Sub $100 exhaust project.

[Sawblade]

Well, I want a louder exhaust, and while I was gutting my catalytic converter today, I started the bike before I put the muffler back on. It made such a great exhaust note, I want to build a custom straight pipe so that sound doesn't get changed at all.

My goals are...
Spend less than $100 overall before chrome or ceramic coating. (probably ceramic)
Sound throaty as hell in the lower RPM range.
Be as easy to remove as the stock muffler.
Retain stock muffler cover and fender brackets.




After doing some measurements on the muffler cover, I've got 2 1.75" holes spaced 7.5" apart on the outside edges. I found on the summit racing website, a 180 deg. mandrel bent pipe with 1.5" ID and 2.25" inner radius which measures out to 7.5" on the outside diameter. My idea is put that bend with the ends facing outward and route the exhaust pipe from the cat into the middle of the bend.

I've ordered the bend and extra to fabricate the pipe from the cat out of, and I'll keep this thread update as I go.

[Tebster _ fz6]

That will be loud in the high revs....lol

[Damnitsjeff]

I don't want to sound tooooooo negative but everyone on the road will hate you along with everyone walking down the sidewalk. Most of the time when a super loud bike drives by me I don't say "that sounds good" it is more like " what an a$$hole!!!!" but I hope it comes out the way you want it to sound. Very seldom do straight pipes on anything sound good.....

[MoeRose]

It will be SO loud @8000 revs your mind will go numb.
Even a gutted pipe is too loud,sounds good to you in your helmet but it is LOUD!

I had a cop turn to look at me as he was on the shoulder the other day and I was a good 1/2 mile from him.He stood there looking at me and I was doing the limit,but it sounds like I was going 200

[Sawblade]

If it's too loud once I do the mock-up, I'll open up the stock muffler and convert it into a straight through glasspack. I still want to do long trips without going deaf, but I liked that specific note.

[Fred]

It's going to want to flow more out of the left hand exit than the right. In fact, it may wind up drawing fresh air into the right outlet! Between that effect, the gutted cat and the fact that you do get reversion pulses in your exhaust, it's possible that your oxygen sensor will be getting a taste of this fresh air, which will throw off your bike's fueling.

EDIT: I just noticed that you have an 06 or earlier. So you have no O2 sensor to worry about. I'm leaving this in though in case somebody with an 07+ decides to copy your idea.

But that's easily fixed with a little more work. Use a section of the inner curve of one of your mandrel bends to make it flow into the right hand pipe like this. You're eliminating the sharp corner and getting more equal flow.

Oh yeah, and as others have said, it's going to be stupid loud. Your neighbors will hate you and the cops will ticket you.

[bertmoog]

How did you gut your cat? Also will that boost performance any or just change sound?

[Sawblade]

Unfortunately, gutting the cat with the stock exhaust didn't change anything. I used a 1/2" drill, a screwdriver and a hammer.

[aussiejules]

it will have changed, just not enough for you, i cut mine out and defenately, noticed sound chage and power change, but only slightly.

[a_sick1]

DO NOT DO THIS...trust me.
straight pipes are WAY too loud.
it will run like crap.
everyone will hate you..including yourself, for doing this.
it will be cool until you ride it for about....50 feet.
nothing sounds better than a glass pack if your going custom...
at least have baffles in it.

thats my .02