Quoted..
This has several positive effects:
1. doesn't obstruct the area of the manifold or port as much since most of the injector is in the inletted section
2. may allow more choice of angle of attack of the injector discharge (more parallel to port align), since the body need not intrude as much
3. less induced bias or swirl due to flow striking exposed injector parts
4. probably not useful here due to turbo, but allows the injector to be closer to the valve - which means less atomization, between the injection point and the valve seat (any vaporized fuel displaces much more air in the charge than droplets). This is useful when the port efficiency isn't high.
End Quote...
In all due respect for someone elses opinion..
It works a lot more like this in real life or at least every efi engine I have tuned in the last 20 years...
If someone has dyno shets to prove otherwise I would love to see them.
1. A properly installed injector does not protrude into the port..
2. At WOT it does not really matter where you aim them Buick indy lights had them aiming away from the valve.. They ran just fine. Kinsler has a lot of them 90 degrees to the port they run just fine.. A lot of passenger cars aim them almost paralell to the port they run just fine... If the port is so lazy that it can not move one thirteenth of it's weight around you have a serious problem other than injector placement or angle. Do not lose track that it is air/fuel ratio by weight not volume...
3. See #1...
4. What?
? A pound of fuel contains x atoms period... The heat of vaporization will cause cooling of the intake charge that will make more room available.... You do not want liquid fuel in any manifold if possible... As a side note any well developed racing engine has the injectors as far away as possible from the valve. They are put closer in passenger cars because they run closed loop. The added distance of moving the injector adds a delay and the loop is harder to keep closed and not hunt all over the place..
Dave