tooter's manifold adventure...

[Shinare]

^^^ RE: "long tube header" - Please forgive this noob question, it really is a question and not a troll, but why does it matter the length of a pipe? Don't you want the exhaust to just get out via the back of your car rather than in the engine bay?

[JustDidIt]

Originally Posted by tooter

Check out the header. LCE makes a really neato design that folds a long tube header into exactly the same space as the stock header. It fits like a glove!

Originally Posted by Shinare

^^^ RE: "long tube header" - Please forgive this noob question, it really is a question and not a troll, but why does it matter the length of a pipe? Don't you want the exhaust to just get out via the back of your car rather than in the engine bay?

Not my wording but makes sense:

Exhaust headers with equal length tubes have been shown to develop slightly more power on an open exhaust system, but not when hooked up to a street system with mufflers. Fact is, most street motors with shorty headers will produce the same power as they would with expensive equal length headers.

Equal length tubes can produce more power, but they have to be the right length for the specific motor at the RPM range where you want the power. What that means is lots of custom fabrication and dyno testing, which translates into lots of time and money.

For racing applications, the slight gain may justify the cost, but competition cars can be more easily built "around the engine" than street cars. When you're working within the confines of a given body style and chassis, with motor mounts, starter, steering linkage and accessories to think about, the way the headers fit become more important.

That's where the compact or "shorty" style header shines. You get a significant performance increase compared to stock exhaust manifolds, at an off-the-shelf price..

[tooter]

Originally Posted by Shinare

^^^ RE: "long tube header" - Please forgive this noob question, it really is a question and not a troll, but why does it matter the length of a pipe? Don't you want the exhaust to just get out via the back of your car rather than in the engine bay?

I just got it because it looks really neato.

[xnamerxx]

Originally Posted by Shinare

^^^ RE: "long tube header" - Please forgive this noob question, it really is a question and not a troll, but why does it matter the length of a pipe? Don't you want the exhaust to just get out via the back of your car rather than in the engine bay?

Its about exhaust scavenging. At a certain length and diameter, the exhaust pulse will create a sonic negative pressure wave at the valve creating a vacuum. That vacuum helps pull up on piston, clear out the cylinder, and suck fresh air into the cylinder. The exhaust itself still exits in the original location in most situations. On most otto cycle engines exhaust contributes to about 5-15% of the engines theoretical performance potential, on 2 stroke engines it can be as much as 40%.
In my case I picked up 7hp and 6 tq over a DC header with the long tube header I designed.

[CrankyOldMan]

Originally Posted by xnamerxx

In my case I picked up 7hp and 6 tq over a DC header with the long tube header I designed.

Is that design, by chance, available for the rest of us? I'm sure there's a thread, but I'm really lazy in the morning.

[xnamerxx]

Originally Posted by CrankyOldMan

Is that design, by chance, available for the rest of us? I'm sure there's a thread, but I'm really lazy in the morning.

Nope, spent a bit too much time with it to show off.

[tooter]

Who could forget the freaking awesome sound of your dyno runs, namer?

http://www.youtube.com/watch?v=fpkgkDjwHVg

I thought of your project every time I saw these.




But like you said, they only adjust for attitude, but not for length.

Had you come up with any other ideas to resolve the issue of engine arc travel? You seemed to be so close to a functional product.

[xnamerxx]

I did, it ended up being a bit of a compromise but a flex joint placed in the right place took care of that problem. So far I have 6+ momths of testing on the car and no failures to speak of(knock on wood).

The main reason I couldn't put it into production because I was never able to find a shop that I could get to mandrel bend the tubes for a reasonable cost. The total cost with labor and mending would have been well into the $1000+ range, so it didn't seem viable as something I could sell.

With all that being said I still don't get tired of the torque it produces, it almost feels like a jeep motor now.

[tooter]

I totally understand. New one-off products are always expensive. Could your header have a bung to accept the stock 02 sensor? And does it end before the stock cat? I'm just curious how much it alters the stock exhaust configuration. Oh, and does it hit anywhere under accel or decel?