epfatboy

iTrader: (3)

Planning on a cross over to an exhaust log. With no real good place to run O2’s to get readings from each bank am I better off dumping them? Or is there still some value in running them in the downpipe or crossover?
I will be running a wideband in the downpipe too.

It’s a JY 4.8 single (8-10psi) in primarily a driver that will see the track 2-3 times a year.

I’m new to tuning this type of tuning so I’d like to make it as easy as possible but I’ll do what I need to do.

JoeNova

You iphone guys are killing me haha.

epfatboy

iTrader: (3)

So you think closed loop?

kingtal0n

iTrader: (1)

the only time I use a narrowband is if I happen to have one in the vehicle for some reason, and I need it to verify a possible bad wideband or bad injection bank behavior. If you set the factory ecu into closed loop the narrowband voltages flip from 0v to 1v around 14.7:1... which will (SHOULD) be evident on the wideband reading.

Ex. I can set the closed loop for the right side of the engine only by using on narrowband in the right manifold. ECU attempts to hold 14.7:1 using that side only: now I see how "off" the LEFT side of the engine is, because downpipe wideband averages both sides. So for example If wideband says 14.5 I am probably 14.3:1 on the other side of the engine. I can then enable the opposite side narrowband and repeat the test for more data.

Not useful for closed loop because Using the wideband in your local climate should ultimately yield higher quality fuel map than "slightly trimmed from 14.7" i.e. there are better ratios for other situations than closed loop can provide. I prefer cruise 15.0 to 15.2 for example.

epfatboy

iTrader: (3)

The problem with using a log is you only get one bank that will be actual, in my case 1,3,5,7.

So your saying run open loop unless you want to validate the wideband. I guess it is easy enough to have a few bungs available for testing.

kingtal0n

iTrader: (1)

Well, I am saying use whatever tools you have. Its just that a wideband IS a narrowband, but so much more. So why would you waste your time trying to fool with 1/100 of a wideband when you have 100/100 of a wideband handy? Its like you are asking "I have a computer from the 80's and a computer from 2020, which one should I use?" well obviously use the newer computer... unless you can think of an off-hand use for the old one (as long as you don't mind its ugly presence in the car). I prefer not to see them so... I put my wideband under the car... and dont have any narrowband sticking out of anything... I tune the engine more based on common sense, not always trusting a wideband number, and if I needed an accuracy check I would just goto my local favorite dynometer.

ddnspider

iTrader: (26)

It really depends on your weather and overlap and stuff. Low overlap and winter to summer temps dont vary by 80*, you should be fine with full time OL and ditch the narrowband O2's, especially if you're tuning it yourself and are ok making tweaks every now and then.

Lsxford

iTrader: (6)

Is that why some people have those € or £ instead of an apostrophe? Because they use an iphone? Sorry OP i have always wondered

Also to note is having O2s pre turbo is said to shorten their life. 1 of my o2s only lasted a few months so it may be true. However they were used sensors lol

epfatboy

iTrader: (3)

I live in NH so a 30 degree swing in 4 hours is a reasonable occurrence in the spring and fall.

I think I'll throw the narrowbands and wideband in the downpipe. Probably start with OL and once I get comfortable tuning I can mess around with CL if I feel like it.

Thanks for all the info.