Dyno Day..what a joke!

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May 20, 2008 | 06:16 PM

#41

BattleShip

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From: I moved to over there

Quote:

Originally Posted by Fastvette94

..I am simply saying I would not trust a narrowband sensor to tune my car.

Some trust them, some don't, but I have trusted them and not had a problem. Now losing ring lands from overboost is another story...

Quote:

Originally Posted by Fastvette94

I run a wideband fulltime in my 10 second corvette. The narrowband O2 shows different mVs at the same AF ratio of the wideband. I've read where the narrowband mv's changes with temperature outside of it's narrow range..

I have not had an O2 change values, maybe the ones you were using were bad--I don't know but it seems we have had different experiences all I can say is they have worked for me in many vehicles from NA to boosted making a few hp and I get down the track ok.

Quote:

Originally Posted by Fastvette94

A narrowband O2 will only tell you if you're above or below 14.7 in my experience, not by how much, to the accuracy I feel comfortable with.

A narrowband does tell you it is just non linear and not accurate as I said above. But my experience has been their measurments are repeatable. Also they report/measure a lean condition as quickly as a wideband...and lets face it if you go lean you're screwed anyway in a motor making power.

I agree it does come down to how comfortable you are with the data. But no system is accurate, repeatable and able to give the data at a rate suitable for a fast revving engine.

Less than 100 samples a sec really is insufficient IMO and I have not seen an O2 that can measure settle and latch a value in anything near that time. The processors can easilly handle it the sensors are the limitation.

Well good to compare notes and opinions with you.

Good luck

May 20, 2008 | 09:09 PM

#42

Fastvette94

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Here's a log of two passes I made while logging the wideband and narrowband on the right bank of the engine.

I missed 2nd gear on the motor pass but the data still shows how the NB mVs and the wideband AF ratio compare.

The nitrous pass was a 150 NX shot with a cold bottle (900 PSIG) so it was rich.

Notice on the motor pass how in 3rd gear the AFR is getting fat according to the wideband yet the narrow stays flat.

Magenta - Wideband (15 samples a second) units - air/fuel ratio
Blue - Stock NarrowBand units - millivolts

I get what you're saying, yes it is a crude tool if you lack a wideband, and it will let you know when you're in the too lean area.

Thanks for the info

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May 20, 2008 | 09:45 PM

#43

chvycmaroz28

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From: New Hartford,NY

u could always buy a ls series motor? haha jk ya get more fuel into her and retune somewhere else

May 20, 2008 | 10:29 PM

#44

BattleShip

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From: I moved to over there

Quote:

Originally Posted by Fastvette94

Excellent. I will look at it in morning evening flew by me. Good comparing notes.

Thanks

May 21, 2008 | 12:45 AM

#45

Elliott's94Z

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From: Oregon Grown

Here is some new info I thought was interesting...looking at a second dyno slip the guy only took my car to 4600 rpm's then killed it?? I would have been pinging that that out almost. Does this sound right??

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