Tuned pipe muffler delete?

[TheAmishSasquatch]

So I was curious what effect there would be on the exhaust pulse wave of a tuned Technigas pipe if the 180* radius & muffler were cut off.  Naturally the result would be a louder exhaust, and naturally the cut tip would need flared slightly for proper resonance of the pulse wave, but would there be any performance gains to be had? anyone done this to a pipe? Any vids/pics? I assume no damage or negative results would occur as all "Tuned pipes" for RC aircraft are essentially the same as what I suggest.

[zombie]

All you have to do is figure the length of the pipe heading from the tail into the silencer, and replace that 180* w/ a straight pipe.

Easy breasy. All the math has already been done. I've cut the silencer off every dirt bike I ever owned, and quite a few for friends. It won't make the bike any faster but it sure sounds like it is.

You might want to try replacing your packing w/ some fiberglass cloth first. Wrap as much or as little as you want around the Perf. pipe.

[BettinANDlosing]

Two strokes without a silencer sounds HORRIBLE IMO. My Leo Vince ZX broke years ago on my old Zuma and I had to ride home, worst headache and I couldn't hear right for a day. I ended up welding the muffler straight back stinger style and it looked actually better if anything. I think the tuned pipe sounds less tuned without the silencer on, and people will laugh at you really hard going 35-40 but with the sound of a million wasps.

[chaz35]

When you get old like me and can't hear anything you will wish you had left the muffler on.  Just saying...  Actually, a properly tuned expansion chamber engineered with the muffler will probably not perform as well without the muffler, which is part of the total design for that particular pipe, that's the way I understand it.  Cheers

[TheAmishSasquatch]

Thanks guys. Was just curious if the muffler was a limiting factor in the system.

[zombie]

Both of those guys are right.

My Jiangwayne pipe cracked at the 180, and i had to ride w/ my head tilted to avoid the vibration in my inner ear. It was HORRIBLE.

I can only assume that the pipe being further off the ground (dirt bikes) it does not reflect the sound off the road. I actually liked the noise back then. Not so much now.

[BettinANDlosing]

Not at all. The two limiting factor in most tuned pipe r is a small washer the the header close to where it mates with the engine, and a mesh cone inside of the expansion chamber. It's required in Europe to have restrictions on those if you still want it street legal, i guess they actually check in Europe. America don't give a sh** what you put on your scooter, or take off for that matter.

[zombie]

There are a few utube vids on Danish, and German police using a portable Dyno to road side test BHP on passing scooters. If the bike makes more HP than is allowed you lose your bike.

That's gotta suck.

[BettinANDlosing]

That's when you say FTP and buy a fully built polini evo motor so you can just dip. What a waste of tax dollars dynoing little scooters. Or even better get a two curve cdi and make a stupid mode with a hidden switch so you can detune secretly haha. Even in Portland where there are a good amount of scooters cops don't have a clue about scoots. Half don't even know you need an endorsement for over 50cc, some aren't sure if you need insurance, and I've been pulled over and asked "how do you have a scooter that does wheelies?" Haha. I've never once heard of someone getting a ticket for going faster than 30mph on a moped. I would hate for that to change i love how they don't know anything about scoots.

[zombie]

It was the same down here until more people started riding 50cc's. The Chief of Police here is the one that told me no Lisc but you need a tag.

Now they all know the laws, and are begging to enforce them. It's like that other thread where a few bad apples ruin a good thing for everyone.

Quick story... I was riding one of my NC 50's, I used an "O" ring on the throttle for a cruise control. I was drinking one of those iced coffee/energy drinks, and talking on the cell. (24MPH tops but no hands for miles) and a sheriff pulled up behind me. No tags/lights/anything... He asked if the local cops bothered me for this, and I said "No. I usually run from them." He looked twice, and laughed. That was 4-5 years ago. Today they taZe you, and impound the bike.

[BettinANDlosing]

Hahaha yeah I'm afraid that's where it's going.

[Areomyst]

In the few dyno tests that I have done, I haven't noticed any difference with out without the silencer except for noise.  In fact, my silencer fell off at one of the drag races (guess the dummy that built the bike missed those two bolts... ).  The ET for the drag run was still constant, but it was a lot louder.

You can, however, change the power characteristics a bit by changing the diameter of the stinger.  I don't do much with modifying exhausts though.  There's some more info here if you like: http://www.pit-lane.biz/t3173p20-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-2-locked

[zombie]

Thanks for the input J. We miss you over here in the basement!

Happy Holidays Bro!