well i finally made it to the track friday night with the meth on the truck. weather was about 70-75 degrees and a little humid. my previous best time was 12.52@105.50. the weather was about 60 degrees with no humidity. the best time i could pull was 12.38@107.50. the only thing ive changed was meth, dual 3in. exhaust, and a bigger intercooler resevoir. the question that i have is how much timing will that meth let me run. right now its running 27 degrees on the launch and is holding around that throughout the run. before the meth it would launch around 20 and drop to 18 throughout the run on a cool night. so we've added around 8 degrees or so. is this getting too high or is it ok? we've seen absolutely 0 knock, and we are running around 11.5 a/f ratio in 3rd gear using a wide band. also, can i go any leaner with the meth? ive heard this is where i wanna be on the a/f, but i didnt know if the meth changes that. all opinions and info is appreciated.

 

If you are running 11.5 while spraying the meth, you don't want to go any leaner. If you are targeting 11.5 without the meth, you'll be rich when the meth is spraying (you want to tune with the meth running).

 

yeah weve tuned with the meth running. it went real rich when we first hooked the meth up. then we leaned it out with the meth running. so that answers that question. what about the timing? how much is too much? im running about 9.5#s of boost.

 

That is a lot of timing.

 

That is alot of timing. What kind of IAT's are you getting with that 2.7. High timing doesn't mean more power. It can fall off on pwer and not get you into kr. Congrats on the stellar times.

 

What he said and Congrads on the new best.

 

God, that is alot of spark w/o KR Are you sure your post was correct about the 27*?

 

I've ran that much timming before, but I also was running race fuel... I also like to shoot for a 11.0-11.2 a/f with meth....

 

my iats are around 120 when i launch and climb to around 158, by the end of the 1/4. and yes 27* is correct. ive heard that when tuning for meth that you need to start by adding 9* and go as high as 15*. is this correct? we've only added 8* so far, but we were scared to add anymore. can anyone tell me about how much theyve been adding with the meth. mine is a 50/50 mix.

 

Tell ya what, I have a similar set-up as you do and was only able to add 3-4* of spark before running into KR when tuning in the meth. I am currently running 11.8AFR with 19* advance. During logging, I see max of 21* until my IAT's adder pulls it back to 18-19* by the end of the run. I will pick up a tick of KR once in a while as well. I got bold and ran 20* base and hit KR pretty bad throughout the dyno pull.

I would start with dialing in your AFR and then go in 2* increments of advance until you hit KR. Are you sure your knock sensors are functioning correctly? How is the sensitivity adjusted in your tune? As stated above, are you running 93 octane or race fuel?