Any point in doing a flex fuel NA build?

[bngl3rt]

I understand people really like E85 for running a crapload of BOOST, but what performance improvements (if any) can us N/A guys expect from it?

I understand it's roughly equivalent to 104 octane fuel, so I can imagine building a high compression NA motor with it, but what about running an octane content sensor and changing timing etc based on the mixture of E85 and regular 91/93 petrol in the tank? Would that even work?

 

[dmscrx]

I understand people really like E85 for running a crapload of BOOST, but what performance improvements (if any) can us N/A guys expect from it?

I understand it's roughly equivalent to 104 octane fuel, so I can imagine building a high compression NA motor with it, but what about running an octane content sensor and changing timing etc based on the mixture of E85 and regular 91/93 petrol in the tank? Would that even work?

E85 with a high compression engine is where it's at. The fuel keeps the engine cooler with high compression ratios and with dyno data I've collected on even a mild compression ratio (ex 12.0:1) it makes more power. We have averaged 10-12 percent more on NA and have seen upwards of 15 percent with turbo vehicles in comparison to normal pump. If you are doing a real flex setup then make sure your compression ratio is proper for the lower octane spectrum of the flex. If you are running e85 all the time then run as much compression as the the fuel will allow you to get away with; and of course piston to valve clearances as well My 32 cents

 

[liftnot]

E85 with a high compression engine is where it's at. The fuel keeps the engine cooler with high compression ratios and with dyno data I've collected on even a mild compression ratio (ex 12.0:1) it makes more power. We have averaged 10-12 percent more on NA and have seen upwards of 15 percent with turbo vehicles in comparison to normal pump. If you are doing a real flex setup then make sure your compression ratio is proper for the lower octane spectrum of the flex. If you are running e85 all the time then run as much compression as the the fuel will allow you to get away with; and of course piston to valve clearances as well My 32 cents

what if you run say 12:1 with E85 and use H2O/meth spray when you only have 91 around(in case E85 is not avail)? would that work?

 

[dmscrx]

what if you run say 12:1 with E85 and use H2O/meth spray when you only have 91 around(in case E85 is not avail)? would that work?

12:1 with 91oct can work with a good standalone but you wouldn't be using the compression to its full potential on that fuel alone. Typically the water/meth stuff is used for high boost with low octane pump conditionally activated by "x" boost pressure. To do that NA you would need to inject it at WOT only to get a decent power curve out of it (with activation you can tweak timing/fuel just like N20 setup), then tune the rest of the map conservatively under all the rest of driving conditions. I don't have any data with your hypothetical setup as most of the high hp NA guys I tune want E85 (readily available where I'm at) but I'm sure you can extract some power out of that setup and have it be reliable. I would recommend meth injection for that setup instead of water though. Hope this helps.

 

[bngl3rt]

Do you think 11:1 can work on 91oct without the water/meth spray?

 

[liftnot]

12:1 with 91oct can work with a good standalone but you wouldn't be using the compression to its full potential on that fuel alone. Typically the water/meth stuff is used for high boost with low octane pump conditionally activated by "x" boost pressure. To do that NA you would need to inject it at WOT only to get a decent power curve out of it (with activation you can tweak timing/fuel just like N20 setup), then tune the rest of the map conservatively under all the rest of driving conditions. I don't have any data with your hypothetical setup as most of the high hp NA guys I tune want E85 (readily available where I'm at) but I'm sure you can extract some power out of that setup and have it be reliable. I would recommend meth injection for that setup instead of water though. Hope this helps.

When you say meth instead of H2O, do yo mean 50/50 mix? OR?
I fully understand H2O injection is more suitable for boost. I am not looking for more HP/Tork. As for us in CA, we don't have easy access to E85 so can;t easily take advantage of the corn juice. I also want the ability to clean the carbon during @WOT as its my 1st wish thus my question on the meth/H2O injection, if it lowers the intake temp, great, if not, no big. I am saving up for an ITB.....maybe a while as my engine runs quite good.

When the time comes for engine rebuild, I wanted to know the max static compression I can get way with 91 octane so thx for your 12 to 1. Now I just need to convince my engine builder this can work as he thinks 12 is too high. IYO, would I be spraying all the time with 12 to 1 thus need a 5 gal tank? or is it depending on the tuner's ability? I have the best tuner of the HKS VPro I'll be using.

 

[BATMANs]

With E85 in either NA or FI is an aftermarket ECU like the AEM S2 mandatory or can u wing it with some minor league witchcraft like piggy back or a screw driver and some home depot parts?

 

[liftnot]

You are Batman...you can get away with a HomeDepot Made in China screw driver....I need all the help I can get so I need real rice power JDM parts:biggrin:

 

[dmscrx]

When you say meth instead of H2O, do yo mean 50/50 mix? OR?
I fully understand H2O injection is more suitable for boost. I am not looking for more HP/Tork. As for us in CA, we don't have easy access to E85 so can;t easily take advantage of the corn juice. I also want the ability to clean the carbon during @WOT as its my 1st wish thus my question on the meth/H2O injection, if it lowers the intake temp, great, if not, no big. I am saving up for an ITB.....maybe a while as my engine runs quite good.

When the time comes for engine rebuild, I wanted to know the max static compression I can get way with 91 octane so thx for your 12 to 1. Now I just need to convince my engine builder this can work as he thinks 12 is too high. IYO, would I be spraying all the time with 12 to 1 thus need a 5 gal tank? or is it depending on the tuner's ability? I have the best tuner of the HKS VPro I'll be using.

H20 Injection is not as good as the meth simply because the meth will not only take away the heat quicker and better, but it will effectively add some octane in the process depending on how much you inject. I typically use VP M1 because of its consistency. If you want to play with mixes that's fine because it's not like you need a heavy mixture for 12:1 compression

I cannot vouch how much you will go through because it is dependent upon how much you actually inject and of course how much you use it (activate it). You will get a feel for needed tank capacity based upon how much you go through while tuning.

While a 12:1 compression will work with that octane, like I said before you won't be able to get the most out of it with just the 91 octane alone. The tuner will more likely be focusing on keeping it safe and not being aggressive with the AFRs and the ignition timing versus making good power. There needs to be a safety margin built into the setup. It's probably why your tuner suggested against it. With 93oct here I will willingly tune up to 13:1 compression with this fuel, but like I said I do more keeping it from knocking than actually making the most power. The game changes with a properly designed quench in the combustion chamber and CNC porting but that's a whole other discussion. With flex fuel you can get away with this because you can keep this high compression setup safe for when the customer wants to run 93 (because it isn't everywhere) and then when he goes to fill up with E85 it will adjust the parameters to make good power automatically. If you don't plan on using added meth injection, flex fuel, or E85 alone, then you should go to a lower static compression and use a non conservative tune to keep that margin of safety and make adequate power.

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With E85 in either NA or FI is an aftermarket ECU like the AEM S2 mandatory or can u wing it with some minor league witchcraft like piggy back or a screw driver and some home depot parts?

HA!