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Im sure this isnt a new thought, but i have a 1998 Honda Shadow A.C.E. 1100, the exhaust pipes are ridiculously restrictive, i dont want to use a hole saw, but does anyone know if 4 or so 1/2 inch holes would allow for a little more noise and change the back pressure slightly or would it just cause problems? Any and all input is good input

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It's more likely to cause problems than not. The best alternative is to purchase a set of tuned pipes and have the carb jetted to match.
 

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Like Dodsfall said it is best to change mufflers or entire exhaust and retune the carbs or fuel injection to match rather than play mad butcher and possibly cause the engine to run too lean just to get more sound or performance if you don't know what you are doing.
 

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Your idea is a very common mod, cheap and sounds good. Start with the 4- 1/2 inch holes spaced evenly and give it a test ride. If it isn't loud enough you can drill more but remember once the holes are there, there's no going back.

I have done this to many bikes and it was fantastic, considering the cost and effort.:wink:

This mod alone won't really affect your jetting but if done with say a K&N filter then the jetting will have to be richened, which is also easy.

Sam:coffeescreen:
 

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Any exhaust mod is only as good as its design. I ride a Victory and know, from dyno testing, that the purely stock exhaust is my best choice for power, not for noise, unless I get crazy swapping out cams. On some bikes you can gain power by changing the exhaust but often the choice you must make is between "sounds cool" and "retains or improves power". Yes, that is a choice. Noise is one of the many ways that an engine can dissipate the power produced in the combustion chamber.
 

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Exhausting

It is really hard to beat Honda exhausts for the amount of power produced.

It is really easy to make more noise, and think you are making more power.
A dyno is the only real way to tell. You could do some timed acceleration runs, or check your top speed.

The exhaust makers should be able to provide verifiable numbers.

Unkle Krusty*
 

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Harley and Victory (and now Indian) riders have been knocking the plugs out of their mufflers for as long as there have been mufflers. Don't see why something similar couldn't be done on an import. My Ultra has the plugs popped out of the otherwise stock mufflers, by the previous owner. Sound level is raised a bit, yet not annoying. Performance isn't changed much, if at all. Depending how much air flow change you make will dictate if you need fuel changes or not. That will vary by bike and how you make the mod. You won't know until you try. The downside is if you don't like it, you'll need to find another set of stock mufflers to go back to stock.
 

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I cut them out of my Honda VTX but as Oldman47 pointed out, I'm not sure I got more power or just more noise. Butt dyno isn't very accurate. I did get more noise though.
 

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I have been a Harley big twin engine builder and enjoyed winning dyno meets!

The Original Poster just wanted more noise.

The good news is, is that his bike has the 'single crank pin,' like the HD engines so it will sound good.

As has been mentioned, noise doesn't equate to HP----unless the fuel air ratio is optimized and the timing advanced a tad to take advantage of the change.

I used to smile as the good ol' boys stood around the dyno, with his stock Harley with a set of 'drag pipes,' consistently showed 10% LESS HP than his Bud's with the all stock bikes:wink:

Sam:coffeescreen:
 

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Midge

A LOT of cruiser guys do that. I did it to my Yamaha. It worked fine. Yes, it increases the noise level a bit. Most guys use "drilled pipes" until they save the money for a better set of aftermarket pipes.

I was happy with the mod after the drilling. I put 1/2-inch holes in the rear end of my pipes - the muffler plate. Probably about 4-5 holes spaced equally around the circumference. This is not a quick job. Give yourself plenty of time to do the drilling.

dT
 

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Drill first with a 1/8" then a 1/4" and then finally with the 1/2."

Sam:biggrin:
 
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