Just wondering what your experiences are with meth injection. I have the ability to activate a solenoid at a certain boost or RPM level with my speed density setup. Im not looking to make crazy power I just want a little added knock protection and maybe squeeze a little bit more power through advanced timing. I was thinking of running a nozzle pre throttle body, the setup is a 20G, 720cc injectors, 255lph pump. Not sure what my AFR should be when spraying meth and what size injectors and all that. Thanks

i have almost the same set up except im on a B16G. i use a 7GPH nozzle.

Nice what AFR on boost? Do you run 50/50? and also could you tell me how much boost your running and do you have a flow gauge for the meth mix?

im running 41 psi in my fuel rail and i use washer fluid and heet. i run 22psi, but once i get a new map sensor for it i will be running 25psi. no i do not have a flow gauge

I run 100% methanol through an M15 nozzle above 10psi with max boost at 28psi on an FP3052. I see roughly 11:1 afr's at WOT. 18°ish timing up top and stock 7.8:1 compression ratio with lots of miles on a tired old shortblock that puts out about 145psi on a compression test.

My meth kit is pieced together and wired into ECMlink so when meth sprays, timing/boost go up and fuel gets pulled. It's not as complicated as it sounds but took some time to get setup right. I make about 80whp more with meth than with straight pump thanks to being able to add boost and timing with it. It has some failsafes built in as well.

On pump gas you will need to tune for 11.3-11.5:1 fuel ratios. Do not try and make your power with timing. Turn the boost up, lean it out and shooting for something in the 18-22* total timing range and your engine will live a long and happy life

You guys running meth, are you triggering the spray at boost onset or at a higher level? Also at trigger what are you running for peak torque timing? I see peak rpm numbers all the time, but wondering where your curve starts and how fast it ramps up.

I use a Hobbs switch to activate meth spray at 10psi. I don't remember where timing is at torque peak, probably something like 13° around 5k RPM. Then it ramps up pretty quick to 18°. I had to dip AFRs into the high 10s to combat knock/preignition at torque peak, but then it leans out to 11.1:1ish again after that. I should probably bust out a 'link log later off my home PC.

I'd love to see a clean 3rd or 4th pull log from your car Mark.

That seems weird your going so rich with meth to fight knock at the peak. What plugs are you using?

I'm only dipping to like 10.8:1 or so. The car just seems happier at torque peak with a richer mixture. I'm running NGK BP7es plugs (the non-projected tip style).

I'll see if I can upload a lot to the 'link forums later tonight.

Send me the link so I don't have to wade through there to find it. Which WB sensor do you use?

I use a PLX m300 with a Bosch sensor that I've had for years.

I wonder if you got some light carbon build up that's making some hot spots. I would think at peak torque with your 7.8:1 compression it wouldn't need to watch knock. (not doubting your set-up or tune, just surprised you need high 10s in the mid range)

With methanol, do you ever need to "purge" the lines before spraying, or is there check valves that prevent drain back in the lines?

I just remembered, those aren't my actual AFR values. My VE map isn't perfect so I have to target a few points below to get the actual values I want. I target 10.8:1, but actually see like 11.2:1 or so. Actual AFRs are in the mid 11's outside of torque peak. Easy to forget all this stuff when you don't touch the car all winter. /ubbthreads/images/graemlins/rofl.gif

No purging needed. I have a check valve at the nozzle that prevents backflow.

Ok, yea that makes more sense then. Lol. I know every car is different, but I was going to say that you might wanna prepare for a new bottom end if it's that touchy. lol. Nope keep beating that unicorn bottom end of yours.

Thanks for the replies everybody, just trying to get an idea of what to expect. I went with a used AEM V2 meth kit. Not sure what size nozzles but it came with a few extras.

Right now my tune is in a state that is in between knocking and having high EGT's. I see around 7 counts of knock on boost and just under 1600 degree EGT's. If I went up with the timing I get more knock but lower EGT's and if I pull more timing the EGT's get a little higher. You guys get the idea I could lower boost but who the f*** wants to do that? So I'm hoping Meth addiction is the answer.

Why are you using EGT to tune with? That's pretty oldschool. Do you have a wideband? I wouldn't run meth injection without one.

What computer are you using? Your knocking pretty bad. I would try and play with your AFR's before the Meth. Make sure everything is in check before adding meth to a possible poor tune or hidden issue that will present itself once you up boost and timing.

Also I thought 1800* EGT was the upper end of safe? Anyone chime in on that?

I have a zietronix wideband and EGT probe just so if I want to mess with timing on the street I know I'm not going to destroy anything. I use a DSMAP jackal setup and I love it. Like I said we only get 91 octane piss fuel in maine.