If you have KR its probley either running to lean or to much timing. Say your running 17deg timing advance and have 7 deg KR. The KR is subtracted from the timing so its actually only runing 10deg Timing advance. You may be able to knock the timing down to 15deg and have 0 KR which is beter than having 17deg advance and 7deg KR. As far as the air/fuel ratio goes you wait to be somewhere between 11.3-1 to 11.8-1 @ WOT. I dont know if you have a wideband to measure this with but if you do thats where you want to be. If your reading off you 02's you need to be running Atleast 900mv @ WOT. Your 02's are really not to accurate and I recommend hooking it up to a wideband to get a good reading. Like everybody said its probley all in you tune. Youll be surprised what a difference a Good tune can make compared to an ok tune. I wouldnt be surprised if you got a good tune went back to the track and ran 105+mph.

 

So you're saying that you're still running the Magnuson supplied VE, PE, and timing tables? With an aftermarket cam, small pulley, and high stalling converter? If so, you need to get a custom tune in that thing ASAP! It's probably running really lean up top, which is why you're seeing a ton of KR.

 

What does 2.9 inches translate to in psi?

 

Should be roughly 6-8 psi depending on the cam.

 

You need a wide band.

 

Thanks for the posts. The O2 mv thing is really helpful. I'll try to figure out why they're so low. I'm still a noob at this tuning stuff

 

At this point I think a nice dyno tune is in order.

 

Dude you need a real tune before you pop your motor

 

First adn foremost, he has a 1999 truck with pretty high miles and 99 the PCM is still installed (I believe). For us old timers who've been around a while, you'll remember the 99 truck PCMs were HORRIBLE dealing with knock retard and timing. I am so glad I'm not still dealing with my old 99 truck.

What he really needs is to get an 02 PCM/tune with the Magnuson superchips loaded on it than begin tuning from there.

 

good memory....I almost forgot about that. I agree with you, he needs to start out with a base calibration from magnuson and tune from there.