tuning with narrowband o2?

[tford]

Is it true that as long as there is no knock, I'm safe pulling fuel out via turbotweak chip? I was told it will show knock if it gets too lean. The wideband readings are 785 wot. It is a little slow to accelerate which leads me to believe it is rich. I need to relocate the egt sensor to pre-turbo & use that to estimate afr. Right now post turbo, it' not getting past 1000 degree F.

 

[jarredsoon]

I am confused are you tuning with a wide band or narrow band O2??
I would not go lower than 760 O2s at WOT and always tune for zero knock.

 

[just plain john]

Ditch both the narrowband and EGT and go wideband. Much more useful tuning aid, and with the correct TT chip you set your desired A/F and the ECM does the rest. Easy peasy.

 

[forcefed3.8's]

When I tuned with narrowband, my car ran faster with the narrowband at .81x than in the .7xx. Now after useing a wideband I see how far off the narrowband was. I don't pay much attention to the narrowband now, but after a pass, I could have a low O2 recorded on the Scanmaster of .71x and the wideband is rock steady at 10.8. The next run, it will show a low of .77x. My friends car showed .81x on the Scanmaster and 11.7 on the same wideband. (My wideband is portable and goes from car to car.) Both of the narrowbands are Denso brand and were new before the outing. His for some reason was stuck showing .000 for the first 15 mins of operation, then started working. Both cars run the proper 14.x AFR on the wideband while cruising, so the sensors are working at that range, the range they were designed to work in.

 

[TurboDave]

I am confused are you tuning with a wide band or narrow band O2??
I would not go lower than 760 O2s at WOT and always tune for zero knock.

Narrowband WOT numbers are useless and quoting any particular value as a tune point is just as useless....
Take a look at forcefed3.8's examples.

And here's my example, while idling and cruising my Wideband also reads smack on 14.7, and the narrowband is doing it's "crossover" thing nicely.

I have my WOT AFR is set to run at 11.4:1 and is rock solid there. Care to take a guess what MY narrowband reads when at 11.4:1? .701 !

But, with all that said, you can generally find a point at which YOUR narrowband numbers start showing knock (NEVER EVER RELY ON SOMEONE ELSE'S NUMBERS TO TUNE YOUR CAR) and go a bit richer from there. Of course fuel AND boost will each have their own unique side effects on knock.

 

[Razor]

The only way I have seen success tuning with a narrow band has been on a track watching the MPH increase on the back half of the track. At that point you lean it out and watch for knock activity. You can take the engine to the edge.

Leaving the engine tweaked out like this will create problems while street driving it.

Tuning on the street.. using the butt dyno.. never ever will you be even close.

 

[clusolynn]

Egt...

Some of the old school guys swear by EGT tuning, and there is an expensive set up for the XFI system to put EGT probes on individual cylinders. I'm not sure exactly how it works, but for the cost and the fact that the "Big Dogs" in Buick racing have individual EGT probes for each cylinder leads me to believe the is more than a little merit in their use. Maybe you should ask for help with the EGT tuning as well, I'm sure there is someone knowledgeable enough on the board to assist. Good luck either way.

 

[Razor]

Some of the old school guys swear by EGT tuning, and there is an expensive set up for the XFI system to put EGT probes on individual cylinders. I'm not sure exactly how it works, but for the cost and the fact that the "Big Dogs" in Buick racing have individual EGT probes for each cylinder leads me to believe the is more than a little merit in their use. Maybe you should ask for help with the EGT tuning as well, I'm sure there is someone knowledgeable enough on the board to assist. Good luck either way.

Main reason they put egt on individual cylinders is because they cant run individual wide bands due to back pressure. And this is done to trim out fuel per cylinder.

Cars without knock sensors can use EGT as a way of seeing any detonation.

I have used it to trim out my timing. Increasing timing drops EGT at the same air fuel.

 

[vacuum 6]

The only way I have seen success tuning with a narrow band has been on a track watching the MPH increase on the back half of the track. At that point you lean it out and watch for knock activity. You can take the engine to the edge.

Yep works like a champ picked up 6 MPH.

Starting 3rd gear o2s were .80 and trimmed it down to .75

 

[bison]

10 years ago when I used narrow numbers they always mph best with numbers in the low .700's to high .600's. I always used the same sensors and only took data from the top of 3rd. playing with fire IMO. Much more effective to get a wide band on there

 

[tford]

thanks for the responses. Sorry for my type-o, I only have the narrowband o2. I will only be tuning at the track to see actual results of any changes. I plan on leaving with no boost off idle to eliminate any inconsistencies on the launch. So as long as it's picking up mph & no knock, it's o.k. to pull fuel out with the chip, right? I think I'll move my egt sensor before though just to have some kind of reliable afr readings as a guide.

 

[tford]

The reason I ask is an old school Buick tuner told me a wideband is overkill for a 95% street car like mine. I'm kind of nervous about tuning like this so I was just wondering if anyone else uses this technique successfully. I guess before widebands were being used, you old school guys had to use something.

 

[tford]

just took the dive

Just said f it and ordered a plx wideband kit with gauge for $230. I'm ditching the egt to open up a spot for the gauge on the a pillar pod. I'm sure I'll be posting with questions on the install in the near future. Thanks for the advice. See ya, Tim

 

[jarredsoon]

ya thats what I did this winter just got a wideband and a power logger with TT 6.0 chip. Not installed yet either.

 

[Mr.Spool]

if you like your motor the wideband is a great tool move so fast you can see where things are heading way quicker than the narrowband but i never had issues tuning off a narrowband either,i still use both.