Just Converted My AEM EMS to flex fuel

Flexer · 30 June 2011

I just got done doing this conversion on my Lotus 7, but it would work on any AEM EMS equipped vehicle. I no longer have my NSX but if I did I would have done the conversion on that car as well.

With E85 stations always popping up and then disappearing, I needed to have the ability to fill up with pump gas or E85 at any time, with any amount of the "other fuel" left in my tank. For some of you, I know that switching over to E85 is just not an option since you don't always have access to it.

Well how would you like to convert your EMS to a flex fuel ECU?

Well its possible. All you need is a Zeltronix E85 gauge and a trip to the junk yard to get a flex fuel sensor off of a equipped vehicle. I got mine off of a Suburban. THANKS CHEVY!

So far I am LOVING it. The ecu responds great to whatever amount of ethanol is in the tank. I can have 1/4 a tank of ethanol and put in pump gas, and the EMS fuels back the car...or be at half a tank of pump gas, and I decide to throw in some E85 to turn up the boost, its no problem the ECU compensates.

So now you know. It can be done. The conversion is not cheap, but is possible. Hope this opens up some new possibilities to those FI NSX's that daily drive there NSX's or road trip them and need to have the ability to run both fuels to produce BIG NUMBERS.

JR

Soundeffects · 16 July 2011

Can you add some more information on what is needed?

Flexer · 17 July 2011

Soundeffects said:
Can you add some more information on what is needed?

A flex fuel sensor off of a GM equipped car....and a flex fuel sensor translator to convert the ac frequency to a 5v out-put signal.

JR

PS. What you need to do is bug DEVIN from AEM about why aem won't build the translator into the AEM series 2 software.

E-Nough Logic · 18 July 2011

Flexer said:
A flex fuel sensor off of a GM equipped car....and a flex fuel sensor translator to convert the ac frequency to a 5v out-put signal.

JR

PS. What you need to do is bug DEVIN from AEM about why aem won't build the translator into the AEM series 2 software.

For tuning do you tune on pure e85 and pump gas and then the software interpolates between the 2 based on the percentage of each? how does the software handle deciding how much fuel the engine needs.

Flexer · 19 July 2011

hybrdthry911 said:
For tuning do you tune on pure e85 and pump gas and then the software interpolates between the 2 based on the percentage of each? how does the software handle deciding how much fuel the engine needs.

You tune one map perfect, and then have the ECU modify that map based on a percentage of ethanol that is, or is not present.

So you can tune pump perfect and have it add fuel for ethanol that is found....or tun E85 perfect and have it pull fuel and ethanol is not found

JR

syndicate · 19 July 2011

Hmm. Thats pretty freakin cool. Thanks.

BATMANs · 19 July 2011

Anyone know who the guy in AZ that has done this successfully to a few turbo'd Z's and GTR?

alpha · 19 July 2011

It's actually pretty simple depending upon what all you want to do. It's not the most ideal way to do flex fuel but it works. In short you use the User Defined Fuel Trim.

Coz · 29 July 2011

Interesting.....

I run both E-85 and 91 octane.
But I have a switch to change from one to the other.

Flexer said:
I just got done doing this conversion on my Lotus 7, but it would work on any AEM EMS equipped vehicle. I no longer have my NSX but if I did I would have done the conversion on that car as well.

With E85 stations always popping up and then disappearing, I needed to have the ability to fill up with pump gas or E85 at any time, with any amount of the "other fuel" left in my tank. For some of you, I know that switching over to E85 is just not an option since you don't always have access to it.

Well how would you like to convert your EMS to a flex fuel ECU?

Well its possible. All you need is a Zeltronix E85 gauge and a trip to the junk yard to get a flex fuel sensor off of a equipped vehicle. I got mine off of a Suburban. THANKS CHEVY!

So far I am LOVING it. The ecu responds great to whatever amount of ethanol is in the tank. I can have 1/4 a tank of ethanol and put in pump gas, and the EMS fuels back the car...or be at half a tank of pump gas, and I decide to throw in some E85 to turn up the boost, its no problem the ECU compensates.

So now you know. It can be done. The conversion is not cheap, but is possible. Hope this opens up some new possibilities to those FI NSX's that daily drive there NSX's or road trip them and need to have the ability to run both fuels to produce BIG NUMBERS.

JR

Coz · 2 August 2011

Talked to Mitch Peterson who was a big part of the designing of the AEM system and now has his own tuning shop and tuns my car...

Here is what he had to say.

Jim
Yep, it can be done on the fuel side of things but there is no way to adjust the ignition timing on the AEM for the different fuels, which typically varies greatly between CA91 and E85. It's something AEM is looking at putting in for a software update for the Series 2 boxes, but not for the Series 1's.
Mitch.

Coz said:
Interesting.....

I run both E-85 and 91 octane.
But I have a switch to change from one to the other.

Flexer · 2 August 2011

Coz said:
Talked to Mitch Peterson who was a big part of the designing of the AEM system and now has his own tuning shop and tuns my car...

Here is what he had to say.

