FAST, Dynojet widebands disagree!

[9secz]

I have a pair of Dynojet Wideband Commanders, one for each bank, and a wideband-enabled FAST ECU. The FAST O2 sensor is in the passenger side collector and the Dynojet O2 sensors are in the y-pipe about 6" downstream from the collector flanges. Here's the problem:

The 2 Dynojets agree with each other, but the FAST wb always reads about 1/2 AFR point richer. I'm thinking that Dynojet has been doing wideband controllers for a long time, and the 2 I have agree with each other, so maybe I should trust them over the FAST wideband. But I'm nowhere near sure about this, and you guys know that 1/2 AFR point can break pistons.

Is the FAST wb known to read rich?


LJ
http://para.noid.org/~lj
http://www.acceleronics.com

 

[norbs]

Test it against an lm-1 wideband for now. I know they are pretty close to the ntk sensor i tested them myself. within .2 BTW you pics of breakage are very entertaining

 

[TurboTR]

1/2 a/f ratio difference between devices is not unusual IME.

TurboTR

 

[norbs]

.5 is terrible for a wideband accuracy, I find it hard to believe. .2 yes anymore i just cant see it unless theres a problem?

 

[bruce]

If you want lab grade performance get a Horiba.
BTW, they use a high spec NTK sensor.

If you want to really get an idea of the combustion process, then you want a 4 gas analyser.

One should tune for the best performance, and note that. Tuning to *get* a specific AFR isn't the way to do it. If you want to accurately compare numbers from one car to another, then use one WB.

Not to mention that sensors fail, and degrade differently from different contaminates.

 

[Otto J]

ALso the wdies bands they run on those dynos I BELIEVE are way more expensive,way more accurate sensor,
As bruce said, Tune your car to a specific a/r it likes,By reading plugs an EGTs.and stay with that on your combo,Ive tuned many cars and have found some to run best at 10.5 and some run best at 12.5.I dont bother with the dyno wide bands if the car has its own.
The one on the dyno will not be in your car under realistic driving and racing conditions,The one with your F.A.S.T system will,ANd thats the one you will use for Tuning at the track on the street