Baffles...
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Tourer
Joined: May 2015
Posts: 359
Likes: 56
From: Dallas
Baffles...
So I got an exhaust on my bike many months ago and It lost all its lowend torque but it seemed to cruise fine and I was just happy to not scrape anymore on turns. Then I got the 1200 put in and the guy who tuned it told me the exhaust was chocking the bike. I decided to tear the baffles out and run tti's and it ran like a freaking dream. rode for a few days like that but it got a bit too loud for me so I put the baffles back in thinking the added back pressure would help lowend torque and although Id lose a bit of sound I would be able to leave the state without worries of being pulled over. It now runs like a flaming bag of crap again so I can determine the baffles are just way too resticting but they do have a ton of dimples in them. I would show a picture but I dont have the bike at my place right now so I pulled up an example. My question is what would actually quiet the bike down a bit but not make it choke on itself?
EDIT: Solution on the second page.
EDIT: Solution on the second page.
Last edited by sawka; Jan 19, 2016 at 07:45 PM.
Seasoned HDF Member
Joined: Sep 2013
Posts: 6,174
Likes: 1,960
From: Great State of Canada
Taking from your post that its a baffle issue, and assuming thats indeed correct,?, I'd be tempted to try the cheap solutions first. Since you've nothing (apparently) to loose, take a drill to your existing baffles and open em up a bit. If thats not suitable, why not remove em again and try DK,s Thunder Torque inserts (lollipop baffles). They're dirt cheap so if you don't like them either you won't be out of pocket much.
I've got the TT's. They are aggressive sounding, but not like hollow pipes, and they do preserve torque.
I've got the TT's. They are aggressive sounding, but not like hollow pipes, and they do preserve torque.
Intermediate
Joined: May 2015
Posts: 49
Likes: 4
From: Kentucky, USA
Cut your baffles in half...or plop down the cash for a real exhaust system, Drag pipes sound cool but they kill performance unless your at 5+ grand on the tach.
http://www.harley-performance.com/harley-exhaust.html < check this out
Sonic pulse. Think of this as a shock wave. This pulse travels through the exhaust and at the end of the pipe actually turns around and heads back toward the exhaust valve. The wave will also pull exhaust gas back along its path and if it reaches the open exhaust valve the gases will dilute the air/fuel mixture in the combustion chamber. Under the right (or wrong) conditions this wave will even push some of the air/fuel mixture back through the intake valve into the intake, a common occurrence with short drag pipes. Torque cones can sometimes reduce this condition.
Thermal pulse. Similar to sonic pulse, this is a wave created by the hot gas exiting the exhaust valve. The thermal pulse also reverses direction at the end of the pipe but unfortunately travels at a different rate, thus reaching the combustion chamber at a different time.
Exhaust gas velocity. This is the rate at which gas travels through the exhaust system. The optimal velocity is 300 feet per minute. For the most part all stock Harley engines require a 1-3/4? diameter pipe to maintain 300 fpm. Bigger is not always better and a larger pipe will actually slow this velocity thus restricting flow.
http://www.harley-performance.com/harley-exhaust.html < check this out
Sonic pulse. Think of this as a shock wave. This pulse travels through the exhaust and at the end of the pipe actually turns around and heads back toward the exhaust valve. The wave will also pull exhaust gas back along its path and if it reaches the open exhaust valve the gases will dilute the air/fuel mixture in the combustion chamber. Under the right (or wrong) conditions this wave will even push some of the air/fuel mixture back through the intake valve into the intake, a common occurrence with short drag pipes. Torque cones can sometimes reduce this condition.
Thermal pulse. Similar to sonic pulse, this is a wave created by the hot gas exiting the exhaust valve. The thermal pulse also reverses direction at the end of the pipe but unfortunately travels at a different rate, thus reaching the combustion chamber at a different time.
Exhaust gas velocity. This is the rate at which gas travels through the exhaust system. The optimal velocity is 300 feet per minute. For the most part all stock Harley engines require a 1-3/4? diameter pipe to maintain 300 fpm. Bigger is not always better and a larger pipe will actually slow this velocity thus restricting flow.
Thread Starter
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Tourer
Joined: May 2015
Posts: 359
Likes: 56
From: Dallas
Sorry for being vague but I'm on my phone right now. I should have been more clear in the original post. The tune was the generic stage one from Harley. There aren't any dyno places around here I've found except a dealership so I decided to pass till I find a real shop. I do in fact have dk's thunder torque inserts and using them alone I got a bunch of decel pop and it was rather loud but it ran great. I am running "Santee holeshot" exhaust. I figured running then thunder inserts with a small free flowing baffle would probably do the trick but I'll try drilling them when I have a chance to work on them if that's the best solution.
