Flex Fuel Kit / E85 Questions!

DarkMaroSS · 01-29-2022, 05:37 PM

Hey guys,
I’m as ignorant as one can be when it comes to using E85, but recently found I have a few gas stations nearby with E85.

I know about the flex fuel kits available for the LT1s and that you need to have the PCM tuned to turn this on and have the proper mappings for this.

My questions about the subject are:
1. Once the kit and the tune is setup, can you mix 93 octane and E85?
2. Do you have to empty the tank completely to use either fuel?

Anything you guys can elaborate on I’d definitely appreciate it.

Puddin · 01-29-2022, 06:18 PM

Quote:

Originally Posted by DarkMaroSS

Hey guys,
I’m as ignorant as one can be when it comes to using E85, but recently found I have a few gas stations nearby with E85.

I know about the flex fuel kits available for the LT1s and that you need to have the PCM tuned to turn this on and have the proper mappings for this.

My questions about the subject are:
1. Once the kit and the tune is setup, can you mix 93 octane and E85?
2. Do you have to empty the tank completely to use either fuel?

Anything you guys can elaborate on I’d definitely appreciate it.

Once it is tuned you can mix 93 and E85. There is no need to drain the tank to run either fuel. The computer will be able to tell what you have in the tank and make adjustments accordingly. Just make sure you have a good tuner.

ste6000 · 01-30-2022, 07:17 AM

Quote:

Originally Posted by DarkMaroSS

Hey guys,
I’m as ignorant as one can be when it comes to using E85, but recently found I have a few gas stations nearby with E85.

I know about the flex fuel kits available for the LT1s and that you need to have the PCM tuned to turn this on and have the proper mappings for this.

My questions about the subject are:
1. Once the kit and the tune is setup, can you mix 93 octane and E85?
2. Do you have to empty the tank completely to use either fuel?

Anything you guys can elaborate on I’d definitely appreciate it.

From what i read you can. It also depends how it is tune. Good shops will start at 93 tune, and then slowly add in E85 to change the % and tune it at different levels. Like 15% mix, 30%, 50%. I could be wrong since I havent had it done, just what i been reading and watching on it.

*Joshinator99* · 01-30-2022, 08:23 AM

Quote:

Originally Posted by Puddin

Once it is tuned you can mix 93 and E85. There is no need to drain the tank to run either fuel. The computer will be able to tell what you have in the tank and make adjustments accordingly. Just make sure you have a good tuner.

laynlo15 · 01-30-2022, 08:55 AM

You can run straight 93 as I did in my C7 in the winter months here in Missouri or a mix as mentioned above. The ECU will determine how much timing to add at WOT depending on the Flex Fuel table your tuner setup in HP Tuners. I set mine up with 5 degrees extra timing based on E70. Obviously the less E content the ECU sees the less amount of timing it will add at WOT. Your base timing is about 22 to 23 degrees. Generally you'll see anywhere from 25 to 30 rwhp gain over the stock 91 octane tune GM puts in from the factory. I've found that anything above E65 or E70 adds no additional performance on a stock NA engine, that means on the dyno or at the drag strip.

Spaceme1117 · 01-30-2022, 09:11 AM

The sensor reads the ethanol content in real time and adjusts timing depending on the %.

When I had my car tuned for E85, my tuner had me get to the dyno with about 1/4 of a tank of just 93 octane gas. He then tuned the car for that.

Next we added about 12 gallons of E85. And then he tuned for the ethanol.

Mix read at about e67 which is fine. Because of the compression ratio of the LT1, e60 is about the max of what the car can take advantage of.

So if I get some E85 in my car I also usually do a mix and try to hit about e65 for a margin of error.

You can get something such as a Banks Super Gauge or Aeroforce and read the actual ethanol number from the sensor

DarkMaroSS · 01-30-2022, 10:43 AM

All this is great info…I definitely appreciate it.

So, e65 would be around a 20% am I right?

Would it be fair to say 30% is the safest blend or not necessarily?

DarkMaroSS · 01-30-2022, 10:57 AM

Quote:

Originally Posted by Spaceme1117

The sensor reads the ethanol content in real time and adjusts timing depending on the %.

When I had my car tuned for E85, my tuner had me get to the dyno with about 1/4 of a tank of just 93 octane gas. He then tuned the car for that.

Next we added about 12 gallons of E85. And then he tuned for the ethanol.

Mix read at about e67 which is fine. Because of the compression ratio of the LT1, e60 is about the max of what the car can take advantage of.

So if I get some E85 in my car I also usually do a mix and try to hit about e65 for a margin of error.

You can get something such as a Banks Super Gauge or Aeroforce and read the actual ethanol number from the sensor

So a 1/4 of 93 and the rest of E85? How much do you normally pour?

tarmelter · 01-31-2022, 03:21 PM

I live in Maine and work in NH. Neither state has an E85 station. The second there is I plan to do this too.

DarkMaroSS · 01-31-2022, 05:34 PM

Quote:

Originally Posted by tarmelter

I live in Maine and work in NH. Neither state has an E85 station. The second there is I plan to do this too.

Trust me…I know what you mean. The gas station I had nearby that I thought had e85 (because I saw it was an ethanol pump) apparently is Ethanol FREE gasoline!

Eitherway I dont have too many options just like you.

Spaceme1117 · 01-31-2022, 06:15 PM

Quote:

Originally Posted by DarkMaroSS

All this is great info…I definitely appreciate it.

So, e65 would be around a 20% am I right?

Would it be fair to say 30% is the safest blend or not necessarily?

What’s great about adding E85 is that any blend is safe as long as the tune is correct. You can run 100% gas or 100% E85 and anything in between and it will be safe. The tune has two timing advance tables and will interpolate between the tables depending on the mix.

As for actual final ethanol content if you are trying to blend at the pump, it is a bit of a guessing game. E85 that you buy can vary greatly in the ethanol content.

There a free apps that you can download to calculate the final e-blend.

Daily1LE · 01-31-2022, 08:34 PM

I just switched to E85 last year. To answer your questions you can run all E85, all 93, or anything in between (assuming you had it properly tuned) and you do not have to drain to change from one to the other. Even 93 has ethanol in it (it's about 10%).

As for blending, I am not sure why you'd wanna blend? You certainly don't have to. I run the highest E85 I can find all summer and use 93 only in winter when I store my car since E85 is not good to leave in tank for long periods of time as it attracts moisture more than 93 does.

On a side note, not all E85 labelled gas is actually 85% ethanol. Around me some gas stations sell "E85" that was reading around E50 on my torque app. I've found a BP that sells E80, but that seems to be the best around me. So my point is you may not always get E85 from the pump either way, so do check where you pump. Somewhere on the pump it will say "minimal E xx%". I've seen anywhere from 50-70 around me, so I guess I'm lucky to have found a station that sells E80.

jeffm5690 · 03-10-2022, 01:04 PM

Are there kits for the 2018 V6? I don’t think so. I know there was for 2012-2015. I am only seeing for the SS/LT1

laynlo15 · 03-10-2022, 02:24 PM

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Just finished mine and was on the dyno yesterday. Here is where we finished up on E57. We are still on winter blend here in Missouri and I also had 1/4 tank of 93 in when I added the E70. Made 431/442, we were a little on the rich side but with the combo I have we were stuck, tried leaning and lost power, tried riching it up and lost power, added more timing and it didn't like it on the low E57. My C7 made more power but we were on E70 when we first tuned it back in 2020. We made 8 pulls and started at 429 and ended up at 431 so our initial tune was pretty darn good from the beginning.

01-29-2022, 05:37 PM	#1
DarkMaroSS Drives: 2018 Camaro SS (sold) Join Date: Mar 2016 Location: Tampa, FL Posts: 81 View My Garage	Flex Fuel Kit / E85 Questions! Hey guys, I’m as ignorant as one can be when it comes to using E85, but recently found I have a few gas stations nearby with E85. I know about the flex fuel kits available for the LT1s and that you need to have the PCM tuned to turn this on and have the proper mappings for this. My questions about the subject are: 1. Once the kit and the tune is setup, can you mix 93 octane and E85? 2. Do you have to empty the tank completely to use either fuel? Anything you guys can elaborate on I’d definitely appreciate it. __________________ 2018 Camaro 1SS \| BBK 92mm TB \| GPI Ported LT1 Manifold \| ColdAirInductions CAI \| Granatelli Wires and MSD coils \| Mishimoto Catch Can \| GMP Black Strut Tower Brace \| NPP Exhaust and 2nd Cat Delete \| Recaro Seats \| GM Stainless Sport Pedal Kit \| GM Carbon Fiber Shift Knob \| Deck Lid Spoiler with Wicker Bill \| Smoked Sequential Taillights \| Smoked Third-Brake Light \| 1LE Front Splitter/Satin Black \| ZL1Addons Splash Guards 2015 Camaro SS/RS (Sold)

