I saw on a YouTube video an item called a Power Coupler, installed with several other mods by the owner. It goes between the intake and the throttle body. According to the video, it eliminates the turbulence caused by the existing piece and feeds more air faster to the throttle body. It costs $20 from MidAmerica and supposedly gives additional 3-5 horsepower.

1. Is this worth considering or is it nonsense?
2. The existing coupler is held by two clamps. The back one is a conventional worm gear clamp, but the front one is not. How would I get it off or would it slide off as I remove the existing one?

 

Looks better than factory. Front clamp slides off. It's kinda a pain though. Hp claims may be questionable if that's the only mod.

 

More than likely you will end with a loss of 3-5 hp. The PCM has 96K of programmable data and the remainder is an Adaptive Strategy GM made during the early testing of the C5. By going to a smooth coupler you are increasing the velocity, slightly, of air entering the Throttle Body. The TB is smaller and will restrict the flow of air, slowing it down. Since the MAF had already adjusted the PCM on the air flow to go through the accordion coupler less gas will be used at the injectors and you will run leaner. Since the TB is the limiting factor for any benefit to be found is to have your PCM reprogrammed. When the early versions of the Veraram were introduced, they often experience stumbling/stalling on decel, the cooler air, ambient, air was more dense and had more oxygen going into the cylinder with lower amount of fuel going through the injectors. Later versions of Veraram eliminated many of these problems.

 

I've got a Vararam sitting around, that's why I'm hesitant to put it on. Had stumbling issues with a conical filter around 45 mph letting off the gas.

 

Seems to be some confusion here...

Unless there are "leaks" between the throttle body and the MAF - any flow modifications to the throttle body will in fact be seen by the MAF, I'm afraid physics prevents the amount of air between two sealed points from changing.

The PCM that calculates and controls how the engine runs actually has what is called fuel trim calculations it makes to adjust for changing conditions like weather and altitude which typically happen often and alters the normal airflow that comes into the engine. This can adjust for small changes in how the air flows into the engine like better air intakes and such. This is not an instant adjustment and takes miles of driving to "learn" and calculate the needed adjustments.

Now once you have started changing enough of the engine airflow characteristics and the PCM adjustments are taken to their limit they begin to have less accuracy and eventually hit a limit where it cannot adjust the fuel any further. This is where tuning comes in, where the computer adjustments are "zeroed out" by modifying the programmed tables with new data.

So generally speaking you will not lose HP from increasing airflow in any area of an engine because the computer has the ability to add more fuel itself based on how it is running.

How do I know all this? Because I tune these cars.

 

One of the problems you encounter in tuning is the C5 uses a 16 bit (1990 PS2) computer chip and eventually small changes can be smooth out to some degree, most Corvette owners will not have the patience for the 40-50 engine cycles for that to happen. The C6 went to a 32 bit computer and helped eliminate this problem. In our club we had several engineers who worked on the development of the C5 and C6 engine management software and that is what they they told us.

 

Those thing were good for carburetor engines as it help smooth out the air before it went into the carburetor.

On fuel injection it is a paper weight that lightens your wallet