[Mike M]

Seabass, Do you have any idea whats inside an o2 sensor? Or how they work? Or their voltage range? How what their internal resistance is? Or better yet, do you have any idea whats inside an A/F gauge?

People have been tuning using readings from O2 sensor for quite some time. I will agree that measuring accurate a/f ratios was not it's original intent, and that there are some variations between sensors, but people have been using them to tune. Successfully.

To say an o2 sensor is not designed to read A/F ratios is quite a general statement. All car manufacturers think its good enough to tell lean from rich. Grant it that that was its original intent, over the years we have learned that we can in fact use the voltage readings to get an accurate picture of how much air is being used up in the combustion process, therefor telling us a fairly accurate A/F ratio.

Now your statement about instrumentation really quite bothered me.

Anyone that knows anything about instrumentation, knows that you cannot buy equipment that accurate out of a Jegs catalog for $100

Anyone that knows anything about *whats inside* instrumentation, knows that you can make something MUCH more accurate than .05v resolution for under $5.

Now I'm certainly no advocate of the cyberdyne A/F gauge, but I assure you, it is accurate to .001 volts (but has a little hysteresis...its inherant of the chip the use inside it) Of course 10 LEDs does nothing to tell you anything about your actual A/F ratio. That is why many of us DSMers use datalogger's (PocketLOGGER, TMO, Ease-Sim, Alex Pepper) or real volt meters (Like the Jumptronix unit, or Fluke Multimeters) to see the o2 sensor voltage. Even those modded Autometer gauges are pretty good.

My point is, to say "dont use an A/F meter" is pure sillyness. I'm not saying *only* use an A/F gauge, but it provides a signal that, while not accurate in your book, is at least repeatable to the point where it can be accurately used to tune with. In my opinion, the more information the better. Why rely soley on EGT when you can have both? Its not going to kill your motor if you shut down because your "inaccurate" A/F meter was reading lean and your EGT was fine. The most it can do is help.

Regards,
Mike Montalvo
digital tuning,inc.
http://www.pocketlogger.com

 

[Mike M]

As for you rancid1g,

Get yourself a boost gauge. Information *cant* hurt, it can only help. There have been many times that something goes wrong..like you blow a vacuum hose off..that can increase your boost and without a boost gauge, you'll never know it. If your gonna play with boost settings then it's a requirement.

I'd definetly stick with the NGK BPR7ES plugs. Wires, go crazy, but stock NGKs work fine.

If your shooting for the 12's, gauges never hurt. You'll need a boost controller. I think you said you got one. That can be used no matter what turbo you go with, so it's a good investment.

Once you start playing with the boost, its imperative that you watch your A/F ratio and EGT.

Once you start flowing more air (exhaust, increased boost), your gonna start to need more fuel. A bigger fuel pump will take care of that. A fuel pump rewire (www.vfaq.com) can hold you over a little.

On my 1g, I ran 13.8 with a test pipe (stock exhaust), a K&N and a boost controller ($1.98 wallmart bleeder valve!).

An HKS Upper intercooler pipe didnt do much for me. You'll need it down the road though.

-Mike

PS: A datalogger is always a good investment :cD