The E85 Mystery

Jordo! · 06-19-2014, 03:20 AM

Octane, tuning, and other in-cylinder transient factors aside, unless we're talking same set-up, same (type of) dyno, etc, I would take that claim with a pinch of salt.

Even if it can be achieved and verified, how long is the motor holding together as torque levels climb past mechanical tolerances? You can crack a ringland if combustion pressures get high enough, even without evidence of autoignition/knock events.

synolimit · 06-19-2014, 10:12 AM

Quote:

Originally Posted by TopgunZ

Seriously bud where are you coming from? Your over on the other thread saying how you want to switch to e85 on an na application then your here dogging it.

Op... Its a way to make more power safely. Its cheaper and readily available race gas. Thats it.

Mods...Lock up the thread before more people become misinformed.

I said over there I'd run e85 only as needed. Only at the track. Not sure if you saw that or not.

It's not cheaper. Saving a few cents per gallon doesn't make up the 30% faster burn rate. It's no where near cheaper!!

TopgunZ · 06-19-2014, 10:23 AM

Quote:

Originally Posted by Jordo!

Octane, tuning, and other in-cylinder transient factors aside, unless we're talking same set-up, same (type of) dyno, etc, I would take that claim with a pinch of salt.

Even if it can be achieved and verified, how long is the motor holding together as torque levels climb past mechanical tolerances? You can crack a ringland if combustion pressures get high enough, even without evidence of autoignition/knock events.

Ill admit that the more power your making, in every revolution, the motor weakens. Rods, pistons, rings, everything.

However, you can make that power with less chance of it letting go due to predet. Also you can stretch out the lifetime of that motor if you are running less boost by using more timing, which is safer to do with E.

TopgunZ · 06-19-2014, 10:28 AM

Quote:

Originally Posted by synolimit

I said over there I'd run e85 only as needed. Only at the track. Not sure if you saw that or not.

It's not cheaper. Saving a few cents per gallon doesn't make up the 30% faster burn rate. It's no where near cheaper!!

You also said "Id be scared to use E85 as a power adder". Now you want to run it on the track.

Again where the hell are you coming from? I said it was cheap RACE GAS. So "a few cents per gallon"? Please show me where I can get race gas for $2.89.

Nobody runs E85 for its amazing cost saving benefits. We run it because its race gas for 1/3 the price.

Ask yourself why they make race gas.

Would anybody not want to run race gas if you could all the time?

synolimit · 06-19-2014, 11:17 AM

Quote:

Originally Posted by TopgunZ

You also said "Id be scared to use E85 as a power adder". Now you want to run it on the track.

Again where the hell are you coming from? I said it was cheap RACE GAS. So "a few cents per gallon"? Please show me where I can get race gas for $2.89.

Nobody runs E85 for its amazing cost saving benefits. We run it because its race gas for 1/3 the price.

Ask yourself why they make race gas.

Would anybody not want to run race gas if you could all the time?

If you're going to quote me do it right. You left off the important part. I said scared because it changes THROUGH THE YEAR!!. I don't run at the track in December with a foot of snow, do you??? Plus even in summer it may not be e85, more like e80-75-70 etc. like my friends before a fill up I'll check the etoh content. If its low ill retune before a track day and not just blindly put it in like a dumb *** and go.

Lol I think VP racing fuel would disagree with you there. And I know why they run RACE gas! Its 100% controlled and perfect everytime and not some different street gas that's always changing and never the same from the multitude of companies that produce it. You thinking its race gas and used as such is like me saying I run a re11, rs3, z1 yok, etc etc on different wheels at different times and it doesn't matter because they're all "race tires."

TopgunZ · 06-19-2014, 11:44 AM

That's why you tune off of E70 then you can only get better quality from there on up. I agree that the fact they differ the content can be a pain.

However, E85 has only been proven to be a far superior fuel to run vs. pump gas by every tuner in the world. You talk about subi guys all the time. Well subi guys love this stuff for a reason. They all are boosted.

Why do you think there are guys that drive 50 miles out of there way with two 5 gallon tanks in their hatch just to run this stuff?

This shouldn't be a "should I run it" discussion. It should be a " Am I boosted and do I have availability"? Then its a no brainer.

Jordo! · 06-19-2014, 04:45 PM

Quote:

Originally Posted by TopgunZ

Ill admit that the more power your making, in every revolution, the motor weakens. Rods, pistons, rings, everything.

However, you can make that power with less chance of it letting go due to predet. Also you can stretch out the lifetime of that motor if you are running less boost by using more timing, which is safer to do with E.

If quenching hotspots are the only issue, then, yes, that follows.

