02 readings

[manwithaGSX]

i hooked up my voltmeter to the number 4 and 24(i think those are the numbers, if not i know i wired the right ones) wire to the ecu to see what my o2 sensor is doing. it seems to fluctuate as described in the many articles i've read. at WOT the reading goes to .85 volts and is steady, and .86 for a brief second every now and then. i read an article on Road Race Engineering's website and it says that i can "get away with" .86 volts on 93 octane gas. does anyone have any other opinions on what i can "get away with"? should i pull the maf out and turn the screw in a little?

 

[andymoraitis]

How lean you can run (lower O2 volts) is primarily dependent upon air/fuel ratios and timing relative to fuel delivery and cool air charge. In layman's terms this would mean that if you log a 3rd gear pull, are getting good timing and not knocking, then .85 to .86 would be fine. However if you're knocking and pulling timing, you'll need to add fuel, lower the boost or raise the octane level to counteract it. So when RRE talks about "getting away" with .86 on 93, it's all in the context of whether you're seeing knock or not. Three to five counts should be your max tuning limit with three being preferred as representative of the "edge" of safe tuning. If you're seeing more, do one of the three things I mentioned above.

My best advice would be to hook up a logger and see what's happening relative to timing and knock.

Let me know if that makes sense,

Andy

 

[manwithaGSX]

yes it make sense. right now i have no way to see how many counts of knock i have i haven't noticed any drop in performance either. i want to get a logger, i have a lot of plans for this car in the scca. is there any brand or type of logger i should be looking at?

 

[andymoraitis]

There are a bunch of sites that you can reference, but here's a good one to get you started:

http://www.pocketlogger.com

You can also find used ones on ebay by searching for "eclipse logger".

Have fun taking the twisties!

Andy

 

[manwithaGSX]

thanks, i'll take a look at it all