6.2L (L9H) Owners - Get all your questions answered here

[bird38]

There are no official hp number for e85. I gained 32hp running e85 over 93 octane with a tune.

 

Don't be fooled by the pulled timing when running e85 that's because it runs cooler, higher octane, and the AFR changes to 9.85.

 

My 93 tune runs 24 degrees WOT and with E85 I'm only running 15-17 degrees. Just be careful messing with timing while running E85 as it won't knock.

 

I put down 363awhp with 160 degree Tstat, cold air intake, and Efilive.

[NemesisC5]

There are no official hp number for e85. I gained 32hp running e85 over 93 octane with a tune.

 

Don't be fooled by the pulled timing when running e85 that's because it runs cooler, higher octane, and the AFR changes to 9.85.

 

My 93 tune runs 24 degrees WOT and with E85 I'm only running 15-17 degrees. Just be careful messing with timing while running E85 as it won't knock.

 

I put down 363awhp with 160 degree Tstat, cold air intake, and Efilive.

 

Thanks for the great info. Do you always run E85 or do you run 93 octane more often? I assume the pcm recognizes the E85 and switches to your custom E85 tune and when you run 93 switches to your custom 93 tune?

Edited April 3, 2014 by NemesisC5

[bird38]

I usually run 93 unless I want to go romp around or one of my buddies wants to run them. There's only one gas station in my state that sells E85 and it just happens to be on my way home from work.

 

 

Every time you add more than six gallons of gas your ECM calculates the ethanol in the fuel. If it's more than 60% ethanol it will then switch to the flex fuel tables. Anything under that and it will default to your high octane timing tables. If it knocks it will then reduce timing and run off the low octane table.

[NemesisC5]

I usually run 93 unless I want to go romp around or one of my buddies wants to run them. There's only one gas station in my state that sells E85 and it just happens to be on my way home from work.

 

 

Every time you add more than six gallons of gas your ECM calculates the ethanol in the fuel. If it's more than 60% ethanol it will then switch to the flex fuel tables. Anything under that and it will default to your high octane timing tables. If it knocks it will then reduce timing and run off the low octane table.

 

I have a custom 93 tune but factory E85 tune. A new fuel station just opened last week with E85 and I am going to fill up soon. Do you think the factory E85 tune will perform as strong as the custom 93 tune? I know there are variables like how sharp the 93 tune is but I would only like your general opinion/guess on what you think. This is the first discussion I've had with anyone on E85 in my truck so I'm starting off with zero information/feedback. Thanks in advance.

[bird38]

Depends who did your tune. I had a black bear tune previously and it didn't compare in power to a dyno tune by tune time performance. They bumped my timing up another 5 degrees among other things.

 

The 93 tune was great for E85 I just went back to tweak it and see how much more power I was getting.

 

It will pull better down low, have better throttle response, and really crank up top. You will notice it for sure. Snot it from 50mph in 2nd gear and you will see what I'm talking about!

[NemesisC5]

Depends who did your tune. I had a black bear tune previously and it didn't compare in power to a dyno tune by tune time performance. They bumped my timing up another 5 degrees among other things.

 

The 93 tune was great for E85 I just went back to tweak it and see how much more power I was getting.

 

It will pull better down low, have better throttle response, and really crank up top. You will notice it for sure. Snot it from 50mph in 2nd gear and you will see what I'm talking about!

 

I bumped my timing 5* over a mail order tune as well and the difference was BIG. Much more responsive.

If I understand you correctly I will notice a difference without changes to tune and filling up with E85?

If that's correct I know where I'm going to fuel up after work!

[bird38]

Yes! Just make sure your current tank is pretty low or your ECM will read it as under 60% ethanol.

 

Do you have Efilive, hp tuners, or Diablo?

 

I think my timing is up 11 degrees overall. Not in all areas of course but around WOT. I can post my high octane timing table if you'd like to see the differences.

[CRSilverado]

Yes! Just make sure your current tank is pretty low or your ECM will read it as under 60% ethanol.

 

Do you have Efilive, hp tuners, or Diablo?

 

I think my timing is up 11 degrees overall. Not in all areas of course but around WOT. I can post my high octane timing table if you'd like to see the differences.

