ZFG Tune

[Edge5280]

Absolutely. Different tunes for 87,91,93

We only have 91 typically here but also 100 pump gas with 10% E. Terriblely expensive but I can blend it up with the 91 to hit higher octane #s. As suggested on the forum was to run a tune with somewhat higher octane and E content. That's the plan anyway E40 and 94+. I'm shooting for 12s at 5000' with nothing but a K&N filter and Tune, and everything  that comes with the car, spare tire, seats etc. A few 10ths away with the 91 e30 tune and lots of spin. I have a  much faster toy but this is my family hotrod. We'll see.

Edited April 15, 2021 by Edge5280

[dolsen]

2 hours ago, Edge5280 said:

Absolutely. Different tunes for 87,91,93

We only have 91 typically here but also 100 pump gas with 10% E. Terriblely expensive but I can blend it up with the 91 to hit higher octane #s. As suggested on the forum was to run a tune with somewhat higher octane and E content. That's the plan anyway E40 and 94+. I'm shooting for 12s at 5000' with nothing but a K&N filter and Tune, and everything  that comes with the car, spare tire, seats etc. A few 10ths away with the 91 e30 tune and lots of spin. I have a  much faster toy but this is my family hotrod. We'll see.

So from a purely chemical perspective, octane is an 8 carbon hydrocarbon and ethanol is a 2 carbon hydrocarbon with an alcohol component attached (an OH in place of an H). With that said, maybe the butchered government definition of octane is different, but octane ratings and ethanol content are not one in the same, but I could see how you can draw an equivalent octane cooling capacity and translate ethanol content to octane (hence the fact that E85 is the equivalent of 113 octane).

 

So, short of redefining octane, I do not agree with your statement, and if I am running an E50 tune, I expect to be able to run a combination of 87 octane fuel (with 10% ethanol content) mixed with E85 (85% ethanol content) to the appropriate mixture to get E50 fuel. However, I still mix 93 and E85, because I am not a chemist and I do not fully understand how it all works.

 

I'm frugal not stupid ?

[Edge5280]

I have time slips and dragy readout, and a real daily driver vs postulations and perspectives. I always love car math and really appreciate where you are coming from. You want to beg to differ at the track or dyno I'm always up for it. I'm sure Livernois would listen to your input as they have different tunes for 91/e30 and 93/e30. 

I test the E85 monthly, always 70% and I'm confident I blend as close as the pump readout can offer. 3 gallons E 85(70) and 6 gallons 91 E10% = 9 gallons E30 with 91 octane. I use ethanol and octane calculators.  I'm not going to split hairs or equations on a family car, but I have pretty consistent results. There is humidity temperature, air pressure drag coefficients and whether I had a cup of coffee or eggs Benedict. I'll stand by E30 93 properly blended makes more power than E30 87. The octane of gasoline has a lesser effect than the other benefits of Ethanol that go far beyond just octane measurements. hp gains are typically better with E than gasoline with similar octane especially in boosted applications.  Still gasoline octane makes a measurable difference. 

Edited April 17, 2021 by Edge5280

[Edge5280]

Gasoline isn't simple. The cam2 I add- Isooctane 26635-64-3 30-70
Toluene 108-88-3 10-25
Naphtha (petroleum), light alkylate 64741-66-8 5-20
Isopentane 78-78-4 5-15
Ethyl Alcohol 64-17-5 7-10
Butane 106-97-8 0-5
Benzene 71-43-2 0.002-0.01

There is also a difference between octane and knock resistance. Ethanol  is a boosted dream.

 

E30 blend Octane difference between 87 and 93 

 

Edited April 17, 2021 by Edge5280
Just bc

[akirby]

2 hours ago, Edge5280 said:

There is also a difference between octane and knock resistance. Ethanol  is a boosted dream.

Huh?  Octane is literally a measure of resistance to spontaneous combustion and that causes knock.

[Edge5280]

My fault in wording. E85 has a higher knock resistance not just because of the octane number, the detonation resistance during compression, but also the cooling effect of changing from liquid to vapor and having a denser mixture. The fuel mixture running before and after the intercooler has the same octane fuel but coming out has a higher knock resistance. 

 

Edited April 18, 2021 by Edge5280

[dolsen]

On 4/16/2021 at 9:39 PM, Edge5280 said:

I have time slips and dragy readout, and a real daily driver vs postulations and perspectives. I always love car math and really appreciate where you are coming from. You want to beg to differ at the track or dyno I'm always up for it. I'm sure Livernois would listen to your input as they have different tunes for 91/e30 and 93/e30. 

I test the E85 monthly, always 70% and I'm confident I blend as close as the pump readout can offer. 3 gallons E 85(70) and 6 gallons 91 E10% = 9 gallons E30 with 91 octane. I use ethanol and octane calculators.  I'm not going to split hairs or equations on a family car, but I have pretty consistent results. There is humidity temperature, air pressure drag coefficients and whether I had a cup of coffee or eggs Benedict. I'll stand by E30 93 properly blended makes more power than E30 87. The octane of gasoline has a lesser effect than the other benefits of Ethanol that go far beyond just octane measurements. hp gains are typically better with E than gasoline with similar octane especially in boosted applications.  Still gasoline octane makes a measurable difference. 

So revisiting this, I recently filled up the edge with E85 and 87 octane because the gas station was out of 93. So to make up for the lower octane fuel, I added a gallon of E85 on top of what my calculations were to fill up the tank (I think it was supposed to be 9 gal E85 and 4 gal 87, so instead I did 10:3). Based on our conversation I assumed my vehicle would pull timing and be slower due to the decreased octane used, so my preconceived notions going into this was that it would "feel" slower. But it turns out the opposite was the case. The car felt faster and felt like it pulled harder. This is likely due to the increased ethanol content.

 

Does the octane of the fuel make a difference in how much timing advance there is in an ethanol tune? sure. But as the concentration of ethanol goes up, the octane of the fuel used to mix becomes more and more negligible.

 

If you're fine tuning a pure drag car, sure the octane is likely very important, but for an ethanol tuned DD, I find it hard to believe that fuel octane matters, at least on an E50 tune. Maybe and E30 the octane of the gasoline is a much bigger deal, but not so much on a powerful, but conservatively tuned E50 DD.