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To good to be true?


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#1 mariner

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Posted 10 December 2020 - 10:00

Again from my favourite Enginelabs site an article suggesting that, with big enough injectors you can more power by simply mixing e85 and 91 octane pump gas in USA

 

https://www.enginela...for-less-money/

 

Obviously the fuel consumption goes up due to the lower energy vs volume in E85 but it seems to good to be true.

 

I thought hat the two fuels were hard to mix properly i. e they might separate in the tank but not sure .

 

 

Any thoughts please?



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#2 Fat Boy

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Posted 10 December 2020 - 18:42

I'm going to play around with this on my personal car. The idea is to create "E30". It's an oxygenated fuel which has a very high knock resistance, but the energy content isn't so low as to cause an issue with volume which requires larger injectors and a higher volume fuel pump (which is the problem with E85). It seems to work well.



#3 gruntguru

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Posted 10 December 2020 - 21:33

I was doing this years ago - had a car that pinged a bit on regular fuel - a splash of E85 works wonders. (How's that for accurate blending?)

 

The bit about wide band lambda meters not reading true AFR is unnecessarily confusing. All you have to do is tune to the same numbers ie if you tuned regular fuel for 13:1 at WOT you can do the same on E85. The meter will still read 14.7 when the mixture is stoichiometric regardless of what fuel is going through the engine. (Personally I prefer to tune using lambda numbers and forget about what the fuel is.)



#4 Bob Riebe

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Posted 11 December 2020 - 03:26

Unless your car is rated for E85 be careful, my Cousin's Chevy Malibu ate its engine, after he not real often but far from rarely ran E85 in it.

The Chey dealer mechanics that put in a new engine said from the way it looked , his using E85 is what fried his engine.


Edited by Bob Riebe, 11 December 2020 - 03:27.


#5 gruntguru

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Posted 11 December 2020 - 03:56

If you put straight E85 in an engine that's not made for it, you are leaning the mixture by about 40%. nuff said



#6 mariner

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Posted 11 December 2020 - 12:01

Using a E85 mix let me get my home made car through its UK  certification (the Single Vehicle Approval  - SVA as it was)

 

You have to meet both a noise limit and emissions limits .The  car has Supertrapp silencers with 12 discs and removing one disc cuts noise by about one decibel but builds up back pressure  I got down to two discs to meet the noise limit but the back pressure enriched  the mixture a lot.

 

I could have played with jets etc but I'm no Holley expert and that takes time.. So instead I blended E85 with unleaded BP race fuel. 

 

Fortunately a neighbour worked for BP and had access to an expert in their fuels research centre who kindly advised on the correct blend.

 

The lower calorific value of the mix flowing through the existing jets got the CO/HC etc down below the required levels all on its own.

 

As the tests are done at 3,000 rpm and no load their wasn't much detonation risk and the engine actually ran much smoother - I think because the race fuel is highly oxygenated on its own. 


Edited by mariner, 11 December 2020 - 12:01.


#7 Fat Boy

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Posted 18 December 2020 - 17:05

Using a E85 mix let me get my home made car through its UK  certification (the Single Vehicle Approval  - SVA as it was)

 

You have to meet both a noise limit and emissions limits .The  car has Supertrapp silencers with 12 discs and removing one disc cuts noise by about one decibel but builds up back pressure  I got down to two discs to meet the noise limit but the back pressure enriched  the mixture a lot.

Literally every SuperTrapp story ever. Good idea that just does not work in practice.