[shinysun]

I did a simple meth.

at 6500 RPM

1 crank rev. needs 9.2 ms and it means 39.13* per ms.
If I start to spray at 350* and end it at 180*, need to rotate 170* and it will take 4.34ms.


I read some article in this forum, saying if the injector PW is over 5.5~6ms , it means you need the bigger injector.
How is the number (5.5~6ms) calculated? I assumed the EOI is at 180*, but is it wrong? Is it spraying beyond BDC? until just before ignition timing -5* offset?

[KingLT1]

I read that article too but I was told 6.5-6.7ms is the limit from a couple different tuners.

That doesn't necessarily mean you need bigger injectors either. It could mean you need more fuel pressure depending on what the rail and low side look like. If both pressures are staying constant and within range, then I would suspect injectors are at their limits.

[Charlie540i]

Anything approaching 6.0ms and over is the limit before crazy shit starts to happen. False knock, throttle closures, torque management, etc....

[KingLT1]

I haven't noticed any issues until 6.5+. I have ran different mixtures of E ranging from 60 to 80% which has moved injector MS from 5.5 to 6.5 and no issues in my logs. I have been running E70 which keeps my injecto MS in the 5.7 range. Figured I don't get anymore timing running more E and it's easy to mix, so why not take some strain off the fuel system.

[shinysun]

Originally Posted by KingLT1

I read that article too but I was told 6.5-6.7ms is the limit from a couple different tuners.

That doesn't necessarily mean you need bigger injectors either. It could mean you need more fuel pressure depending on what the rail and low side look like. If both pressures are staying constant and within range, then I would suspect injectors are at their limits.

The both pressure are quite stable, hitting the target very well.