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Posted: Tue Apr 15, 2008 12:22 pm
by MyPRodOL
I was just saying in case you didn't know that... A lot of people don't...
Some people like to know their fly kw's to know how much power his motor makes and then to see how much it looses... this allows you to try different diffs and drive-line, oils etc...
The difference in wkw and fly kw can then be compared to see your losses and gains etc to compare.
Posted: Tue Apr 15, 2008 7:53 pm
by veecee
MyPRodOL wrote:@ VEECEE - I know... there is more than one term for that... its referred to as the dreaded boost cut...
Its the same theory, comes down to the same point... o and it can pop your motor.
What happens is... your stock MAF works in VOLTS, meaning certain air flow will calculate to certain VOLTS. If its small sensor it can't read too much air, thats why you fit a bigger sensor like the Z32 etc.
So now you boost.... more than the sensor can read, and it zero's out. the ECU goes into Fuel cut mode as it can't understand the values given from the MAF and that can cause the motor to run lean... which will cause immediate knock, and this can result in a popped motor. As we all know... bad knock can blow a motor in seconds.
This won't always happen, but it can...
first of all - boost cut means that SOMEHOW the ECU stops the engine from boosting. unlikely! and fuel cut means that the ECU cuts fuel. totally likely. so its not the same thing.
second of all - if the computer cuts fuel - that means that no more fuel goes into that cylinder. at all. it will be dry within a cycle i reckon. not so dangerous. not something you want to happen, but not the end of the world.
it would be best if the computer cut spark. safest way, plus you'd get a nice popping banging sound out the back!
Posted: Tue Apr 15, 2008 7:56 pm
by mario_200sx
Sorry, just want to know, how does the car work that it doesnt boost full in 1st gear?
Soz for hi-jack....
Posted: Tue Apr 15, 2008 7:59 pm
by veecee
it doesnt,
maybe yours doesnt boost quick enough before the revs run out in first gear. you have changed the turbo right - you have a 0.64 exhaust housing? that means your boost comes in later than other sx's with T25's.
remember that first is a very short gear, doesnt give you much time before you need to change???
Posted: Tue Apr 15, 2008 8:03 pm
by mario_200sx
ok, then I was miss informed, thanx.
But I must say that it boosts up to 0.7 bar before Im close 5000-5500rpm?
Doesnt make sense?
Posted: Tue Apr 15, 2008 8:22 pm
by veecee
i was grasping a bit with the runs out of revs comment!
but the ECU on the ca18det doesnt control boost. so it cant stop the engine from boosting full in one particular gear.
actually - the ECU doesnt even know what gear the car is in at any point in time.
LOL.
Posted: Tue Apr 15, 2008 9:46 pm
by THEO 3K - ZN
So back to the topic on hand, what is the most one can do with the std ecu? Cos i'v upgraded my turbo to a TD04H
Posted: Wed Apr 16, 2008 6:53 am
by Toby
Sorry to go off topic again, but I read somewhere that the car doesn't boost in reverse gear... how does that work?