Special message to you:
When you define injection-duration in pure time, like mS (that is
milliseconds, 1/1000 of a second) you know nothing about the total time
available for injection. Don't you see?
If a 4-cyl engine with sekvential injection runs at 4000rpm (66,6rps),
you'll have a total time of 30mS available between each injection
pulse. In other words, this sets a limit on the pulsewidth available.
If you instead use the term duty-cycle at 4000rpm, you'll know exactly
both the on time and off time of the injector. If at 4000rpm you have a
duty-cycle of 95%, means injector on 28,5mS and off 1,5mS.
So, don't tell me that duty-cycles isn't possible to use, it's far
better than just using mS figures.
End of lesson.
By the way, since I know Backyard Mech. are reading this aswell, I'd
like to say: I believe I earn the same amount of money in an hour, as
you do in a day. Have a nice day.
Yep, whatta load of gobbledygook crap!
1. the number of cyls is moot, you're talking about 1 cylinder per
2. Fuel delivered per open time depends on differential pressure (fuel v
manifold) x orifice size plus latency of the solenoid action.
3. Open time depends on air moved per intake stroke in cfm
I see nothing there that requires knowledge of duty cycle OTHER than need
to find maximum rpm available at Fuel Pressure x orifice x air mass at
In other words, WTF are you going to do with duty cycle? All you need to
do is know the open time is in the design params for power @ rpm... unless
you intend to use it to diagnose FPR and Fuel Pump operation.
I'll just keep diagnosing my OWN cars, thank you.
- - - - - - - -- -
Ten years ago, Hast, I made more in a week than you made in a month.. or
maybe two.. but some folks retire.
Which also means nothing when it comes to understanding how things work.
Which he doesnt.
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
Hey Bob, whatcha been up to?
Saw on the news that there were some funnel clouds up in
Minnesota, none got too close I hope.
We had two down here today, but by the time I got the truck on
the road, they were gone (damn).
Is the snow cover gone up there yet? ;-)
Been dodging the heat down here, the Raytek said it was 104*
yesterday, damn glad the shop has A/C.
Been hot and mostly dry here, as for snow.... what the hell is that? We
haven't had shit for snow since I got into snowmobiles back in 98.
Just bought 12 acres in the country last weekend so I will be pretty busy
for the next couple of years. The place has a ton of potential but lets just
say it's a little "rough" the way it stands...lol. On top of that it looks
like I will probably be relocating the business to somewhere not quite so
flood prone in the near future.
So you're one of those guys that actively chases tornados? I'm just about
always outside when the weather turns bad.... we had one touch down a couple
of miles away maybe 2 years ago and it was like a block party. Everyone
standing in the street watching the funnel cloud. Of course it was obviously
moving away from us.... no way in hell would I get in my car and try and
catch it! I'll gladly leave that to you...
Compute it however you want... but I fail to understand this overwhelming
desire you have of adding steps to the process.
In the field, we use mS exclusively.... Look at it this way, the PCM knows
how much air is entering the cylinder.... the PCM also knows how much fuel
will be injected for each millisecond of "on" time... and the PCM has a
target called mass fuel desired.... No need for unecessary computations nor
the waste of processor cycles. Simple... here's the "trigger", we turn on
now and off after so much time.
FWIW, if you are nosing over at the top end, why not consider a higher flow
injector. Or is that too simple, too?
If you earn in an hour what I earn in a day, you could buy yourself a decent
Ok, the hurricane is back again, (thanks for that) and in fact without
a spelling checker, since I don't have one, but might need one. (thanks
for bringing it up, Bob)
Still, I succeed to replace the batteries in my remote, and I also get
the polarity right when changing my light bulbs...not everyone can do
After all, my intention wasn't to start a war, my time is much too
valueable for that.
No use keeping the discussion on.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.