Thread Starter
|
Tourer
Joined: May 2015
Posts: 359
Likes: 56
From: Dallas
Cut your baffles in half...or plop down the cash for a real exhaust system, Drag pipes sound cool but they kill performance unless your at 5+ grand on the tach.
http://www.harley-performance.com/harley-exhaust.html < check this out
Sonic pulse. Think of this as a shock wave. This pulse travels through the exhaust and at the end of the pipe actually turns around and heads back toward the exhaust valve. The wave will also pull exhaust gas back along its path and if it reaches the open exhaust valve the gases will dilute the air/fuel mixture in the combustion chamber. Under the right (or wrong) conditions this wave will even push some of the air/fuel mixture back through the intake valve into the intake, a common occurrence with short drag pipes. Torque cones can sometimes reduce this condition.
Thermal pulse. Similar to sonic pulse, this is a wave created by the hot gas exiting the exhaust valve. The thermal pulse also reverses direction at the end of the pipe but unfortunately travels at a different rate, thus reaching the combustion chamber at a different time.
Exhaust gas velocity. This is the rate at which gas travels through the exhaust system. The optimal velocity is 300 feet per minute. For the most part all stock Harley engines require a 1-3/4? diameter pipe to maintain 300 fpm. Bigger is not always better and a larger pipe will actually slow this velocity thus restricting flow.
http://www.harley-performance.com/harley-exhaust.html < check this out
Sonic pulse. Think of this as a shock wave. This pulse travels through the exhaust and at the end of the pipe actually turns around and heads back toward the exhaust valve. The wave will also pull exhaust gas back along its path and if it reaches the open exhaust valve the gases will dilute the air/fuel mixture in the combustion chamber. Under the right (or wrong) conditions this wave will even push some of the air/fuel mixture back through the intake valve into the intake, a common occurrence with short drag pipes. Torque cones can sometimes reduce this condition.
Thermal pulse. Similar to sonic pulse, this is a wave created by the hot gas exiting the exhaust valve. The thermal pulse also reverses direction at the end of the pipe but unfortunately travels at a different rate, thus reaching the combustion chamber at a different time.
Exhaust gas velocity. This is the rate at which gas travels through the exhaust system. The optimal velocity is 300 feet per minute. For the most part all stock Harley engines require a 1-3/4? diameter pipe to maintain 300 fpm. Bigger is not always better and a larger pipe will actually slow this velocity thus restricting flow.
Edit: they are the quiet version of the TTIs
Last edited by sawka; Jan 12, 2016 at 07:59 AM.
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Seasoned HDF Member
Joined: Sep 2013
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From: Great State of Canada
"Note to self, read before posting" ! 
Apologies, I missed that you were using TTI's already. I dunno if there's a huge difference but there are a couple of models of TTI. Have you considered trying the ("quieter" ???) set ? The guys at DK are pretty square shooters. I personally would trust what they had to say on the matter,,,, but I'm Canadian
.
Apologies, I missed that you were using TTI's already. I dunno if there's a huge difference but there are a couple of models of TTI. Have you considered trying the ("quieter" ???) set ? The guys at DK are pretty square shooters. I personally would trust what they had to say on the matter,,,, but I'm Canadian
.
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Club Member
Joined: Jun 2007
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From: Bedford UK
Your pipes are just fancy drag pipes. In the notes that PaPaBlista gives above there is an omission, which is that every vehicle on the planet, with two or more cylinders, comes with an integrated exhaust - in other words the exhaust outlets from the cylinders are joined together in some configuration. Your bike had a balance pipe when it was new, for a jolly good reason, which is that the exhaust from each cylinder is used to boost the performance of the other cylinder. That gives us improved low/mid range torque. There isn't a way of restoring that with separate pipes, which will get into their stride at high revs.
Thread Starter
|
Tourer
Joined: May 2015
Posts: 359
Likes: 56
From: Dallas
Your pipes are just fancy drag pipes. In the notes that PaPaBlista gives above there is an omission, which is that every vehicle on the planet, with two or more cylinders, comes with an integrated exhaust - in other words the exhaust outlets from the cylinders are joined together in some configuration. Your bike had a balance pipe when it was new, for a jolly good reason, which is that the exhaust from each cylinder is used to boost the performance of the other cylinder. That gives us improved low/mid range torque. There isn't a way of restoring that with separate pipes, which will get into their stride at high revs.
Had I rode that hard during the test ride and knew the scraping was an issue I would have immediately gone to a triumph dealership and picked up a Bonnie instead. But I got the bike to where I enjoy riding now without scraping except for pegs, which isn't too often or unexpected, and now I just need to sort the exhaust volume issue out and I'll have my dream bike setup.
Last edited by sawka; Jan 12, 2016 at 08:14 AM.