[E85 and C5 Corvette Compatibility]
Thread Starter
Melting Slicks
Joined: Jul 2008
Posts: 3,002
Likes: 216
From: Houston Texas
2018 Corvette of Year Finalist
2017 C5 of Year Finalist
Just to throw this out there just for some reference. I am running DW 95lb injectors. My base fuel psi is 65 so they are actually 108lb inj at that pressure and I am running a boost referenced system on 14 psi so far it traps 125mph in the 1/8 155+ in the 1/4 @ 3300 lbs. I havent had it on the dyno but with that MPH and weight its making roughly 900whp and my duty cycle is 98%
What is the best ET so far?Ben, I would just make sure you're using viton seals on all the new stuff and regulator is alcohol compatible. Wouldn't worry about the transfer lines as much since they're low pressure anyway. Not sure on the filter socks in the tanks.. Our earlier ones use a big sock on PS tank siphon, the 01 and later don't have a sock on them. Probably not a big deal though.
I'm planning on corn myself, but switched to the Haltech with flex sensor. Regular pump last fill had 8% alcohol. During the winter they dilute the E85 down, so would want some sort of content sensor at the very least if using stock PCM still. I don't remember what the % was Bret told me when he put some in his car last, but it was significantly under 85%.
You might be able to do something cheap by putting a Continental GM flex sensor in your return line, give it 12V and measure the frequency on output wire. 50hz = 0% alcohol, 150hz = 100%
I'm planning on corn myself, but switched to the Haltech with flex sensor. Regular pump last fill had 8% alcohol. During the winter they dilute the E85 down, so would want some sort of content sensor at the very least if using stock PCM still. I don't remember what the % was Bret told me when he put some in his car last, but it was significantly under 85%.
You might be able to do something cheap by putting a Continental GM flex sensor in your return line, give it 12V and measure the frequency on output wire. 50hz = 0% alcohol, 150hz = 100%
Houston has been seeing a range of 80% to 92% for the last year depending on what station you use.
Do you ever manually test the ethanol content or adjust the tune for it? Can you see a difference on the wideband between 75% and 85% ethanol?
Thread Starter
Melting Slicks
Joined: Jul 2008
Posts: 3,002
Likes: 216
From: Houston Texas
2018 Corvette of Year Finalist
2017 C5 of Year Finalist
Any other comments?
I have a friend that tuned his car on 88% ethanol. He said he only races if the range is 85% to 90%. One time the blend was 98% and the car was almost out of fuel based on the injector duty cycle.
Does anyone have experience with what range you can get away with based on the tune and ethanol content range? Keep in mind this is in regards to racing. I realize you can put E70 in the tank and still drive around.
I have a friend that tuned his car on 88% ethanol. He said he only races if the range is 85% to 90%. One time the blend was 98% and the car was almost out of fuel based on the injector duty cycle.
Does anyone have experience with what range you can get away with based on the tune and ethanol content range? Keep in mind this is in regards to racing. I realize you can put E70 in the tank and still drive around.
Safety Car
Joined: Jan 2008
Posts: 4,797
Likes: 52
From: Boise
It's not that much different. I've seen as high as 90% in Boise. Some people swear up and down it makes a huge difference, but I personally have not and i log my car almost every time I drive.
I'll put it this way...this past TX2K I just took my car off the trailer in Houston, made no changes to the tune at all and filled up with whatever was in the pump down there and had 0 issues. And that's with adding in the factor of elevation chance (about 2,800 ft difference).
In short....make sure 70ish or more and don't worry about it.
Edit: The range in which E85 is safe and can make power is huge. Even if your AFR changes a little it's still close enough
I'll put it this way...this past TX2K I just took my car off the trailer in Houston, made no changes to the tune at all and filled up with whatever was in the pump down there and had 0 issues. And that's with adding in the factor of elevation chance (about 2,800 ft difference).
In short....make sure 70ish or more and don't worry about it.
Edit: The range in which E85 is safe and can make power is huge. Even if your AFR changes a little it's still close enough
Melting Slicks
Joined: Dec 2012
Posts: 2,312
Likes: 8
From: Frisco Texas
Can you trick you car into being flex fuel by settings the the main fuel tables to E85 and (from what I heard) the second fuel setting for pump. I heard there is another fuel table for the car if you get bad gas.
Drifting
Joined: Feb 2006
Posts: 1,585
Likes: 15
From: New Hartford IA
It's not really going to knock so to speak and we have been getting e70 around here most of the time now. I'd say tune for e70 and if it goes up some it's not going to hurt anything unless it's showing super lean or you run out of fuel up top.
My friend runs E70 in his RX7 that I built a iron 6.0l for and runs a turbonetics 7575 non intercooled with Meth. He has pushed it to 18-20psi and high 9's at 150 in a 6 speed car. He never puts gas in over the winter like I tell him, but his pumps (255hp) continue to work and he hasn't had any of the black goo problems either. I'm quite surprised it has been fine with his lack of maintenance and a older car to boot.
My friend runs E70 in his RX7 that I built a iron 6.0l for and runs a turbonetics 7575 non intercooled with Meth. He has pushed it to 18-20psi and high 9's at 150 in a 6 speed car. He never puts gas in over the winter like I tell him, but his pumps (255hp) continue to work and he hasn't had any of the black goo problems either. I'm quite surprised it has been fine with his lack of maintenance and a older car to boot.
Last edited by slow ride; Feb 13, 2015 at 08:20 AM.
Safety Car
Joined: Jan 2008
Posts: 4,797
Likes: 52
From: Boise
C6 has the flex fuel tables
