BIGGER is BETTER!!! A FAQ on the Bosch 550cc injectors for R53

Left to right 330:380:550:440

 

That's what I thought......so the 550 spray pattern is a heck of a lot better than the 440.

 

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.

 

Aha! I have it now. It's my own inexperience that led me to bring it up, I've never tried to piss into the wind

 

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?

 

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....

 

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.

 

Thats pretty much what i asked earlier... Good to know i suppose.

 

Blah! I gotta get some info on what my 380s are doing with the head .

 

Wouldent it be hard to judge where duty cycle is maxed out due to running 380s vs the stock injectors the leeway would be slightly higher or will your software account for this.
and obviously we all still know that 112% is not possible its just then static at that point in the open position.

 

Colin, from my limited understanding, I think I see where you're coming from--the injectors are maxed out at what they can spray at 100%, they have a definite limit at what they can put out, there is no such thing as a spinal tap injector that goes to 11, but duty cycle is something different--once the injector is maxed out, if you keep pushing the RPM's up, you get over 100% duty cycle. Extremely rudimentary, but I THINK the gist of this is right....

I'm in the process of going from 380's to 450's, in the VERY near future.