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Discussion Starter · #1 ·
So I have been looking at different options for my exhaust, and have realized that they are all very expensive. After looking I decided I really like the short pipes, (not exactly sure what you call them. The ones that barely stick out from the bottom of the bike). It got me wondering if it was possible to use some of the short ones that you can get from Auto zone. If its possible it might help me get rid of the giant thing I have right now.
 

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fatass needs corndogs
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Back pressure effects air flow. Anything is possible with the right fuel settings whether that be carb or EFI. It may work but expect to lose power until you get the right setup.
 

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lɐʇuǝɯᴉɹǝdx&#4
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If you mean something like a short glasspack "Cherry Bomb" muffler, I don't see why not. When I get to that point, I'm considering just putting some cheap small glasspacks from Summit on the end(s) of my headers / collector. I expect a couple 9 inch long, 3" OD, 1.75" ID glasspacks (for $14 each) could work great.

And yes, ideally you need to adjust jetting / fuel balance for any intake / exhuast changes.
 

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A buddy of mine has a lil autozone special rice burner "performance" muffler on his kat. You know the muffler u put on to make ur car sound like it doesnt have a muffler lol.
It works great and sounds pretty ok too.
We put in stage 2 jets and re-synched carbs. Runs great looks pretty good too.

Sent from Motorcycle.com Free App
 

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Discussion Starter · #6 ·
Hmm... I really want to do this, and my bike needs re-jetted anyway. The guy before me did something and right now it does not run optimal. I just am not really sure what I am doing when it comes to Jetting so I haven't done it yet. But it is good to know it is possible.
 

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The reason those exhaust systems are so expensive is that they are engineered through a good deal of testing to provide the right back pressure and vacuum at the exhaust outlets while reducing weight, fitting up perfectly and looking good. Then comes the brand name.

Feel free to skip the next few paragraphs if you don't care about the why and the how.

The waves of pressure in the exhaust gases and the sound waves influence the engine's ability to vacate exhaust gases from the cylinders. When engines develop their best horsepower and torque at a certain RPM range, it has to do with this phenomenon as well as a variety of other factors. At any RPM, there are negative pressure waves (vacuum) occurring at the exhaust outlets, as well as positive pressure wave, like the sucking and pushing of an ocean wave at the beach. Engine tuners will design exhaust systems so that at a certain RPM range (based on personal preference) those negative pressure waves are synced with the exhaust valves opening so that they suck exhaust out of the cylinder.

This allows for valve overlap. Normally the exhaust valve is closed during the intake stroke and vice versa. However, we now have a force sucking exhaust out of the cylinder. Combine that with the fact that the hot exhaust won't mix well with the cold intake and we can now keep the exhaust and intake valves open simultaneously without exhaust accidentally going out the intake valve into the intake manifold. Basically, the engine can "breathe" better, which is a term you'll hear people say a lot. Increasing the flow of gases per second allows greater power output.

You've probably seen "VTEC" written on the side of a car more than once. It stands for variable timing exhaust cams. The timing of the cams in this case is synced to the pressure waves in the exhaust system at a range of different RPMs, which essentially makes the power curve straighter.

----------------------------:sleep:

To be clear, any exhaust that you buy from a major company is going to be better than something you make yourself unless you are an engineer. If you want to go cheap, you WILL get cheap results. That's not to say that a slip-on and a set of custom headers isn't going to work ok for you. The rejetting is best done by a professional; it's not easy to do right and if you want your bike to run optimally, expect to spend many hours of trial and error until you get it right (maybe) if you plan on doing it yourself.

My recommendation is going with a name-brand slip-on or full system and then taking it to a shop to get rejected professionally. The results are worth it.
 

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Look on CL I just found a m4 exhaust really cheap
It's one that just pops out behind your foot.

Also you could buy a used exhaust chop it and make it just pop out the bottom. I have a yoshi with mid pipe and springs I'll sell you for $75+ shipping you can chop up and mount right behind your rear set
 

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Fooking old git
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Sorry to disagree, A stainless steel system cat back for my Alfa cost £300. Thats two boxs and lots of pipe.
A brand name slip on can cost double, most power gains on a bike exhaust are with the headers, these are expensive for no reason than they are " bike exhaust with loads of R&D and a small market" so since when has a world wide market numbering 1000's of sales a small market?
Don't be brain washed, you pay through the nose because its for a "motorcycle"
Set of 4 tyres for my Alfa, 16" rims mid range, £70 each, £280. Rear tyre for the R6 £120. How many tyres do Bridgestone sell a year?
Just compare like for like, car V bike, ?????????

I run a stubby can with a dp killer insert, for back pressure, direct from the down pipe collector, K&N a/filter, Dynojet with some dyno time, I spent less on the dyno time than on a "brand" system?

Have fun
 
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