Thread: Need Advice on Water/Meth Injection

Hey guys,

I'm considering doing water/meth injection on my car but I'm not sure what exactly I need. I have read that it needs to be tuned to adjust the AFR to account for the methanol, and that it will require a wideband oxygen sensor to tune properly. I would plan to spray 70/30 mix so I can just buy washer fluid. My questions are:

1. My canned tune currently commands 11.0 AFR at WOT. Instead of going to the expense of buying my own tuner, could I just have someone bump it to 12.0 or so and be good enough for meth?
2. If so, could I then forego a wideband? I don't really care about squeezing the most power out of my car, just want to drop a few pulley sizes without chipping a piston.
3. If I do need a wideband, can I just wire it up without a gauge? I'd rather just install the sensor if I can because I don't care about having an AFR gauge on my dash.

The reason I ask these things is because I don't want to spend $400 on HPTuners and $200 on a wideband kit if I don't need to. I know, I know, you can only pick two of cheap, fast, and reliable.

And if you have any experiences with water/meth you think would be helpful, feel free to share.

no. best to get your own tuner. saw someone selling their DHP for $300 in the for sale section
get a wideband
best to wire it up with a guage so you can see how its working and if the controller or nozzle ever ends up not working properly and you see it go lean and be able to let off before breaking something in the motor

if you want to gain horsepower and/or use meth injection, you gotta pay to play
also alky/meth injection generally richens the overall AFR

if you want, get a tuner, injectors, and switch to e85 and it'll be more worthwhile than meth injection without all the tuning headaches

intercooler would be better and less hassle to tune. if anything get a full size and not the short stack. you can get them now cheaper since ppl end up demodding them. still best to invest in a wideband and tuner.

if you're really tight on funds and on a budget then you can piece together your own meth kit. I did years ago and used the devils own controller and pieces from home depot and mcmcaster-carr. with my AFR at like 10.5-10.9 on a 3.6" down to at least 3.4" with timing ranging from 25-29* on stock cam and 2.93 gears I was running mid 13s at like 102-103 on street tires with a 2.10-2.15 sixty foot on average. the downside is again, it was a hassle tuning with the meth injection and trying to run as lean as I can. -20*F washer fluid isn't the best mix to run but in a pinch it works. best to run a 90/10 methyl to water mix and not 20/80

get tuner, get meth, buy real meth, mix it 50/50 with distilled water. i bet you could run a 3.2 with meth and nothing else, buy a wideband and a tuner. 3.2 pulley is where stock injectors are about maxed out.

as far as the tuning, you need to pull fuel from the maf to make the afr say 12.6 ish on the wb, then spray the meth, it will make up the afr by at least a point, your goal should be 11.5 ish, engine will feel its strongest on that afr, 10's it will dog, 12's it will likely knock. you lower the timing while doing this tuning to avoid kr. once the target afr is met spraying the meth, you can start to turn up the timing.

this is mine. i got a load of bolts on, 42 injectors, gen 5 N* with a 3.0 pulley cause the 2.8 maxed out my injectors, yt 1.95 rockers, ported heads, na bottom end headers, fsic and aem meth kit. its a progressive controller, meaning it starts to spray at 5 psi then sprays max at 10. i make 13 ish. start and max are fully adjustable in the car. so if you stay out of boost aka drive it normal the meth will last. but if your wot all the time you'll be refilling the tank daily lol

https://youtu.be/3xQrn7pNTZM

theres places that sell it, but you can almost always get it a race track. where i get mine from. 5 gallons is 30 bucks in your own can, 35 for a 5 gal can. that makes 10 gallons in all. the last 10 gallons i made last year sometime, i still have like 4 gallons left i think.

i started out on washer fluid, so i saved the jugs, what i store and mix my meth up in. milk crates work good for holding em secure too. i normally keep a full tank, and a spare gallon with me. once i crack the jug open, i bring out another one to replace it with. you dont want to run out.

Unfortunately, the only track within 300 miles of me closed down last year, so I can't get meth that way. That's one reason I was planning to run washer fluid. I figure I can always add HEET or something similar if I end up wanting more methanol content.

The thing with methanol though is that after spending $400 for a tuner, $160 for a wideband with gauge, and $400 on a meth kit, that's almost $1000, at which point I might as well just do an intercooler setup that I can install once and never have to worry about again.

run both lol you'll still want the tuner no matter what, and the wb is needed once you start dropping pulleys and tuning, fsic you should be able to run a 3.2 pulley, but injectors will be near maxed, so 42's should be installed to be safe and leave ya some room to grow. 42's got me to a 2.8 on the gen 3 blower.

ic with a ported lim will drop your boost a lot, iirc 3.2 i was making like 8 psi.

Hahaha I wish I had the money to run both. I'd guess my trans will take a dump before then though. 175k and still going. Maybe I'll start with the tuner and wideband, then go to meth once I get the hang of it and save some more money. I'm sure I'd use the tuner anyway if I move on to something LS-based a couple years down the road.

The other thing for me to consider is that I live at high altitude - about 4500 ft - so the thinner air should mean I don't run out of injector until a little farther along. I currently make only about 6-7 psi of boost with headers and a 3.6 pulley on my Gen V. I figure I can go to a 3.2 pulley before upgrading injectors.

maybe a 3.3 with a ic on a gen 5. they work better.

just tuning it will wake it up. trans tune being the most of what you'll feel, and removing some tm.

Yeah my current mail-order tune has some trans tuning done to it, and it honestly made the biggest difference in the way the car drives. Don't think I'd push it any farther on a basically stock trans though. Don't want to break any hard parts.

o buy my devils own alky controller along with tb spacer and variousnozzles lol.