did you drill out your seats from the .093 to .110? it does seem that the 4972/4973 air metered carbs run a lot harder with a lot less mods than any other production t-quad.

I had the car out last night. The jetting modifications worked just right. I made 5 passes and the A/F ratio was 12.7. The car picked up .05 in et and .5 mph. The weather was almost the same as last week, but the track was terrible. I spun on two of the runs. I did not get a chance to try openning or closing the air door because I ran out of time.

I'm not worried about the carb being rich at idle, I'm worried about it being right at full throttle. We were running metering rods that were .051 at the end and the primary jets were .091. That made the openning .040. I will start out with #71 Holley jets and go from there.

The carb is a 9077 and was built by a shop in St Louis. I don't know much else about it.

Thanks for the responses and suggestions. I made two passes at 11.87 and since my index is 11.85 I plan to go to the Division 7 race the end of the month. I have a set of radial slicks on order. I tied a set before and they were 1.3 faster then bias tires on my car. I'll probably be the lowest qualifier on the ladder, but at least I'll be able to dial the index or lower so I'll have a bit of a chance. I'll let you know how it runs.

Raul

Anyone ever try making an adjustable stop for the upper limit of the metering rod tree? Couldn't you fab up a small threaded stop so at WOT the tree wouldn't go quite all the way to the top of it's travel? I would think that would allow you to tune the primaries leaner without pulling jets or rods...?

Secondary spray-bar work ?

... my thoughts? .. I was going to add MORE but SMALLER holes(in new tubing) ... for better atomization of the fuel.

A miss-fire will never show rich on an O2 sensor because it measures oxygen not fuel. If it miss-fires it won't use any oxygen so the sensor will actually read lean.

Kevin

Interesting thoughts......