I tend to be smart enough to not pee into the wind, learned the 1st time.
I have information coming soon that will help show how all this works. However, it is the start of race season and the guy is busy. So lets all leave it to rest for now.
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Nathan, never ask you to actually do it again....once is usually enough, at least it was for me..... Lol
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ScottinBend Space CowboySupporting Member
Isn't the injector on the far right the 440? And the 550 the one next to it?
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Left to right 330:380:550:440
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ScottinBend Space CowboySupporting Member
That's what I thought......so the 550 spray pattern is a heck of a lot better than the 440.
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ColinGreene Well-Known MemberMotoring Alliance Sponsor
I thought what we were learning about spray pattern in this thread was its not as crucial as previously thought, or has my reading comprehension seriously gone down hill?
Seemed to me that mike said that the air flow in the intake tract aided atomization.
or did i miss something. -
How about pissing in a category five hurricane; the conditions inside that chamber would be no less violent when one considers the pulsations and the speed at which the air is moving....
My hat's off to you if you never discovered that warm life lesson.....lol -
This is why Velocity is a KEY in a ported Head and intake. If you notice the roof of that port is raised, as most the air flow is on the roof.. IF the entire intake runner was just enlarged ( ported) the velocity would slow do to add'l volume, and need more RPM to accomplish the same velocity and result.
Just me.................................
Thumper -
RPM? Do you mean more pressure, more air by volume?
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MINIMARK, as you know... the higher the rpm the faster the pistons are moving , which pulls in more air, and when restricted into a intake runner size, increases the velocity and this increases the volume that the engine takes in.. As we are talking velocity, the volume isnt important in this at this time?? yes??
Thumper -
True in an NA engine but when you open them up on a boosted engine do you not loose pressure in the head negating some of the benefit if you don't increase the volume of air being compressed?
Just asking..not saying at all that your wrong. It has been known for a long time that porting and increasing valve size and openings done correctly can and will increase performance. But by the same token; done wrong it can diminish performance .... -
Nope. The only time when increased velocity results in increased volume per moment of time, is when the vessel shape/diameter remains constant. Fluid diameter (the valid apple to apple comparison) also changes with vessel shape, air is a fluid BTW. A restriction does not increase volume, density can be increased through compression or temperature manipulation, but that is a different physical law.
A reminder that burning fuel turns the crank, how the available air mixes with fuel when entering the combustion chamber has a great influence on efficient combustion. -
So your saying given the same amount of air and boost that if you decrease flow resistance (larger openings) and the ability to move more air through that you would not loose pressure?
If that is the case, why wouldn't you just use manhole cover size valves?
Just learning here... -
Sorry, I just edited my post. Said increase and meant decrease flow resistance....
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Pertaining to this thread...The injector size does not increase VE.
VE= volumetric efficiency
The atomization of the fuel starts but does not end at the fuel injector in a MINIs engine. Some injectors like the one this thread was started about are more efficient at atomizing fuel than other brands and types of fuel injectors. -
ColinGreene Well-Known MemberMotoring Alliance Sponsor
Thats pretty much what i asked earlier... Good to know i suppose.
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Here is a log of the factory S injectors with 16% pulley and a header (in 4th gear at 6700rpm, injectors are operating at 108% duty cycle):
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Injector Duty Cycle at various mods & sizes
Here is some quick reference info on injectors and their duty-cycle (DC):
=> Stock injectors with no mods (100% FACTORY stock) ~133whp on Dynojet = injectors at 88% duty-cycle at 6500 rpm (this is from an Automatic-S)
=> Stock injectors with 15% or 16% pulley (at 14.7psi) ~175whp on Dynojet: injectors at 107% at 6700rpm
=> JCW 380cc with a 15% pulley / cam of some type /V1 header ~ 200whp on Dynojet = injectors at around 112% in the 6800rpm
=> RMW 440s with 15% pulley ONLY ~185whp on Dynojet with tune = injectors at 84% duty-cycle at 7100rpm
=> Bosch OE 550cc with 15% / cam shaft / GP IC / Mynes V2 header ~205whp on Dynojet= injectors at 72% - 74% at 7500rpm
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