HD mufflers vs Yamaha mufflers

[jfoster]

For those that have put HD mufflers on their RSV or RSTD, did you feel they had better exhaust flow. I'm considering putting RSV mufflers on my Roadking (shocking yes). I personally liked the quieter sound and to me, my RSTD sounded better than the stock RK. I'm more curious if the Yamaha's are more restrictive?

[Eck]

My opinion (for what it is worth)

Air flow.... I feel is the same.

I put HD mufflers on my RSV.

It made the sound "throatier" (a little deeper). Other then that I didnt notice anything else.

Airflow however, one would have to really measure that using a gage, which I did not.

[jfoster]

Thanks Eck.

[rickardracing]

I put HD Ultra Classic mufflers on mine for awhile. They had more flow because I took a 1" hole saw and drilled out the baffles. Now, I have Samson 29" turn outs.

[Guest tx2sturgis]

If you dont have 'true duals' you may end up with a slight mismatch from side to side.

 

 

 

 

[latchkey]

Besides the deeper sound, can`t tell no difference

[Wrench]

Hmm, interesting swap. I put a set of stock R/K's on my other Venture and really did'nt notice much difference in the sound. I hole-sawed them and that really opened them up, and I guess that caused them start breaking down the packing, because they got progressively louder as time went on. Keep us posted on how this swap goes, it's piqued my interest.

[First_N_Last]

Besides the deeper sound, can`t tell no difference

 

Same with me - can't determine any difference

[djh3]

Seat of the pants tells me the RK flow a little more. But cant prove it. I think the reason for the sound difference may be the way the inside is constructed and method of baffles. I think the Yamaha uses chambers and change of direction zig zag if you will and the HD uses an end plate and a tube with holes.

[Guest tx2sturgis]

Let me put this another way, jfoster:

 

If your bike has the y-pipe header, or a crossover, then DONT use RSV mufflers.

 

If you have 'true-duals' you might be ok, assuming you have access to remaping or dyno testing of the results.

 

But the more basic question is: Why?

 

HD and the HD aftermarket make a wide range of quality, balanced, matched and tested exhaust components, and experimenting with unknown mufflers could result in a overly lean or restricted condition, or in the case of the y-pipe configuration, maybe even a mismatched situation.

 

Its possible it might have good results, but its also possible that you could lose horsepower, torque, or possibly have one or both cylinders running too lean or too rich.

I think overall, its a bad idea.

 

 

 

 

 

 

[SilvrT]

experimenting with unknown mufflers could result in a overly lean or restricted condition, or in the case of the y-pipe configuration, maybe even a mismatched situation.

 

Its possible it might have good results, but its also possible that you could lose horsepower, torque, or possibly have one or both cylinders running too lean or too rich.

 

I think overall, it's a bad idea.

 

 

Well, let's see .... if nobody experimented installing HD RK mufflers on the RSV .....

 

I'm just sayin.

[Guest tx2sturgis]

Well, let's see .... if nobody experimented installing HD RK mufflers on the RSV .....

 

I'm just sayin.

 

Yeah, and I always advise against that also. But...the Venture is not subject to ECM mapping, (and will tolerate small changes in airflow without re-jetting) and also, IF you can find a pair of mufflers from an HD that are the same left and right, and that dont have the catalytic junk, then you are probably OK.

 

FL (touring) Harleys, depending on year, may have the y-pipe headers, which normally means that the stock mufflers have different baffling on the left vs the right. The mufflers may not be the same inside. Which means there may end up being an imbalalance of horsepower or fuel/air ratio from left to right if mounted on the Royal Stars. The V4 with carbs is obviously able to tolerate the imbalance, especially if the owner does a carb synch. And it turns out that many Royal Star owners just seem to want to 'cheap-out' on this stuff. Its a bit like the guys who spend 10 or 20 grand on a used or new Venture, then put a pair of $20 fog lights on and think it looks good. In 6 months the brackets crack or the chrome rusts. But, to each his own.

 

If a rider has the money in the bank to go buy a new (or recent) Harley RoadKing, knowing it has a very sophisticated, computerized closed loop fuel injection system that needs to be precisely remapped for a major change to the intake and exhaust system, and then 'cheaps out' and hangs used metric non-tested mufflers on it, I will express my opinion about it. If that rider chooses to ignore it and has good or bad luck, then so be it.

 

The front and rear cylinders on a newer fuel injected Harley are not always mapped the same, and the left and right mufflers that are made for it, either factory or aftermarket, are often constructed slightly differently to accomodate the different levels of back-pressure that the ECM expects to see and compensate for.

 

In the old days, you could assume that the left and right mufflers were identical. But nowadays, that aint necessarily true.

 

Here's a thought: Why not just buy the slipons that were designed for the bike? They will bolt right on, and the dealer can remap the ECM for the known mufflers level of baffling.

 

Just my 2 cents.

 

 

Related info:

 

http://www.harley-riders-guide.com/harley-davidson-efi.html

http://www.harley-performance.com/harley-exhaust.html

http://harleytechtalk.org/htt/index.php/topic,22984.0.html?PHPSESSID=qjs6hplgc56emuecbf75m056h2

Edited January 30, 2013 by tx2sturgis