RyansQuick6 – Fellow Mod, I agree with you. In the old days of carburetion, I experimented with carb spacers and even occasionally a ‘Tunnel Ram’ setup with some Holly carbs. The benefit being: Having two carburetors on a tunnel RAM system provided a greater mixture of air and fuel and control of the ratio of air to fuel as the two are introduced into the plenum. The cylinders of the engine, which feed directly from the plenum, performs best when the fuel and air are evenly mixed and absorbed. This was also the basic theory of putting spacers in the intake path. Unfortunately, the tradeoff was; due to the longer path the fuel air traveled, the throttle response was slower as it took longer for the fuel air to reach the cylinder.
Now let’s look at our CT’s. The 3.5L engine is a MPFI (Multi Point Fuel Injection) engine. This engine needs no real mixing of the fuel air, it’s MPFI. That means that there is one fuel injector for each cylinder. Using a throttle body spacer, which is 0.75 inch thick cannot possibly do anything (by itself) to increase horsepower or MPG. Because these spacers come equipped with a 1/8th inch NPT threaded port, which is the standard size for nitrous applications, these spacers were probably left over parts from some nitrous manufacturer.
You have to keep going back to the manufacturers mindset. If this spacer really worked, don’t you think that Honda would have these on every car? HRC (Honda Racing Corporation) has some of the best engineers, research, and test equipment in the world. Even though HRC works mainly with the motorcycle line of Honda, some of their technology does funnel down to the Honda cars. HRC is a wholly owned subsidiary of the Honda Motor Company Inc.
Dyno tests have proven that these throttle spacers make absolutely NO DIFFERENCE in HP or MPG.
Picture of a 3.5L engine with the spacer installed.
To summarize: RyansQuick6 hit the nail on the head – Total Scam.