Originally Posted by Kingtal0n

atomization, hmm
thoughts

1. the injector does not spray through an open intake valve in a factory installation, instead the fuel is injected to the closed intake valve in order to warm the fuel by virtue of cooling the valve.
I am not sure it is a good idea to set the injector timing for low speed operation to post-overlap (after intake valve opens) for a number of reasons. Perhaps the valve will run hotter now (its almost a certainty). Perhaps the fuel is more likely to wash down the cylinder walls (being that it is injected cooler, it didn't get a chance to warm on the valve). So atomization improvements are welcome if the fuel is being directly injected to the cylinder through an open valve. That said, how will you be SURE yours is doing that in an installation to take advantage of this slight benefit?


2. If the injector timing is set to spray through open intake valve, the spray duration can only be very short (just until the valve closes) so this is merely a low-speed property (atomization is only useful at low engine speeds and low/cruise situations). Anytime the engine is using say 30% or more (more engine load, starting to make power) of it's injector "duty cycle" it means the injector is on much more often, so there is no way to avoid closed-intake valve injection for the majority of situations. In other words, atomization improvements are welcome but only for the extremely low speed/output situations where injection duty cycle is at it's lowest ranges and only if the injection is timed to begin exactly after the exhaust valve has already closed. In many applications one needs to degree the cam, then perform a calculation using the actual closing degree of exhaust lobe to get the maximum 'window' for injection.

personal opinion
I'll never use a sub 1000cc injector again on an sr20 lol
and I'll never own a sub 500hp 2.0L either, the turbo tech has really gotten good enough you can say that now

Originally Posted by Kingtal0n

someone asked for an elaboration of the injector comment,

How to choose injectors in 2019

In the past, say from 1995~ to 2002~ roughly. It was a very good idea to match the size of the injector to the exact power you expected to make for street cars, because it gave the best resolution in the fuel map for daily driving and economy features, and if you wanted something larger say 80lb/hr+ you were usually stuck using low impedance units with poor control for low speed operation. It punished you hard for choosing a huge injector if you didn't actually need one.

However, injectors are remarkably easier to control these days, and computer-microprocessors have become more reliable and much faster as well. Circuitry (injector drivers, amplifiers, techniques and basic ICU for controlling voltage signal) has improved.
What that means is you no longer need to suffer when using larger injectors.
You can now buy 1000CC, 1400CC, probably even 2000CC injectors that will run and drive fairly well in a daily driver application, especially when using high volume flow fuels like E85.

If that wasn't enough, there are two other benefits to using a much larger injector than needed for the application:
1. The injector driver will run cooler during max output, thus it will be more reliable, the injectors will be at a lower duty cycle using larger injectors.
2. larger injectors give more weight to injector timing curves, since more fuel is injected in the same amount of time, more fuel can be fit into a short window.

And lets not forget room to grow is on the table