GStwin.com GS500 Message Forum

I think everyone may know about the exhaust drill mod. (Drilling with a 12" extension into the rear outlet of the exhaust can). But I've got something that I tried that turned out to have a more aggressive/throater sound...

If you look at the back of a stock GS can, it looks something like this  (o)
  LOL  ;)   Anyway, the center outlet  (about 1" dia) is even with the outer surrounding outlet (about 2.5" dia.) I'm not sure why this is, but here's what I done...  I took a dremel and cut off approx. 3/4" off of the center outlet. Cutting in an angle pointed downward. The center outlet is now offset inward . The angle shape reflects the sound off of the outer outlet. The outer outlet now acts as a megaphone.  the end result is a very surprising and pleasing sound.  Logic would point to the more you cut, the louder it would be... but start with 3/8- 3/4 to see what you prefer.

Combined with the exhaust drill, it's the next best thing to an aftermarket exhaust. First, I do recommend you try the "cut mod" before the "drill mod" as you may like the cut without the added loudness.

:thumb:  
RFD

could use a picture for clarity!?

I would like to try your suggestion, could you post some pics or email them to those that are interested?

Could someone do a soundbyte comparison (before/after cut)?

I'll try to post some pics soon. Forget the soundbyte. :?
Trust me guys, you'll like it.

Yeah yeah, we definitely need a decibel-level scan in Soundforge or something!   :mrgreen:

yeah yeah then I could synthisize it and put it on my keyboard!
:guns:

Here is a pic of the mod.

http://www.gstwin.com/gallery/view_photo.php?set_albumName=member_bikes&id=ait

Please post your results and keep us informed.

8)
RFD

might have to try that, dont care for much louder just a richer sound.

bump

Curse my desire to leave things stock!!

Quote from: RedFuelDluxPantablo,..... I don't get the knee thing.

Read Pantablo's sig then look back for pics of his kid with the new clear tupperware beanie thats the new Harley rage.

a sound file would be nice.

jake

Yep.. it sure would. :roll:

Quote from: RedFuelDluxPantablo,..... I don't get the knee thing.

You had to be there...previous post of mine regarding proper way to wear a beanie helmet. Came up in the posts...regarding the picture.

had to be there-

Ok guys.....enough with the emails and PM's about posting a sound file.  :roll: Just trust me.....you'll be surprised at what a difference and really like the results.


:thumb:
RFD

Sound files rarely do exhausts justice unless you have a nice speaker setup with a sub etc otherwise it never really sounds the same.

I was gonna do this but I got a deal on a yosh so no go.

I'm not sure what you mean by "Cutting in an angle pointed downward".  Are the inner and outer outlets still concentric? or is the inner outlet at an angle to the outer one?  I looked at the picture but I couldn't tell.

Please explain, this sounds like a cool mod!! 8)

Rob

The inner and outer tubers are not concentric. Only the inner tube was cut. Looking at the picture, the longest point of the inner tube is at the top while ths shortest is at the bottom. Thus pointing "downward".  

I realize it's difficult to tell from the pic, but I hope this clears it up a bit....

RFD

The inner pipe is cut at an angle. In a 45 degree backslash. Like slash-cut balogne-sausage pipes on a Kawasaki ZL600 or ZL1000 or Eliminator. Or slash-cut pipes on Chevy full-sized pickups. Does that help?

But, this would be a difficult job to do cause you have no room to work on the inner pipe.  Is there some easy way to cut the inner pipe (please use layman term so that the majority of us would understand).  I am willing to do this mod while waiting for the sound file once I understand the procedure and have the right tool for the job.

Thank you in advance.

Thanks scratch and RedFuelDlux ... that clears it up!

That's the kind of mod I like .. cheap!

Rob

The best tool to use is a Dremel with a cut wheel. If you own a motorcycle, then you need a Dremel. They are the most useful tool out there. I use it all the time on my GS and dirt bike.

Just one last thing, I just thought of, what about rust?

Thanks RFD.

Now, what do I need to know about Dremel tool ? Does it come in different sizes & models and where is the best place to buy ?

I am excited about doing this Exshaut mod...

Use High Heat Engine Paint to defeat the rust.

The cheapest places to buy the Dremel is Wal-Mart or Home Depot. Get the electric version, not the battery-pak version. They just don't have the power the others do. There are tons of add-ons. It should come with an assortment of cutting wheels.

Black and Decker also makes a little cheaper Rotary tool that should do the same job. Good Luck!

:thumb:
RFD

FYI
Rider Experiment:

http://www.gstwins.com/forum/viewtopic.php?t=4630

Oh yeah, I probably should've posted this long ago, (especially since everyone is requesting a sound file) but if you're wondering about how your bike would sound and want a loose representation of the mod simply crank up your bike and cup you hand around the exit of the exhaust can.  You hand should be positioned as if you were holding a beer.   8)  

You're simply reflecting sound and now your bike should have a noticable "Thud" .

:thumb:

RFD

Yep. I was going to make a similar post.  Also, you can get different sounds if you cup your hands in different shapes.  

As an update:  I cut about 1/2" off of my pipe.  First I cut off about a 1/4" and noticed that I got a little deeper of an exhaust note.  I then cut off another 1/4" and found the exhaust note didn't change much.  I noticed at this point that the exhaust had a kind of farting sound when you back off the throttle and the engine decelerates.

Rob