Off-Road Avenger: Tuning A Holley Truck Avenger For The Trail
Let me start by confessing that I am not a carburetor tuning expert. There are those skilled old timers that can tune a carb by ear and carry spare jets in their pocket. For the rest of us though, there is no need to be intimidated by a carburetor. We recently added a 770 cfm aluminum Holley Truck Avenger on top of the 460 engine and wanted to share how we chose the carb and the fine tuning we performed to make it work great on the trail. Note that we were not as concerned with maximum power potential as we were with crisp throttle response, linear power, and the ability to idle at any angle.
We’ll start with some carburetor basics and how they apply to the 4×4 world. We will focus on four barrel carburetors that are commonly run on V8 engines—if you have a four cylinder or six cylinder you are likely better off with a smaller two barrel carb, but many of the same principles still apply.
[portfolio_slideshow id=32177]
In my experiences, a stumble off idle (especially on a new Holley) is caused by the throttle plates being too far open at idle. This causes the transition circuit to be in use at idle. So, as the throttle plates open, the transition circuit doesn’t function, causing a momentary lean mixture and stumble.