Quick question about EMU and Auto Tune (Upsizing injectors)
 

I'm going to be installing a smaller nose pulley (MP62) and bigger injectors on my '99. I are n00b when it comes to tuning the EMU that my car runs with. It was last tuned by someone else. It will again be tuned by someone else but I at least need to get it running well enough, post injector install, to drive it about 30 minutes to the tuner.

I'm upsizing from 350cc to 550cc injectors. Currently the before/after injector sizes in the EMU setup are both set to stock and all the tuning is done in the INJ table. Is simply switching on autotune going to be enough to get the car running over to the tuner or do I need to first scale the map across the board to compensate for the injectors?

TIA.

Its been a while since I used the EMU, but I seem to remember just setting the before and after sizes and things working pretty well. Since both of yours are set to stock, I would suggest just setting the after to stock +200 and see if it runs. Then let them tune it however they want once you get it there. Of course you could always just swap the injectors once you get there.

*Disclaimer: YMMV and everything I just told you is probably wrong.

From what I've heard from EMU tuners, it doesn't like if you put in "after" injectors that are more than 20% over stock or something ridiculous like that. That's why it's tuned like it is now.

I thought of adding +200cc to the "after" injector size but I figured it was more of a % issue.

So...if it currently says 240 but I really have 350, moving to 550 would mean I need to make it...

240/350 = x/550

x*350= 240*550

x = (240*550)/350

x = 377

Thank you 4th grade math. I suppose this should be the first thing I attempt. Even if it runs like crap at least it runs, right?

Thanks. If anyone else has insight I'll appreciate it.

This works for me.

Warm car up, and set lag at idle so a/f hits 14.7. That's it!