exhuast pipe home made and fmf performax help!!

[jorge_sublime]

hello. I'm putting together a homemade stainless steel exhaust. but I have some doubts, q diameter tube manifold to use? 1 3 / 8 inch think strategic q right? or would be better to 1 3 / 4 inches? ayuendeme please. Q muffler I use is a fmf Performax. was an old xr 600.
anyone know how it works inside the pump fmf powerbomb? please help in the election, I will pay homemade tig. q is the most recommended. thanks.

here in Argentina a powebomb fmf pipe does not go less than 340 dollars. the oem not sold. q so that's why the decision to put something home made. if you have any extra advice please say ...

 

[jorge_sublime]

nothing?

 

[MotoArts]

1-3/8" should be more than fine.

Larger diameter will lose exhaust gas velocity and hurt torque a little. That small engine can't turn enough RPM to take advantage of large tubing.

 

[jorge_sublime]

gracias.si 1 3 / 8 is more like the original, I q I will use this measure.
more advice? long? the curve? by q vi q could be more direct in the warrior. mantega I would help me or how long the original? I'll just start uploading pictures of how to do.
please advice or action is to be welcomed

 

[MotoArts]

I would think that a more gentile radius (smooth curve) would have more of an effect than overall header length.

I question the value of changing the complete exhaust system, as compared to a slip on, especially in a near stock engine. To me, the stock header looks to have nice bends. A slight increase in diameter is probably where the power increase comes from on a modified quad and a complete system. Remember, the head is only 2 valve, and has a restrictive exhaust port to begin with.

I would look at several complete systems and try to make similar bends and routing for your head pipe.

 

[jorge_sublime]

if I start getting ideas of how. q 1 3.8 and decided it seemed to me much more, with the curve respexto then the most desirable is a rather broad? ..
I was looking to do the kind of fmf powerbomb. but I have doubts about how is the fmf pump. anyone know? is only as a pre-chamber on the exhaust? Camera pre tb eh seen apart. gain some extra power?

 

[MotoArts]

In my years of seeing 4 cycle exhaust systems on everything from race cars to tractors, I have never, ever, seen any "pre chamber" in a system that has proven to be worth anything. Any slowing, then re-accelerating of exhaust gas velocity simply causes reversion (basically "stalling") of the flow.

Two cycle engine... now that is a somewhat different story.

Yes, it looks nice, but I'd pass on the 'Bomb.
I could be way wrong, but it's just my opinion.

 

[jorge_sublime]

ok excellent. q is seeking opinions and advice! =).
I'll get started making pipe in 1 3 / 8. is the same as the original. someone has a fmf powerbomb? known diameters measures etc?.
am beginning to assemble the pipe. looking for information on how is the bomb inside. tb data but found several different versions of how it is. seems only a recovery chamber, some say as a glasspack inside. etc.
I am taking photos and climbing. if they put other system does not please I'm interested oem diameters measures. and thanks for the data.

 

[jorge_sublime]

anybody more data?

 

[jorge_sublime]

please! help, I'm still in doubt as to use tube. here alone with 1 1 / 2 inches. but it is a little girl q's original warrior, and my other option is, 1 3 / 4 inches but I see it much bigger and I have fear q subtract power from the engine.
forum search did not find much information really can help me q, q lei a forum fmf powerbomb pipe diameter is less than q the original factory. diameter which is that someone would know tell me?
and if any advice, I live in Argentina really is very costly here 400 350 dollars, and the change in my country is so much money. if not I recommend always remembering q q only 1 1 / 2 1 3 / 4 q are the tubes I can get. Thanks in advance

 

[3504life]

This sounds like a lot of work for no reason just use a stock head pipe. I have never used/ seen the powerbomb but I'm thinking/ guessing the little bubble in the middle of the pipe is just like an expansion nothing inside then back to stock pipe size that creates Venturi which kinda sorta helps with flow. But it also creates back pressure

 

[jorge_sublime]

I do not get the tube stock, in fact very expensive = q a powerbomb, and costs a lot where I live (Argentina Buenos Aires) to get it. so I got in this draft handmade exhaust.
my big problem with it not q, q tube diameter the same factory, just 1 1 / 2 inches, and q is smaller tube factory. or 1 3 / 4 inches but it is larger q tube factory. I feel great. I read many forums talking q q exhaust valve diameter equal output. q but does not really do.
why would mimic the powerbomb or make a new exhaust but rather q q work with the materials I have at my reach. ideas need more advice please. realmete much they would appreciate

 

[jorge_sublime]

I kept looking good info, and come to this http://www.freepatentsonline.com/7506722.pdf. but I still need to pump my doubt about the diameter of the exhaust outlet of the cylinder. q many say should be the same diameter as the intake manifold? if so 1 1 / 2 inch would run em right? The largest stock is about 40mm. please. I want to get this question so I can get started to be welded and uploading the photos to go through all aa greetings

 

[jorge_sublime]

...nadie sabe?

 

[jorge_sublime]

header finish look my pictures, its my homemade power bomb fmf =),