2013 ZL1: FPCM FSCM flash after BAP, E85 and 850cc injectors?

[turabo87]

I'm preparing myself for next stage of tuning with a 2013 ZL1. First round of tuning went very successful, but it's time for more power and safer injector DC%, and I have some questions:

BEFORE:
Mods: 2.55" upper, JLT intake, LT 1-7/8 headers, 93 octane MAF tune.
586WHP/591WTQ STD on Dynojet (88F day), and injectors maxed out unfortunately.

UPCOMING:
All the above + E85/flex fuel, FIC 850cc injectors, and a Kenne Bell BAP.

I already have the new tune pre-ready with the FIC injector data (unscaled) populated in the PCM tune, but I'm unsure if the new injector data or the BAP will require any modification to the FSCM/FPCM. I'd rather not touch the FSCM/FPCM but again, I'm not sure if the BAP or 850cc injectors and use of E85 will require any tweaking to the FSCM/FPCM. I'd love some input here to avoid as much trial and error on tuning day. Thanks.

[NotSure]

IMO it is worth licensing and tuning, ESPECIALLY with your changing of the injectors and the addition of a BAP. There's not a lot of info out there on it, I don't know if it is because it's another $50, not totally needed, or what. Considering the cost of the speed parts, $50 is a spit in the bucket. I don't think most people that are on this forum would make engine mods and say (in reference to the ECM), "meh, the fuel trims will take care of it." and not make any cal changes.

One thing that I have seen is that the Long Term pump trims seem to be a global modification. In other words, if overall the duty cycle is too low, the LT trims will go up, but that is applied across all fuel flow rates. So it seems to be best to make up a math that adds LT and ST pump trims, put into a graph that matches your Openloop DC chart, and apply those changes there. For example, if you are too "lean" at high fuel flow rates, but just right at low flow rates, your overall LT trims may go high which will require your ST trims to remove duty cycle at the low flow rates.

Also, there is no feature in HP to reset the pump trims, you need a scan tool to do so. Or, just be aware of this when you use the log data. You may make some changes to the Openloop duty cycle chart, then in the next log you may see the LT trims gradually change over the course of the drive as it learns. This is why I suggest adding LT and ST trims together.

You want to log:
Desired fuel pressure
Actual fuel pressure
Fuel pump duty cycle
LT pump trims
ST pump trims.
Control module voltage
And of course all the other engine stuff.

Are you going full flex fuel...planning on having some varying amount of E and 93 at any given time? This I do not know how it affects the pump trims, as I am just now getting into burning corn at the same time I have changed to a bigger pump. Maybe with all the changes you are doing right now, it would be best to tune on 93 until the ecm and fscm are fully dialed in, then start throwing in some E? I say this as I don't know if the software accounts for the increased volume requirements for higher E content. From what I am seeing, I am suspecting that it does not, and just relies on the pump trims to account for fuel changes.

For your BAP, that higher voltage should be invisible to the FSCM, so keep that in mind if you need to make any changes to the Min DC chart.

[BigTuner]

Hello,

I have a 2013 ZL1 running on E85. I would advise that 850cc injectors and a BAP are not going to be enough to make much additional power on E85. I would highly recommend bigger injectors like ID1050x or ID1300x and an auxiliary pump or a Fore or Squash fuel pump setup. The 850cc injectors and BAP will be okay for some more power on 93 but won't be enough for E85.

[turabo87]

Hello,

I have a 2013 ZL1 running on E85. I would advise that 850cc injectors and a BAP are not going to be enough to make much additional power on E85. I would highly recommend bigger injectors like ID1050x or ID1300x and an auxiliary pump or a Fore or Squash fuel pump setup. The 850cc injectors and BAP will be okay for some more power on 93 but won't be enough for E85.

So, here's the facts and how I got to 850cc FIC injectors:

2013 ZL1 stock injector size: 53lbs/hr @60PSI, peaked at 120-130%DC after 2.55" pulley and bolt ons with 93fuel at 6500RPM.
53lbs/hr@60PSI is roughly 51lbs/hr @58PSI (interpolated)

I calculated extra 30% larger to get into safe 90% DC with target AFR at 6500RPM, with 93.
Then another 30% on top to get it to around 90% DC with E85.
That's a compounded 69% larger size.

The FIC 850cc are advertised as 94lbs/hr@58PSI. 94lbs/hr@58PSI vs. 51lbs/hr@58PSI is about 84% larger, which is plenty below the 69% that I previously calculated that was the minimum additional flow I needed. I don't think there's much room for any more mods after that, but I believe it's adequately sized based on my math.

As far as the BAP, I'm not convinced it'll be enough to provide the 30% more flow required with E85. I'm relying on the owner's due diligence for this. I wouldn't be surprised if I see fuel pressure drop with E85 under WOT.

PS: I already had licensed the FPCM/ FSCM. I'm thinking of just raising the "Maximum Boost Pressure" limits and increasing MAX Pump DC to about 96% from the stock 90%, to avoid losing fuel pressure with E, but I don't want to risk burning the pump either.

[BigTuner]

So, here's the facts and how I got to 850cc FIC injectors:

2013 ZL1 stock injector size: 53lbs/hr @60PSI, peaked at 120-130%DC after 2.55" pulley and bolt ons with 93fuel at 6500RPM.
53lbs/hr@60PSI is roughly 51lbs/hr @58PSI (interpolated)

I calculated extra 30% larger to get into safe 90% DC with target AFR at 6500RPM, with 93.
Then another 30% on top to get it to around 90% DC with E85.
That's a compounded 69% larger size.

The FIC 850cc are advertised as 94lbs/hr@58PSI. 94lbs/hr@58PSI vs. 51lbs/hr@58PSI is about 84% larger, which is plenty below the 69% that I previously calculated that was the minimum additional flow I needed. I don't think there's much room for any more mods after that, but I believe it's adequately sized based on my math.

As far as the BAP, I'm not convinced it'll be enough to provide the 30% more flow required with E85. I'm relying on the owner's due diligence for this. I wouldn't be surprised if I see fuel pressure drop with E85 under WOT.

PS: I already had licensed the FPCM/ FSCM. I'm thinking of just raising the "Maximum Boost Pressure" limits and increasing MAX Pump DC to about 96% from the stock 90%, to avoid losing fuel pressure with E, but I don't want to risk burning the pump either.

Just remember your fuel pressure will almost certainly be starting to drop off with only a BAP so you won't be getting that 58 psi, and our cars use a return less system that does not have vacuum\boost referenced fuel pressure, therefore to get the actual pressure across the injectors you need to subtract your boost, so you will be seeing more like 48psi across the injectors at best depending how much boost you are making.

I am running 2.55 upper, 9.05 lower, aux pump, ID1050x injectors, ported snout, ported LS3 90mm TB, 5" JLT intake, headers and flex fuel as well as various supporting cooling mods etc. I maintain a minimum of 60psi fuel pressure during WOT and I still see 80+% duty cycle in parts of the run, so while I am running more power I am also running bigger injectors and better fuel flow/pressure. So from my personal experience I am concerned you will be wasting your money, I'd honestly skip the E85 if you aren't going for big power rather than have a borderline fuel system for minimal gains, because if you try to get the maximum out of that E85 you will definitely run out of fueling.