DI Fuel Pump pressure drop , etc. - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Pearlj10 · 08-05-2020, 08:08 PM

Hey folks,
I recently installed my Overkill Stage 1 supercharger on my 2011 LLT. I did a few email tune logs/revisions with Will but wasn’t feeling the power consistently so I went to a local tuner (Arizona Elite Motorsports) for dyno tune. Tuner (“Dr. Bill”) said that my DI pump was dropping from 1800 psi to 800 psi at 6100 rpm and also that I was getting spark blow out in the high 5k rpms. Tuner recommended a booster pump in the trunk and to decrease spark plug gap from .032” to .026-.028” gap.

I sent the logs to Will and he noticed the tune was running rich at the low rpms, just right at 4500-5000 rpm, and rich again after that. He said running rich at high rpms would cause a drop in DI fuel pump psi.

Local tuner says it’s something much more than running rich and the pump correcting fuel pressure for it. He’s firm on a lack of adequate fuel at high (relative to my setup) boost (9.5 lbs). He’s confident that reducing plug gap will fix blowout issue. At 6k rpm, tune was making 362 rwhp.

Any suggestions on this conflicting information I’m getting are much appreciated.

Thanks!
Chris

Tajefe Couple · 08-05-2020, 09:48 PM

I'm not usually a huge Will Overkill fan but he is one of the best when it comes to these DI V6 platforms and his response seems plausible. Did Will send you a new tune to load and see if it helps?

Pearlj10 · 08-06-2020, 09:17 PM

Will did send a revised tune and I'm still seeing the serious fuel pressure drop. I did three hard throttles today and it happened each time, albeit at slightly different rpms between 5600 or so and 7000. Looks like I can't post the data log/hpl file on the forum (?).

JANNETTYRACING · 08-07-2020, 10:40 AM

Quote:

Originally Posted by Pearlj10

Hey folks,
I recently installed my Overkill Stage 1 supercharger on my 2011 LLT. I did a few email tune logs/revisions with Will but wasn’t feeling the power consistently so I went to a local tuner (Arizona Elite Motorsports) for dyno tune. Tuner (“Dr. Bill”) said that my DI pump was dropping from 1800 psi to 800 psi at 6100 rpm and also that I was getting spark blow out in the high 5k rpms. Tuner recommended a booster pump in the trunk and to decrease spark plug gap from .032” to .026-.028” gap.

I sent the logs to Will and he noticed the tune was running rich at the low rpms, just right at 4500-5000 rpm, and rich again after that. He said running rich at high rpms would cause a drop in DI fuel pump psi.

Local tuner says it’s something much more than running rich and the pump correcting fuel pressure for it. He’s firm on a lack of adequate fuel at high (relative to my setup) boost (9.5 lbs). He’s confident that reducing plug gap will fix blowout issue. At 6k rpm, tune was making 362 rwhp.

Any suggestions on this conflicting information I’m getting are much appreciated.

Thanks!
Chris

It is true that if the Lambda is lower than .82 or what ever is commanded the fuel demand is higher yes fuel pressure will drop.

When High side pressure drops injectors open longer, well past the time limit of 6 milliseconds that is what will cause misfire this has nothing to do with plug gap.

A quick look at Low side pressure, High side pressure and injector opening time tells us everything we need to know.

Ted.

tlavoie87 · 08-13-2020, 04:47 AM

send me an email i have run the overkill supercharger on my LLT and tuned myself before converting entire driveline to LFX and dElphi .. i can tell you right now the bosch ecu has COT tables thats we can ot access causing a rich condition.. depending on your boost level the HPFP will be good to about 400WHP.. also with the bosch if you command more than 2250 at the HPFP the ecu does not like it .. again been downthis road many times hence why i went to delphi.. now twin turbo 500+ WHP

Pearlj10 · 08-15-2020, 04:18 PM

PM sent. Thanks!

LuckySave · 05-16-2021, 10:10 AM

Hello all, I would like to offer up another possible solution for pressure drop. Specifically for the HP Tuners platform on my LFX. I'm not sure what else this will work on at this point. In the tune software under the system tab there is a table for fuel system voltage vs Intake air temp. My table was set to 11.5v. Increasing the voltage similar to the setup In the ZL1, I set my voltage to 14.4v across the board, but in the higher range, another tuner has confirmed that increasing the voltage was beneficial up to 16v. I did notice a much steadier and better fuel supply for the forced air application.

