i saw at http://www.suprastore.com/fjowidbano2s.html
that they have wide band O2 device than can help you know your A/F ratio but i'm not sure if it can do A/F Vs. RPM. now is there such a device that can read A/F ratio Vs. RPM? and this can help you tune your PCM without the need for a dyno? right? i'm trying to find a solution for tunning my PCM since we don't have dynos here in Kuwait. also is there any device that can sense detonation Vs. RPM so that you can adjust timing accordingly? i want to use such devices on my 94 Z28. any one has info on that?

 

You're full of questions lately, dude! I have the FJO wideband setup. You can indeed use it on the street and you will actually have a more accurate AFR tune (wind resistance and actual weight of the car uses more fuel on the street).

The FJO will let you graph measured AFR vs RPM at 1/30 second intervals on a PC or Palm PDA. Once you have these numbers, you can use PEvsRPM to adjust your AFR at different RPMs. From experience, it's about 5% for a .5 move in AFR.

-Alex

 

Alex, thanks for the reply. i got it for the fuel but what about the timing how do i know that i need to retard timing when i have supercharger and how do i know that i need that much of timing retard?

 

Knock sensor...

-Alex

 

you mean reduce timing according to knock retard. that means

new timing = timing - knock retard

is there knock retard Vs RPM table program that i can refer to such that i can retard timing? is that included in the LT1edit data logger?

 

No, usually the amount of timing pulled by the knock sensor can be too much. If you get any knock, reduce WOT timing a degree or so where it starts - you want to keep the timing curve smooth with no abrupt changes. If you continue to get knock, you will have to reduce timing further. Sometimes the KS picks up false knock though.

You can get a general feel for what timing should be by looking at what the SC kits out there do. Vortech recommends 1 degree of retard per pound of boost at a minimum. That would mean with 10lbs, you should pull 10 degrees from your WOT timing at whatever RPM makes 10 psi. Less timing would need to be pulled at lower boost levels. This, of course, all depends on your air intake charge (intercooled/aftercooled).

What I wrote are just guide lines that Vortech laid out for their SC kit on a stock LT1. Just trying to give you some numbers to work with.

-Alex

 

i can measure the psi from the map sensor, right?

also for the wide band O2 sensor i need to hook it after the y-collector of the y-pipe, right?

 

No, the stock MAP is 1 bar. You would need an external guage tapped off the manifold.

I have mine after the collector of my long tube. Somewhere near where you current O2's would work fine. Placement is not super clritical as they are heated units.

-Alex