Will removing baffles completely on my 4-1 hurt anything?

[HiSPL]

[HiSPL]

OK, the yamaha looks like it *might* have a tiny little baffle on it.....

[gotjeepzj]

I didn't want anything super loud, so I'm not harming the motorcycle community. My gs is an L model. It's a cruiser. Bags, windshield, etc. Why not have it sound more like a cruiser? My 4-1 sounded a little to racey for my taste and I wanted something with more of a rumble.

[Road_Clam]

Why would you do this to your street bike? To draw attention to yourself? You are just harming the motorcycle community in general when you make that much noise, and it doesn't make it any faster. As far as harming you bike, it won't, just look at all the Harley dorks with their straight pipes.

But taking out your baffle is a bad idea.

As far as making a race baffle, are you actually going to race a GS1000L.

Go easy on the guy, you making him up to be a Harley owning, Randy redline racer. He is going to draw FAR less attention to himself, and do FAR less harm to the motorcycle community than operating a YZ250, or a KTM500 in the local pits or trail anywhere near residential property. (But you do ONLY race your bikes on closed course AMA aproved competition race tracks right?????)

[gotjeepzj]

I cut out one of the three sections and drilled holes through the round disc and the other 2 sections. It did make it a little louder but not the sound I liked. I'm still toying with the idea of cutting everything off except the cone on the end. My theory is the escaping exhaust will rapidly expand as the megaphone enlargens and will then be forced from the 3" outlet end through the 1 1/5" hole in the cone thus creating back pressure. Does this sound feasible?

[HiSPL]

Yup.......

[Detman101]

Straight pipes do not automatically mean no back pressure. Length of the pipi and curves also effect it

This is what I also noticed Scotty.

With the can off of the mac 4-1 exhaust the bike seems to pull harder but it also uses up more gas and is hella loud. However, the bike runs just the same and the plugs look good after I rejetted to be safe.


When I gut the cans off of the stock exhaust the bike wouldn't run 2 miles without sputtering out. That experiment is what led to this photo.



Having to stop every 2 miles and being stuck on the side of the highway in the dead of the night is no fun. I bought the 4-1 right after this adventure in exhaust modification.

[Detman101]

A week?? Don't worry, I highly doubt you even came close to harming the exhaust valves. What WILL burn valves, is improperly jetted, drag piped exhaust with extended "highway" rpm usage.

Awesome, Good thing I rejetted the mains. Doing the chain conversion today so the can goes back on for transport to my buds garage.

[matterri]

I bought a set of Mac replacement mufflers for my GS850GL chopper project. I plan on cutting the baffles out of them for no other reason than to make the bike louder. Hopefully I won't hurt the image of the motorcycle community in my area for doing this \\/ . (like it'll even come close to the amount noise from the harley's) I'm still not convinced either that no baffles will hurt my engine or valves for lack of backpressure. From the reading I've done, most of this "backpressure" stuff is just an old wives tale. I'm sure I'll take some criticism for that.8-[ Seems to me any restrictions in the exhaust on any engine, such as mufflers and baffles, just hurt flow. I'm no engineer or bike mechanic, this is just what seems right to me. What about the old school Honda CB chops that run straight pipes about half the length of the bike. Short and wide open. What are some thoughts on this??

[Detman101]

I bought a set of Mac replacement mufflers for my GS850GL chopper project. I plan on cutting the baffles out of them for no other reason than to make the bike louder. Hopefully I won't hurt the image of the motorcycle community in my area for doing this \\/ . (like it'll even come close to the amount noise from the harley's) I'm still not convinced either that no baffles will hurt my engine or valves for lack of backpressure. From the reading I've done, most of this "backpressure" stuff is just an old wives tale. I'm sure I'll take some criticism for that.8-[ Seems to me any restrictions in the exhaust on any engine, such as mufflers and baffles, just hurt flow. I'm no engineer or bike mechanic, this is just what seems right to me. What about the old school Honda CB chops that run straight pipes about half the length of the bike. Short and wide open. What are some thoughts on this??

Well, I know from experience that Backpressure ain't no old wives tale.
It, or the lack of it, was the cause of me taking 4 hours to get from baltimore to Silver Spring the summer before last.

[matterri]

Why?? Please explain.

[scotty]

This is what I also noticed Scotty.

With the can off of the mac 4-1 exhaust the bike seems to pull harder but it also uses up more gas and is hella loud. However, the bike runs just the same and the plugs look good after I rejetted to be safe.


When I gut the cans off of the stock exhaust the bike wouldn't run 2 miles without sputtering out. That experiment is what led to this photo.



Having to stop every 2 miles and being stuck on the side of the highway in the dead of the night is no fun. I bought the 4-1 right after this adventure in exhaust modification.

I love those bar end mirrors. They deliver a message for sure:-D

[gotjeepzj]

I've noticed the bike consuming more gas now. Anyone have an explanation for this? What's left of the baffles is now really black from carbon. I thought it should have the opposite effect. If the reduction in backpressure should've lead to a lean condition from what I've read here but that's not the case. It might just be me being paranoid, it could just be some bad gas. Thoughts?

[Detman101]

I've noticed the bike consuming more gas now. Anyone have an explanation for this? What's left of the baffles is now really black from carbon. I thought it should have the opposite effect. If the reduction in backpressure should've lead to a lean condition from what I've read here but that's not the case. It might just be me being paranoid, it could just be some bad gas. Thoughts?

Well, I'm guessing...Guessing...that having the can on the bike keeps some sort of balance in the engine that regulates how much the fuel can move into it. Because gas is thicker than air the backpressure keeps the fuel flowing at a slower rate. The air stays unchanged since...it's air.

So, the backpressure....in essence...keeps your fuel flow regulated by it's presence.

I realize now that I overjetted when I went up a size to run with no can on my bike. I could have left it the same and had better gas mileage.

[dtkid]

I gotta jump in here and ask a racing question. It actually concerns one of those vehicles with 4 wheels......the type I am rarely seen in (pretty much only when riding in the passenger seat while the wife drives and I sip beer from a quart dixie-cup.)

A buddy of mine races on the dirt-track circuit. He recently (I helped) put a huge motor (I think it was a 454) in a Camaro and I noticed that the header had little bitty (small diameter) head pipes coming from the manifold. I asked him why the pipes on the header were so small in diameter and he said that the back pressure allows for more torque.?????????????

Do ya'll know this to be true? I must admit I don't have a substantial understanding of the relationship between horsepower and torque but I know they are different parameters. CAn anyone ellaborate????