2 Bar tuning with meth kit

[Mike04]

What is the best course to follow when setting up a 2 Bar OS tune with meth? I am using the meth kit as a power adder. It is set up to start spraying at 3lbs of boost and progressively increases flow.

Should I;

1. Get my car's VE table set by go into open loop and logging with the meth disabled for this part of the of the tune so my VE is accurate for gas only. Once my VE is set, then go back and use Boost Enrichment to cut fuel back when I use the meth.

2. Get my car's VE table set by go into open loop and logging with the meth enabled. This would make my VE not totally accurate with gas due to the meth added but should work as long as the meth is flowing.

I think I would accomplish the same thing either way.

Those who have used meth, how do you set up your tune?

[Mike04]

I've decided to go with option 1

[b727pic]

How are you going to cut back on BE and be "safe" should the Alky not squirt? Will PE save the day? just asking cause I don't know.....

I took a slightly different approach, dialed in the ve, got my AFR's where I wanted them with BE and PE tables. once that was done I slightly lowered my VE in and around max KPA and RPM to keep my AFR right around 10.7...rich I know but trying not to blow the motor should something happen to the meth system.

I kept my base timing tables pretty low up in the Max power ranges...right around 10*-11*. I then added the timing I wanted to see, in the IAT adder section....since my IAT sensor is relocated just before the TB it is seeing what is actually going in the motor.....no alky along with high IAT's = low timing....on the other hand alky working = full timing. Seems to be working like a champ for the moment anyway.

I would love to lean out the top end a little more, if I knew for a fact that something else was waiting in the wings to save the day should the meth not blow!!!

I'm interested to see how your approach works.....

[EC_Tune]

Once you tune for meth, it's part of the fuel system, no way around it.

You can't really have a "fail safe" unless you purely tune for fuel, no meth, and just put the meth on top and run rich. If your fuel pump failed you would have the same result.

I like and use option B. Your commanded AFR remains correct that way. I like to use AFR/PE/COT spark to add/subtract spark from the main spark table in PE mode so that you ensure correct spark based on your commanded AFR.

[Mike04]

Once you tune for meth, it's part of the fuel system, no way around it.

You can't really have a "fail safe" unless you purely tune for fuel, no meth, and just put the meth on top and run rich. If your fuel pump failed you would have the same result.

I like and use option B. Your commanded AFR remains correct that way. I like to use AFR/PE/COT spark to add/subtract spark from the main spark table in PE mode so that you ensure correct spark based on your commanded AFR.

So setting up the VE with the meth being sprayed and then using the AFR correction table to pull timing if I go lean in the rpm range under boost. Basically setting the table to pull timing if my meth doesn't work proper. If I hit leaner than 11.8 the table could pull a few degrees and if a hit 12.0 it would pull a few more degrees at whatever RPM range.

If I am understanding this right it sounds like a great fail safe. I have always been afraid that my meth may not work correct one time and BOOM.

[Frost]

No sorry, it doesn't measure AFR, it commands.... so if you go lean, you go lean. Best bet is to put the IAT AFTER the meth, and set the IAT spark table to pull timing bigtime if IAT exceeds some value ... can't tell what year your car is, but if it's newer, you can ADD to the PE value if the IATs go up as well. The IAT is kinda of slow moving so this isn't a sure thing, though it caught my car one time when I needed it. Make it pull a LOT of timing, that way you can KNOW that something is wrong if it happens.

[EC_Tune]

^^^ Definitely.

[Mike04]

OK, I'm going to set up my VE table with the meth flowing, then lower my timing in the Main Spark Advance Table, and add it back in through the IAT Spark Table.

That way high IAT will keep my timing low and I will feel the power loss and hopefully get out of the throttle.