100oct tune vs. meth? (pros & cons both)

[typhoon 28]

So which makes more sense?

whats more cost effective?

power to cost ratio, things like that?

[AreSTG]

I can only ocmment on your question about cost. I am willing to bet that after the intial cost of a meth system, it would be the cheaper one. Reason being, some systems, at least, can be set not to spray until certain boost (or some other parameter that correlates to load). So, if you stay out of high boost, just like normal you use less gas, but also you won't be using meth either.


However there is also the point to be made that this first concept assumes you will run 100 octane 24/7, or meth 24/7. It would be possible to get that new map switching ability and run 91 octane 99% of the time, and then switch maps for 100 octane when u need it. thus, the cost of "running" 100 is only there when your run it. yea, this would equire the cost of a tune to be able ot run seperate maps, but you need a tune for the meth as well.

so that's my opinion, take it or leave it... i owuld have let somone more experienced answer, but that hasn't happened and your post is sitting here dead. possibly my misinformation will bring the pros out of the woodwork!

[Matz]

meth scares me. I know there are failsafe mechanisms and all, but for me, I'll stick with the higher octane solutions.

[dabaysevo]

^+1 Plus the OP has an 03, the map switching working with the IC sprayer button is a nice feature to have.

[turbotiger]

You can't just magically switch between 91 and 100 on the fly unless you have a seperate fuel cell for the 100, seperate fuel pump, and remote valve to redirect the fuel return to the fuel cell. You'll also start diluting the smaller fuel cell with 91 fuel everytime you switch because of the 91 still in the fuel return line.

With Meth, you can switch it on and off on the fly. You also consume alot less meth than 100 octane fuel.

[dabaysevo]

Well I figure there will always have a little bit of 91 in the tank. You have to run it down as much as you can before the switch. The car should never be tuned to the ragged edge where that 1-2 gallons of 91 octane will make the car knock crazy. It requires a little bit of planning but it isn't that difficult. I have been in the habit of this ever since I had my Xede, I would always know how many miles to my destination and would only fill up the tank based on how far I was going. Then I would get to my destination just as the tank gets near empty. Obviously I would only do this when going to drag race or to the track. I think this mental math stuff would be the only downside to running 100oct over meth.

[earlyapex aka jack ass]

You can't just magically switch between 91 and 100 on the fly unless you have a seperate fuel cell for the 100, seperate fuel pump, and remote valve to redirect the fuel return to the fuel cell. You'll also start diluting the smaller fuel cell with 91 fuel everytime you switch because of the 91 still in the fuel return line.

With Meth, you can switch it on and off on the fly. You also consume alot less meth than 100 octane fuel.



FlexFueling is currently being worked on with the stock ECU. Octane sensor in the tank, interpolation between maps depending on octane level. It's going to be the roxorz. Espically for E85.

[AreSTG]

You can't just magically switch between 91 and 100 on the fly unless you have a seperate fuel cell for the 100, seperate fuel pump, and remote valve to redirect the fuel return to the fuel cell. You'll also start diluting the smaller fuel cell with 91 fuel everytime you switch because of the 91 still in the fuel return line.

With Meth, you can switch it on and off on the fly. You also consume alot less meth than 100 octane fuel.



FlexFueling is currently being worked on with the stock ECU. Octane sensor in the tank, interpolation between maps depending on octane level. It's going to be the roxorz. Espically for E85.

:shock: :shock: :shock: badass, and its that simple that a sensor can judge octane just by sitting in the gas? I would think there's mroe too it. Is this an expensive sensor or cheap?

[cornercarver]

FlexFueling is currently being worked on with the stock ECU. Octane sensor in the tank, interpolation between maps depending on octane level. It's going to be the roxorz. Espically for E85.



Tell us more! Definitely interested!

[earlyapex aka jack ass]

:shock: :shock: :shock: badass, and its that simple that a sensor can judge octane just by sitting in the gas? I would think there's mroe too it. Is this an expensive sensor or cheap?


This is how the OEM FlexFuel vehicles do it. GM makes a "flexfuel" sensor which basically reads the octane level of the fuel in the tank. Currently it's a $300-$400 part. Currently It outputs a voltage depending on the percentage of ethanol found.

Currently, that voltage can and is being used to switch maps on the fly with the current "alt-map" mod. Interpolation is still being worked on.

[cornercarver]

That sound's about right. What would the final cost be?

Either way I am definitely interested. Do you think you would have it working well by the fall time? I plan on heading out there for a tune by then.

[earlyapex aka jack ass]

Well currently these are measuring ethanol percentage but people are looking into octane as well. We will see how the development goes.

[earlyapex aka jack ass]

They have a bunch of cool stuff in testing, one being a display showing the sensor output:

http://ws.wamnet.com/~gryan/ethgauge2.jpg

http://ws.wamnet.com/~gryan/EthanolMonitors.jpg

Any engineers on this board interested in working on something like this with me?

[dabaysevo]

:shock: :shock: :shock: badass, and its that simple that a sensor can judge octane just by sitting in the gas? I would think there's mroe too it. Is this an expensive sensor or cheap?


