KX 125 help

[Drewltr450]

My friend wants a pipe for his kx125 what pipe makes the best gains?

[krt400ex]

i prefer the fmf fatty header with their shorty silencer. the fatty adds more through the whole range with a the most right in the middle. the shorty helps the bottom and midrange. the bike should run stronger off the bottom and midrange. that is where it will do its best work and it will still pull hard and cleanly right into the top.

if you like more top end go with their power core 2 silencer and the SST header. pro circuit is good too, but i dont like them as much.

[SET THE STAGE]

Originally posted by krt400ex
i prefer the fmf fatty header with their shorty silencer. the fatty adds more through the whole range with a the most right in the middle. the shorty helps the bottom and midrange. the bike should run stronger off the bottom and midrange. that is where it will do its best work and it will still pull hard and cleanly right into the top.

if you like more top end go with their power core 2 silencer and the SST header. pro circuit is good too, but i dont like them as much.

2-stroke silencers won't show any noticeable power differences, just sayin'. a lot of my friends throw silencers on their stock pipes because they're too lazy to rejet and just want the look.

[krt400ex]

Originally posted by SET THE STAGE
2-stroke silencers won't show any noticeable power differences, just sayin'. a lot of my friends throw silencers on their stock pipes because they're too lazy to rejet and just want the look.

thats funny cuz i noticed the difference between that and the pro circuit factory silencer i have. the factpry silencer helped it pull the to end...and the shorty gave it noticeably better bottom

[SET THE STAGE]

placebo effect.

[krt400ex]

lol. sorry for all the spelling mistakes. on a laptop. not used to the keyboard

[John451]

Originally posted by SET THE STAGE
placebo effect.

Nope. It gives a lil power. Look up the dynos. I've done em myself for clients and they give more power, usually around 2-4+ hp

[SET THE STAGE]

Originally posted by John451
Nope. It gives a lil power. Look up the dynos. I've done em myself for clients and they give more power, usually around 2-4+ hp

i'm sorry, but i refuse to believe gaining 2 to 4 horsepower by swapping out an extension to an expansion chamber.

[John451]

Originally posted by SET THE STAGE
i'm sorry, but i refuse to believe gaining 2 to 4 horsepower by swapping out an extension to an expansion chamber.

Its basically the same thing as a muffler on a car, you can get the different ones to increase power. I know the dirtbikes have the expansion chamber and all but if you compare the sound of it withhout the silencer to it with it, it's louder without it so it's doing something.. But it's not really GAINING any physical power but it's gaining HP in the way of taking power from one section and moving it to another.. So if it has all bottom end, you get a longer pipe to move more power to the topend by giving it more back pressure. But at the same time it decreaases the bottom end a little but putting it on the dyno proves that it gives it a better HP rating than stock becasue it's putting the power to better use so it can shift better and accelerate much faster.

[CSR400EX]

Originally posted by krt400ex
thats funny cuz i noticed the difference between that and the pro circuit factory silencer i have. the factpry silencer helped it pull the to end...and the shorty gave it noticeably better bottom

agreed, i used to race dirt bikes and soon will again, but i could definitely tell a difference in a short silencer vs. a regular length one. short ones give it more bottom for tight tracks like indoor racing, and the longer ones give more over rev power for long straights.

[Drewltr450]

shorty im guessing is going to be intensly loud?

[krt400ex]

they are loud, but they sound nice and they are not all that much louder than the regular length.

[John451]

Originally posted by krt400ex
they are loud, but they sound nice and they are not all that much louder than the regular length.

Yeah, Im runnin a shorty on my 250 which most people find doesnt work because they've never heard of a JET. But it does make a difference in low end over the stock pipe. If you get a pipe that's longer than stock it gives it better topend.

[sc400ex_rider]

shorty silencers add power read any manufacturer's ad's. same thing as long tube headers vs shorties, tri-why headers even 180 degree headers and crossover tubes, it all does some thing. why do the banshee sand dragers run no silencer?.....the perforated core creates turbulence which creates back pressure the shorter the core the less turbulence the less back pressure. WOW some people dont know chit. just cause some billy bob never heard of it dont make it not true. if you dont know what non of this is READ :rolleyes: