i'm trying to figure out the proper afr for meth injection. stoich for meth is lower than gas. so i would think that a richer afr with meth would be ok. my tune is set to 11.5 with pe and be and when i first get into boost its around that. then as the meth kicks in it gets richer and richer. i try to tune the ve to it but it doesn't seem to work that way. i know its the meth causing it to get richer cause it increases with idc. i have the meth kick from sts which runs off the idc. i'm starting to think that a kit that goes off pure pressure would be easier to tune.

so with this all being said is 11.3 to 10.3 ok if its the meth doing it?

 

I like it up in the mid to high 11's myself and I'd think even with a low afr lovin' turbo low 10's would be leaving too much on the table.

 

Mine seems to like 11-11.5 either way. I can feel it bog on anything below 11.0. I try to keep mine at 11.5 at 19 degrees of timing up to 14psi and it seems to be pretty safe so far.

 

You need to retune for the meth. It's true that stoich for methanol is lower than for gasoline, but you aren't running a pure methanol motor.

I tune to 11.5 with the meth. My boost VE is crazy looking (it's backwards almost).

There's a thread here somewhere in which we discussed this in more detail.

 

Try and maintain 11's at least. 11.5 if you can. I've tuned mine 2 ways. With VE originally now with commanded AFR. Either way worked but its easier to tweak with commanded AFR.

I maintain a good AFR curve 11.5 to 11.8 at WOT.... where it counts, but part throttle pulls I go pig rich, down in the low 10's at times.

 

yeah the part throttle is where is seems to be hard to get just right. the wot i had good but with the new cam i'm having to start all over again. i thought i was the only one with a crazy looking ve table in boost. now in lock up i get some real strange readings that are even hard to get right. at 70 going up and down hills i get boost real easy at around 30% throttle. ok i'll just keep going at it then and get it straightend out. it seems like if the meth would hit at the same time every time it would be perfect. but boost isn't always the exact same with turbo so the meth won't be either.