EOIT = Performance gain?

[chassis]

So, I have searched this out and have done a lot of reading on this topic but in the end i'm still on the fence if this actual performance gain or is it a remedy for idle issues and the rich smell. I did not see any dyno draphs of an A/B comparison of the timing change only. There are a few " that felt better" posts but is it real? I cant get me head to wrap around seeing any big gains in the upper rpm region but I seem to think there may be something to be had at part throttle cruise conditions. I would appreciate some feed back in the regard, does anyone have a dyno sheet with the change and if so can you post your results. Or feel free to chime in with your thoughts, thanks guys.

[Widebody06]

It has to be pretty simple...if your AFR is correct for maximum power, it really doesnt matter when the fuel goes in and how much goes out the exhaust. That said, there has to be minor influences on reversion effects and a few other second order factors but almost everything about cams with enough overlap to cause EOIT to be off also means you make power above the RPM range where EOIT changes have much influence. Dont forget with the optimum 80% duty cycle, timing is not much of a factor when the injector is working most of the time. So yes, fuel econ can be improved, sometimes a lot and low end driveablity too with some modest improvements in low rpm torque but stuff you work to improve on the dyno...I'd say nope.

[DSteck]

You need a huge injector to even begin to be able to tweak power with injector timing.

[mowton]

Mostly to minimize "fuel short circuiting" (and tearing eyes) as Greg Banish calls, it in large valve overlap cams. Also, as I understand it will readjusts injection spray due to stock cam duration values to better hit a closed valve which allows for better evaporation and burn.

Ed M

[chassis]

So, short answer...... not worth messing with performance wise? How about strictly for at idle condition?

[DSteck]

I've been successful in reducing the idle smell with big cams.

[MikeOD]

So, short answer...... not worth messing with performance wise? How about strictly for at idle condition?

It helps at idle...and can even help smooth out some big cam surge that can be hard to get around.

[Higgs Boson]

definitely worthwhile if you have overlap....

[LSxpwrdZ]

I posted dyno results from my personal car that was running way oversized injectors... The gain was quite significant as well. I don't remember what thread I posted it in a year or so ago.

[BBA]

One question: Since we do not have SEFI, the PCM runs the injectors in two banks, as evidenced by the Injector Bank Select Table. It makes more sense that the value would only impact those cylinders where the bank lines up with overlap, and the other cylinders would be less impacted. So is this even something that really makes any difference?

[DSteck]

Uh. The ECM absolutely is sequential fuel injection.

[ElecTech]

One question: Since we do not have SEFI, the PCM runs the injectors in two banks, as evidenced by the Injector Bank Select Table. It makes more sense that the value would only impact those cylinders where the bank lines up with overlap, and the other cylinders would be less impacted. So is this even something that really makes any difference?

Uh. The ECM absolutely is sequential fuel injection.

One of those LOL moments.

[BBA]

Uh. The ECM absolutely is sequential fuel injection.

I had always believed that and would have responded your way had I not ever thought about that table. So what is the reason for the 0 and 1 values for the bank table (other than just driver and passenger side cylinders for O2 sensor switching for fuel trims).

So, not considering that confusion, I'm still confused on the EOIT values, are the target angle settings really camshaft angular degree values, instead of crank degrees, where the PCM cuts off injector opening per cylinder? (I ask as the values are listed with greater than 360degrees.)

[Widebody06]

"the PCM has an end of injection target in crank degrees (not in the editor for LS1's but is there for LS2's). it calculates the start of injection angle from the desired injector pulsewidth and works back from the EOT."

Chris...

http://www.hptuners.com/forum/showth...highlight=EOIT

[DSteck]

(other than just driver and passenger side cylinders for O2 sensor switching for fuel trims).

Answered your own question.