Meth vs. Meth water opinion

[ttz06vette]

Hey guys, your opinions regarding meth vs meth/ water injection in twin turbo 07C6Z06. I have run straight meth for the last 10 years vs. race fuel for octane and safety in my forged LS7. It allows me to run good timing up top @ 16* with no Kr on 93 octane pump gas. I usually need to replace the meth pump every 3-5 years due to the corrosive nature of the meth. With meth spraying from 3200rpm@ 8 lbs of boost up to redline@ 16 lbs boost my AFR?s go from 11.5 to 10.5. I don?t want to pull fuel from the tune in case the meth fails, but the car definitely runs rich from about 4K rpm up. In a perfect world I would like to keep it in the 11’s.
I started experimenting with a 50/50 mixture of meth and water. It brought my AFR?s up to 12 - 13?s which is higher than I wanted to go. My question is, I still have zero Kr even at top boost with 16* timing because the water/meth still is doing what it should and disrupting the flame front in the cylinder burn process. I just lost octane vs. 100% meth. Do you think these AFR’s are OK as long as I have no Kr? The car still runs great this way and decreasing the richness is apparent in the exhaust residue, plugs, etc. Thoughts?
P.S. - I have the Lo Octane spark table set lower just in case I do get Kr

[GHuggins]

I don't like to run anything boosted much less a build like that any leaner than a 12 afr. With turbo's I always try to target 11.7 or a lambda of .8... Even with sensitive knock and timing being able to be pulled things can go south real quick... On the opposite end of the equation however - overly rich can be just as bad. You can wind up with fuel building up in the ring lands and igniting, but usually down in the 9's is where that'll happen. If the goal is to save pumps without being so rich you might want to try a 75/25 mix?

[RDF1]

I agree. For turbo trucks that are heavy and towing i shoot for 11.2afr in boost.
I would for sure richen your W/M mixture up to get your AFR inline.

Are you using M1 for your methanol?

[ttz06vette]

Thanks…yes M1. I’ll try 2/3 meth and 1/3 water next tank fill. In the end I would rather have meth cause the rich AFR’s than fuel(gas) to preserve the rings and prevent cylinder wash.

[Alvin]

Hey guys, your opinions regarding meth vs meth/ water injection in twin turbo 07C6Z06. I have run straight meth for the last 10 years vs. race fuel for octane and safety in my forged LS7. It allows me to run good timing up top @ 16* with no Kr on 93 octane pump gas. I usually need to replace the meth pump every 3-5 years due to the corrosive nature of the meth. With meth spraying from 3200rpm@ 8 lbs of boost up to redline@ 16 lbs boost my AFR?s go from 11.5 to 10.5. I don?t want to pull fuel from the tune in case the meth fails, but the car definitely runs rich from about 4K rpm up. In a perfect world I would like to keep it in the 11’s.
I started experimenting with a 50/50 mixture of meth and water. It brought my AFR?s up to 12 - 13?s which is higher than I wanted to go. My question is, I still have zero Kr even at top boost with 16* timing because the water/meth still is doing what it should and disrupting the flame front in the cylinder burn process. I just lost octane vs. 100% meth. Do you think these AFR’s are OK as long as I have no Kr? The car still runs great this way and decreasing the richness is apparent in the exhaust residue, plugs, etc. Thoughts?
P.S. - I have the Lo Octane spark table set lower just in case I do get Kr

Yikes.

no way i'd let it go that lean. Contrary to what a lot of people think on the internet... 12.5-13.5 is like prime melt down AFR for a boosted engine.

Between pumps failing and what not.. are you sure this is the safe route to go? I'd prefer to do a build that didn't need it but if you wanted extra for a race or something you could pull gas and replace it with meth to see a gain.

Or hell.. E85 Now that would be a safer way to go.

[ttz06vette]

I agree. I’m still in the 10’s up top but need to richen it up from 3200 - 4500rpm. I have been watching Kr close.