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my understanding is that if all you do is the filter and not pipes, all the benefit you get is a reusable filter. If you do pipes, there is no circuit pn the v-rod that will adjust for the mixture. There are several opions.... dealer reflash of the ecm, a TFI or DFO, a Power Commander, or the HD race tuner. list is in increasing order of cost and tunability. There are a lot of people here knowledgeable on each of these units...

Greg
 

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I agree with Greg. The stock mufflers are the primary restriction in the stock engine system. They provide the necessary backpressure to allow the stock system to run. If you change to the K&N filter, the muffler backpressure will be the same and thus a neglegable (if any) amount of additional air will flow thru the new filter. No real hp gain, but you will have the convenience of a rechargeable filter.
 

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Biker Pilot
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If the pipes are the primary restriction and limit the airflow, then why do folks get better performance when they run topless? (or is that only w/ race tuner / pcIII, etc?)It seems that they would not be able to increase the airflow if the pipes limit it that much.
 

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the topless mod comes in conjunction with the SE filter, some kind of pipe change, and some kind of fuel management device. I dont think SE filter, topless, with no other mods will yield any improvement. But, still dont have a dyno around ehre to verify it, so its just my :2cents:
 

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Crash said:
If the pipes are the primary restriction and limit the airflow, then why do folks get better performance when they run topless? (or is that only w/ race tuner / pcIII, etc?)It seems that they would not be able to increase the airflow if the pipes limit it that much.
The improvement is with the addition of low restriction pipes and a different flash / tuner. The system restictions are first the stock mufflers, second stock air filter, third stock air box cover. Modifications to the last two without changing the mufflers and map will not gain any hp advantage.
 

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spit happens
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I have to disagree.You will notice a difference with just the filter and topless.It is snappier off the line,and better throttle response.The stock filter is made from paper.The K&N is a oiled cotten filter.It flows more air than a paper element.The more air you can get into the engine the more power it will make.Yes it will run leaner.
And yes you will need some kind of fuel richment device.
 

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vrodvinny said:
I have to disagree.You will notice a difference with just the filter and topless.It is snappier off the line,and better throttle response.The stock filter is made from paper.The K&N is a oiled cotten filter.It flows more air than a paper element.The more air you can get into the engine the more power it will make.Yes it will run leaner.
And yes you will need some kind of fuel richment device.
Quite right Vinny. :plause:
 

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vrodvinny said:
I have to disagree.You will notice a difference with just the filter and topless.It is snappier off the line,and better throttle response.The stock filter is made from paper.The K&N is a oiled cotten filter.It flows more air than a paper element.The more air you can get into the engine the more power it will make.Yes it will run leaner.
And yes you will need some kind of fuel richment device.
Vinny, how much additional hp do you think that you are getting? ChopperSteve is claiming only a 2-5 hp and 5 ft-lb torque increase with his muffler mod and a reflash. I doubt that you will get much of this without removing the muffler backpressure.
 

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spit happens
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I have the Turbotec pipes now.Before them was the Supertrapp V-5 pipes.
I did this when I had the stock pipes.no flash no PC or RT.It's really noticable down low in the rpm's.Itwas only mybe 1 or 2 hp.It gave it more throttle response.And a cool sound of rushing air being sucked in, when you snap open the throttle.

Yes,you will get alot more gains out of the filter with an EXHAUST.

I can tell you this about the V-mod muffler.I went to my old dealer(week ago) who sold me the bike,for a free oil change.And while talking a service guy.He said that my old ST setup is still the most power they got from a v-rod to that day.I dynoed at 113hp on their dyno.And he said the best v-mod mufflered v-rod got 109hp.Same dyno,same tuner.and he baselined at 102hp.That's 7 hp.Not bad,but not enough for me.
 

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my dealer wont even talk to you about anything but HD parts. :whack:
 

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wish I could... only one for about 200 miles. Okie gave me a link to a dyno guy here, but bad number. Sooooooo, :banghead:
 

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vrodvinny said:
It's really noticable down low in the rpm's.Itwas only mybe 1 or 2 hp.It gave it more throttle response.And a cool sound of rushing air being sucked in, when you snap open the throttle.
Vinny, I'm sure your right. It's possible since at low rpms, the backpressure hasn't completely built up yet. I'm sure that as rpms increased, the hp advantage decreasd or lost all together. Have a good one bud...
 
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