Max performance tuning a 3.5 EB between E-85 and 93 differences

[Seishuku]

Yeah, fuel system is pretty loaded there... Port injection is really dragging the LPFP down, the problem with getting better flow out of the LPFP and leaning on the port injection to take up the fuel demand slack is that you're losing out on the power that you'd otherwise gain from pure DI, but then that's already far over taxed as well (already seeing nearly 1000PSI HP actual) and better LP pump isn't going to fix that.

You didn't log it there, but what does the actual lambda look like, is it actually holding commanded lambda?

[Davem3261]

Your stock lift pump should be able to keep up with E35. I noticed that you are only commanding 45%DC, make sure that's bump to 50%. Also, the pump voltage needs to be 15v in the 72/73 psi@ 4.7. Your port injectors are probably wide open with that low fuel pressure.

[Perna00]

Thanks for the info! I’ll adjust them and run another test with a lambda reading also to see if I’m still able to keep up with it. I also previously commanded 90% as a warm mix of DI vs PI. Should that be adjusted or is that just targeted until it realizes pressure is an issue…?

Your stock lift pump should be able to keep up with E35. I noticed that you are only commanding 45%DC, make sure that's bump to 50%. Also, the pump voltage needs to be 15v in the 72/73 psi@ 4.7. Your port injectors are probably wide open with that low fuel pressure.

[Perna00]

I increased the duty cycle, voltage table, and max voltage limits?and still desperately starting for fuel in the rail. I see they sell a dw-400 pump for around $250 that I can swap. I believe someone said the whole pump assembly from a raptor is about the same price but I?m finding it over $450. Anyone happen to research available pumps and have a good link/site for it?

[Perna00]

I found my pump. Just got to install it after it arrives. Does anyone have a recommendation on port injector size to be able to run E85?

[09Vic]

I found my pump. Just got to install it after it arrives. Does anyone have a recommendation on port injector size to be able to run E85?

Seems like from what I could find the stock injector is a 47# (B556V bosch) injector. Word on the street is you need 30% more fuel. I suppose some of that could be made up with duty cycle and so on. If I was going to make an educated guess I would go with a 60 to 65 lb injector and adjust duty cycle as needed from there.


EDIT: Seems to GT500 was built with 60ish lb injectors... Dunno if they will fit but a place to start I suppose.

https://lmr.com/products/mustang-fue...tor-size-chart

A place to start.

[Perna00]

Thanks for the reply. I’ll check into the 60/65# range. I know the direct injection can’t keep up with a high blend for DI/PI so the 65 might be the better option.

[Davem3261]

Injector dynamics 1050x would be my first option. Fuel Injector clinic is another good vendor. They have smaller options. 65 is too small of an increase, go bigger. Do not go the cheap route on port injectors. Your truck idles on the port injection. It will not idle well without a quality injector. The motorcraft PN for the fuel pump is PFS1136 for the 36 gallon tank. Someone might be able to help with the fuel pressure if you post up a tune file.

[Perna00]

Is there any effects from going with a larger injector? If not, maybe it’s better to be safe unless it has some other effects I’m not aware of.

[Perna00]

I just got the low pressure fuel pump installed (DW400). I?m about to get some E85 and see how everything works out. I previously had my warm blend to be at 80% DI. Has anyone found the best percentage to keep most performance and not run out of fueling on the low or high end?

[Perna00]

I might need some help on this one. I filled up with E-85 and I hit a torque demand limit around 600 which I didn't think I would. However, at the end of my run, the service wrench came on and it limped home. I restarted it a few times and it went away but it wouldn't give me a read code to follow up with. Maybe I need a few other PID's to check...? Also, let me know if this log looks typical or if there is something else I need to adjust and fine tune. It is a first E85 attempt so it is a work in progress (feel free to roast me if needed). I did notice my low pressure is keeping up with the demand the entire time and the high pressure rail seems to be keeping up "most" of the time. It did drop down a few times. Would that mean I should definitely get some larger port injectors for the fueling source? I was under the impression if the DI can't keep up with the fuel, it compensates with the PI. If the rail is still low pressure, does that mean it is out of options...? Thanks for any advice.

May 20th E85.hpl

[Perna00]

I believe my turbo was over speed based on the airflow limit. I?ve raised it but haven?t tried WOT again. I was looking through my tables and I noticed that the desired high pressure fuel tables are different between flex fuel and regular. Should these be copied to the higher tables from the regular fuel tables to the flex? The flex should be higher if I?m thinking properly due to the higher demand of fuel unless there is something else in the equation I?m not factoring. Any opinions?

[Perna00]

And so I continue on with my research and troubleshooting, hoping that I get some responses to some questions for a more solid approach from other tuners out there. My latest find is that I previously had my warm blend around 80% on the last two rows under heavy load. I originally increased these for the cooling and stability effect of direct injection. Because my high-pressure fuel rail is not following my desired pressure but I now have a higher volume lift pump, would it be better to lower this blend percentage down to 70 or so to allow the port injectors to take up more of the fueling demand and allow the pressure to increase on the direct injection side ? I believe by using E 85 that I may not need as much cooling affect from the direct injection site… Thoughts?

[engineermike]

Is your hpfp hitting 100% duty cycle when it’s not hitting desired pressure?

[Perna00]

The lift pump stays under 42% duty cycle the entire run. The high-pressure fuel pump regulator DC hits 100% just moments after the throttle plate hit wide open. Somewhere around 3,000 rpm.

[engineermike]

Ok that’s actually a good thing then. The gdi is doing all it can do. The way the logic works is that it calculates how much gdi it wants (warm blend x required fuel flow) and compares that to how much it is allowed to deliver (the lesser of soi-eoi clip and max injection angle) and injects for the lowest of these three durations. Whatever remains to be delivered then reverts to the port injectors. It’s true that maximizing gdi isn’t as important on e85, but having more gdi blend will still help with knock suppression and take some load off your port injectors if they are nearing their limit.

[Perna00]

That’s definitely good news then. Would I now have to look at injector duty cycle to figure out if my fueling is limited or would that directly reflect into the lambda readings?

[engineermike]

There’s a couple of ways to go about it but at least two things show up before lambda is affected. One, you can log injector duty cycle and also max duty cycle. When they meet, you’re out of capacity. The other isn’t as intuitive but the logic is always calculating a torque limit based on fuel capacity available. If you log driver demand limit and see it switch to “insufficient fuel flow”, that means the driver demand torque from the dd table is more than what the fuel system can support. At that time, you’ll see the etc torque request fall from the numbers in the dd table. When engine brake torque exceeds this etc torque request, it will cut throttle.

[Perna00]

Perfect, that should give me a supported answer on whether or not I need to change the port injectors. I’ve currently set my boost pressure exactly where I want it so that I know what my max fuel demand will be. I believe my only remaining step is to adjust the timing, but I’m waiting to see if HP tuners is going to set up the parameter to adjust advance when alcohol is detected first.

[Perna00]

A few updates to the thread. I got the 1080’s since the fuel system couldn’t keep up with the E85 without them. It was close without them but was leaning out too much for comfort when going into heavy loads. Now it’s running perfectly after the injectors. I’m starting to adjust timing which I was able to gain 5 degrees across all borderline tables without issues and the rest will be slowly with testing. My only discouragement was that HP doesn’t have a table like some of the other ford platforms to adjust spark based on alcohol content. That would be perfect if so. It can limit air load based on alcohol but that’s about it.