Cutting Your Exhaust Pros & Cons??

[Green Machine]

Forum Sponsor

Looks better.

I don't find it to look better, kinda like when old lady puts on a mini skirt

 

[油井緋色]

Not quite. Changing the tuned length and changing the amount of damping at the end will change the way the pressure waves bounce around in there. If that ends up sending a "bad" reflection back to the engine, it will run poorly in whatever RPM range it affects and no amount of fiddling with the fuel injection will solve it. You can make it run "less badly" but never "good", if the engine is being made to swallow a reflected positive pressure pulse of exhaust at the wrong time.

Exhaust systems for street bikes are designed and tuned to function correctly when they have a muffler at the end. Usually, taking it off will make the engine lose power. Shortening it isn't quite as bad as completely removing it, but it's heading in that direction.

Thank you for the informative post. I always knew, based on dyno charts, that slip-ons generally reduce power but could never explain why.

Input??

Does that look like a street bike to you? Huge difference between cutting an exhaust and putting a full system in.

 

[Green Machine]

I do not believe that is street legal, maybe in the Philippines or Guam, but not here, just sayin

 

[Brian P]

Input??

You missed the word "street" in the post that you quoted.

You CAN engineer an exhaust system to function without a muffler - it will generally have a megaphone as shown, it will generally have a separate exhaust outlet for each cylinder (or at least, only cylinders having non-overlapping exhaust strokes are joined), and it will be incredibly loud, and those are incredibly loud! Top fuel drag cars are another example; separate outlet pipe from each cylinder and no mufflers. Suffice it to say that the only engineering criteria for noise was to make as much as possible!

 

[moosrdunk]

so even better than just cutting the slip on down to size something like this ...

http://www.youtube.com/watch?v=UXudPazI-o4

basically removing the slip on exhaust and placing the shorty pipe not to worried about having issues with police or anything if it becomes a problem I would just take it off and place my old slip on exhaust back on.

My overall concern is damaging the engine , fuel consumption and any negative effects etc.. basically just prematurely wearing down the bike unnecessarily

 

[KarGo]

so even better than just cutting the slip on down to size something like this ...

http://www.youtube.com/watch?v=UXudPazI-o4

basically removing the slip on exhaust and placing the shorty pipe not to worried about having issues with police or anything if it becomes a problem I would just take it off and place my old slip on exhaust back on.

My overall concern is damaging the engine , fuel consumption and any negative effects etc.. basically just prematurely wearing down the bike unnecessarily

Do you even know, how loud this **** is?

 

[Roomie]

Do you even know, how loud this **** is?

Add how much that it sounds like ass and that around here you're getting pulled over for sure the second a cop hears that crap. Also looks like bunk

Sent from my SM-N900W8 using Tapatalk

 

[muay_thai_dan]

I actually think the regular long pipes look better than the shorty ones.... but, i must admit, i love how ridiculously loud and raw the megaphone/gp slip ons are. it is indeed obnoxious and you are asking for trouble from police, but the sound is so sweet......

 

[Low rider]

OMG, that's butt ugly.

http://www.motorcycle-superstore.com/15324/i/jardine-gp1-dual-slip-on-exhaust

Like these. I have a friend that has something similar, no baffle, horn shaped (sound amplification). We can't even talk to each other on red lights lol

Yes it looks better but it's about as heatscore-ish as typical undertail fender eliminators.

 

[hedo2002]

Well then expect to be removing it after the FIRST ride..lol The Police ARE going to be stopping you for it, and you will get a ticket. So let's review. You just spent money on an exhaust you will never again be able to use, (unless your doing track days only with it). Then there is the cost of the ticket. Then lastly is the cost of the INCREASED insurance resulting from that ticket.

So con, con, con

Pro PERHAPS visually for you

so even better than just cutting the slip on down to size something like this ...

http://www.youtube.com/watch?v=UXudPazI-o4

basically removing the slip on exhaust and placing the shorty pipe not to worried about having issues with police or anything if it becomes a problem I would just take it off and place my old slip on exhaust back on.

My overall concern is damaging the engine , fuel consumption and any negative effects etc.. basically just prematurely wearing down the bike unnecessarily

 

[Roomie]

Well then expect to be removing it after the FIRST ride..lol The Police ARE going to be stopping you for it, and you will get a ticket. So let's review. You just spent money on an exhaust you will never again be able to use, (unless your doing track days only with it). Then there is the cost of the ticket. Then lastly is the cost of the INCREASED insurance resulting from that ticket.

