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Holley Carb Truck Avenger - Off Road Avenger - Tested

Posted in Product Reviews on July 1, 2002
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Photographers: Cole Quinnell

Our jobs here at 4-Wheel & Off-Road allow us to do some pretty cool stuff. We get to meet the big names of the auto industry. If you see us out on the trail we're getting paid to be there, and we get to lay our hands on tons of cool new parts months or even years before the general population gets to. And every once in a while, we get to voice our opinions as these products are being developed. Such was the case with the Holley Truck Avenger.

Many months ago, Holley Vice-President of Marketing and Sales, Butch Bass, asked if 4-Wheel & Off-Road would like to evaluate a few prototype off-road carburetors that Holley was working on. Holley wanted to enter a carburetor into the off-road market and wanted to get it right the first time. We agreed, and a few weeks later found ourselves in triple-digit heat flogging three horribly performing carburetors. We ran each one through its paces while taking tons of notes on every aspect of their performance. Then we boxed up the carbs and our notes and shipped them back to Holley.

Visions of hitmen in Holley logo shirts coming for us swirled in our heads because of the way we trounced the prototypes. Instead, Holley was receptive to our findings. Finally, some months after we shipped back the prototypes we received the finished version. Now, we give you the new Holley Truck Avenger.

What's New for Off-Road
The new Holley carburetor employs a lot of new technology that was developed specifically for this application. For one, the vent tube is one piece to help prevent fuel spillage in rough terrain and at angles. Also, the metering blocks have been redesigned to operate at angles of up to 40 degrees while climbing and 30 degrees during side-hill and nose-down descents. The needle and seats are spring-loaded from the factory, the fuel transfer seals have been upgraded to Viton to resist leaking, and clear sight plugs come standard. There's a quick-change vacuum secondary cap for, uh, quick changes, and an electric choke is standard. The big news, however, is the new annular booster design that increases low- and midrange punch. Holley says that the new booster design works so well it may be introduced into its street carburetor models. Finally, technology developed for the off-road market is crossing over to other areas and not the other way around.

Performance Impressions
We guess the biggest compliment we could pay the new Truck Avenger carburetor is that it wheels nothing like a Holley carb. We'd say the Q-Jet had better keep one eye pealed behind it because the new Truck Avenger is poised to steal its thunder.

Climbing: This carburetor loves it when the vehicle's nose is pointed skyward. We put it on a few dramatic climbs with the nose at 45-50 degrees and the engine just chugged along without loading up at all. Likewise, during steep hillclimbs under throttle with the engine spinning at a moderately high rpm, the carburetor performed seamlessly.

Side angles: Once again, we put the vehicle on a side angle of about 35-40 degrees and the carburetor just idled all day long. The carburetor seemed to work a bit better when the vehicle's attitude was nose-high. When the nose was lower than the rear and the vehicle was on a side angle you could hear the engine begin to run a bit rougher, but it didn't seem in danger of stalling.

Descents: This proved to be the carburetor's only weakness. When the nose of the vehicle is pointed down at an angle of 30-35 degrees, the carburetor will begin to load up the engine ever so slightly. Increasing the angle beyond about 35 degrees allows the engine to load, run rougher, and eventually stall. However, we have to note that this happened with most Q-Jets we've driven as well.

Rockcrawling: Whether in low range or high range, the engine didn't stall approaching obstacles and we were able to drive with as much finesse as we could muster. The carburetor allowed very good slow-speed control.

Whoops: The spring-loaded needle and seats must be doing their job because we experienced very little bog in the whoops. When things got really nasty there was a bit of stumbling and hesitation, but once we made it to a less-harsh section the engine recovered quickly and smoothed out.

Sand: This is where the power test comes. We noted good seat-of-the-pants feel with only a slight loss in higher-rpm power compared to a Street Avenger.

Bottom line: We think Holley got it right. The Truck Avenger seems to work every bit as well as a Q-Jet in most circumstances and even better in some. Do you smell a heads-up shootout in the making?

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