straight pipe

[Joe Dirt]

Any straight pipe is gonna be too loud. A smaller one might be even louder than a larger one.

Remember our B3 was built for economy. Being loud and slow is embarrassing. You're also gonna lose some low end torque probably which is where all the economy is. You don't get good gas mileage when all your torque is over 4000 rpms.

mine seems to get good milage

[bhazard]

"Good" is relative. What is good to you? I averaged 48 mpg while I had the b3, and had a best of 53. I thought that was "good". Metro XFi's can get well over 60 mpg though regularly. To me thats gooder.

If youre only getting say, 40 mpg, that may be good to you but thats not that good to me.

[Joe Dirt]

"Good" is relative. What is good to you? I averaged 48 mpg while I had the b3, and had a best of 53. I thought that was "good". Metro XFi's can get well over 60 mpg though regularly. To me thats gooder.

If youre only getting say, 40 mpg, that may be good to you but thats not that good to me.

i average 44 in town running it like a raped dog, 47 on the freeway at 75

[Pocket_Rocket]

^ you want to remove all the mufflers then ask if its going to be loud? Do you understand what a muffler does & how it does it?

As far as size I have 2in from the header back. I really dont know whats up with the idea of loosing torque with a less restrictive exhaust. I was running with an open header for a month and sure didn't feel like I lost any power, hearing maybe, but no power loss

It's all about scavenging. Imagine a flow of water, from your sink for example. Put a small hose on that, and the water will come shooting out at high speed with a high pressure because of the restriction. Put a stove pipe on there and the water will come slowly trickling down, because of the low pressure. So the faster the water goes, the more inertia it has, like the burnt gases from your engine. The faster it goes, the more it's going to create a "scavenging effect" in the combustion chamber when the exhaust valve opens, kind of like a chain of people holding hands, on top of a water slide; if one goes down the slide it's gonna pull the next one, and the more people going down the slide, the faster it's gonna pull the ones at the top down. So if your burnt gases are travelling fast enough, it's going to pull out the dwelling gases from the combustion chamber, leaving room for fresh air and fuel, and since the intake and exhaust valve opening often overlap, it's going to help you pull more air in the cylinder, so more power. Of course, the goal is to find that perfect balance between flow and back pressure. Well for a N/A car at least; turbo cars are another story...

[Aspire SVT]

i lost all of my low end torque due to my 2.25 mandrel bent stainless, catless exhaust. should prove useful for the B3+T project buts as for now its doggy, almost seems like boost because you can feel the torque curve come back at around 2500-3000 rpm.. it seems like my scavenging went to hell because the wide bands reading around 13.8 on a low end accel