sm0kinvette

Hello,
On shell pump 93 gas my current AFR at WOT is 11.5-11.8.

I am going to spray a mix of 50% meth and was wondering what afr I should shoot for?

I know the proper way would be on a dyno but not many places here in Chicago want to tune with meth injection

Unreal

Max power? Max Safety? Meth Dependent or not? You need to decide what you want out of it, and go from there.

sm0kinvette

looking at safety and keeping temps cool for now. in the future possibly add timing.

Unreal

Then don't touch the tune, and just add a small nozzle. 5 or 10gpm. I would run 100% meth.

Tech

I added 100% meth and picked up 50 rwhp without touching the AFR. I'd have to look at logs or tunes to know if I tweaked timing. I think I may have but I'm not sure.

sm0kinvette

i am going to run boost juice 50/50. does a 625/ml nozzle sound good? start spraying at 3psi (35%) and (100%) by 8.

should i lean it out some?

JetstreamGS

No offense dude but judging by your questions, I wouldn't attempt to tune the car yourself. Take it to a professional.

Detoxx03

100% meth is where it’s at

Tech

If you want safety and lower IATs (as you've said), then you probably have no need to touch the AFR. If you want max power, then lean it out but you'll be meth dependant and more prone to blowing something up. Make a pull with whatever mix meth you want and post back what your AFR is. Anything above ~10.3 will be plenty safe (assuming gasoline).

sm0kinvette

i will report back. will do a log with injection and without.

Six-Gun-Todd

If you're using boost juice do not lean it out at all....the 50/50 mix tends to offset itself and doesn't contribute to added combustibles. Really doing yourself a disservice by not running 100% meth, very little benefit if any to boost juice in anything but a diesel.

0MVP @ TheRaceEngineShop

realcanuk

Running 50/50 will be just fine if that's the route you choose. It helps with cooling and definitely richens up the mixture quite a bit. Whether you decide to lean it back out is up to you.You have to decide how dependent you want to be on the meth. Some want as much power as possible, and some would rather have the cooling benefits but stay on the safe side.

I have been running 50/50 on both my builds for 5 years and both made great power for what they were, with no issues.

Kingtal0n

Water is essential for controlling EGT and preventing a motor that isn't built with ring gaps for boost or piston oil squirters to help survive those conditions. Many turbochargers have max inlet temperature around 1380*F as well. If a setup is already safe A/F wise from any fuel related damage (i.e. dynamic compression ratio vs pump gasoline) then I would not be so quick to inject methanol (expensive) when I could be injecting pure 100% water (not expensive) just to hold down EGT and not screw with a/f at all.

rajahhindi

Hey Jody,
When you were running 50/50 meth on your eforce, did you lean
it out and add timing for more power? ie if you could? Or did you
just run the meth over the tune and run rich? Was your car ever the stock ls2 with the meth? Thanks.

realcanuk

I was stock with the meth. I was running windshield washer then so about 40% meth. I always leaned it out some but left it rich enough that if the meth should happen to have any issues, the motor would still have a chance to survive. I cant really remember if I added any timing or not back then.