2015 6.2 L86 E85 dyno tune numbers

kgkern01 · February 25, 2020

Just got my 2015 6.2 Sierra dyno tuned after adding the ethanol sensor, also did 8-speed tuning. Only mods are Volant intake, home ported throttle body, and E85 conversion with dyno tune, also on heavy Nitto Ridge Grapplers. 380rwhp/435rwtq. Pretty happy with the numbers.

TRKLGND · February 25, 2020

How did you tune the 8 speed? I thought the TCM was locked.

How much power did you make on premium unleaded? That would be the only way to know if the E85 mod is beneficial.

Where I live, the mpg loss from running E85 makes the fuel cost about the same as running premium. I'd have to make quite a bit more power to justify filling up 30% more often.

I'm asking because I am thinking about some mods for my 2018 6.2L 8-speed.

Jaychevy81 · February 25, 2020

You have to get the module unlocked when I put the supercharger on mine I was going to get it done but I didn’t yet.

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Denali34 · February 25, 2020

You can also buy a Unlocked TCM from HP Tuners ready to go instead of having down time sending it off to be unlocked. Its only like 299.00. Thats what I did with mine to avoid a delay. Plug and Play

kgkern01 · February 25, 2020

37 minutes ago, paracutin said:

How did you tune the 8 speed? I thought the TCM was locked.

How much power did you make on premium unleaded? That would be the only way to know if the E85 mod is beneficial.

Where I live, the mpg loss from running E85 makes the fuel cost about the same as running premium. I'd have to make quite a bit more power to justify filling up 30% more often.

I'm asking because I am thinking about some mods for my 2018 6.2L 8-speed.

My tuner said that the early 8-speeds are tunable, but the later ones you have to send the TCM off For tuning because they are locked. I didn’t dyno it before I did the FlexFuel conversion, but bone stock L86 dyno’s that I’ve found tend to be in the 330hp/365tq range. So the air intake, smoothed throttle body, and E85 tune got roughly 50rwhp/70rwtq. Which I’ve seen others gain 35-40rwhp/40-50rwtq off just Doing the E85 Swap and tune, so 20hp/tq off intake and throttle body is about right.

Jaychevy81 · February 25, 2020

I did a slp tvs1900 on my 5.3 it woke up after that lol. I had it dyno tuned it put down 480 RWhp. It’s fun to drive.

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cstmg8 · February 25, 2020

Which e85 kit did you go with? I think I'm going to start with e85, smaller pulley, throttle body, headers and Dyno tune with tcm.

This will probably have me at about the reliable limit for the tranny.

Does anyone know the limits of the fuel system?

kgkern01 · February 25, 2020

3 hours ago, cstmg8 said:

Which e85 kit did you go with? I think I'm going to start with e85, smaller pulley, throttle body, headers and Dyno tune with tcm.

This will probably have me at about the reliable limit for the tranny.

Does anyone know the limits of the fuel system?

I actually just bought a GM sensor, Russell female fuel line connectors and put it in line where the tank soft line connects to the hard line, then extended the sensor plug 18”. Only $70 worth of parts and no cutting fuel lines. The 8L90 is rated up to 738ft/lb of torque, which should be around 575 rwtq, so if you’re approaching that with the blower then it may be upgrade build time for the trans?

kgkern01 · February 26, 2020

So now after driving it around a few days the torque difference alone is worth it to convert in my opinion.

truckguy82 · February 26, 2020

44 minutes ago, kgkern01 said:

So now after driving it around a few days the torque difference alone is worth it to convert in my opinion.

Did you have it tuned prior to running e85?

my 0-60 went from 5.8 to 5.0 with just a tune, all from low end torque

I’m assuming the huge increase you feel is not from the e85 and mostly from the tune

cstmg8 · February 26, 2020

I actually just bought a GM sensor, Russell female fuel line connectors and put it in line where the tank soft line connects to the hard line, then extended the sensor plug 18”. Only $70 worth of parts and no cutting fuel lines. The 8L90 is rated up to 738ft/lb of torque, which should be around 575 rwtq, so if you’re approaching that with the blower then it may be upgrade build time for the trans?

Awesome. Do you happen to have the part numbers or a link? I'm sure I can find it with some googling. This sounds way better than cutting a fuel line.
I'm not sure on the horsepower and torque numbers, Callaway has it listed at 560/553.
I need to get a base dyno done, then a tune. I know they have the tune very safe and super rich.

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kgkern01 · February 26, 2020

20 minutes ago, truckguy82 said:

Did you have it tuned prior to running e85?

my 0-60 went from 5.8 to 5.0 with just a tune, all from low end torque

I’m assuming the huge increase you feel is not from the e85 and mostly from the tune

It was not tuned prior to the E85, but with just a base E85 map loaded, the base pull was only down 10rwhp, 12rwtq vs the final pull. Adjusting AFR and timing further on subsequent pulls didn’t gain anymore than the final numbers. Plus, even the stock 5.3 is factory rated what 30-35 hp/tq more on E85, with .5 less compression, 0.9L smaller displacement, smaller cam. So the gains for the 6.2 converting to E85 are not really surprising.

Edited February 26, 2020 by kgkern01

truckguy82 · February 26, 2020

7 minutes ago, kgkern01 said:

It was not tuned prior to the E85, but with just a base E85 map loaded, the base pull was only down 10rwhp, 12rwtq vs the final pull. Adjusting AFR and timing further on subsequent pulls didn’t gain anymore than the final numbers. Plus, even the stock 5.3 is factory rated what 30-35 hp/tq more on E85, with .5 less compression, 0.9L smaller displacement, smaller cam. So the gains for the 6.2 converting to E85 are not really surprising.

I’m not talking about the hp

i’m talking about the torque management.

I literally knocked almost a full second off my 0-60 from just a tune , which probably has hardly any hp increase.

what you feel on the low end has a lot to do with the oem tuning nannies. I don’t doubt the extra hp feels nice too though.

kgkern01 · February 26, 2020

5 minutes ago, truckguy82 said:

I’m not talking about the hp

i’m talking about the torque management.

I literally knocked almost a full second off my 0-60 from just a tune , which probably has hardly any hp increase.

what you feel on the low end has a lot to do with the oem tuning nannies. I don’t doubt the extra hp feels nice too though.

True, I’m sure dialing back the torque management in the tune helped quite a bit, but the (estimated) extra 35rwhp/45rwtq from the E85 part of it didn’t hurt lol.

BlackBearPerf · February 26, 2020

On 2/25/2020 at 5:03 AM, paracutin said:

How did you tune the 8 speed? I thought the TCM was locked.

How much power did you make on premium unleaded? That would be the only way to know if the E85 mod is beneficial.

Where I live, the mpg loss from running E85 makes the fuel cost about the same as running premium. I'd have to make quite a bit more power to justify filling up 30% more often.

I'm asking because I am thinking about some mods for my 2018 6.2L 8-speed.

Not sure if this was answered, but it's the 2017 and newer, 8 speed, or 10 speed TCM that is locked, if the vehicle is a 2015 8 speed, that would be tunable.