Tuning problems w/ hacked mafs

[daniel240]

well i finally got my car on a dyno last week and made 179hp and 200ft/lbs torque running rich. my a/f's were all over the place between 11 and 9. this was using 370cc injectors w/ a hacked mafs w/ 2.6" ID running a blow through setup retarding timing .5deg/psi with btm running 8psi w/t3/t04e. so i made a few changes to lean it out and i switched to a 2.75"ID pipe and converted it backto a pull through type mafs. i dynoed it again today and made slightly less hp than the first time however i was running real lean. my a/f's were right at 13. i was also detonating. this was with the btm still retarding timing at .5deg/psi. i made 1 more run and retarded my timing 1.5 deg to se if i could stop detonating and i lost nearly 30hp and there was still some detonation. one interesting thing i did notice from last time was my a/f's were much smoother. im sure this is due to running the mafs before the turbo. running it as a blow through type they were all over the place. so im going to keep the mafs before the turbo and try to richen it up. im either going to go with a pipe in between 2.6 and 2.75" id or use an fmu with the 2.75" id to richen it up, i havent decided yet. i know someone on here is doing this. i just hope my dyno numbers go way up from what they are now because i know i should be a lot higher. i also did a compression test and was good at 180 in all 4 cylinders.
Modified by daniel240 at 7:01 PM 9/5/2004

[huguetpj]

Maybe I didn't see it.... but how many PSI?

[daniel240]

running 8psi. im going back to the dyno to do some more testing saturday. I switched back to a 2.62ID mafs running it before the turbo. also found out that i was supposed to be doing 4th gear pulls on the dyno, i was doing them in 3rd.