K4fxd
Well-Known Member
Wrong.AFR sat around 13.6-13.7 when they should have been closer to 13.
The idiot dash gauge should read 14.1 on the stock tune with any amount of E
Sponsored
Wrong.AFR sat around 13.6-13.7 when they should have been closer to 13.
Except when I logged it and it was still 13.6-13.7. Plus the fact that on my Flex tune right now running E50 the dash reads 11.5-11.7 like it should.Start running real logs and you will find quick that dash gauge means zero, nothing except to confuse people.
It really doesn't. Timing is what will gain HP, and it isn't much when you're comparing 93 vs e30. e85 has less energy than gasoline hence needing more of it. It wont make more power without the paired added timing.If you're gonna be snarky you need to be correct.
ethanol makes more power even at the same timing, its always a good choice.
Correct. Need more fuel and more timing to make more power on E85.It really doesn't. Timing is what will gain HP, and it isn't much when you're comparing 93 vs e30. e85 has less energy than gasoline hence needing more of it. It wont make more power without the paired added timing.
No you’ll make more power at the same timing, there is more energy in the cylinder when running ethanol.It really doesn't. Timing is what will gain HP, and it isn't much when you're comparing 93 vs e30. e85 has less energy than gasoline hence needing more of it. It wont make more power without the paired added timing.
Ok I did.No you’ll make more power at the same timing, there is more energy in the cylinder when running ethanol.
Take a second and look up the energy per unit volume of the two fuels, then calculate the total energy at the two stoich afrs.
I think the key word there is at the stoich AFRs. You need more ethanol than gas to run at stoich if I understand this whole thing correctly.No you’ll make more power at the same timing, there is more energy in the cylinder when running ethanol.
Take a second and look up the energy per unit volume of the two fuels, then calculate the total energy at the two stoich afrs.
no you didn't do it right.Ok I did.
Im curious, have you tested you theory?
its linear though, so if its more at stoich its more at PE. More all the time.I think the key word there is at the stoich AFRs. You need more ethanol than gas to run at stoich if I understand this whole thing correctly.
The flex tune recalibrates the dash gauge. The stock tune will show stoich as 14.1 with any fuel, or it should. Again it is worthless for tuning.Plus the fact that on my Flex tune right now running E50 the dash reads 11.5-11.7 like it should.
On paper that's amazing but like other's stated in the same thread you shared, there isn't much gain to be had. It's a waste of time unless you're increasing timing. Not sure of many people who will just run e85 without adding more timing. It's pointless. So maybe it does make a couple more HP at the crank but you won't feel a difference and may not even see it on a dyno and could be lost in the drivetrain, unless you increase timing. On a hot summer day in Florida you may notice a difference but nothing significant.no you didn't do it right.
do this math for ethanol and gasoline:
https://forum.hptuners.com/showthre...le-or-wasteful&p=735061&viewfull=1#post735061
gasoline = 18.4k btu/lb, gasoline stoich = 14.7:1
ethanol = 11.5k btu/lb, ethanol stoich = 9:1
at an airflow mass of 30 lbs/min:
ethanol: 30/9 = 3.3 lb/min of fuel * 11500 = 38333 btu/min
gasoline: 30/14 = 2 lb/min of fuel * 18400 = 37551 btu/min
it it putting more energy into the cylinder.
thats just at stoich its already making more power, when you go to power enrich it gets greater, because you can't enrich gasoline as much as you can enrich ethanol.
Ethanol makes more power than gasoline, all the time. This doesn't count for efficiency, the design of the engine will lend itself to being more efficient with one fuel over another. That's why it works so well on this engine, the engine itself works well with ethanol and you're getting the additional benefit of high octane. Ethanol is a twofold power adder. That's why its so good.
also its a percentage, so as you flow more air the absolute increase in power gets larger.
Wait Junits,If you're gonna be snarky you need to be correct.
ethanol makes more power even at the same timing, its always a good choice.
yep you nailed it, its less power per unit volume but its stable at a much higher volume. So the total power in the cylinder is more.Wait Junits,
I'm not saying you are wrong here because I've followed you in other threads and you obviously are not an idiot on this topic. I'm the idiot here but I'm trying to learn...
But HOW can ethanol make more power than gasoline with the same mount of fuel being mixed since ethanol makes quite a bit less energy/BTUs per volume when compared to gasoline?
Or, am I not reading deep enough into your statement and you are indirectly saying that ethanol does make more power when the appropriate HIGHER volume of fuel is used through a dedicated ethanol tune OR even the stock ECU does it job by adding more E-fuel to the combustion chamber?
Or, all things being the same, does the higher octane ethanol allow for a longer flame front in the combustion chamber, thus making more power, similar to how a longer barreled rifle will usually create higher bullet muzzle velocities than a shorter one (I'm a gun gun; hoping my analogy rings with you).
Sorry if this is an uber-simplistic question.
Edit 1: Sorry, I should have read ahead more before responding. Not that I wouldn't enjoy a response to this stoopid question anyway...
Edit 2: I put @350 miles on the GT yesterday using my 89 Octane gas to 91 Octane E19 mix and it seemed to work perfectly! I tested it a couple times by manually shifting the car into a high gears at low speeds, trying to create an engine knock and there was none to be had. Also, since the traffic coming back North into MI. was so flippin' heavy, I jumped off the interstate and onto some 2 lane "farm roads" to bypass the mess. So, I had the chance to put the car into sport mode and run a couple Zero to "wife screaming SLOW DOWN!" bursts up to @120 and it seemed the car was "in the groove" there too...
Like I calculated, I saved about $9/fillup this way without any significant/noticeable loss of performance.