You should do it. If there shop is 300 feet long they must be good! [sm=laughat.gif]

 

the need for back pressure is a myth for the most part.

if you want to learn more about why it is i recomend u go pick this book up from the store and read it. David Vizzard book, How To build Horsepower.

 

I say go for it. At least someone is willing to try and make improvements to their bike. If he gets it wrong, he can start over. Why are you guys so cynical?

I say, it ain't your's until you crash itand customize it.

 

The way I see it, It may cost me about $150 + $190 forthe harnesswith the cut-out. wtf people? Even if i dont gain anything atleast im trying.

pciii has that harness for $190 and has something like the msd ignition to open/close a relay or whatever by rpms/throttle.It does a LOT more though.
Here isthe link.http://www.powercommander.com/powerc...ction_hub.aspx
I know half of you are just telling me to not waste my money and buy a full system.. And if this doesnt work then I will. I'm only going .25 over stock pipe size. Like I said i'll dyno before and after. even if i build 3 of them costing 150 thats only 450. how much is a full system?

If I can get any improvement i'll give you guys the info to get one done in your area.

 

I like how you only try to make fun of how large the building is. How many local custom exhaust shops are that large? They have serious money invested into exhausts, and thats all they do. They arent far from PR - Pacific Raceways. Used to be called sir - seatlle international raceway.

 

I never said they raced f4is. i said bikes. along with about everything else...

 

my point is,I understand they are an exhuast shop, and they build all kinds of exhuast. but the proof is in the pudding. how many other bike exhausts have they built, tested, modified, and retested? If they are mainly for cars and stuff, or choppers, straight flow through headers will work. How effecient you think "jesse james" exhausts are? they look cool, he built them himself, and the bike runs. but I dont think thats the type of thing you are looking for, but that may be what you get for a 150

Also, if you have to have it rebuilt 3 times, and spend 450$ on new exhuasts. whats the harm, its cheaper than a full system?.true,but,a couple of people have mentioned that you could do harm to your motor. How much is that going to cost to correct?

I just think, that with all the time andmoney that race teams pour into exhuast systems, you are going to be hard pressed to get anything even remotely close for $150.
If your not cheap, as you stated, why not just buy the tested and proved exhaust systems? And get more "bang" for your buck.then satisfy your creative custom ideas for something a little less.....of an exact science. I am all for custom work to make your bike "yours", but I think this may not it.

but, if your dead set on doing it, do a little more research. asthe fact that you dont even know what material they are made of tells us that you have not researched exhausts nearly enough to do what you are wanting to do.

 

the "How to Build Horsepower" is directed towards cars, no back pressure isn't nearly as important to cars as it is to sportbikes because our engines HAVE to be a lot more efficient and the valves and engine parts take much more of a beating (how many cars do you have to rev to 12,000 RPMs to get maximum power???) the theories are the same for cars and bikes but thats where it ends, why do you think there are so many car exhaust shops??? because cars aren't nearly as picky and you can gain power just by making the pipes bigger, wouldn't it be nice if it were that simple for bikes... but its not, sportbikes already have very efficient exhaust systems (minus the can of course) and to make more power exhaust manufactureres spend weeks to months designing, testing and tweaking exhausts to squeeze a few extra HP out

if you want to do it, have fun
all I'm saying is don't expect to gain a bunch of horespower (or any at all)

 

the principles of building a car engine and motorcycle engine are the same. what alows a motorcycle to rev to 12,000 rpms is the fact that motorcycles engines have less moving mass of pistons and connecting rods. and some race cars have extremely high rpms. how many big block engines do you see that run at the same rpm of a 4cyl car engine? does that make them any more fickle or more likely to damage? but this is besides the point.

the idea behind the lack of back pressure which is the issue at hand here is that it damages the valve this simply is not true. the fact that an engine redlines at 3000rpms or 18,000 rpms are irrelevant the exhaust system and valves work the same way

i want you to explain to me why back pressure is needed in a bike besides saying a bike engine is so picky wood.
i relize that bikes are made to run efficiently from the factory but if he want to build a set of headers what do u car as long as he wont destroy it.

the comparison to car muffler shops is silly i mean no disrespect to you when i say that. why are there so many car muffler shops then bike muffler shops? well for starters how many cars on the road compared to how many bikes. and ill bet you wont find to many car muffler shops to build you a set of custom of headers either.

if you have any legitimate information to read to prove your point that goes into detail ill be glade to read it. or even willing to discuss your argument besides saying that it runs at 12000 rpms and it’s a fickle motor.

I don’t mean any disrespect to you either woody

 

I am not making fun of the size of the building. I am making fun of your comment. Does the size of the building make them good at what they do. No.
Who ever told you at that shop they could make a header that would make more or better power than your stock header does not know what there saying. A muffler you can do anything with. A steel tube with a bolt going threw it can work as a muffler. But headers are not the same.

Have fun trying to tune it once you get your header on. A power commander will not be able to do it. What shop is this in Washington state.

I don't know why you are getting so upset. People are just giving you there opinions. In the end it's your bike, your money, do as you like. But maybe you found a shop that can make a $150 dollar header that makes more power than name brand headers.
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$150 dollars for custom header.

$300 dollars for 2 hours on the dyno.

A look on the customers face, as the guy on the dyno revs his bike past 10 grand, then lets off the throttle letting the bike decelerate, watching up close and personal as the bike sucks a valve.

PRICELESS.