Knock on Scanmaster

[CutterTurboT]

I just got a scanmaster and hooked it up...I was playing around with it and made some runs with it...I'm running 17psi boost at 39-40 FP on 93 octane...The scan master was saying that I was having about 3.0 of knock and the 02 mil at WOT was about 830....the instructions say I need to be in the 750-770 range? Don't know much about it...What is a bad knock reading ?? isn't a lil between shifts normal?

 

[TurboDave]

3 degrees of retard isn't too bad, but don't let it get much higher than that.

830 is a little rich, but plenty safe for pump gas.

I would NEVER EVER shoot for O2's much below 800 on street gas. You're at about as much boost as the car can handle on street gas, and trying to run the O2's much lower than 800 is really going to wreak havoc.

 

[bruce]

Originally posted by TurboDave
3 degrees of retard isn't too bad, but don't let it get much higher than that.
830 is a little rich, but plenty safe for pump gas.
I would NEVER EVER shoot for O2's much below 800 on street gas. You're at about as much boost as the car can handle on street gas, and trying to run the O2's much lower than 800 is really going to wreak havoc.

Oh?.
I was at 820mv, and hooked up a WB and saw that that 820 was 12.8 AFR. I'd hardly call that rich.

In dialing up to 11.8, the car really really runs strong.

NBs are at best guessing, they are not temp compensated, and EGT changes their output. They also happen to be back pressure sensitive.

If your going to monitor an O2 use a WB.

Wonder way so many people pop headgaskets around here?.

http://diy-efi.org/diy_efi/projects/diy_wb/

If you want to DIY a WB.
Lurking at DIY gets you info on GPs for boards and parts kits
For $150 you can make a real WB. Not lab grade but a heck of alot closeer then the BW ever thought of.

 

[TurboDave]

Originally posted by bruce


Oh?.
I was at 820mv, and hooked up a WB and saw that that 820 was 12.8 AFR. I'd hardly call that rich.

In dialing up to 11.8, the car really really runs strong.

NBs are at best guessing, they are not temp compensated, and EGT changes their output. They also happen to be back pressure sensitive.

If your going to monitor an O2 use a WB.

Wonder way so many people pop headgaskets around here?.

http://diy-efi.org/diy_efi/projects/diy_wb/

If you want to DIY a WB.
Lurking at DIY gets you info on GPs for boards and parts kits
For $150 you can make a real WB. Not lab grade but a heck of alot closeer then the BW ever thought of.

All perfectly valid points. Unfortunately, the vast majority of us don't have the skills necessary to construct such a device from scratch from the info provided on DIY. We must therefore rely on what's available "over the counter". That's where it gets real expensive and out of reach for most of us to just run a Wideband O2.
Most opt to got with a complete solution like stand alone PCM w/wideband O2 (Felpro etc.)