So con, con, con

Pro PERHAPS visually for you

As said in here.... it's like the undertakes that shove the plate in front of the rear wheel. Looks clean and all but the costs from driving infractions makes it not worth the risk. Pipes you can hear coming for miles will get you nailed.

Sent from my SM-N900W8 using Tapatalk

 

[MarcosSantiago]

Thank you for the informative post. I always knew, based on dyno charts, that slip-ons generally reduce power but could never explain why.

90 to 95% of people who instal a slip-on do not make any effort to tune the bike at all. If anything, they through in a high-flow filter (aka K&N), making things worse.

Some people actually think that, because the bike has fuel injection, it will be able to detect any changes in air intake, ignition, and exhaust, and the FI will adjust itself for maximum power <faceplam>.

That is an urban myth. While the FI systems on motorcycles have a numbers of sensors to compensate on changes, these adjustments are minor, and are not performance-oriented. So, the fact is that the FI system cannot compensate automatically for any change you throw at the bike. Will it run? Sure, but usually with less power.

Even the people who have the approx. $400 to installing a PowerCommander, they are depending on some else to create a map for their bike model, while using the exhaust model that they got.

Very few owners actually have the time and interest to get into it hard-core, to buy a PowerCommander, learn to use, try different maps, and at the end create their own custom maps to account for other changes (such as the aftermarket air filter, geographical location, etc). These are the guys that can afford to pay for many dyno runs until they actually tune the bike properly.

In my opinion, that is why, based on dyno charts, slip-ons generally reduce power on a bike.

 

[油井緋色]

I actually think the regular long pipes look better than the shorty ones.... but, i must admit, i love how ridiculously loud and raw the megaphone/gp slip ons are. it is indeed obnoxious and you are asking for trouble from police, but the sound is so sweet......

Really?

I think the stock 2008-2010 GSXR pipes are disgusting!

 

[Roomie]

This doesn't look bad.

Better than some stubby metal thing that's just there to be obnoxious

Sent from my SM-N900W8 using Tapatalk

 

[unL33T]

Pros: Maybe slightly less weight.
Cons: Will sound like crap. Will likely run like crap. Good waste of time.

 

[estone]

Do whatever you want - one piece of advice. You can always go shorter, but not the other way around. So don't be too generous with how much you are cutting off, you might regret it.

 

[chrias]

I cut down my Yosh pipe to 10" on my 02 CBR F4i when I had it. It did get louder and I never had it tuned. I did get a little bit of popping through the exhaust gearing down but not too bad. The bike still ran perfect with no tuning or power commander.

I also cut down my carbon fiber Akros on my Hayabusa to 9". There is no packing in the mufflers and it will pop and shoot flames when I downshift. The bike sounds like an animal when I'm on it. I have no issues with idling or the engine running poorly.

 

[MarcosSantiago]

I cut down my Yosh pipe to 10" on my 02 CBR F4i when I had it. It did get louder and I never had it tuned. I did get a little bit of popping through the exhaust gearing down but not too bad. The bike still ran perfect with no tuning or power commander.

I also cut down my carbon fiber Akros on my Hayabusa to 9". There is no packing in the mufflers and it will pop and shoot flames when I downshift. The bike sounds like an animal when I'm on it. I have no issues with idling or the engine running poorly.

I guess I just have a different opinion... to my mind, a bike that is popping and backfiring and shooting flames is not running perfectly. It is eaither too lean, to rich, there's a leak somehwere, sparkplugs are misfiring, etc.

But I guess it could be a matter of opinion. To each its own, I guess...

 

[chrias]

I guess I just have a different opinion... to my mind, a bike that is popping and backfiring and shooting flames is not running perfectly. It is eaither too lean, to rich, there's a leak somehwere, sparkplugs are misfiring, etc.

But I guess it could be a matter of opinion. To each its own, I guess...

That's not always true. All cars/bikes experience a backfire/pop through exhaust but you won't hear it due to the factory muffler and/or catalytic converter.

The reason my Busa is shooting flames is because there is no fiberglass packing to absorb it and I don't have the pair valve plugged which allows fresh air into the exhaust. If I plug the pair valve then I will reduce the popping through the exhaust. So, basically my Busa has a straight exhaust.

 

[muay_thai_dan]

Really?

I think the stock 2008-2010 GSXR pipes are disgusting!

yeah heh I really dont think it looks that bad, especially that gsxr's pipe. Dont get me wrong, and after market pipe would looks nicer, but i dont find the stock ones that bad!

Forum Sponsor