[Torquem]

Local tuner said I could run full E85 on my lt4 no problem with long tubes, cai, ported TB, and a tune. I did a search and it seems some people are saying that it will work, others that it wont. I'm wondering if this is because the LT1 might be different on the low side than the LT4? Curious how many guys are running full E85 on stock fuel system with no issues (on lt4). Thanks for any info!

[big dave]

From what I've read, I don't think you'll be able to run full E85 because the fuel system wouldn't support it with those mods. You may be able to get away with E50.

I've been researching a similar setup for my car so I'll be subscribing to this thread to see what others say.

[ssmofo]

Get the E85 kit from Ted Jannetty, he can enable it and tune for you.

[TJay74]

A ZL1 even with the full LT4 fuel system from the factory wont be able to run full E85, the fuel system doesnt have enough headroom. The lowside is fine, the high side (high pressure pump) cant keep up.

E50 is about the limit on the stock stuff until you put in a cam with a +32% fuel lobe.

[Dixie ZL1]

Originally Posted by Torquem

Local tuner said I could run full E85 on my lt4 no problem with long tubes, cai, ported TB, and a tune. I did a search and it seems some people are saying that it will work, others that it wont. I'm wondering if this is because the LT1 might be different on the low side than the LT4? Curious how many guys are running full E85 on stock fuel system with no issues (on lt4). Thanks for any info!

Similar mods and E40 is the limit. At E40 there’s no discernible HP or TQ improvement I’m going to add an aux pump to run full E85.

[Jason18ZL1LE]

Originally Posted by TJay74

A ZL1 even with the full LT4 fuel system from the factory wont be able to run full E85, the fuel system doesnt have enough headroom. The lowside is fine, the high side (high pressure pump) cant keep up.

E50 is about the limit on the stock stuff until you put in a cam with a +32% fuel lobe.

That’s not entirely accurate. The high side pump is fine, but only if you use a proper cam for it, your wording makes it sound as if even after a cam the LT4 isn’t enough and that’s false.

[Stephen12ZL1]

flex fuel sensor and enabling the tune is an easy way to gain 30-40hp with almost no effort. The problem with the tune is obvious (warranty) but it is tempting. I did this in my 2018
Silverado 6.2 and the results were amazing.

[Jason18ZL1LE]

Originally Posted by Stephen12ZL1

flex fuel sensor and enabling the tune is an easy way to gain 30-40hp with almost no effort. The problem with the tune is obvious (warranty) but it is tempting. I did this in my 2018
Silverado 6.2 and the results were amazing.

Thats true for Silverado LS and SS/LT1 however the LT4 is already nearly out of fuel with the incredibly small cam lobe.

A ZL1 owner cannot simply bolt in a flex fuel sensor and run it. To TRULY run E85 you NEED additional cam lobe at a BARE minimum a fuel pump voltage booster (DSX lowside is highly recommended rather than overvolting the stock pump) to keep the car safe.

[Stephen12ZL1]

as stated above and I believe Jannetty has shown E50-60 can be safely run with the stock fuel pump, cam (fuel lobe), etc and not be any issue. Obviously, log your data after install to confirm all parameters are in range.

[7LitreC5]

Where did you get the sensor for the 18 Silverado? I've been thinking of doing the same to my 18 Tahoe 6.2.

Originally Posted by Stephen12ZL1

flex fuel sensor and enabling the tune is an easy way to gain 30-40hp with almost no effort. The problem with the tune is obvious (warranty) but it is tempting. I did this in my 2018
Silverado 6.2 and the results were amazing.

[Stephen12ZL1]

https://youtu.be/YIfBSlPJwr8

https://youtu.be/ezb58gNGJRk

https://youtu.be/O_WeWK06zWM

[Stephen12ZL1]

Originally Posted by 7LitreC5

Where did you get the sensor for the 18 Silverado? I've been thinking of doing the same to my 18 Tahoe 6.2.

Watch the videos above and his tutorial is very good. You have to enable the tune which is the most annoying part. The good thing is GM already has all of the tables in the tune...they just aren't enabled in the 6.2 vehicles. I Purchased the sensor from Amazon and it is the same sensor that's for a 2011 impala flex fuel 3/8". Get the GM part (continental) and not the cheaper version as the first sensor I received was dead. If you do it like the guy installed it in the video there was no cutting or splicing required. My truck is a standard bed crew cab so I had to get an extension harness to reach the sensor location.

[TJay74]

Originally Posted by Jason18ZL1LE

That’s not entirely accurate. The high side pump is fine, but only if you use a proper cam for it, your wording makes it sound as if even after a cam the LT4 isn’t enough and that’s false.

My wording and info is correct, I have the full LT4 fuel system from the gas tank all the way up to the engine on my car. It is supercharged and puts down 650rwhp on E50.

On the stock cam if you have the full LT4 fuel system the low side will be fine, it will hold 70psi with no issues. The high side pump will run out at WOT high rpms and wont be able to hold more than 2500psi from around 5750rpms until the rev limiter at 6500rpms.

As I said, once you add a +32 fuel lobe cam to the setup it changes everything, but you will still run into issues being able to run full E85.

[7LitreC5]

Thanks. I'll take a look under the Tahoe when it warms up her and make sure that it has that pigtail. Installation looks super easy in the videos.

Originally Posted by Stephen12ZL1

Watch the videos above and his tutorial is very good. You have to enable the tune which is the most annoying part. The good thing is GM already has all of the tables in the tune...they just aren't enabled in the 6.2 vehicles. I Purchased the sensor from Amazon and it is the same sensor that's for a 2011 impala flex fuel 3/8". Get the GM part (continental) and not the cheaper version as the first sensor I received was dead. If you do it like the guy installed it in the video there was no cutting or splicing required. My truck is a standard bed crew cab so I had to get an extension harness to reach the sensor location.