i have a 2000 rcsb with 5.3, whipple supercharger @ 6psi, jba shorties, 42# injectors, meth injection, shift kit, boost-a-pump, cai. still has stock converter and cam. I was curious on what the air/fuel ratio u guys would recommend running and also how much timing? lemme know if you need to know any more about the truck. I took it to the track and it was running 11.2 a/f ratio. It was around 50* outside. I thought it would have ran alot better. It ran slower than it did 3 years ago when i didnt have meth injection, traction bars, bigger injectors, tune, and electric fans. 13.7 is all it would do. It was very doggy of the line. I was just wondering if the tune needs modified more. I just thought that adding $1000.00 worth of mods would help the performance out alot more. Not make it slower. The more pulls i did the slower it got.

thanks

 

PM 03sierraslt since he isn't posting in this thread.

 

11.2 is on the safe but conservative side. you'd probably get much better results with a higher 11 AF. What's your WOT timing at now?

 

I don't think you'll gain much at all by leaning it out. How much advance timing are you running??? what are your IAT???? how about your mix?

 

With the methanol on is it at 11.2 A/F on the gauge? I was told with methanol spraying it would go into the 10's or lower A/F if fuel isnt pulled from the motor injectors.

 

the meth mix is 50/50 water and meth, i didnt have a logger hooked to it at the track to see what the timing was at. Im waiting on the guy that tunes it to get some free time to see if we can figure out what is wrong. just wondering what numbers i should be seeing when we get to that point. I have the meth start spraying about 3-4 psi. it was pretty cool outside so i was just expecting it to run alot better, especially with the meth and bigger injectors and tune.

 

my setup is almost identical to yours, except i'm not using meth. mine doesn't seem to like the afr around 11.6-11.8, i'm going to try 11.0-11.2 when i get some free time. timing makes a big difference too, i can only get about 16 at my current afr.

 

if i cant get it to run better with the current setup, im ditching the whipple and going turbo. i just think after spending over $1000 on performance parts, it should run faster than my last pass before all the mods, not slower.

 

you need to move the IAT sensor to the discharge side. Then log it.
Then add timming. Without the Meth, I was seeing 170+ IAT temps, so I could only put
15-16 degrees of timming in it. With the cooling of meth, plus the extra octane, you should be able to go up. That is were your power will come from.
If you just ad meth and don't tune for it, you are just making a richer mixture and not taking advantage of the timming you can run.

 

i have the temperauture sensor located where the egr port was on the intake plenum. After i put the meth on, we did another tune. it was rainin so we couldnt get the greatest pulls.