Also, if E85 has a lower stoichiometric ratio than regular petrol I believe that translates into more potential energy (i.e., combustion pressure) to get out of it, so that could be contributing too.

I have no idea what the actual mechanical tolerances are on a stock VQ37HR longblock, tho...

Are there any confirmed breaks from overpower as opposed to detonation?

Nixlimited · 06-19-2014, 05:38 PM

Quote:

Originally Posted by Jordo!

Also, if E85 has a lower stoichiometric ratio than regular petrol I believe that translates into more potential energy (i.e., combustion pressure) to get out of it, so that could be contributing too.

Ethanol has significantly less potential energy than gasoline. That's why it takes significantly more of it (think huge injectors) to make lots of power. But it's excellent for knock resistance.

Per Wiki: Gasoline has 114K BTU/gal to Ethanol's 76K/gal.

djtodd · 06-19-2014, 11:35 PM

Quote:

Originally Posted by Jordo!

Are there any confirmed breaks from overpower as opposed to detonation?

Not that I know of. I'm sure mine will go eventually. I flog the hell out of it at the track pretty regularly. And that's 600+ whp on stock internals. But of course that's one of the main reasons I went with e85.

I'm just treating it as an experiment at the point. How long can I beat on it at these power levels at the track before it fails? We'll see!

Jordo! · 06-20-2014, 04:31 AM

Quote:

Originally Posted by Nixlimited

Ethanol has significantly less potential energy than gasoline. That's why it takes significantly more of it (think huge injectors) to make lots of power. But it's excellent for knock resistance.

Per Wiki: Gasoline has 114K BTU/gal to Ethanol's 76K/gal.

I think the key value here is latent heat of vaporization vs. amount of fuel needed to achieve peak torque, which is a factor related to stoichiometry -- check out p. 117 on down at this link.

http://martysgarage.info/manuals/bell2ttuning.pdf

It's from A.G. Bell's book on fueling 2-stroke engines, but he has the exact same formulas/rationale in his 4-stroke supercharged tuning book.

Anyway, in theory, less efficient, but more energy ultimately produced as a consequence.

Now, if E85 ends up breaking about even, then it's just less efficient, but has a higher auto ignition threshold and higher octane, in which case never mind my other point

Nixlimited · 06-20-2014, 10:25 AM

Quote:

Originally Posted by Jordo!

I think the key value here is latent heat of vaporization vs. amount of fuel needed to achieve peak torque, which is a factor related to stoichiometry -- check out p. 117 on down at this link.

http://martysgarage.info/manuals/bell2ttuning.pdf

It's from A.G. Bell's book on fueling 2-stroke engines, but he has the exact same formulas/rationale in his 4-stroke supercharged tuning book.

Anyway, in theory, less efficient, but more energy ultimately produced as a consequence.

Now, if E85 ends up breaking about even, then it's just less efficient, but has a higher auto ignition threshold and higher octane, in which case never mind my other point

Those are great books BTW!

NOBLE|370Z · 06-21-2014, 10:57 AM

Some great discussion taking place here.

It would be nice if VQ owners knew whether our cars are power limited at 550WHP due to engine internal strength or if it's based solely on detonation. This is important to distinguish because guys with stock motors and FI should know what the limiting factor really is.

If a tuner could get 700WHP out of my stock engin, regardless of fuel, would I really feel comfortable keeping it there (even if there are no signs if detonation)? Definitely not lol

I'm getting my car tuned in a couple weeks and I want to be prepared so I think I'll play it safe. I'll have two maps. 1 for 91 and another for 94 octane. Regardless of the amount of power he can get with the 94 I will make sure to use a boost setting that maintains no more power than 550WHP. When someone can produce information indicating it's 600WHP then I'll change it at that point. For the long haul I think that's the best approach - IMO

NOBLE

Seb@SZ · 06-21-2014, 12:30 PM

Quote:

Originally Posted by NOBLE|370Z

Some great discussion taking place here.

It would be nice if VQ owners knew whether our cars are power limited at 550WHP due to engine internal strength or if it's based solely on detonation. This is important to distinguish because guys with stock motors and FI should know what the limiting factor really is.

If a tuner could get 700WHP out of my stock engin, regardless of fuel, would I really feel comfortable keeping it there (even if there are no signs if detonation)? Definitely not lol

I'm getting my car tuned in a couple weeks and I want to be prepared so I think I'll play it safe. I'll have two maps. 1 for 91 and another for 94 octane. Regardless of the amount of power he can get with the 94 I will make sure to use a boost setting that maintains no more power than 550WHP. When someone can produce information indicating it's 600WHP then I'll change it at that point. For the long haul I think that's the best approach - IMO

NOBLE

One BIG issue that doesn't come up is the fuel pressure drop associated with a stock fuel pump assembly AND keeping it returnless. Over time the drop can get worse leaning out the AFRs. I HIGHLY, and I stress HIGHLY, recommend forced inducted 370Zs run a return style fuel system. From what we've gathered, fuel pressure drops become apparent near and around 450 whp.

djtodd · 06-21-2014, 03:42 PM

Quote:

Originally Posted by NOBLE|370Z

Some great discussion taking place here.