This is how the OEM FlexFuel vehicles do it. GM makes a "flexfuel" sensor which basically reads the octane level of the fuel in the tank. Currently it's a $300-$400 part. Currently It outputs a voltage depending on the percentage of ethanol found.

Currently, that voltage can and is being used to switch maps on the fly with the current "alt-map" mod. Interpolation is still being worked on.


Could this feature be used with 100oct? I was kind of wondering if it could be used to address Turbotiger's concern about 91oct diluting 100oct when switched? So that the sensor reads the octane based off the mix of 91/100 and adjust accordingly.

[earlyapex aka jack ass]

See my posts above

[cornercarver]

can you give an estimate on final cost? some of us poor people gotta know what to save up to :lol:

[dabaysevo]

See my posts above


:(Â* I'll go back to sleep now.

[earlyapex aka jack ass]

can you give an estimate on final cost? some of us poor people gotta know what to save up to :lol:


At this point, I have no idea honestly.

[turbotiger]

FlexFueling is currently being worked on with the stock ECU. Octane sensor in the tank, interpolation between maps depending on octane level. It's going to be the roxorz. Espically for E85.

Eh? I thought these GM sensors only measured the amount of alcohol, not octane in the tank. I know this is being used / tested in the megasquirt realm. It has the code to run this already.

[earlyapex aka jack ass]

FlexFueling is currently being worked on with the stock ECU. Octane sensor in the tank, interpolation between maps depending on octane level. It's going to be the roxorz. Espically for E85.

Eh? I thought these GM sensors only measured the amount of alcohol, not octane in the tank. I know this is being used / tested in the megasquirt realm. It has the code to run this already.



yup, currently only alcohol content as I mentioned in a previous post. I've seen octane sensor/calculators as well but they are probably a bit more money. ;)

[whtrice]

I would think it would be pretty easy to determine alcohol percentages in the fuel and sense but wouldn't it kind of require a "rolling" map to adjust for it. Fixed levels could compensate with a fixed map but if the octane varies.....???? Would you run a conservative map until the sensed mixture became steady?







FlexFueling is currently being worked on with the stock ECU. Octane sensor in the tank, interpolation between maps depending on octane level. It's going to be the roxorz. Espically for E85.

Eh? I thought these GM sensors only measured the amount of alcohol, not octane in the tank. I know this is being used / tested in the megasquirt realm. It has the code to run this already.



yup, currently only alcohol content as I mentioned in a previous post. I've seen octane sensor/calculators as well but they are probably a bit more money. ;)

[earlyapex aka jack ass]

The idea is a interpolation percentage between maps based on octane rating. The stock Evo ECU already does this between the low/high octane fuel and timing maps, although I don't think it's fast enough currently for what we are talking about. The Evo 9's interpolate between timing maps based on Mivec advance. This is what the smart people are looking into. :)

However, currently you can run the "alt map" mod and it will switch over to a set of maps when the flexfuel sensor reads a certain voltage. All you need to do is map what voltage you want it to see before it switches maps. This is currently working and possible.



I would think it would be pretty easy to determine alcohol percentages in the fuel and sense but wouldn't it kind of require a "rolling" map to adjust for it. Fixed levels could compensate with a fixed map but if the octane varies.....???? Would you run a conservative map until the sensed mixture became steady?







FlexFueling is currently being worked on with the stock ECU. Octane sensor in the tank, interpolation between maps depending on octane level. It's going to be the roxorz. Espically for E85.

Eh? I thought these GM sensors only measured the amount of alcohol, not octane in the tank. I know this is being used / tested in the megasquirt realm. It has the code to run this already.



yup, currently only alcohol content as I mentioned in a previous post. I've seen octane sensor/calculators as well but they are probably a bit more money. ;)

[whtrice]

I see. Actual map change would not happen until it reached a certain voltage threshold from the sensor. Small changes in fuel variance would not be effected. A larger change would get a map change.
As small changes of octane wouldn't really benefit from a map change anyways.

[cornercarver]

wow we went way off topic... but excellent discussion! :lol:

Bryan, can you keep all of us updated on your progress? This is a really good idea, and not just for evos. There are companies out there doing the same thing to other vehicles, but they are rather expensive. If you offer this at a fair price and with the way gas is going, you may attract other customers other than tuners.

[Matz]

Any engineers on this board interested in working on something like this with me?


Which part? Just wondering what you had in mind. I'm sure you know (like everyone else here) that I have a tough time actually completing any projects unless it somehow prevents me from autoxing the evo.

[AreSTG]

i can't resist

Bryan... so what you are saying is this system you are working on can tell octane?Â* i've heard of others that read meth/eth but octane??

[earlyapex aka jack ass]

i can't resist

Bryan... so what you are saying is this system you are working on can tell octane? i've heard of others that read meth/eth but octane??


I'm not working on anything currently. The idea is to get something working with octane, but it's still being researched.

[typhoon 28]

So basically, if I do your 100oct + map switching tune, Id have to burn up or make it puke out all remaining 91oct ($4.60/gal) for pump style or sunoco drum 100oct ($8+/gal). Or is there a 95oct map available to add 100 to 91 to make 95 if necessary? won't be as much power, but won't have to waste any gas either. I actually get o.k. fuel economy on yer 91 tune buy the way, thanks.