[axotlprogeny]

After doing some research, I think I have a answer to my own question:

Long Answer

A WBO2 sensor doesn't care what the fuel is, gas, methanol, propane, etc.
It measures the ratio of oxygen left in the unburnt gases exiting the engine; in essence measuring true Lambda instead of Air/Fuel Ratio. The sensor output is then calibrated for AFR based on which fuel is burnt. When replacing fuel with another fuel type, like when injecting water/MeOH, thinking in terms of AFR will not make sense because of the the different stoichiometry of the fuels.

The magical number for turbo gasoline cars is 12.5:1, which works out to around 0.85 Lambda. Now when injecting MeOH, you should still shoot for this target. Including the MeOH, the target fueling should be 15% rich.

Short Answer

Inject MeOH, try to hit target AFR of 12.5 based on WBO2, back off a little at knock.

Sources

Methanol Injection Dilemmas

Gasoline, Methanol, AFR, Lambda, and Stoichiometry.

[Vettezuki]

Awesome. Thanks for the info.

Questions:

Injecting a little MeOH probably doesn't alter the energy content by volume all that much. Now, as I remember, it's a different story with E85. I think they have to target substantially richer AFR because of the lower energy content by volume.

I guess I'm trying to sus out the difference between tuning for a little MeOH injection and running E85 (85% ethanol).

[Damian]

Right, E85 must run richer due to its lower energy content, I think its 9:1? I ran it for awhile in my Eclipse and loved how aggressive I could get with my tuning.

[axotlprogeny]

You completely right. E85 has much less energy density than gasoline. I found a nice table on Wikipedia listing a comparison between Gas, E85 and 100% ethanol:



Gasoline stoichiometric AFR = 14.7 Lambda = 1
Gasoline max power rich AFR = 12.5 Lambda = 0.8503
Gasoline max power lean AFR = 13.23 Lambda = 0.900
E10 stoichiometric AFR = 14.0-14.1 Lambda = 1
E85 stoichiometric AFR = 9.765 Lambda = 1
E85 max power rich AFR = 6.975 Lambda = 0.7143
E85 max power lean AFR = 8.4687 Lambda = 0.8673
E100 stoichiometric AFR = 9.0078 Lambda = 1
E100 max power rich AFR = 6.429 Lambda = 0.714
E100 max power lean AFR = 7.8 Lambda = 0.870

Something else that goes hand in hand with this is the Stoichiometry of Regular E10 fuel used in California.

I have 740cc injectors. My car likes my injector flow scaling to be set about 5% lower than the actual flow (Flow Scaler = 703cc/min, Actual Flow = 740cc/min), which lines up pretty close to the difference between pure gas and E10. I don't know if this is the proper way of handling this, but it seem to work pretty well.

[Damian]

With ECUflash, you never put the exact injector size in there. You have to scale them, which is about 5-15% lower than actual size. But, different fuels can throw off your scaling just by changing your fuel maps. I hate scaling injectors, and I hated doing them again when I ran E85 in my Eclipse. But E85 is great stuff, would be a million times better if California wasnt so anal about storing it at gas stations (cant be stored under ground). But E10 shouldnt affect anything at all, most stations are E10 blend.

[axotlprogeny]

Hi Damian,
I am using Romraider for tuning and ECUFlash for writing to the ECU. Supposedly Romraider is better at getting the scaling right. My stock injectors were dead on with the rated flow. I have heard from several people to start scaling low and go up until your fuel trims are pretty close to linear. From your experience, is this the correct method?

Romraider has a nice little tool for scaling injectors and adjusting latency that works pretty well. They also have one for MAF scaling. I really wish they would start working on Evo tuning integration. The possibility is there...

[Vettezuki]

Originally Posted by axotlprogeny

Hi Damian,
I am using Romraider for tuning and ECUFlash for writing to the ECU. Supposedly Romraider is better at getting the scaling right. My stock injectors were dead on with the rated flow. I have heard from several people to start scaling low and go up until your fuel trims are pretty close to linear. From your experience, is this the correct method?

Romraider has a nice little tool for scaling injectors and adjusting latency that works pretty well. They also have one for MAF scaling. I really wish they would start working on Evo tuning integration. The possibility is there...

Is there LS1 support for Romraider/ECUFlash?

[axotlprogeny]

I wish. Currently it's only Subarus, but the framework is there for any ECU. The coding is done in Java, all the ECU table definitions and logger definitions are all basic XML, and of course, it's all open source. All they need is someone to map out the ECU tables for the ECU you wish to edit. Unfortunately, Romraider is only good for editing the tables. You also need some piece of software to flash the file onto the ECU.

[Damian]

Originally Posted by axotlprogeny

Hi Damian,
I am using Romraider for tuning and ECUFlash for writing to the ECU. Supposedly Romraider is better at getting the scaling right. My stock injectors were dead on with the rated flow. I have heard from several people to start scaling low and go up until your fuel trims are pretty close to linear. From your experience, is this the correct method?

Romraider has a nice little tool for scaling injectors and adjusting latency that works pretty well. They also have one for MAF scaling. I really wish they would start working on Evo tuning integration. The possibility is there...

Yup, thats how we do it. I start 15% lower than actual injector size, and slowly work your way up along with adjusting your latencies. I hate doing injectors though, Im not a very patient person, and you need to be patient with injectors. I found a website that has the different latencies for different injectors and Ive found it a good starting point. I use Evoscan, Logworks, Scantech, and ECUflash for everything I do. The new Evoscan 2.6 is pretty good now. It does the same as before (datalogging) and now it does CEL reading and clearing them, and it does the same thing that Logworks does, so I dont even use Logworks anymore.


Sean, I wish I could use this on the LS2, but my current cable doesnt even work on mine for anything. The new cble would work for checking CEL codes and clearing them, but no one has even tried to crack the ECU for this purpose. I really would like someone to give it a shot.

[axotlprogeny]

Damian, which cable do you use? I have a Mitsu compatible Tactrix cable if needed.