored separately. Cutting fuel can not damage a single thing in theory, as with no fuel there will be no combustion.
Note, that is the reason why rotaries "breath fire". They spit out flames a lot because even though after you hit the rev limiter, it does not cut fuel, just spark because of the oil/fuel propagation. So it keeps dumping some fuel and oil in.
Note, that is the reason why rotaries "breath fire". They spit out flames a lot because even though after you hit the rev limiter, it does not cut fuel, just spark because of the oil/fuel propagation. So it keeps dumping some fuel and oil in.
fuel cut is fine... but, im not so sure it even cuts fuel. i think it shuts spark off momentarily... because EVERY single time ive seen fuel cut on any car, it ALWAYS shoots out a big puff of BLACK smoke... as in unburnt fuel.
rotaries have oil injection which draws right from the sump. they have four oil injectors to lube the apex seals. this is either mechanical or electrical pump driven depending on year. its independant of ECU, spark or fuel. if the engine is spinning, oil is injecting.
and having ZERO fuel in your engine doesnt hurt anything... having slightly less fuel hurts alot of everything. zero fuel means zero combustion... zero combustion means zero heat. zero heat means zero melted things. fuel cut is kind of like turning your engine off w/ the pedal too the floor... nothing is going to get hurt.
infact, we have a big bridge here and i did that. i put it in 3rd gear at 65mph on the top of the 21 story bridge and killed the engine. i was coasting down the bridge w/ engine braking. then i floored it and i heard my turbo start to spool. i was making 2 psi w/ the engine OFF! lol. it sounded really cool.
rotaries have oil injection which draws right from the sump. they have four oil injectors to lube the apex seals. this is either mechanical or electrical pump driven depending on year. its independant of ECU, spark or fuel. if the engine is spinning, oil is injecting.
and having ZERO fuel in your engine doesnt hurt anything... having slightly less fuel hurts alot of everything. zero fuel means zero combustion... zero combustion means zero heat. zero heat means zero melted things. fuel cut is kind of like turning your engine off w/ the pedal too the floor... nothing is going to get hurt.
infact, we have a big bridge here and i did that. i put it in 3rd gear at 65mph on the top of the 21 story bridge and killed the engine. i was coasting down the bridge w/ engine braking. then i floored it and i heard my turbo start to spool. i was making 2 psi w/ the engine OFF! lol. it sounded really cool.
i thought what killed the rotaries is the temporary lean condition when you cut the fuel. if it pings, you will hear the sound of the cash register as you buy a gasket kit and new apex seals.
but back on topic, good to hear that fuel cut on mkiii's is actually spark cut. never would have guessed...
but back on topic, good to hear that fuel cut on mkiii's is actually spark cut. never would have guessed...
lol... well you can give that bling straight to me. he owes me a few gaskets anywho 
seriously though, Fuel does not lubricate the apex seals in a rotary. when there is too much fuel in a rotary, all the oil is stripped away and you lose all compression in the rotary. then you have to pull the lower spark plugs out and add a Tsp of ATF to each side of the rotor face to gain the compressoin back. if you are lucky and are flooded out but still have compressoin. you have to pull the EFI fuse, floor it and crank to burn away all excess fuel.
rotaries dont cut fuel either. they cut spark. mazda knows that detonation is the #1 killer of rotaries, second to overheating. it would be dumb of them to remove fuel from the engine. but, of course, anything is possible.
shaeff... technically, there is nothing wrong w/ turning the engine over manually. the oil pump is still direct drive and is lubing the engine. the ecu controls all spark and fuel so youre not loading up the engine with raw fuel, creating a bomb.
anywho, if the 7M ecu cuts fuel as well as spark, it wouldnt explain why there is always a big cloud of unburnt fuel that shoots out. its crazy...
seriously though, Fuel does not lubricate the apex seals in a rotary. when there is too much fuel in a rotary, all the oil is stripped away and you lose all compression in the rotary. then you have to pull the lower spark plugs out and add a Tsp of ATF to each side of the rotor face to gain the compressoin back. if you are lucky and are flooded out but still have compressoin. you have to pull the EFI fuse, floor it and crank to burn away all excess fuel.
rotaries dont cut fuel either. they cut spark. mazda knows that detonation is the #1 killer of rotaries, second to overheating. it would be dumb of them to remove fuel from the engine. but, of course, anything is possible.
shaeff... technically, there is nothing wrong w/ turning the engine over manually. the oil pump is still direct drive and is lubing the engine. the ecu controls all spark and fuel so youre not loading up the engine with raw fuel, creating a bomb.
anywho, if the 7M ecu cuts fuel as well as spark, it wouldnt explain why there is always a big cloud of unburnt fuel that shoots out. its crazy...
chris bell said:lol... well you can give that bling straight to me. he owes me a few gaskets anywho
PFFFFT! dont get me started again whore