01-30-2022, 10:43 AM	#7
DarkMaroSS Drives: 2018 Camaro SS (sold) Join Date: Mar 2016 Location: Tampa, FL Posts: 81 View My Garage	All this is great info…I definitely appreciate it. So, e65 would be around a 20% am I right? Would it be fair to say 30% is the safest blend or not necessarily? __________________ 2018 Camaro 1SS \| BBK 92mm TB \| GPI Ported LT1 Manifold \| ColdAirInductions CAI \| Granatelli Wires and MSD coils \| Mishimoto Catch Can \| GMP Black Strut Tower Brace \| NPP Exhaust and 2nd Cat Delete \| Recaro Seats \| GM Stainless Sport Pedal Kit \| GM Carbon Fiber Shift Knob \| Deck Lid Spoiler with Wicker Bill \| Smoked Sequential Taillights \| Smoked Third-Brake Light \| 1LE Front Splitter/Satin Black \| ZL1Addons Splash Guards 2015 Camaro SS/RS (Sold)

01-31-2022, 03:21 PM	#9
tarmelter Drives: 2022 1SS 1LE Join Date: Nov 2021 Location: Maine Posts: 105	I live in Maine and work in NH. Neither state has an E85 station. The second there is I plan to do this too. __________________ 2022 Shadow Gray Metallic 1SS 1LE A10 Rotofab Dry ST delete.

03-10-2022, 01:04 PM	#13
jeffm5690 Drives: 2023 2SS 1LE Join Date: Nov 2009 Location: NY Posts: 142 View My Garage	Are there kits for the 2018 V6? I don’t think so. I know there was for 2012-2015. I am only seeing for the SS/LT1 __________________ 2024 2SS 1LE Hyper Blue Front/Rear Dashcam (Blackvue) 2018 2LT/RS Hyper Blue Cosmetics - Bow tie Front/Rear Dashcam (Blackvue) 2010 2LT/RS IBM K&N Aircharger MRT V2.0 Exhaust Trifecta Tune Soon to be added: Elite Catch Can Iceolater Vmaxx Ported TB Cosmetics - Rally Flags, Door Sillplates Electronics - Escort Hardwired

01-30-2022, 08:55 AM	#5
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,882	You can run straight 93 as I did in my C7 in the winter months here in Missouri or a mix as mentioned above. The ECU will determine how much timing to add at WOT depending on the Flex Fuel table your tuner setup in HP Tuners. I set mine up with 5 degrees extra timing based on E70. Obviously the less E content the ECU sees the less amount of timing it will add at WOT. Your base timing is about 22 to 23 degrees. Generally you'll see anywhere from 25 to 30 rwhp gain over the stock 91 octane tune GM puts in from the factory. I've found that anything above E65 or E70 adds no additional performance on a stock NA engine, that means on the dyno or at the drag strip.

01-30-2022, 09:11 AM	#6
Spaceme1117 Drives: 2017 Camaro SS, 2011 Corvette GS Join Date: Feb 2019 Location: Erlanger, Kentucky 41018 Posts: 859	The sensor reads the ethanol content in real time and adjusts timing depending on the %. When I had my car tuned for E85, my tuner had me get to the dyno with about 1/4 of a tank of just 93 octane gas. He then tuned the car for that. Next we added about 12 gallons of E85. And then he tuned for the ethanol. Mix read at about e67 which is fine. Because of the compression ratio of the LT1, e60 is about the max of what the car can take advantage of. So if I get some E85 in my car I also usually do a mix and try to hit about e65 for a margin of error. You can get something such as a Banks Super Gauge or Aeroforce and read the actual ethanol number from the sensor

01-31-2022, 08:34 PM	#12
Daily1LE Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2019 Location: IL Posts: 122	I just switched to E85 last year. To answer your questions you can run all E85, all 93, or anything in between (assuming you had it properly tuned) and you do not have to drain to change from one to the other. Even 93 has ethanol in it (it's about 10%). As for blending, I am not sure why you'd wanna blend? You certainly don't have to. I run the highest E85 I can find all summer and use 93 only in winter when I store my car since E85 is not good to leave in tank for long periods of time as it attracts moisture more than 93 does. On a side note, not all E85 labelled gas is actually 85% ethanol. Around me some gas stations sell "E85" that was reading around E50 on my torque app. I've found a BP that sells E80, but that seems to be the best around me. So my point is you may not always get E85 from the pump either way, so do check where you pump. Somewhere on the pump it will say "minimal E xx%". I've seen anywhere from 50-70 around me, so I guess I'm lucky to have found a station that sells E80.

03-10-2022, 02:24 PM	#14
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,882	Just finished mine and was on the dyno yesterday. Here is where we finished up on E57. We are still on winter blend here in Missouri and I also had 1/4 tank of 93 in when I added the E70. Made 431/442, we were a little on the rich side but with the combo I have we were stuck, tried leaning and lost power, tried riching it up and lost power, added more timing and it didn't like it on the low E57. My C7 made more power but we were on E70 when we first tuned it back in 2020. We made 8 pulls and started at 429 and ended up at 431 so our initial tune was pretty darn good from the beginning.

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