need help , have problems with true duals
Thread Starter
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Tourer
Joined: May 2008
Posts: 439
Likes: 1
From: Spain (Europe)
need help , have problems with true duals
hello.
I have a 09 rkc. I used to ride with stodk non cat headpipe, kerker mufflers se ac and sert.
I didnt like the sound of the oem 2-1-2 headpipe. didnt like the look at all for a classic so I went with bub7 true duals for 2009. I run a sert custom map with 1-1 throttle response (trying to imitate cable throttle response)
bub7 TD look great in a rkc BUT:
I have lost a lot of torque in low rpm (I know you lost low rpm torque with duals but I lost TOO MUCH)
kerker muflers used to sound allright (deep, medium loudness) now the sound way too loud, so loud that I started 2 cars alarms while ridding.
I feel the bike has no backpreasure, when I hit gas the bike seems to acelerate but this only last 1 second, inmediatly looses torque. I had a much better performance with stock headpipes.
my question is, Is it possible that bub7 true duals headers changed SO MUCH the response and sound of the bike?
how is it posibble that the sound at iddle remains almost the same but when I hit gas the bike is loud as hell?
anybody with bub 7 true duals headers and supertrapp or kerker mufflers had the same problem?
Thank you for your help
I have a 09 rkc. I used to ride with stodk non cat headpipe, kerker mufflers se ac and sert.
I didnt like the sound of the oem 2-1-2 headpipe. didnt like the look at all for a classic so I went with bub7 true duals for 2009. I run a sert custom map with 1-1 throttle response (trying to imitate cable throttle response)
bub7 TD look great in a rkc BUT:
I have lost a lot of torque in low rpm (I know you lost low rpm torque with duals but I lost TOO MUCH)
kerker muflers used to sound allright (deep, medium loudness) now the sound way too loud, so loud that I started 2 cars alarms while ridding.
I feel the bike has no backpreasure, when I hit gas the bike seems to acelerate but this only last 1 second, inmediatly looses torque. I had a much better performance with stock headpipes.
my question is, Is it possible that bub7 true duals headers changed SO MUCH the response and sound of the bike?
how is it posibble that the sound at iddle remains almost the same but when I hit gas the bike is loud as hell?
anybody with bub 7 true duals headers and supertrapp or kerker mufflers had the same problem?
Thank you for your help
Advanced
Joined: Oct 2009
Posts: 61
Likes: 1
From: Powell, OH
Same problem with V&H True Duals
OK, I have the V&H true duals and I noticed the same thing . . . lots of torque lost.
How it was explained to me is the scavenging. When you move to true duals, you lose the scavenging . . . especially the scavenging of the front piston by the rear one. Thiels Wheels explained hence why the 2-1-2 or the 2-1 is so much better . . .
How it was explained to me is the scavenging. When you move to true duals, you lose the scavenging . . . especially the scavenging of the front piston by the rear one. Thiels Wheels explained hence why the 2-1-2 or the 2-1 is so much better . . .
Road Warrior
Joined: Apr 2006
Posts: 1,469
Likes: 0
From: 310
I changed over from the stock 2-1-2 to V&H dressers and didn't really notice any loss. I did however have another map (PC-V) in hand for "duals" with my set up but never loaded it. I kept the same tune I had and I had no issues and didn't notice any loss. After that, I did take it in for a Dyno tune which made it run better in the low end and louder.
Maybe you need to have your tune redone?
Maybe you need to have your tune redone?
Thread Starter
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Tourer
Joined: May 2008
Posts: 439
Likes: 1
From: Spain (Europe)
I have re-tuned the bike after installing true duals and have no better results.
I Love the look of true duals but dont know if the look worth the lost of torque...
the noise its brutal! never thought that there was going to be such a hugh diference using the same mufflers with true duals and oem 2-1-2
I'm think of buying harley davidson street legal mufflers in order to have more backpreasure and quiet the bike but dont know if this will help or not.
other thing im thinking its to buy se 255 cams in order to bring the torque back.
I Love the look of true duals but dont know if the look worth the lost of torque...
the noise its brutal! never thought that there was going to be such a hugh diference using the same mufflers with true duals and oem 2-1-2
I'm think of buying harley davidson street legal mufflers in order to have more backpreasure and quiet the bike but dont know if this will help or not.
other thing im thinking its to buy se 255 cams in order to bring the torque back.
Road Warrior
Joined: Aug 2008
Posts: 1,442
Likes: 8
From: south
If you think it's loud now just wait till you install the 255 cams.
The cams build more cylinder pressure and that equals more noise.
I installed the 255 cams in mine and the Reinhart TD became quite loud, but I like it.
The cams build more cylinder pressure and that equals more noise.
I installed the 255 cams in mine and the Reinhart TD became quite loud, but I like it.
Road Warrior
Joined: Sep 2007
Posts: 1,271
Likes: 1
From: Northern MI
Can't say I noticed any loss of torque due to true duals install (V&H). I think you need to mess with re-mapping your system....what are you using...Power Commander?? As far as going with a street legal muffler...WTF?? Setting off car alarms isn't a bad thing...is it???
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Road Master
Joined: Jul 2007
Posts: 1,212
Likes: 1
From: Maryland
This is the reason I haven't pulled the trigger on the true dual setup. Would these help?
http://www.debrix.com/ProductDetails...tCode=95117-M1
http://www.debrix.com/ProductDetails...tCode=95117-M1
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Cruiser
Joined: Jul 2009
Posts: 122
Likes: 1
Not surprised you lost power with these pipes. Pretty common to lose power with such long pipes. It has been pretty common knowledge that the best pipes have 24" or so headpipes with a crossover at that point. Like the earlier person said, you have no scavaging in your system. There is a reason why all good headers on all engines have a collector to pull the exhaust throught the system. Just dumping exhaust into a long tube will kill the power of any engine.
Road Warrior
Joined: Nov 2007
Posts: 1,800
Likes: 307
From: Houston, Texas
When you say you have had it retuned, was it done on a dyno by someone who knows what they are doing?
You are going to loose a little torque but it shouldn't be huge noticable difference. If you haven't yet, get it tuned on a dyno by someone who knows how to use it. There are no HD SERT maps for true duals. I'd question the map.
It could be as simple as the throttle response setting. If you have it programmed to open the throttle body all the way at low RPM's when you twist the grip wide open, it is going to fall on it's face. You loose all the velocity in the intake manifold and the cylinders don't get filled properly. On a stock setting with the electronic throttle, the ecm doesn't open the throttle body all the way until the rpms come up a little to improve acceleration.
You are going to loose a little torque but it shouldn't be huge noticable difference. If you haven't yet, get it tuned on a dyno by someone who knows how to use it. There are no HD SERT maps for true duals. I'd question the map.
It could be as simple as the throttle response setting. If you have it programmed to open the throttle body all the way at low RPM's when you twist the grip wide open, it is going to fall on it's face. You loose all the velocity in the intake manifold and the cylinders don't get filled properly. On a stock setting with the electronic throttle, the ecm doesn't open the throttle body all the way until the rpms come up a little to improve acceleration.