100% Methanol = Rich Mixture ?
 

I'm planning on injecting methanol but what i want to know isn't meth a fuel so wouldn't my AFR read rich?

If so i would have to lean out my injectors when the WI is activated!

Does anyone have any experience with Rich AFR when meth is injected?

Re: 100% Methanol = Rich Mixture ?
 

When injecting all methanol, you will run much richer A/F. As a starting point, using the injector duty cycle near WOT, first figure out how much total gasoline your all your injectors are supplying (cc/min). Then, you must know the flow of alcohol being injected (cc/min). Start by decreasing the total fueling from your injectors by one half the amount of alcohol being injected, since methanol has about 1/2 the energy (BTUs) of gasoline. The real problem is what the wide band oxygen sensor is seeing. Since you now have a "new" fuel mixture of gasoline and alcohol, you also have a new stoich value. Gas is 14.7, methanol is about 6.4. Taking a ratio of the the total mix will get a proper stoich value. For my particular mix the new stoich works out to about 13.3 when injecting alcohol. For the wideband sensor to display this new stoich value you need to have the ability to re-calibrate the wide band oxygen sensor output to match. It can be a real bucket of worms when trying to tune to target A/F ratios.

OK that sound like a real big bucket of worms...

thanks for the info but can you tell me or direct me as to do the calculations for these values.

how much total gasoline your all your injectors are supplying (cc/min)
Currently my injector size is 380cc
I'm using the 0.6mm jet

i also have a stand alone so my WOT cc/min can be altered

HELP :?

I know i'm digging this topic up but does anyone have information on injecting methanol into there air flow for cooling and fueling purposes?

what is the difference in AFR readings?

No one after letting this sit for two years !!!!!

Anybody :shock: :shock: :D

I retuned today for 20% of my total fuel being methanol. This tune os now much faster than previous tunes. Ignore the afrs and tune to lambda only.

Scott

thanks for posting sd

but can you tell me how do you make your 20% methanol injection? Is it by spraying 100% meth?

Also i'm not following you when you say "Ignore AFR and tune to Lambda"
Can you explain further ... :?:

Sure i spray 100% meth into the throttle body with 2 jets and a controller.

You can tune it using a wide band 02 sensor. an egt gauge and knock detector is also preferable during tuning.

AFR is a calculation from lambda.. When you make a blended fuel by added one or more differant types like this the stoich alteres. You could waste your time by working out the new stoich but why bother. lambda is a constant thing unlike afr which alteres. eg petrol 14.7:1 and ethanol 9:1. If you added the two fuels together it would create a differant stocih value. Therefore 14.7:1 on you afr gauge wold no longer be stocih. it would be above stoich Does this make sense.

howeva 1.0 Lambda is constant. you could mix petrol with meth or meth with coca cola 1.0 lambda would still be complete combustion. Therefore if you tune to a lambda value you will tune for a fixed value.


Scott

sdminus@yahoo.co.uk

Awsome explaination sd i get what your saying .... but pardon my lack of experience but how would i go about measureing lambda?

Correct me if i'm wrong but if i get what your saying when measuring lambda i will tune the ECU so as to get as close to 1.0 across the band ?

Interesting !

Dont tune for 1 lambda on boost. I tune to around 0.95L cruising 0.80 on low boost and 0.78 on 15 psi. Your values will probobly be differant.

You will need a good AFR meter like the innovate LM-1. It will display lambda as well as afr. The meter works by measuring The Lambda value and then multipling it by the stoich of the fuel you have selected to display afr

so if the lambda shows

0.80 L and the meter is set to petrol the display will read 0.80 L and 11.76 AFR

But

if you were tuning Straight methanol and you had the meter still set to petrol the Lambda would still show 0.80 which would an actual 5.28 afr, even thought the meter would dispaly 11.76 afr .

You will need to aim for a set Lambda. Im not sure what value your engine will like but im sure somebody can tell you. If somebody can tell you what afr to run then divide that afr by 14.7 eg

11.76:1 (drop the :1)
11.76/14.7 = 0.80 Lambda

If you want to tune with afr then you will have to calculate a new stoich value for the fuel type. If you are adding methanol over the whole rev range it would be quite easy. Howeva if you only add the methanol on boost (creating a blended fuel) You will not be able to do this (Basically it would be the same as running 2 differant fuels. 1 for cruising and another for boosting) stick with tuning to lambda.

try this forum for more guidance and reasearch.

http://www.innovatemotorsports.com/forums/index.php

This is the company whos forum is above but they make the Meter Innovate LM-1
http://www.innovatemotorsports.com

Scott


:smile: