Just got done installing the AMS ball / disc style 780cc injectors, and I have a couple questions about sorting out the idle from you expert tuners out there.

In talking with Quantum-racing (thanks Mark), it was commented to me that due to design of larger injectors, I would actually want to ADD fuel at 500 - 1000rpm 0% throttle position with the E-Manage to get it to idle properly.

I went into the eManage support tool, and on the Main Unit Parameters tab, I set the A.A.V. RPM start position at 0rpm, and point 1 at 1000rpm - then went to my Air Flow Adjustment section and began messing with the values at 500 and 1000 rpm for 0% throttle position. At this time I also entered in my stock injector size as 560, and entered in the value of 780 as my new. It showed a conversion rate of something in the 0.718 range. With the initial values of 0 correction, the car would not idle.

I ended up adding 12% at 500 rpm, and 15% at 1000rpm and it idles - but not great. I was pulling about -.3800 Kpa to -.4200 Kpa vacume at idle before, and now it's at -.3400 Kpa to -.3900 Kpa. the idle seems to seek more, but it still stays within the 700's to very low 900's.

I tried turning Anti-Engine stall on with a throttle position of 1%, and the idle went to a rock solid 1000rpm - but the S.E.S. light came right on. I shut off the engine stall feature.

I'm struggling with understanding why I need to ADD fuel at idle instead of remove it; but it seems to work. If any of you experts out there can education me on the 'whys' and what I can do to sort out the idle to pull a little better vacume, it would be greatly appreciated!

 

woot - on the upside, it cured my fuel cut issue at anything over 1.2 bar. This thing pulls HARD now

 

I suggest that those injectors are a bit on the large side for what you are doing IF your mod list in your signature is up to date.

You may want to look at some 660 injectors

As for your fuel cut, I can provide you with a reflash that will eliminate your fuel cut completely and leave everything else stock

Also - I can reduce your fuel maps by a set percentage to accomidate any size injectors while keeping you in the same eact ign timing zone. Piggy backs will BUMP up your ignb timing when you reduce the air flow - so on a piggy back getting around the fuel cut with bigger injector acutally OVER advances your ign timing to the point that you have to PULL timing with the emange in certain zones to avoid detonation or you wind up with a very rough trg curve after the factory ecu starts pulling timing. The reflash avoids all this becuase you do not alter the maf signal

On the subject of the emanage - I think you are doing something wrong there.

I suggest that you reduce the size of the NEW injector on the injector change screen. I ran into the same issue, try doing like 720 - thats the size I needed to input to get a decent idel.

My thought is leave the fuel map alone - just keep playing with the injector size - which si kind of your master fuel level till you get it close

 

Thank you for the input - I will mess with the upsized injector size settings on the eManage and report back with my results. I will start with 720, which is what you suggested.

The reason I went 780's is because I intend to run between a 56mm to 60mm trim turbo by next year. 'theoretically', I should be able to run with these injectors decently until I get the turbo.

I would love to get the Dyno Flash, but the only way I'd do it is if I could somehow get my car to CT for a dyno run. Tuning by mail sucks

Here's the pic for those who've been asking over AIM :

 

Tuning through the mail does suck! We only offer a rev limit change package that includes boost fuel cut and a top speed limiter removal through the mail. Other tunes have to be either dyno tested or street tested with a wideband.

I just remembered that my fuel pressure was very high - you may even go down to 690 or 700 - try that. For some reason the emanange calculation is slightly OFF from what those injectors are rated at. It might be interetsting to have them flow tested.

 

I would guess you have all types of over run at idle. With 780 injectors and a big pump.Do you have a A-FPR and FPG?

 

I ended up setting the injector upgrade size to 670 instead of 780, and it idles soild with no fuel correction at idle whatsoever. Runs rich through the powerband though, max EGT was like 760C - so I'll have to tune it again, but having an idle is a good thing