Anyone know what the best AFR guage is and how do you install it, I've seen the Dawes Device and the K&N one but there must be more choice than that.

 

K&N? Don't believe they make AFR meters!

Of the ones I've seen, the Dawes gets it closest thanks to confining itself to the voltage range you really need to see, and using a high enough resolution, although its values are a little high for my preference. Many of the others have too many LED's, and cover too wide a voltage range - thus losing the resolution necessary in the 0.8 to 1 volt range.

TBH, the "best" AFR meter you can get is probably as simple as an LM3914 LED display driver, a handful of LED's and a couple of potentiometers, less than £5 from RS, Maplin, Farnell and so-on. A fraction of the cost of the commercial units, and not only can you install it where you like (mine's integrated into the instrument cluster and looks OE), you can set it to read whatever values you like.

If you're up for a bit of DIY, have a look at John's post here.

 

Technically speaking, the "best" AFR meter should display genuine widerange lambda data, using a proper widerange lambda sensor rather than just tapping into the cars regular narrow band sensor.

 

ive got this one

 

best or the most expensive

 

Or neither.

 

The cheapest DIY AFR kit can be obtained from Jaycar and does the job very well. It uses the parts Greasemonkey described, and comes delivered in the post for just over £12. Easy to mount as Greasemonkey described.

Les