It would be nice if VQ owners knew whether our cars are power limited at 550WHP due to engine internal strength or if it's based solely on detonation. This is important to distinguish because guys with stock motors and FI should know what the limiting factor really is.

If a tuner could get 700WHP out of my stock engin, regardless of fuel, would I really feel comfortable keeping it there (even if there are no signs if detonation)? Definitely not lol

I'm getting my car tuned in a couple weeks and I want to be prepared so I think I'll play it safe. I'll have two maps. 1 for 91 and another for 94 octane. Regardless of the amount of power he can get with the 94 I will make sure to use a boost setting that maintains no more power than 550WHP. When someone can produce information indicating it's 600WHP then I'll change it at that point. For the long haul I think that's the best approach - IMO

NOBLE

There are quite a few of us running 600+ for some time now. But admittedly no one with 20k miles or so. Just give it time

I'm convinced 600 with proper fuel, cooling, and tune is well within limits. Proof is in the pudding

Jordo! · 06-22-2014, 10:35 PM

Quote:

Originally Posted by Seb@SZ

One BIG issue that doesn't come up is the fuel pressure drop associated with a stock fuel pump assembly AND keeping it returnless. Over time the drop can get worse leaning out the AFRs. I HIGHLY, and I stress HIGHLY, recommend forced inducted 370Zs run a return style fuel system. From what we've gathered, fuel pressure drops become apparent near and around 450 whp.

Can't you just upgrade to a higher output pump?

Between that and bigger injectors I'm surprised there would be much drop off unless we're talking a lot of boost pressure.

What lph and injectors are the high horsepower Z's running vs. OEM specs?

06-19-2014, 03:20 AM	#16 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 418	Octane, tuning, and other in-cylinder transient factors aside, unless we're talking same set-up, same (type of) dyno, etc, I would take that claim with a pinch of salt. Even if it can be achieved and verified, how long is the motor holding together as torque levels climb past mechanical tolerances? You can crack a ringland if combustion pressures get high enough, even without evidence of autoignition/knock events. __________________ Enjoy it. Destroy it.

06-19-2014, 11:44 AM	#21 (permalink)
TopgunZ A True Z Fanatic Join Date: Jun 2012 Location: Minneapolis Posts: 2,651 Drives: 06 350Z , 09 370Z MT Rep Power: 6834	That's why you tune off of E70 then you can only get better quality from there on up. I agree that the fact they differ the content can be a pain. However, E85 has only been proven to be a far superior fuel to run vs. pump gas by every tuner in the world. You talk about subi guys all the time. Well subi guys love this stuff for a reason. They all are boosted. Why do you think there are guys that drive 50 miles out of there way with two 5 gallon tanks in their hatch just to run this stuff? This shouldn't be a "should I run it" discussion. It should be a " Am I boosted and do I have availability"? Then its a no brainer. KevinN and mikey1600 like this. __________________ ROTREX SUPERCHARGER TUNER KITS - $6799/ CUSTOM STILLEN AIR TO AIR KITS -$2100/ 700+ WHP!! WWW.TOPGUNSPEEDWORKS.COM Last edited by TopgunZ; 06-19-2014 at 11:53 AM.

06-21-2014, 10:57 AM	#27 (permalink)
NOBLE\|370Z Base Member Join Date: Sep 2011 Location: Calgary AB Posts: 61 Drives: 09 Nissan 370Z Rep Power: 14	The E85 Mystery Some great discussion taking place here. It would be nice if VQ owners knew whether our cars are power limited at 550WHP due to engine internal strength or if it's based solely on detonation. This is important to distinguish because guys with stock motors and FI should know what the limiting factor really is. If a tuner could get 700WHP out of my stock engin, regardless of fuel, would I really feel comfortable keeping it there (even if there are no signs if detonation)? Definitely not lol I'm getting my car tuned in a couple weeks and I want to be prepared so I think I'll play it safe. I'll have two maps. 1 for 91 and another for 94 octane. Regardless of the amount of power he can get with the 94 I will make sure to use a boost setting that maintains no more power than 550WHP. When someone can produce information indicating it's 600WHP then I'll change it at that point. For the long haul I think that's the best approach - IMO NOBLE megalapagas likes this.

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