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Are straight pipes bad???

71K views 24 replies 14 participants last post by  Colinwilke 
#1 ·
Yesterday I had nothing better to do so I unbolted the exhaust on my Triumph Daytona and WOW, I really liked how it sounded.

My question is: if I leave the muffler off and just run the straight pipe, is the lack of back-pressure bad for my engine???

Thanks guys
 
#4 ·
Problems I see

1. legal - not so much

2. If all you did is unbolt it and the remaining pipe is too short there is a potential to introduce cold air when you rap it up. Causing a sucked, bent, broken, or cracked valve.

3. By losing back pressure you COULD loose torque, and COULD gain high end HP. But most likely the first.
 
#6 ·
straight pipes arent that good for a bike, because when you let off the throttle, the sudden lack of hot gases being pushed out can cause cold air to be sucked in, which can damage your exhaust valves, and make for a VERY pricey repair.

police will DEFINATELY like to follow and stop you often too.
 
#9 ·
Thanks guys - I appreciate the responses. It sounds like the risks are more than it's really worth so i'll just leave the pipe on. It's got a Triumph Race muffler on it which is basically straight through...only a few baffles around the outside of the pipe, but i guess it's enough to makes a difference.

Thanks again!:dthumb:
 
#12 ·
straight pipes screw up two strokes too. two strokes NEED back pressure to run well. I've never run a two stroke anything and had good experiences with straight piping it.
 
#14 ·
i agree and disagree with the opinions in this thread. if you just take off your muff, then yea it could be harmful to your bike. however if its a actual open pipe full exhaust, then i dont forsee a problem. ive had a 4 into 1 open pipe on my bike for years, no problems whatsoever, and ive been in the engine to verify that. ive pulled up next to cops numerous times and if anything they just roll their window up. it will change your a/f mixture so you will have to tune for it. you lose some low end power, gain some high end. whether or not you notice it depends how you ride.
 
#15 ·
I understand dynce... even my chop is basically an open pipe setup. But you can create backpressure with pipe diameter changes and bends. However, I don't see that being the case with most rocket exhausts.
 
#16 ·
true, gotta go whole new setup pretty much, cant just drop the muff.

brocks performance and muzzy's makes some good open pipe setups for sportbikes tho-and they do come with baffles so "wide open" is an option in case you wana creep out at nite, or its just too loud for ya
 
#18 ·
now this is a VERY good argument. quieter bikes do less damage to hearing than a loud pipe will. I even notice a difference on a stock bike vs aftermarket muffler, let alone straight pipes.
 
#21 ·
straight pipe

hey dnyce.... i was readin bout wat u wrote about 4 into 1 pipe...i juss took off my muffler and cat converter off my gsxr 600.. i lost a little bottom end but feels like i picked up some top end (plus lost some wait)...i have a pipe running from my headers to the straight pipe and its damn loud...but is will it f*** up my bike....thanks for the help.....tryin to figure out the mechanics from you guys....
 
#22 ·
hey dnyce.... i was readin bout wat u wrote about 4 into 1 pipe...i juss took off my muffler and cat converter off my gsxr 600.. i lost a little bottom end but feels like i picked up some top end (plus lost some wait)...i have a pipe running from my headers to the straight pipe and its damn loud...but is will it f*** up my bike....thanks for the help.....tryin to figure out the mechanics from you guys....
 
#23 ·
Straight Pipes Bad? Yes

If you put Drag Pipes on, that is what U should be doing! Other wise you can waste your money putting Vance Hines Drag Pipes on and loose low end torque and will mess up your Gas Mileage. I did fix all of that when I purchased a 2004 HD Springer with those loud ass pipes on it. I bought baffels wrapped them in a heat blanket, or baffle material got 15-20 more miles to the gallon and great long hill pulling without shifting down it the mountains. And if you do your research you can damage your vales running straight pipes.
 
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