Jim
Yep, it can be done on the fuel side of things but there is no way to adjust the ignition timing on the AEM for the different fuels, which typically varies greatly between CA91 and E85. It's something AEM is looking at putting in for a software update for the Series 2 boxes, but not for the Series 1's.
Mitch.

I am sorry to say....your friend Mitch is wrong. Tell mitch the secret is having the nitrous map trigger at a certain amount of ethanol. Is it perfect. No, but the timing table totally advances once I am running 60% ethanol or greater.

Just FYI. Don't want to offend mitch or anything.

JR

Coz · 2 August 2011

Will pass it on to Mitch.
We used a Nitrous overlay on my 91 map for E-85.
Not automatic though, I have to flip a switch.

Flexer said:
I am sorry to say....your friend Mitch is wrong. Tell Mitch the secret is having the nitrous map trigger at a certain amount of ethanol. Is it perfect. No, but the timing table totally advances once I am running 60% ethanol or greater.

Just FYI. Don't want to offend mitch or anything.

JR

Coz · 2 August 2011

JR,
Passed it on to Mitch and here is what he responded with...

"Yep, that kinda works but it only flips over timing between 91 and e85 at a 60% ratio (or whatever ratio you want) rather than being an ignition adjustment/trim based directly off alcohol percentage. An ignition switch over point of 90% more E85 would be a better value.

At the switchover point, where you are running 60% e85, the timing would be set for 100% E85, which may be too much timing. Conversely, if the timing would be set for 60% E85, you may not have optimum power because the timing would be set for 60% where you are actually running 100%.

Make sense?

The AEM software does not have a function that allows a gradual timing adjustment based off alcohol content, yet."

Flexer · 12 August 2011

Coz said:
JR,
Passed it on to Mitch and here is what he responded with...

"Yep, that kinda works but it only flips over timing between 91 and e85 at a 60% ratio (or whatever ratio you want) rather than being an ignition adjustment/trim based directly off alcohol percentage. An ignition switch over point of 90% more E85 would be a better value.

At the switchover point, where you are running 60% e85, the timing would be set for 100% E85, which may be too much timing. Conversely, if the timing would be set for 60% E85, you may not have optimum power because the timing would be set for 60% where you are actually running 100%.

Make sense?

The AEM software does not have a function that allows a gradual timing adjustment based off alcohol content, yet."

It does make sense but Mitch and you are just a little off. I don't have it switch at 60% ethanol for my 100% ethanol tuned timing curve....that would be just stupid.

What I did is I tuned the cars timing on pump gas, and at 60% ethanol using the nitrous map. If I run more ethanol than E-60....so lets say E-85, and ran 85%, well its still only going to run the E-60 timing curve, but hey....those extra 4-5 degrees of timing is A HECK OF A LOT BETTER than running the same timing curve that my 91 pump runs........

and in your original response you said that you couldn't have the ECU adjust the timing....not perfectly, but good enough...sure. On actual E-85 I could probably get another 2 degrees more timing......but NONE OF THE PUMPS IN MY AREA ACTUALLY PUMP E-85.....

2 of the pumps pump E-60, and one does E70.......and the one that pumps E-70 pumps E-90 in the winter.

All of these pumps are marked E-85, but like I always tell people, Out of the 7 gas stations that I have EVER filled up with.....not ONE has actually pumped E-85. That's why having this gauge and letting the ecu do the tuning is the BOMB! :biggrin:

JR

PS. HEY DEVIN, STOP FARTING AROUND AND BUILD THIS INTO THE AEMTUNER SOFTWARE!!!

Coz · 12 August 2011

OK, well...I wish you the best of luck with your venture....

Flexer said:
It does make sense but mitch and you are just a little off. I don't have it switch at 60% ethanol for my 100% ethanol tuned timing curve....that would be just stupid.

What I did is a tuned the cars timing on pump gas, and at 60% ethanol. If I run more ethanol than E-60....so lets say E-85, and ran 85%, well its still only going to run the E-60 timing curve, but hey....those extra 4-5 degrees of timing is A HECK OF A LOT BETTER than running the same timing curve that my 91 pump runs........

and in your orriginal response you said that you couldn't have the ECU adjust the timing....not perfectly, but good enough...sure. On actual E-85 I could probably get another 2 degrees more timing......but NONE OF THE PUMPS IN MY AREA ACTUALLY PUMP E-85.....

2 of the pumps pump E-60, and one does E70.......and the one that pumps E-70 pumps E-90 in the winter.

All of these pumps are marked E-85, but like I always tell people, Out of the 7 gas stations that I have EVER filled up with.....not ONE has actually pumped E-85 :biggrin:

JR

Flexer · 13 August 2011

Coz said:
OK, well...I wish you the best of luck with your venture....

Thanks Coz. Adventure is over. Maxed out the turbo on the car at 31 psi of boost. What can I say....ethanol is like magic gas. Been running the ECU this way for 3 months now with no problems, perfect starts, and great power.

Good luck to you and your tuner and I hope you guys get everything figured out. Remember the AEM can do WAY more than most people ever take advantage of.

JR

doc_tai · 30 November 2012

Any update how the car hold up with this flex fuel set up

Just Converted My AEM EMS to flex fuel

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