08-05-2020, 08:08 PM	#1
Pearlj10 Drives: 2011 Camaro 2LT Join Date: Oct 2018 Location: Az Posts: 367	DI Fuel Pump pressure drop , etc. Hey folks, I recently installed my Overkill Stage 1 supercharger on my 2011 LLT. I did a few email tune logs/revisions with Will but wasn’t feeling the power consistently so I went to a local tuner (Arizona Elite Motorsports) for dyno tune. Tuner (“Dr. Bill”) said that my DI pump was dropping from 1800 psi to 800 psi at 6100 rpm and also that I was getting spark blow out in the high 5k rpms. Tuner recommended a booster pump in the trunk and to decrease spark plug gap from .032” to .026-.028” gap. I sent the logs to Will and he noticed the tune was running rich at the low rpms, just right at 4500-5000 rpm, and rich again after that. He said running rich at high rpms would cause a drop in DI fuel pump psi. Local tuner says it’s something much more than running rich and the pump correcting fuel pressure for it. He’s firm on a lack of adequate fuel at high (relative to my setup) boost (9.5 lbs). He’s confident that reducing plug gap will fix blowout issue. At 6k rpm, tune was making 362 rwhp. Any suggestions on this conflicting information I’m getting are much appreciated. Thanks! Chris Last edited by Pearlj10; 08-05-2020 at 08:09 PM. Reason: Typo

08-05-2020, 09:48 PM	#2
Tajefe Couple Drives: Never just fly under the radar Join Date: Jul 2015 Location: Kansas Posts: 1,531 View My Garage	I'm not usually a huge Will Overkill fan but he is one of the best when it comes to these DI V6 platforms and his response seems plausible. Did Will send you a new tune to load and see if it helps? __________________ 1-8-4-3-6-5-7-2 Old Skool

08-13-2020, 04:47 AM	#5
tlavoie87 Built Not Bought Drives: 2010 Twin Turbo LFX Join Date: Jun 2016 Location: Massachusetts Posts: 618	send me an email i have run the overkill supercharger on my LLT and tuned myself before converting entire driveline to LFX and dElphi .. i can tell you right now the bosch ecu has COT tables thats we can ot access causing a rich condition.. depending on your boost level the HPFP will be good to about 400WHP.. also with the bosch if you command more than 2250 at the HPFP the ecu does not like it .. again been downthis road many times hence why i went to delphi.. now twin turbo 500+ WHP __________________ 2010 Twin Turbo LFX In Memory of my DAD Gone but never Forgotten 2014 "Built Not Bought!' Sponsors: OverKill Motorsports

05-16-2021, 10:10 AM	#7
LuckySave Drives: Gen5LFXfi Join Date: Feb 2021 Location: Wa Posts: 13	Fuel system voltage helps with fuel pressure Hello all, I would like to offer up another possible solution for pressure drop. Specifically for the HP Tuners platform on my LFX. I'm not sure what else this will work on at this point. In the tune software under the system tab there is a table for fuel system voltage vs Intake air temp. My table was set to 11.5v. Increasing the voltage similar to the setup In the ZL1, I set my voltage to 14.4v across the board, but in the higher range, another tuner has confirmed that increasing the voltage was beneficial up to 16v. I did notice a much steadier and better fuel supply for the forced air application.

08-06-2020, 09:17 PM	#3
Pearlj10 Drives: 2011 Camaro 2LT Join Date: Oct 2018 Location: Az Posts: 367	Will did send a revised tune and I'm still seeing the serious fuel pressure drop. I did three hard throttles today and it happened each time, albeit at slightly different rpms between 5600 or so and 7000. Looks like I can't post the data log/hpl file on the forum (?).

08-15-2020, 04:18 PM	#6
Pearlj10 Drives: 2011 Camaro 2LT Join Date: Oct 2018 Location: Az Posts: 367	PM sent. Thanks!