http://www.markvanderkwaak.com/dbbp/tech-tips/mm.html 

Nice idea - so, did you make one??

Jaycar sell a kit for something similar. only three leds to indicate mixture though.
RICH....GOOD....LEAN.


http://www.jaycar.com.au/productView.asp?ID=KA1758&CATID=25&keywords=&SPECIAL...

Nice idea, I might make one some time.

I suppose that if you had dual carbs you could tune each side individually by putting the sensor in one side's exhausts at a time.

A $15 kit from Jaycar; part KC5195.

I fitted the Jaycar kit to my Humber, using a sensor from a Daihatsu Charade, fitted by drilling hole into (2") down pipie just after exhaust manifold and using a TV aerial mast clamp to hold it in, worked fine, but still needs to be calibrated to be accurate as far as the exact fuel air ratio, rather than indication of what is happening, I was happy with 2nd option, I have seen no good way to fit to kombi so far let alone the beetle, as the sensor needs to be projecting inside the pipe, so is fairly restrictive in a small pipe, & must not be too far from heads as it requires very high temp to operate & distance from head also affects the accuracy of a reading.

yes, but the air/fuel mix indication, may not be as accurate by the time it gets down past muffler, ideally
on a kombi you would have one each side just where each pairs into standard muffler at end of header,tempted to try it one day

These are all narrow band right,i dont think there that accurate,from what ive read thay just say lean or rich and u dont know how rich or how lean.:o

I am not sure how to define narrow, I forget the specs but I regarded it as wide, even when idling the indication would flick over a few leds, it is not 3 Leds as originally stated at top of post. actual accuracy is set by turning a trimpot & so can be calibrated if you have access to a u-beaut analyser. I found it very useful with my triple carbies setting them up & by the reading could easily tell if there was a problem ie if engine spluttered a bit you could straight away tell whether it was shortage of fuel or excess of fuel, on a standard spec single carb motor they are little more than an interesting toy, but anything else they are very useful. On cars that are fitted with the sensor as standard (all modern EFI cars) the sensor is usually fitted centrally in the collector box area of the exhaust manifold as that is where there is the least restriction & it picks up the average mixture from all cylinders to send info to computor

http://www.competitiondata.com/air_fuel/pg2_wb_vs_nb.htm 
http://www.turbobits.co.uk/acatalog/digital_air_fuel_ratio_gauges.html  :thumb theres an error here in the text next to the wb graph :thumb

[ Edited on 16-11-2005 by lugnuts ]

[ Edited on 16-11-2005 by lugnuts ]