Lambda voltage
Turbo Mini Forums

Just fitted a sensor this morning(top fork nut of a kawasaki fit's a treat)

Wired it up to a multimeter as I have no gauge yet.

I'm getting .50 to .75 volts out of it(after a couple of miles drive to make sure its hot) so I take it that is a bit rich

Think it should be .45 can anyone confirm

Forgot to mention my sensor is from a rover 620? out of the elbow on a t25 it's a bosch 4 wire

Edited by Dangerous on 17th Sep, 2006.

Metro turbo weekend driver,Mini turbo in the making again!

There's a link here to a graph.



I'd say you were running about right. You want to see about 0.1 to 0.3 under WOT.

EDIT: I'm wrong - should be 0.8 as evo said.

Edited by Paul S on 17th Sep, 2006.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

no, you want to see around .8v under WOT

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Well thats 2 opinions

I turned the mixture half turn weaker and now get
.4 idle
.5/.6 normal driving
.7 flatout up hill
0/.2 no throttle down hill

This is with a std bdd needle so I take it I don't need to fit the 10psi one,as that will make it richer

Do I need to go for the heavy spring or thicker oil

Metro turbo weekend driver,Mini turbo in the making again!

Aha I see
wideband sensor more voltage=leaner
narrowband more voltage=richer

mines a narrow so about right till R/R time

Metro turbo weekend driver,Mini turbo in the making again!

Found the info now guys

AIR/FUEL RATIO
GAUGE READING
14.7/1 0.50v
14.6/1 0.60v
14.5/1 0.70v
14.2/1 0.80v
13.5/1 0.85v
13.2/1 0.90v
13.0/1 0.92v
12.5/1 0.94v
12.0/1 0.95v

Happy turbocharged engine likes to be above 0.92v under the load.

Metro turbo weekend driver,Mini turbo in the making again!

wheres the rest of it? theres nowt below Stoich!!!!

narrowband sensors are accurate at 14.7:1

Thats as good as they get. If you are using them as a tuning tool, be very very aware that they are very innaccurate anywhere else.

their response is very non-linear, making it very difficult to use them reliably.

So tread with caution, or be sensible and buy a wideband.

Circa 0.9v should be ok on boost, but given they arent accurate/repeatable up there, its still not 100% safe.

Dont know where Dangerous got those readings, but they dont sound right to me.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Found them here
http://www.zeitronix.com/questions/O2questions.htm

Metro turbo weekend driver,Mini turbo in the making again!

By their comparison, 0.94v = 13.0:1...

To suggest a turbo engine will be happy around that, isnt quite true.

A turbo engine will melt pistons at 13.0:1 It is far too lean to even think about using.

That said, their voltage shouldnt be far off, I totally disagree with their suggested AFR's to match the voltage.

But pressure and sensor temp does affect the output voltage by quite a bit.

Buy a wideband.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

13.0:1 is rich though???

Metro turbo weekend driver,Mini turbo in the making again!

Up to you.

I would never run a turbocharged engine at an accurately measured 13.0:1 AFR

I may just tempt fate at 12.0:1, but even that is pushing it a little for safety.

11.5:1 for me.

If it was normally aspirated, then 13.0:1 would be fine.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will