Fuel/ airflow limit HELP

[super6ute]

Hi,
I seem to have hit some sort of limit causing loss of increase of fuel flow from 5000rpm

Combo is NGC3 CAN Controller.
426 cube, F1-A Procharger (struggling through a 6pk belt)
2000cc bosch injectors, running on pump E85 currently at about an E80 mix.
Dual nozzle Snow performance kit currently injecting about 1100cc/m at full flow.

In the log you'll see the 2 stages off water/meth come on (in the AFR trace) then at 5200rpm starts going lean due to lack of increase in injector flow.

FWI- first jeep I've tuned so i'm positive I've missed something simple. Cars currently making close to 900 whp on a good run with less belt slip. (Going to slow charger down some more to rectify this).

838hp. belt slip. fuel limit..hpl22.3.16 meth tuning v2.hpt

[Mep_q8]

Just a few things I can point out, your going into boost without entering PE mode. Also log Injector Duty Cycle, lets see how your fuel pump is standing up (Do you have a fuel pressure gauge?)

With the amount of meth your spraying, you shouldn't see any lean conditions. Can you let me know your reason behind setting the stoich to that value?

[super6ute]

Thanks Trailblazin.

See attatched image for duty cycle. As you can see it's hitting a window of 42%. Along with total airflow of about 1000 g/s at that point which also seems to hit a window
,even though it went higher earlier in the pull.

[ATTACH=CONFIG]57589[/ATTACH



I've just dropped TP WOT thresh down to 1.9, which will hopefully be enough to bring PE in earlier.

Stoich is set for E85, do you think I should work with unleaded Stoich for any reason?

Thanks, your input is much appreciated.

[super6ute]

SRT8. sceenshot.png

[super6ute]

Bump

[Mep_q8]

I would also rescale your VE table to command a higher resolution for WOT Fueling.

[super6ute]

As in add a few more load sites?
Yes would be a good idea. I dont think there will be such a big jump in numbers once I find this problem though.

[06300CSRT8]

Stoich is stoich, I wouldn't try to tune it the way you have. Looks to me like you are just bumping up against your FA Max limit (set to 0.103 in ENGINE>FUEL>GENERAL tab). You are commanding 0.120 at times after 5200 but most you are going to be delivered is your max.

Further to Trailblazin recommendation on rescaling your VE table, you should especially do this to your FA Power Enrich table. Right now you have that set to max at a 1.50 pressure ratio even though you are well over 2.0. Again, youre just riding on the bottom row and tossing out the rest of the table this way.

[RonSSnova]

Just curious how you ended up with the numbers you entered for the injector data?

I'm tuning a 426 Jeep with the F1A right now. Pump gas though.
6 rib as well. It literally smokes the belt past 5000 rpm. So we replaced the 3.2" pulley with a 3.6" and much better. We lost boost, but the belt isn't slipping so it stays constant.

[06300CSRT8]

Appears to be using ID's info straight off their website. ID's are bosch

[RonSSnova]

The table just looks wrong. Nothing like the break points Dodge uses.

[06300CSRT8]

Which table?

[B00STJUNKY]

The table just looks wrong. Nothing like the break points Dodge uses.

It's not necessarily a bad thing to change the breakpoints to be different than what Dodge had in there originally.

In fact, for folks using really large injectors 900+ cc/min, it's good to rescaled the breakpoints to gain more tuning resolution in the very low end of the pulsewdith range, like 1.2ms and lower, which is the range that a good majority of engines are going to idle at on gasoline with injectors that big.

If you've ever looked at injector characteristics data from the companies that publish it, you'll see that fuel quantity vs pulsewidth in these low ranges is anything but linear. It's not until closer to 2.0 ms where they start to stabilize and become more linear, and that's the point where you don't need such fine tuning resolution.

Basically, it really doesn't matter too much what breakpoints someone decides to use, as long as the corresponding fuel quantity data is accurate at those breakpoints.

Though, as described above, there are definitely methods of selecting optimal breakpoints that will lead to better calculated fuel quantity vs actual delivered fuel quantity consistency

[SultanHassanMasTuning]

if you can, rework your injPW/ Fuel Mass/Chrg tables to get control of your injector

a brief look at your log, seems like your only hitting around 9ms of your injector

[super6ute]

Stoich is stoich, I wouldn't try to tune it the way you have. Looks to me like you are just bumping up against your FA Max limit (set to 0.103 in ENGINE>FUEL>GENERAL tab). You are commanding 0.120 at times after 5200 but most you are going to be delivered is your max.

Further to Trailblazin recommendation on rescaling your VE table, you should especially do this to your FA Power Enrich table. Right now you have that set to max at a 1.50 pressure ratio even though you are well over 2.0. Again, youre just riding on the bottom row and tossing out the rest of the table this way.

So just to clarify, your using pump (no alcohol) stoich in alcohol applications also?

Thanks for everyones input. Going back on the dyno tonight to try a few things. Gone to a 4.0" blower pulley now so belt slip wont be an issue. (running an ATI overdrive BTW)

[doc350]

Stoich is stoich, I wouldn't try to tune it the way you have.

I'm going to have to disagree here. Stoich is going to change based on the fuel type. If it were a lambda reading, then yes, lambda is lambda. But for what he is doing here, it looks to me like he has his FA Stoich set properly. (although maybe a little rich since he is only at E80)

I do agree with your other points though.

[06300CSRT8]

That was my fault, I misread and thought he was running 93 pump and then spraying meth under WOT. Missed the e80 "pump"

[super6ute]

For anyone who has this issue, just to clear up. It was FA ratio max under FA limits. I upped this and it was sorted.
Thanks to everyone who had a look.