Using AI at any ratio............YOU STILL TUNE FOR Petrol AFR figures

NOTHING CHANGES AFR-wise.

here's a read on the subject often misunderstood....

http://www.innovatemotorsports.com/f...ht=rice+racing

 

I've been doing the same for a few years already without issues...

I feel your pain, i've been seeing people taking it over the edge with these crazy calc's that makes them believe they need to run different afr...

 

thanks for the post Rice.

after reading both your posts and a few others to this point the lightbulb finally clicked ON. so instead of tuning to some mix afr number i just tune to what i like on the knock and egt and i will find the number resembles pretty closely the afr i ran on pump. it is good by 9s and 10s. at least i know my ignition will fire just about anything.

i am embarassed about this as much as i am looking forward to leaning it out.

again, thanks for hammering on this important point.

howard coleman

 

Thats totaly correct..

I go out of my mind somtimes trying to explane something that is so simple to customers when Tuning there cars.. thay seem to have some comlicated throrts that tells them that you can not tune an engine running Methanol or any other fuel exept pump fuel with a A/F meter that does not display Lamda..

It does not change... 1 lambda = 14.7:1 AFR petrol and thats it!! its the stoich point of the fuel you are running that changes.

did I make sense there

Stuie
RX Performance

 

The ones that normally make those claims are the ones that have not tried it or come to terms with the concept of 'lambda vs afr's'.
Sometimes it is true that the same lambda used to make safe power on regular fuel might be a little different for what's needed on methanol but that depends on application. It's all based on tuning experiences with the said combination and all the same rules most must be applied during a tuning session.

 

So, would you tune for Racegas AFR's or 93 octane AFR's ?

 

I didn't want to start a new thread since (I believe) my questions sort of relate to this subject:

1.) How will Meth affect the Oxygen Sensor?
(I'm converting from c16 which murdered it. )

2.) Do you guys run the o2 sensor constantly?
(or plug bung-hole ? )

3.) Do you go back to narrowband for street use?

 

re post 6...

if running methanol 20%, or in that neighborhood, you will likely find approx 4 degrees less timing v racegas will get you where you want to be.

AFRs will vary from car to car and to your risk tolerance but low to mid 11s should work for most.

re post 7

methanol will not damage your O2 sensor. generally lead is the culprit which does not exist in pump gas or methanol. i run my O2 sensor all the time and do not use the narrow band sensor.

howard coleman

 

hey guys well im planning on getting the AEM 50:50 BUT my question is can i make this work with my stock ecu? do i just simply boost more till my afr is back to the way it was? i have a 1988 T2 with gslse 680injectors on the secondary's boosting 14psi my afr on my wide band is 10.7-11.5. stock intercooler stock turbo stock ecu. can this w/m kit work?

i was simply thinking of setting the system to activate at 14psi (when my afr is good) then boost more when the kit is activated until i reach the 10.7 - 11.5 afr again. sort of new to this

 

also will my stock turbo be able to withstand more boost with the kit?

 

Yes but not in the way you're imagining.
No, not a good idea.

Yes the kit will absolutely work.

First - 14psi on the stock HT-18 is very much shortening its life span. Power won't increase much above 12psi as I've seen on the dyno, so by running 14 you're mostly just killing the turbo without much gain in the power department.

Next, you need the ability to tune the fuel if you plan on using methanol (or at least, very much of it) and for your purposes an SAFC would work fine. You also have the option of running straight water which won't richen your AFR's but will provide some cooling and knock protection. The best setup on a stock turbo FC would be to run a small pre compressor nozzle and a larger aft nozzle. There's alot of neat things that happen when you inject before the compression of the intake charge.

No. The limitations of the stock turbo are purely mechanical. Adding chemical intercooling to the equation just makes it better for the engine - not easier on the turbo. As I mentioned 14psi is stretching the limits of getting a reasonable lifespan out of the turbo, spraying meth won't make its bearings hold together

 

Thanks alot for the answers really helpful, i really dont have an option with what im boosting, since i dont have much control of fuel i compensate with the boost, i think id be running to rich for 12psi. plus i still got the original turbo as a spare just incase, i swapped in the 91 turbo(got it for free with exhaust maifold)also got an msd 6a dont kno if that helps out im guessing it should in the power stroke.

So you are saying to spray just water pre turbo then pre intake manifold? or with 50:50 . Also how much HP you think this might give me?with water and with 50:50 (if i keep boosting the same)

 

^It won't change HP much. You will however see benefits in cooling and knock prevention. Stop playing games with boost and no fuel control. You NEED fuel control at the very least!

 

Thanks for the heads up! I plan on doing this on my TII vert pretty soon.