i took off about an inch from the header then cut the silencer off.i replaced it with a briggs and stratton silencer,just like the zr pipe.i did'nt touch the belly.with just this i mod and tuning i got good performance all around,bottom to mid was great and a little more top end.i did'nt weld the pipe,i used a rubber heater hose and clamps.not bad for a $10.00 pipe.
I got an old stock pipe that I've cut out about 1" off the header but have done nothing to the chamber. Maybe alittle difference but not much. Hit up hackmunch and maybe he can direct you to the web site the has all the formulas on how to make a pipe for a 2 stroke.....Its more than just cutting and welding, all the sizes make a difference as well. As for welding, have fun melting holes in your pipe (right hackmunch.....lol) braze it like he was saying cause I had to braze his pipe and my own a few times.....pipes broke in different spots the braze always held up.
As it turns out the stock cone size, header and stinger I.D. are pretty close to what they should be. I used java pipe and a bunch of reading on rc and dirtbike sites to get a feel for what I wanted. Used a mig welder and I didn't have any problems with burnthrough. And I'm not that great with a welder. (Its always strong, just not always pretty, hehe)
The most important thing here is to get the header pipe out of the first cone. So make sure you cut the weld off the divergent cone and get that pipe out of there, even if your just shortening the header. Clean it up with some solvent a grinder and a wire wheel before you weld it up.
A wire feed MIG welder is definitly the way to go but I didn't have the extra 250-350 bucks to spend on one and already had the oxy/acet torches at home. I'm going to mess around with the pipe and see what I get.
A wire feed MIG welder is definitly the way to go but I didn't have the extra 250-350 bucks to spend on one and already had the oxy/acet torches at home. I'm going to mess around with the pipe and see what I get.
I am going to try my tiny arc welder on some sheet steel to see if it's going to work okay. If not, I need to cough up and buy some high silver brazing wire. That $hit is expensive, but it's strong and easy to work with. Cutting the pipe up is easy, I have a 10" miter saw that will dice it quick.
Well me and hackmunchhave modded a stock pipe and it doesn't do $hit.....oh wait, I was to lazy to put it on tonite but when i do I'll let all of you know how it works. What we've done is take an inch off the header, remove the excess crap that the manufacturer welded into the header and silencer sides of the expansion chamber and lenghtened the belly of the X-chamberby almost 4 inches. With the formula hack is using this should put the start of our powerband somewhere around 6000-6500 rpm. I'll keep you all posted!!
Well me and hackmunchhave modded a stock pipe and it doesn't do $hit.....oh wait, I was to lazy to put it on tonite but when i do I'll let all of you know how it works. What we've done is take an inch off the header, remove the excess crap that the manufacturer welded into the header and silencer sides of the expansion chamber and lenghtened the belly of the X-chamberby almost 4 inches. With the formula hack is using this should put the start of our powerband somewhere around 6000-6500 rpm. I'll keep you all posted!!
if posible take pictures b4 you put it on
thanks!!
Well guys I added a 3 1/2 in piece of 2 1/4 ID exhaust pipe to extend the belly of the stock pipe and cut off about an inch off the header right at the start of the expansion chamber, cleaned out the extra crap inside of the expansion chamber(meaning the excess pipe left in there from the factory)at header side and the silencer side of the chamberwelded it back together and we tested it today. It made a big difference over the stock pipe, you can actually feel when the powerband hits the pipe. We think that you could actually go longer with the belly and leave the haeder alone but you MUST remove the excess from the inside of this pipe. I can't really say that it's better than the IP-2 or the Jetpro pipes because my stock carb is a piece of trash so I couldn't really get it dialed in right but a definite difference over the stock pipe. If I can figure out how to post pics on here I will have them with a stock pipe next to the pipe we created.
We cut the belly and added 2 1/2 inches to it, cut the header about an inch and a half shorter and took the excess out from inside the belly. It should be back on the bike sometime this week
Has Anyone Attempted To Run The Chamber Under The Frame And Above The Fairings? This Way Muffler Can Be Mounted On The ''swingarm'' Like The Fullsize Sportbikes.i Cant Seem To Keep The Junk Muffler From Snapping Off,what About Using A Silencer Off Of A Small C.c. Mx Bike? Ive Been Running Champion Cj6 Plug ,what Do You Recommend? Any Feedback Will Be Helpful.
I cut the header off this morning and removed the extra pipe in the cone. I also shortened the header 1 inch. I did not work on the belly at this time. I took it for a quick spin a few minutes ago. The changes gave me a considerable power increase all the way through. I also got 2 mph on the top end. The pipe hits harder now, with the power band coming on at 5/8 throttle. I need to install my adjustable jet and do some tuning. Very nice performance boost, the best single mod I've done so far.
The main advantage you will gain with this mod is you will now have the power to regear for more topend, or regear for more lowend to pull sick power wheelies! Give it a try.
Here are two photos of the mod. One shows the pipe after it was cut. The small piece is part of the header that sticks into the divergent cone. This is bad bad bad. Removing this is the main reason I cut my pipe. The other photo is the pipe ready to weld together. The header has be shortened about 1 inch. This reduces the pipe length to the convergent cone and raises my power band rpm. The effect on performance was very noticable. No tiny incremental increase here, lows and mids are very nice and the pipe kicks at 5/8 throttle.
Nice job EoD. If you are mainly interested in top end, you don't need to add to the belly. Although Iam glad I did. It pulls harder in the low to med range which is what I needed for short tracks and parking lots. Gets "on the pipe" sooner. I wouldn't add more than 2.5 inches though or you'll be sacrificing peak power.
As I recall, the stinger (muffler end) was also too short and was sticking into the cone, but not as much as the header was. I made a new longer stinger out of thicker walled pipe (same id) and cleaned up the joint on the stinger end of the cone too. Iam not sure how much difference that made because I did it all at once. But the stinger breaking off was what caused me to cut it up in the first place. And I figure every little bit helps.
Hey! make sure you check your plug to make sure your not running too lean!
Took some drilling on my jet to get the plug brown again. I also bored the carb out a bit with a slight flare on either end for better venturi action, that helped.
i just want to say a few comments here! me and eviloompa modded stock pipe (he allready said so in earlier post) 1st off i will say that it did gain some hp but still no where near the rpm range that ip2 pipe has! i think if you can extend belly about 6" longer than factory and keep header short this would be a good low end pipe for someone that does not have the $ for a real performance pipe! on another note take ip2 and extend header about 1" and see how that pipe can really haull as$!!! me and evil will prob extend belly to 6" and try it out! good luck guys
Nice job EoD. If you are mainly interested in top end, you don't need to add to the belly. Although Iam glad I did. It pulls harder in the low to med range which is what I needed for short tracks and parking lots. Gets "on the pipe" sooner. I wouldn't add more than 2.5 inches though or you'll be sacrificing peak power.
As I recall, the stinger (muffler end) was also too short and was sticking into the cone, but not as much as the header was. I made a new longer stinger out of thicker walled pipe (same id) and cleaned up the joint on the stinger end of the cone too. Iam not sure how much difference that made because I did it all at once. But the stinger breaking off was what caused me to cut it up in the first place. And I figure every little bit helps.
Hey! make sure you check your plug to make sure your not running too lean!
Took some drilling on my jet to get the plug brown again. I also bored the carb out a bit with a slight flare on either end for better venturi action, that helped.
have fun with it...
Thanks. You do get a nice increase in the lows/mids from just cutting that extra pipe out of there. It really hamstrings the pipe. I didn't want to add belly as it would increase my total length and I wanted a litlle more top end. Considering how little I changed the pipe, the difference is surprising.
Well...my stock pipe cracked at one of the joints, while it was on it was a monster though! I put my friends stock pipe from his pollini. Great power band and looks sick on there too. Works just as good as my modded stock pipe, if not a little better. Took a little bit or heating to the header to bend it to make the pipe clear the head.
