The only comments I don't really agree with are those that say I didn't gain any power. While I'm sure it the stock system flows very well, the two resonators and mufflers have to do some restricting. The difference may not be noticeable, but I bet if I threw the car up on a dyno, I'd see a subtle increase in my numbers.
I'll take your bet. How much do you care to wager? I've done it. I agree that they (resos and muffler) theoretically do some restricting, but not until the power level is north of 300 whp. They do not restrict the maximum exhaust flow from the K04 turbocharger our engine uses. North of 300 whp, the restriction is not really the presence of resos or the muffler, but the diameter of the entire system -- it would need to be enlarged to 3 inches.
It has to to with the CFM flow rate of the CBE. If it flows a higher CFM than the turbo exhaust outlet can push out of the engine, the exhaust piping, resos and muffler are basically invisible to the engine. We have a very small turbo and it can only flow a certain amount of air in on the compressor side and a certain amount hot gasses out on the exhaust side. This is finite.
When I went catless DP/RP, I conducted an experiment and dynoed with and without the CBE connected. I just let the CBE hang loose. Got the same numbers within the margin of error -- actually the CBE produced 1 hp more and 2 lbs of torque more, but that is all within the measurement margin of error.
As an engineering student, you might think about the flow output from the K04 turbo exhaust. It is a finite maximum flow rate at full boost. If there is no restriction upstream of the CBE (I have a 3 inch catless DP/RP), would you not agree that if the downstream pipes flow a higher rate than the flow of the gasses they receive, there is no power loss?
Think about this:
1. Blow into a soda straw as hard as you can. You can feel the restriction, because the pipe can only flow a CFM much lower than your lungs can exhale.
2. Blow as hard as you can into a large auditorium room - exhale as hard as you can. There is no restriction. None.
3. Now make the room smaller -- say half that size, or a third that size, or a quarter that size, or 1/10 the that size. The room can still receive your maximum volume of exhaled air with no restriction.
4. At some point as you decrease size you will eventually encounter a small enough space that a restriction will take place.
With our K04 turbocharger, the stock CBE, even with resos and muffler is still larger and flows at a higher rate than the maximum output from the turbo. So no gain by removing it.
Some other exhaust on some other vehicle with higher gas flow, might produce a different result. Or, if you ever go to a higher flowing turbo upgrade like one the Garrett turbos offered by some of our vendors, then, yes, you would need to step up to a CBE that would flow better.
Care to wager? If I'm wrong, you'd have the cash to buy a good textbook on theromdynamics.
Sorry to have to disagree.
