why does everyone say to get rid of shorty exhaust? : Suzuki GSX-R Motorcycle Forums: Gixxer.com

**vnms96** · 08-09-2012, 02:52 PM

I keep reading on here where people say to get rid of the short exhaust, is there an actual reason for this? Or is it just looks wise?

**Apok** · 08-09-2012, 03:02 PM

Personal Taste. looks, no peter measuring contest over how loud a bike is, etc.

Some era cans were short, srad wasn't one of 'em!

**vnms96** · 08-09-2012, 03:16 PM

I have a semi short m4 can on mine. It started out a regular size m4, but i was bored at work and cut it down. In my opinion it looks a lot better. It's not that loud either, just nice and deep.

**Apok** · 08-09-2012, 03:22 PM

The reasoning behind most people making it shorter is they don't have the funds/don't want to spend for a new can after they crash or what not.

So instead take a few minutes and a couple bucks cut the rashed part off, put together, bam like new.

^Which is understandable.

**vnms96** · 08-09-2012, 04:52 PM

My bike was dropped by the previous owner and it was rashed up on the can. The fairings were saved by the sliders.

**Armi** · 08-09-2012, 04:57 PM

Cos' it affects harmonics

**GSXR-Freak** · 08-09-2012, 05:01 PM

Armi is right.
The hamonics have to do with where the motor makes it power. Companies spend a LOT of time on R&D to make them work correct for each motor. So why change that.

John

**vnms96** · 08-09-2012, 05:02 PM

And how does it do that? My bike rides smooth, no vibrations from the engine, nothing. It's the can that came with the m4 exhaust, just shorter.

**vnms96** · 08-09-2012, 05:04 PM

Quote:

Originally Posted by GSXR-Freak

Armi is right.
The hamonics have to do with where the motor makes it power. Companies spend a LOT of time on R&D to make them work correct for each motor. So why change that.

John

That makes sense. That's why I asked it here.

**Apok** · 08-09-2012, 05:05 PM

^^ You wouldn't notice the difference on normal street riding.

**kbarrow07** · 08-09-2012, 07:51 PM

majority of the people here are track riders, they will notice a difference, but like Apok said you wont notice a differnce on the street, i could tell a small difference in my bike when i had a yoshi rs-3 and when it was straight piped (go ahead i know im gunna get a squid remark for that)

**ccmhunt** · 08-09-2012, 07:58 PM

Quote:

Originally Posted by vnms96

And how does it do that? My bike rides smooth, no vibrations from the engine, nothing. It's the can that came with the m4 exhaust, just shorter.

I love explaining everything for the zillionth time.

It wasn't just the style back then to have long cans. Just as header diameter, collector design, mid pipe length, crossover tubes, etc are a result of exhaust tuning, so were canister length.
Positive and negative pressure waves wash back and forth through the length of the pipe and pipe and can design affects the timing of said waves and their arrival back at the motor. Good pipe design, among many other things, takes into consideration the design of these so as to ensure that negative pressure waves do not arrive back at the exhaust valves at periods of valve overlap and therefore bring with it burnt exhaust into the combustion chamber, and and in some cases into the intake track. Then, the next firing cycle attempts to ignite a mixture of of new fue/air and burnt byproducts.
Typically this is done to overcome the pronounced dip in the midrange produced by cam timing. Shortening the exhaust canister makes this worse. Ironically, most people think their bike got faster, because what they feel is their bike accelerating out of this hole that is has make worse (that itself they can barely feel).
But, what do I know.

**vnms96** · 08-09-2012, 10:19 PM

Ccmhunt, you haven't explained it to me a zillion times. This is the first and last time you'll ever have to explain it to me. Now I know, I'll buy a new can, I don't really like the look of the point cans. But I'm smart enough to take good advice. Thanks to all who helped with an answer.

**ccmhunt** · 08-09-2012, 10:28 PM

Your good, but if you hang around you'll see that the same thing come up again and again, and the same incorrect information gets dispensed again and again, whereupon a few of us have to continually reiterate what it factual. Whether it be directed at you or not is not relevant.

Moto_Joe · 08-09-2012, 10:37 PM

Too many people negate proper can design for sound and looks. It is sad really. They are a tuned length.

What people comonly call "back pressure" is not actually that, but are actually reverberation pulses.

As CCM said, there is a REASON the cans are designed as they are. Same with that SRADS often collected different in the 4 to 2 area compared to later gens (correct me if I am wrong here, but srads are 1/4 and 2/3 together to the collector where later gens were 1/2 and 3/4).

all of this stuff matters.

Hacking stuff that engineers did all sorts of R&D on rarely does any good.

**ccmhunt** · 08-09-2012, 10:52 PM

The oem collected 1/2 and 3/4, but good Hindles, not all, the better real Yosh, Skorpion(pre Akra), and some others collected otherwise. Not just this but the third collector was way back and the cans were 19"plus.

Moto_Joe · 08-09-2012, 10:57 PM

Yeah, I put a SRAD Hindle on my 03 to boost midrange because the way it collected 1/4 2/3 iirc, and yeah the hindle can was skinny and LONGGGGGGggggg

**vnms96** · 08-10-2012, 09:15 AM

the m4 can on mine was around 19" also, so instead of ordering a different brand, would you say it's wise to order a replacement m4 can for my bike?

**ccmhunt** · 08-10-2012, 01:27 PM

Is it a bolt on,or a complete system?

**vnms96** · 08-10-2012, 03:40 PM

Complete system. The can slips on the the new midpipe.