Exhaust Ideas ... again.

[7milesout]

I'm working with an unsubsidized budget of $0. I've seen some murdersickle straight through mufflers like I had on my racebike. My suspicion tells me that might sound good. Problem is, I / we try to run our 3-Tappers around at (relatively) low rpm. I think that generally equates to F.A.R.T.C.A.N. sound no matter what is glued together behind an inline engine (less than 6 cute cylinders). Plus those are nice aesthetically pleasing mufflers, too cute to glue to the underside of a Mirage.

It would help if I started a (what's the panhandling web based money transfer thingie called?
(youpayformylackofselfresponsibility or something like that)) and y'll all could go in there and transfer THOUSANDS EACH to support my research. I'll use it ONLY for research ... promise!

[inuvik]

Here's a G4 with a Cherry Bomb!

[Wallythacker]

hahahaha

I hate it when my budget is zero. the performance or quality of the finished product is usually, but not always, very indicative of the budget. I have cobbled together some amazing junk myself over the years, but there was usually some massive donor material to start me off.

[7milesout]

That cherry bomb is not too bad. Just a little louder than I'd like. I don't want my neighbors to have to tolerate it. I don't know if the perfect exhaust exists. My Scamp's exhaust at idle and light throttle might be close though.

[Grumpy Bear]

Here's a G4 with a Cherry Bomb!

That's actually quite nice. Thanks for the clip.

Riding Brit singles and twins, which are low rpm motors, with glass pack mufflers sounded pretty good on moderate cylinder capacity.

[7milesout]

I wonder where, within the exhaust stream, that cherry bomb is located? It sounds like it is at the end. What I'm thinking might be a good combo is:

• removal of the 2nd cat (for efficiency (power and fuel)), if little to no difference,
• a cherry bomb (or cherry bomb type of muffler) in the stock muffler location,
• plus the factory resonator.

Should result in a nice sound. I think, from what I gather, a muffler with a short pipe after tends to be louder (I.E. if the muffler is located near the rear bumper). So, putting a cherry bomb type muffler near the stock location and therefor having longer pipe and resulting less volume than the one on the video, keeping the resonator, might be just about right.

Reckon?

[Grumpy Bear]

I wonder where, within the exhaust stream, that cherry bomb is located? It sounds like it is at the end. What I'm thinking might be a good combo is:

• removal of the 2nd cat (for efficiency (power and fuel)), if little to no difference,
• a cherry bomb (or cherry bomb type of muffler) in the stock muffler location,
• plus the factory resonator.

Should result in a nice sound. I think, from what I gather, a muffler with a short pipe after tends to be louder (I.E. if the muffler is located near the rear bumper). So, putting a cherry bomb type muffler near the stock location and therefor having longer pipe and resulting less volume than the one on the video, keeping the resonator, might be just about right.

Reckon?

I do. Swap the OEM for the Cherry. Keep the resonator as is. OR replace with a second Cherry.

[Space Wolf]

I'm slow, but I have an idea, and could experiment.

What do you think this set-up would sound like?

Basic - Do you think this would give it the deep sound you'd want? I too love the sound of the 6V71. I've started calling our engine a 3I24. (3 cylinder Inline, 24 cubic inches each cylinder).

Stock set up on the left (as far as I know, for the 2017's and newer). 2nd kitty missing and muffler missing on the right. Resonator remains. I might be able to experiment this for reasonably cheap.

Course I'm broke busted splintered shattered scattered covered chunked scalloped sliced and diced these days. Ain't got me no fun money, just bills. But I might be willing to miss a house payment to give it a try...

Attachment 27004

You also want to delete the catalyst? Wouldn't that be dangerous? AFAIK an engine designed to have a catalyst will have a higher CO emission when operated without catalyst than an engine which is designed to have no catalyst. (The latter will have a higher NO_x emission, but that won't kill you in a bad ventilated environment)

/edit: somehow I missed that the thread is much longer. Sorry if this comment is a bit outdated.

[sunbeam]

Mirage has 2 cats. The red highlighted section is the rear cat.
If you remove the cat, this will change the fuel mixture from what I understand, meaning you will need a new tune.
Probably going to cost more than $0.

[7milesout]

Mirage has 2 cats. The red highlighted section is the rear cat.
If you remove the cat, this will change the fuel mixture from what I understand, meaning you will need a new tune.
Probably going to cost more than $0.

@sunbeam - If you mean the red highlighted item in post #1, that red highlighted item is the resonator. I think generally they're empty inside. That volume change (I don't know how to say this correctly) throws off the resonant frequencies, at least by a great deal, so that it greatly reduces or eliminates drone.

@Space Wolf - No problem with the late timing. I, for one (I'm sure there's others) don't mind some thread drift or late comments or whatever. You never know what might come out of such things. When and if I get off my dead lazy arse, I'm going to swap my stock exhaust with one in which I will experiment. So, if I don't like what's going on with my experimental exhaust, I'll put my stock exhaust back on. In post #7 (I believe it was) in the far bottom left is the 2nd cat. 2nd cat at least on U.S. models of my 2020 model year. I'm going to drop that catalyst, but keep the first catalyst. I'm going to look into it a bit more, but it seems the 2nd one really only helps emissions with the first seconds after startup. Sounds counter-intuitive, you'd think the first one would be the pre-cat. It must have to do with the materials of the 2nd cat. Anywho - from my understanding it only helps about 1% or 2% as much as the first, from my understanding. I may get nothing out of removing it. I'll collect data (dragstrip).

I got all discombobulated this weekend. I spent a couple hours loading sticks / brush / yard debris onto my utility trailer Friday after work. Only to have it rain hard at about 6 am Saturday, then find out the recycle center was closed. Then my son wanted to use the truck I was going to, so I had to unload grass bags out of the back and clean the bed out because he was wanting to truck camp in the bed. He wasn't at home at that time to do it himself. It was wet and sloppy the rest of Saturday so I didn't make it to the junkyard as I didn't want to have to lay in the slop. Then had a kill-dawg headache the first 2/3rds of Sunday. Then the wife wanted to duke it out Sunday once I felt better ... what a waste of a weekend.