Air/Fuel Meter and O2 Sensor, Keep that car in tune! Options

[Justinp71]

Well it seems that a good way to make sure your car is using the proper amount of fuel is to add a Air/Fuel meter, especially since few of these cars have modern computers. So I am looking at what options are available.

It looks like one option is to buy a kit from pelican:

http://www.pelicanparts.com/cgi-bin/ksearc...r=PEL-SW85-2437

Option 2: Use an 80-83 911 o2 sensor and add an aftermarket gauge...(Which I guess is similiar). I would like to use this sensor, b/c there is a chance I may use an 81 CIS system later on.

So... does anyone have any recomendations and/or suggestions?

[Gint]

We've been running an LC-1, with an XD-16 for about 3 years constant now
we leave it in and turned on for every single run, every single day

our tracks vary in altitude from 5,000 to 900 foot and we rejet for each different one.

it's interesting data actually and can pick up on things you would otherwise miss
3 weeks ago we went to texas for a 3 day weekend.
my Innovate told me something was wrong at full throttle as it started spiking lean intermittently

turns out I sucked an intake gasket slightly

you couldn't feel it by seat of the pants.
but you could see it on the guage.

I added the rare and often unused auxillary enrichment circuits to my IDS carbs this year and completely had to re-think my jetting. I could of never done this without the innovate. the car feels absolutely the same but I'm now able to keep my AFR from 12.5 tp 13.5 (1 full point) where I was only able to run from 12.5 to 14.5 (2 points) previously.

the LC-1 shows a double curve now that the car gradually leans out from 4,000rpm until about 6,000 rpm and then the auxillaries kick in (vacuum draw) and the car goes towards the heavier/richer mixture and drops from 13 back to 12.5 at 6K.... then gradually leans itself again.

You don't feel any of this
but you can see it

in fact on the first lap out it doesn't follow this pattern and runs lean for 1 lap
my theory is that the aux enrichments need to "prime" or build suction and it takes about 2 hard runs to redline before they are primed or full of fuel

I can watch the weather change on the guage
I run lean in the mornings and rich in the afternoons based on the change in ambient temp.

again you don't feel any of this
but you can read it on the guage and change your jetting

That's a great post. Thanks Brant.