Going back to pump gas from E85

[FetzerValve]

Like the title states, I'm looking to go back to pump gas after running E85 for the past couple years. Main reason being that E85 isn't the easiest to find in my area and I drive a long stretch of highway (about 360 miles) that doesn't have any stations. The truck is a 6.2 with a Borg S475. My initial tune (blackbear autocal) worked for the past few years but I'm at the point that I'd like to fiddle around with the tune myself rather than waiting months to hear back from Blackbear. Back when he tuned it, he mentioned that I'd have to run E85 at boost levels greater than 10#. I'm at 12# now but recently turned it down to 9# after noticing my fuel pressure dropping to ~30# above 4500 rpms (still on stock flexfuel pump). I'd like to switch the tune up to a pump gas tune but I'm a little lost as to how to go about it.

For the experienced folks out there, should I tune strictly for pump gas or should I take advantage of the flex tables and tune based on ethanol content? I don't have an actual sensor, just the stock flex fuel virtual sensor. I've been watching goatrope's vids as he seems to have a good grasp of GM engine tuning, but he moves so quickly I find myself getting lost trying to follow his logic.

Thanks for any help you all may be able to provide.

2010 6.2 Silverado
Borg S475 @ 9#
850cc injectors (rated at 43#, so closer to 1000cc @ 58#)
Stock flex pump and returnless system

Current tune: Rev. 9-FFDP from forum enabled upshift adapt.hpt

[5FDP]

I would try putting pump gas back in it and hope that the virtual flex fuel brings your stoich back up in a timely matter. I'd drive it around for a bit before flooring it.

Or just run it really low of fuel, put pump 91/93 in it and change the stoich to exactly what you want it to be for the fuel you are running. 14.68 for E0 and 14.1 for E10.

I'd watch your timing and knock in boost with pump gas. You have a spark adder table I'd be watching to make sure it's not adding in too much extra timing.

[FetzerValve]

Much appreciated, Sir. I was hoping you'd reply to the post. I'm running a trans tune that you posted to help out another gentleman and it was night and day better than what I had before. You have been a great resource to me and the rest of the people on this forum.

I'll throw some 91 in it and see how it acts. I know I have an exhaust leak in my crossover at the flex that is causing some funny readings from the wideband, so I'll get that fixed before I make any real changes to the tune. Currently, at WOT on the E85 tune, my wideband is showing a lambda of .9. It used to be down around .84, so my guess is either the leak in the crossover is causing it or possibly the cooler air we are getting now that it's not the summer anymore.

For timing, my high and low octane tables are quite a bit different than a stock file I pulled from the repository. Same goes for most of the base correction tables; Fuel, IAT, ECT and VCT. Would you recommend I leave those as-is for now or copy over the stock timing tables from the repository file?

[HarryD]

Definitely don’t go copying stock values back into random tables. Especially none to do with spark or fuel. Most of your fuel stuff is injector specific.. post your tune and a log file if possible and someone will have a look. You can email it to me if you’d like I’d be glad to have a look. We have a similar setup, and I’m glad to help.. but im no pro

[FetzerValve]

Definitely don’t go copying stock values back into random tables. Especially none to do with spark or fuel. Most of your fuel stuff is injector specific.. post your tune and a log file if possible and someone will have a look. You can email it to me if you’d like I’d be glad to have a look. We have a similar setup, and I’m glad to help.. but im no pro

Thanks for the response. Tune file is posted in first post. I'm currently running the E85 out of the truck so I can refill with pump gas. I'm not planning on changing the injector specific fuel settings. Once I get the E out and some pump gas in, I'm planning on putting the 6# spring in the wastegate and getting some data logs.

