mvvette97

iTrader: (18)

I'm gunna be doing some tuning on a friends LT1 Z28. He has a 383 with the LT4 heads and intake and a nice cam. It has the procharger that is pushing about 16 psi of boost. He is also running the FAST stand alone injection system. He just installed a meth kit the other day. I done some tuning on the idle and cruise but not the wide open yet. Should a guy shoot for about 12.1 with no meth so when the meth is active it will richen up? It's gunna be interesting tuning this thing.

EPP

iTrader: (22)

I'd start at 11.5/1 without the meth and then see what the meth does. It really depends on whether you want to rely on the meth, or use it more to help cool the inlet air temps. Bob

AFASTYZFR1

iTrader: (55)

The stoich of meth is like 9.x to 1


Depending on how much meth you are going to run you afr should be a little richer than 11.5 to 1

hellbents10

iTrader: (10)

No if he is simply reading lambda that does not matter. Still should shoot for 11.5.

AFASTYZFR1

iTrader: (55)

What doesn't matter? afr is afr

If he is spraying enough meth (relying on it) the afr needs to be slightly richer because the stoich of meth is lower than gas

ls1290

iTrader: (20)

As stated, target about 11.5:1 AFR unless you are spraying more than 50% methanol. If that is the case, just switch over to E85.

Zombie

iTrader: (2)

That is not an accurate statement at all. AFR varies based on the fuel used. Lambda is the same though. If you use a wide band setup for gas on any other fuel you use the same "AFR" readings as gas. 14.7 on a wide band is stoich on any fuel because it's actually a lambda of 1.0 being displayed as the air fuel ratio of gas.

To summarize my complicated explanation, if you are mixing fuels, keep tuning for the same AFR you were previously and all will be OK.

For running meth I'd tune without it to 11.5 AFR then add the meth in for a 11.0 afr.

Josh@PremierAutosports

iTrader: (11)

Also if you are letting the fast make the adjustments to correct the AF ratio you will need to change your target AF. If you are comanding 11:5:1 and bring in the meth the fast will pull back fuel to bring it back to 11:5:1

AFASTYZFR1

iTrader: (55)

Thats what I'm saying in my posts above......AFR needs to be richer than 11.5 to 1 if a good amount of meth is being used.....I agree, try and tune your friends set up to around 11.0 to 1 on the meth