Max power on stock fueling?

[Prof]

Agreed - emperical testing is the best form of knowing...
 
But it can be an expensive lesson if it costs you an engine - hence people come onto forums and ask questions - but being a forum - anyone and everyone may answer.
 
If enough people say 85% I tend to take the hint that is something to pay attention to.  But the only way to know for sure is to test this yourself.
 
On the eManage - 100% duty means that the injector is on all the time.  On some ECU\'s the 100% refers to injecting during the whole cycle of combustion - and so you can even see over 100% duty ratio - doesn\'t mean the injector is on more than 100% of the time - it physically can\'t be, but just that injector duty might be say 5ms with an induction window of only 4ms - hence it\'s 125% duty - are you confused.. :confused:
 
Trying to calculate fuel usage is a mare - as not all of the fuel will go into the chamber in one hit - you end up leaving some on the side of the intake pipes, and some from last time goes in with you\'re current charge - they call this tau.
 
Tuning after market style is probably a lot less maths and more knowing / monitoring / testing / dyno...  The Maths bit just gets you in the ball park.

[SiH]

:Thumbs-up

are you confused.. :confused:

Very. That\'s why I let people far cleverer than me map my car, and just use my smashy caveman hands to put lumps of metal in the bay

I remember seeing 105% on my AVCR at one time, and my brain nearly melted when someone tried to explain using words like \'latency\' and \'hysteresis\'.

Out of interst, I\'m now trying to find some graphs of low vs duty, and failing hard. I;\'m intrigued to see what sort of percentage the efficiency drops off by. In pictures that my \'E\' at A level physics brain can understand.

[turbotoaster]

Injectors max out at about 90% duty cycle, going further will cause them to vibrate and only 1/2 the fuel will be injected and the engine will run lean.

Safe max on injectors is about 85%, I wouldn\'t push stock fueling on a rotary that far, its ok a bit more, but they aren\'t exactly new injectors, im waiting to uprate my secondaries before upping the boost on mine, its not worth the risk, few hundred pounds on fueling upgrades vs £3k engine rebuild if it detonates? No brainer for me really :2Rolleyes

ermm i think you need to clarify what your saying a bit clearer mate as at the moment you are way off the mark.

for example going going from 95% to 100% allowed me a little more power, i was constantly monitoring my AFRs, if they start to lean off ill know i have hit the limit of what the injector will flow, its common truth to normally say that the increase in flow from say 80 to 85% is different than 95-100%(say \'half\' as you put it)

i can only assume this is actually what you refer to as anything else is incorrect.

Oh yeah, I\'m not denying that driving them above a certain duty induces an element of risk and upredictability, but \'vibrating\' and only injecting \'half\' the fuel?
The prose I\'ve quoted implies that venturing above 90% duty halves the amouny of fuel injected - All evidence I\'ve seen debunks that. It may yield diminishing results when winding up the duty too far, but reducing it by that amount?

An awful lot of peole run injectors way beyond the 85% (or 90%, or 80%...) \'guideline\' that many people quote with no ill effects at all, on thousands of different set ups all over the world. Belt and braces suggests you don\'t, but it doesn\'t mean it doesn\'t work for a lot of people.

It also depends what\'s being measured in terms of duty as well - for instance, 100% \'duty\' on an AVCR isn\'t actually 100% injector duty - it\'s something else related to it that I\'m far too stupid to understand.

The internet is full of chinese whispers tuning advice, and I think sometimes people need to be wary of perpetuating this. Says a man who\'s just stated an internet \'fact\' in his post.

i think sih he probably means what i put in my responce post but didnt quite word it correctly....cut him some slack, he drives an fc :p

[m1tch]

Ok, I bow out, im not going to be running my 20 year old injectors above 85%