[Tom Vaught]

Sorry for not posting lately on the Holley Carb thread.
I am getting a new Garage Door 18 foot by 8 foot to replace the HEAVY WOOD door that decided to fail after 50 years of service. "Piece of junk"/ NOT!!!!!!!

So I had to clean the garage so that the workers could remove all of the old garage door stuff and not damage the GTO (That means I had to figure out how to get it out of the garage the day of the Garage Door swap.)

So only one more step now. Garage Door Swap Day.

So I have time to post while they are building the door.

First topic for today is a little bit of carb history vs today's modern EFI
systems.

As the Emissions and F.E. Standards got tougher, Holley and other carb manufacturers had to get involved in designing Emissions Carbs to help the OEMs meet the standards.

One way that they did that was by using a "Feedback" system on the Carburetor to meet the NOx requirements. Feedback systems are also called "Closed Loop" systems.

With a "Closed Loop" system, the amount of fuel and air passing thru the engine is controlled by ENGINE DEMAND as well as air flow thru the carb venturis.
The "Closed Loop" systems were able to "balance" the components of the exhaust to allow a "Three Way Catalyst" to be used. To find out where they where in this "balance" they used a NEW TECHNOLOGY involving a Bosch Lambda Sensor (a Oxygen Sensor).

Now Holley had been using a Bosch PRO Lambda system to tune Holley Carb Performance Calibrations several years before the Emissions and F.E. Standards were in place. So the best investment you can make if you are tuning carbs for a living/FUN or Racing is to invest in a Oxygen Sensor Air/Fuel Ratio (Lambda) system.

The next "TIP" or comment is to talk about the Holley "Mile Dial" and "Quarter Mile" carb systems/Bowls that allowed you to change jetting on the Fly while driving down the road.

Davis Vizard, a well known Dyno Tuner, used his Quarter Mile Doal System to change jetting on the carb on the dyno without removing the fuel bowls. You could get about a 5 jet size change with the system.

That being said, most of the systems are long gone now.

A Road Race Guy (Silver State ON ROAD) racer type guy used a pair of the systems to tune a dual quad system for 150 mph dashes across the desert during the desert cool nights. Basically a NASCAR type application with no turns involved. Point A to Point B type racing. Today we have the Holley and Edelbrock Throttle Body/ Port Injection systems doing the same thing only better and used by the average Pontiac Guy on the street.

So the Holley parts have been there for a long time just much more 'sophisticated' now vs the old Quarter Mile Dial systems.

Tom V.