Would like to compare it to my stock high octane table. Would need to see your AFR spark correction table too unless you have zeroed this.

Edited April 3, 2014 by CRSilverado

[NemesisC5]

Yes! Just make sure your current tank is pretty low or your ECM will read it as under 60% ethanol.

 

Do you have Efilive, hp tuners, or Diablo?

 

I think my timing is up 11 degrees overall. Not in all areas of course but around WOT. I can post my high octane timing table if you'd like to see the differences.

 

Currently on Diablo custom tune that I added timing to. Three rpm ranges to change. I added 5*, 4*, then 3* in top rpm range. Sounds like I left some on the table with you adding more timing up top than low-middle like I did. So you added more timing upper rpms? If so sounds like I need to get my head on straight and take it up a little.

 

I do own HP Tuners but have not used it in 3 years.

[CRSilverado]

 

Currently on Diablo custom tune that I added timing to. Three rpm ranges to change. I added 5*, 4*, then 3* in top rpm range. Sounds like I left some on the table with you adding more timing up top than low-middle like I did. So you added more timing upper rpms? If so sounds like I need to get my head on straight and take it up a little.

 

I do own HP Tuners but have not used it in 3 years.

 

Need to use your HP Tuner to read your intune file so you know for sure with the Intune file. That's what I did with mine and found I had a tendency to not get into the truck what I wanted. Had to go back and make changes based on what I read in the HPT read file.

[bird38]

Ok i will post some of my tables to give you a basic tune. You need to match all of these as they will work together! Ive been running these number for a while and no problems. Countless hours of scanning and its been on the dyno three times. You are all safe!

 

These tables are in HP tuners and comepare stock tune vs my tune. These numbers are the difference so you need to ADD or SUBTRACT to your STOCK values based on what you see below!!!

 

My AFR correction table is set to zero across the board.

 

High octane timing table

 

IAT timing correction

 

PE Throttle/predal hot

 

PE EQ Ratio

Edited April 3, 2014 by bird38

[NemesisC5]

 

Need to use your HP Tuner to read your intune file so you know for sure with the Intune file. That's what I did with mine and found I had a tendency to not get into the truck what I wanted. Had to go back and make changes based on what I read in the HPT read file.

 

 

I didn't think of it that way, didn't consider viewing the Diablo tune as HPT file? I purchased the Diablosport inTune because I read and was told that the Diablosport tuners don't leave the footprints on the PCM like HPT or EFI. A GM Tech 2 can see that the tune was viewed but no footprints of a change in calibrations. Again, just what I've read and been told. Tonight going to Best Buy to purchase a laptop to start playing with HPT again. Thanks for the good advice.

[bird38]

Every tuner leaves a foot print. The only way to save your warranty is to buy a spare ecm/tcm or "brick" it if something major happens.

[CRSilverado]

Ok i will post some of my tables to give you a basic tune. You need to match all of these as they will work together! Ive been running these number for a while and no problems. Countless hours of scanning and its been on the dyno three times. You are all safe!

 

These tables are in HP tuners and comepare stock tune vs my tune. These numbers are the difference so you need to ADD or SUBTRACT to your STOCK values based on what you see below!!!

 

My AFR correction table is set to zero across the board.

 

High octane timing tableHot Spark.jpg

 

IAT timing correction

IAT.jpg

 

PE Throttle/predal hot

PEHOT.jpg

 

PE EQ Ratio

PE2.jpg

 

I assume you zeroed out your Spark Correction Gas table? Hard to determine actual advance with a compare table. IAT could go a little more. I have mine zeroed to 113* but running slightly richer than you. Did you use a wide band and set your MAF?

[CRSilverado]

 

 

I didn't think of it that way, didn't consider viewing the Diablo tune as HPT file? I purchased the Diablosport inTune because I read and was told that the Diablosport tuners don't leave the footprints on the PCM like HPT or EFI. A GM Tech 2 can see that the tune was viewed but no footprints of a change in calibrations. Again, just what I've read and been told. Tonight going to Best Buy to purchase a laptop to start playing with HPT again. Thanks for the good advice.

 

Only way I could get it right. I can't imagine what some are getting in their files without a way to check what you have actually done.