So you're going to waste horsepower by increasing the load on your alternator to gain horsepower?

It'* all give and take, nothing for free.

Why don't you just keep things the way they are (the right way) and call it good?

Supposing that I have flying batteries above my car hooked up to a Shop Vac that sucks exhaust straight out of the exhaust ports, would I see a benefit?

And more realistically, does it make sense to imagine a highly heat resistant fan in the exhaust pipe that sucks exhaust gas out?

I like describing the process as water in a pipe, but the highway analogy works pretty well too.

One trick to getting a good basic exhaust system is to make an effort to have all the header tubes the same length between the flange and the collector. The rationale being that the velocity of the gasses comming out of each cylinder port are about the same, and since no two cylinders fire at the same time, each pulse of moving/expanding gasses hit the collector alone and have full use of the entire diameter of the pipe to expand in. That'* just a starting point though. The worst exhaust is the log styles with unequal lengths...they usually only work right in a narrow rpm range before the pulses start hitting each other.

Scavaging the exhaust gases out of the cylinders is good, but it is more a function of the camshaft and exhaust runners within the head rather than the header tubes. The best way I can describe this is a siphon hose... the expanding exhaust gasses behaves like a fluid..get it moving in the right direction and it'* own mass will keep it moving. This happens within the heads. It also needs an open intake valve to let air into the cylinder at the same time the exhaust gasses are trying to suck it out. (Overlap of the intake & exhaust cam lobes allows this to happen.) A good header system can promote it or kill it, but the action of scavaging the cylinders takes place at the exhaust and intake valves.

As a demonstration of exhaust scavaging, listen to the next rice rocket that passes you and downshifts into a corner...lots of time you can hear a popping noise in the exhaust note.. that'* the sound of scavaging the cylinders...not only is hot exhaust gasses going out the heads, but a little of the fresh mixture is getting sucked across the head and out the exhaust port too, lighting off inside the hot headers and making the POP! noise.

clm2112, that'* why you're the gearhead. Thanks so much! I think I now understand. I'll find some more stuff to read over time, I'm sure, but I should be good for now. Thank you all very much for your participation!

Now, does anyone know who makes good street headers for the '01 SSEi.

That'* a bit off topic, but the short answer is:

TOGs (The Other Guys)
SLP'*
PaceSetter (lowest quality, cheapest price)

That'* why I didn't notice a drop in torque when I removed my cat. I installed the TOG'* at the same time.

Well, does that mean I can put a 4" straight pipe out of the back of my catalytic converter? What if I put in a pipe so big and yet with enough clearance that it can fit a heat resistant fan big enough to provide some vacuum?

You crack me up Radomir.

Thank you, Paul. I just didn't have the heart.


Radomir, what exactly are you after? A larger exhaust diameter than BadSSEi for bragging rights?

Or do you want performance?