[jim_howard_pdx]

Loud is a function of noise cancellation done by the muffler, not by the exhaust tube diameter.

You can go 3" 4" or 5" pipes and still be as quiet as stock. You just have to use a stock/restrictive muffler.

As you add horsepower, you do create MORE exhaust and sometimes the unburned fuel will continue to burn in the headers as the fumes exit the combusion chamber. That happens in all my high overlap engines, and it will make for a really weird exhaust noise if you try to use regular mufflers. They will eventually blow out as they collect fuel and then explode......

We used to run Chrysler Hemi mufflers on our big blocks in the 70's. It would be a little more rumble than a stock exhaust, but it would sound really tame. But the things were made to exhaust a 435 hp engine, so the flow and the backpressure were great for a street ride. I know several muffler shops that highly recommended these before the delta flow style flow tech mufflers came around. Now everyone is back into LOUD.

I am using Edelbrock's RPM stainless mufflers and they are a good mix between loud and soft. The chrysler hemi mufflers are quieter and I feel they flow just fine for a street car.

Again, the X flow or H pipes by themselves do not make the exhaust LOUDER. They just allow it to all flow better. Muffler choice is where the LOUD can be tuned up or down. The quieter you go, the more top end horsepower you lose.

The best of both worlds is an exhaust system cut off, run quiet through the mufflers, or switch to open exhaust when at the track. This is a really fun way to go, but adds about 200 dollars or so to your budget and if you try running the bypass on the street, the ticket can be upwards of $350.00.