Or does it have to be done on a dyno? Daft question, maybe, but it would be very handy to know if it could.

Raymond.

 

Get yourself a lambdalink or similar AFR gauge installed mate. Just piggyback off a wire at the ECU (solder it properly) - if you want to know which one, send me an email.

The only glitch is that the sensor itsefl reads lean when hot....so the figures are only "trustworthy" during quick blats (make sure to let things cool down if you're out doing multiple runs).

(S.A.M. remembers a dark evening in the north of London with R19KET in the shotgun seat...*lol*...sweet sweet times)



/J

 

I was wondering the same. Had a run on the select monitor the other day but it was probably not useful because

1 I was 3 PSI down on boost and not really running very high revs

2 I don't know whether the select monitor would detect lean running

If the select monitor is a good method, then perhaps you could try this. From what folk have said on other threads, it seems that AFR on the dyno may not be reflected in road usage.

With all this talk about induction kits and MAF confusion/lean spots, I will be following your thread with interest.

 

Hi there.

I already have a Lumenition AFR gauge fitted but I'm not too sure of its value because the lights (10 of them) flash up and down the scale very quickly as the ecu does its stuff. Under acceleration I get the highest or second highest green lights on which is fine (green=rich and there are 3 of them) but under cruising conditions it is really not clear due to the aforementionmed flashing because it alters with every 0.1 volt change by the ecu. I have a fair few induction and exhaust mods and wondered if I could confirm the meter readings.

Raymond.

 

Top

 

Have you got any values for the various leds on the Lumenition gauge?

My car (a bit tweaked - VF24, Link...zorst and so on) runs at 11,5:1 - 12:1 during WOT, this is middle green on the Lambdalink (middle of the "rich" zone).

I think most of these gauges work the same way, it's a small IC that converts voltage to a graph bar.

/J

 

Hi /J

Im pretty certain that the lights are in steps of 0.1 volt and there are 10 of them so the range is 0.1 - 1.0v. Under acceleration, then, I am getting 0.9 or 1v. It's the steady speed that I want to check and it's not very readable because of the rapid changes. Cheers.

Raymond

 

Raymond,

The flashing you mention, do you mean it runs backwards and forwards from lean to rich and back again non-stop ? If so, that is totally normal on cruise. It is the ECU constantly changing the fueling as it trys to aim for the perfect mix (and keps missing )

However, saying that, it all depends on how long it spends time at the lean end of the scale.

The important thing is that it remains nailed to the upper end of the scale while on full throttle. Any time it doesn't do that, be very worried.

As for dyno. Yes, you can put the car on a dyno and using a gas bench get a very accurate 'real' reading of the fueling under all conditions. However, I wouldn't bother unless you have a specific problem.

Cheers

Ian

 

Ian,

That's exactly what I mean. The lights race up and down the scale and only stay static under full throttle when the highest green one stays lit or under throttle lift off when there is none lit at all. Sounds OK then. I was reading another thread which mentioned lean mixture under part throttle cruising conditions and it got me wondering because I was trying to decipher the AFR but it wouldn't stay still for long enough.

As a matter of interest I looked at Gunson's site last night (