While the truck runs pretty well in its current configuration, I'm seeing a lot of different things in my tune that I'm not happy with.
1. DFCO is not enabling at all. I'd like to get it working to help with fuel economy as I'm currently in the 8mpg range (E85).
2. Intake cam timing is quite a bit different than the stock compare file. Not sure if this is because of the turbo setup and I'm not experienced enough to fiddle around with that.
3. After installing a Circle D 3200 278mm stall the truck feels slower when just cruising to work. Feels like the trans is slipping until I mash the gas, at which point it really takes off. I tuned the TCC lockup behavior and pulled a trans tune from a post that 5FDP put up for a truck similar to mine.

I should probably just take it somewhere to have it tuned, but I like to learn and do things myself.

My plans for the truck have changed, as I'm not really looking to make big power like I originally wanted. Ideally, I'd run the truck in the 10-12# of boost range with conservative timing for the pump gas. The truck will be getting a long-travel setup in the future as I'm not really looking to do any street racing anymore. I'm too old to be putting lives in danger racing other people on the streets. I'd like a solid 5-600 wheel horsepower, reliable daily driver on pump gas. I need to be able to drive the truck about 400 miles across the state without having to rely on finding E85.

Am I crazy to think that I can re-tune this thing for pump gas on my own? My original tune for the turbo setup was provided by Blackbear through an autocal email tune, so I don't really know what all he changed. I pulled a stock file from the repository and checked the comparison log but there is just too many changes for me to keep track of. Ideally, I guess I'd start from scratch and get the truck running well on a pump gas tune, but I'm just unsure of where to start and can't afford to smoke the motor with my beginner tuning skills.

[HarryD]

FetzerValve;667150]Thanks for the response. Tune file is posted in first post. I'm currently running the E85 out of the truck so I can refill with pump gas. I'm not planning on changing the injector specific fuel settings. Once I get the E out and some pump gas in, I'm planning on putting the 6# spring in the wastegate and getting some data logs.

While the truck runs pretty well in its current configuration, I'm seeing a lot of different things in my tune that I'm not happy with.
1. DFCO is not enabling at all. I'd like to get it working to help with fuel economy as I'm currently in the 8mpg range (E85).
2. Intake cam timing is quite a bit different than the stock compare file. Not sure if this is because of the turbo setup and I'm not experienced enough to fiddle around with that.
3. After installing a Circle D 3200 278mm stall the truck feels slower when just cruising to work. Feels like the trans is slipping until I mash the gas, at which point it really takes off. I tuned the TCC lockup behavior and pulled a trans tune from a post that 5FDP put up for a truck similar to mine.

I should probably just take it somewhere to have it tuned, but I like to learn and do things myself.

My plans for the truck have changed, as I'm not really looking to make big power like I originally wanted. Ideally, I'd run the truck in the 10-12# of boost range with conservative timing for the pump gas. The truck will be getting a long-travel setup in the future as I'm not really looking to do any street racing anymore. I'm too old to be putting lives in danger racing other people on the streets. I'd like a solid 5-600 wheel horsepower, reliable daily driver on pump gas. I need to be able to drive the truck about 400 miles across the state without having to rely on finding E85.

Am I crazy to think that I can re-tune this thing for pump gas on my own? My original tune for the turbo setup was provided by Blackbear through an autocal email tune, so I don't really know what all he changed. I pulled a stock file from the repository and checked the comparison log but there is just too many changes for me to keep track of. Ideally, I guess I'd start from scratch and get the truck running well on a pump gas tune, but I'm just unsure of where to start and can't afford to smoke the motor with my beginner tuning skills.[/QUOTE]



please do not use this file ever for anything, im completely guessing on these changes and slick don't even know what these tables mean. not to mention im pretty much doing what i told you NOT to do ... furthermore putting this file into your ecu, perhaps merely downloading it could and will likely kill or seriously injure you, your computer, and your vehicle. and if for some wild reason you decide that you want to anyway, then shit goes south.. DONT SUE ME BRO!

i gave it the once over and swapped some parameters that work well for me. if this truck has a big cam the idle terms may be too tight. and i rescaled your map. so you may want to do a few sd logs to rectify. BUT your tune is maf only above 800rpm so you may not even see any difference there.