does a performance exhaust pipe really make a difference?

[epyon96r]

Im looking at some performance exhaust pipes on ebay and what not and they do not look much better than the stock ones(diameter wise), has anybody hear installed one and can tell me if its a real improvement. Im actually thinking about creating my own.

[inuyasha]

Hi
On a 4t scoot the gains are negligible though the tone is a lot nicer. its the last thing i upgrade when modifying a 4 t
On a 2 t scoot the gains can be quite significant when the pipe is properly matched to the engine
Take care and ride safely my friend
Yours Hank

[carasdad]

EXACTLY as Hank said above. On my 2T the pipe was like night and day..on my gf's 4T the pipe gave a slight increase only...but on the brighter side her engine ran much cooler...and it sounded awesome coming from a Lil Pink Scooter. Even the Harley guys at the local Biker hang out would give give her 2 thumbs up as she roared by...

[techie610]

I agreed with the above posts.
My 2T ran amazingly better, and my 4T did pretty good. About 12 degrees cooler, and 5-7 MPH faster. But, the sound is much better. Gave it a deeper growl, instead of a wimpy Hum.
I opened my stock pipe, removed everything, drilled the inlet hole .25'' bigger, and replace the fiberglass mat. No more baffles, screes, or restricting tubing.

[prodigit]

I just drilled out my 4 stroke exhaust, on both my 50 and 150cc bike, and noticed a decrease in mid-range torque, but also have now a bit heavier exhaust tone.

[epyon96r]

Thanks for the input. Failed to metion, but yea, I am a 4t. with that said, If the exhaust pipe helps a little, would a larger carb be a better thing to upgrade. I already made my free flow muffler, and I was thinking about making a better pipe than the ones I see on ebay using parts from a store I seen on ebay...I would have to take the parts to a local muffler shop since i cant weld :( Just give me any reccomendations, Im all ears.

http://stores.ebay.com/Speedway-Moto...4&_sop=2&_sc=1

[skuttadawg]

If you increased the out flow then you need to install a larger main jet to not be running lean . Some stock pipes are made out of crappy pot metal that rots away and falls apart .

Would help to know if you have a 50 or 150 . Yes there most of the time will be a modest gain along with better sound too . You could drill two holes in the end or cut off the nozzle tip , bore out the hole and weld on a larger tip . To get the most out of a better flowing exhaust a Uni or K&N airfilter can do wonders , even more with a ported head with larger valves . Note exhaust mods as well as airfilter mods both require you to upjet and make take testing a few sizes out in order to fine tune it . I would get a jet kit which has several sizes and is cheaper than paying per jet price . Here is some http://www.partsforscooters.com/Stre...e=21%2C40%2C63

[prodigit]

In my opinion, you don't need to rejet when changing the exhaust. Only when changing the air intake, as it could affect the AF ratio. But the exhaust generally does not affect the AF ratio, it can only limit the amount of fresh fuel/air mixture that enters in a cylinder, by not allowing the cylinder to get rid of all the exhaust gasses at the exhaust stroke.

[epyon96r]

I could see how one would not need to rejet if the difference between the stock exhaust pipe and the performance pipe is minimal. Or If the rider has a stock air box still. Or a stock muffler since that will still keep it restricted. I have a performance air filter and a free flow muffler. I did have to rejet after the air filter mod. The last thing needing to be done would be to upgrade the pipe. might need to rejet after that. I will most likely make one thats even less restrictive than the ones i see for sell.

The exhaust side can affect the a/f ratio as well. I think. Dont quote me lol. I am thinking and I can see your point. I dont know how to explain it, but from working on vehicles, I know that changing headers and pipes and mufflers can increase hp. And that has to come from more air flow.(then the efi would throw in more gas to compensate, or it would need a rejet if carburated)

Then again, maybe the unrestricted exhaust just might let the combusted air out the chamber quicker so there is more room for the already mixed a/f mixture. I think you might be right prodigit...my head hurts :(

Also, would a larger carb be better to? Its a 24mm currently

[epyon96r]

skuttadawg, I have a 150cc

[jct842]

On my 150 I welded up an adapter to screw on a briggs and stratton muffler. Got a tiny bit of gain but the biggest advantage is the weight I lost hanging off the back of the motor. So many have OEM mufflers that viberate, crack, fall off, and ruin the rest of the pipe coming off the head. It was a bunch louder but never got loose or had any problems with it. Along with the muffler I put a free flowing air filter on so I did rejet. As far as loud, no louder than when you mow the grass! Maybe a little less.

[epyon96r]

Ive looked for a briggs and stratton and I cant find one. you got a link for one? Im rocking a shorty muff Its light, but the briggs I seen was even lighter. Heres a pic of mine




When I make my custom exhaust pipe I will get a better muffler. One of these 8x3x3 or 8x3.5x3.5 or 6x3.5x3.5 or a briggs. something small and light. Oh and relatively cheap, these muffs are less than $20

http://www.ebay.com/itm/New-Speedway...item1e7e5e6c2e

http://www.ebay.com/itm/New-Speedway...item1e7e5f9b23

http://www.ebay.com/itm/New-Speedway...item58a30be6e9

[prodigit]

you can make your own muffler very easily.
Just get a pipe, perforate it with many tiny holes. Get a bigger pipe where the smaller pipe fits in, and get 2 lids, to close off the pipes.
The taller the cylinder, the deeper the sound.
The wider the cylinder, the deeper the sound, and the better the muffling.

[epyon96r]

I could make another muff, smaller and skinnier, still with a good diameter inner pipe. The materials wouldnt cost too much, but this ebay muff is cheap as well and would look better than what I could put together(and I wouldnt have to put it together). OR a briggs muff, thats small and cheap too

[Guest_3]

Go big or stay on the porch with the little dawgs. .