supertrapp question

[xman23]

alright if you take off the endcap and all the disks and run it that way would it be bad for your motor, im guessing you would have to rejet it, any ideas? thanx

[nouseforaname90]

People do it all the time. Half of the Supertrapps that I see have no endcap because the person took it off for a louder sound, or they lost it. Go ahead and do it.. it shouldn't hurt anything. It will be more or less a straight pipe and yes you definately will need to rejet.

[Dammit!]

It won't run any better. Only thing it will do is piss people off from being so loud.

[deathman53]

wrong, the end cap is used for tuning the motor for bottom, mid, or top. I have a tc system on my crf450r quad(suppertrapp can) and it is alot of bottom end and mid(open end cap and no discs). I have a 350x supertrapp on my 200x and I have 7 discs and the end cap it is bottom to top, When I reduce the discs, it is more bottom end, and jetting is affected by the amount of end caps too, you have to play with what kind of riding you do and figure it out, then adjust the jetting.

[NOS_350X]

By removing the endcap you will have more of a top end bike. Peak hp will gain quite a bit. By having the discs in there your giving it more backpressure and more torque. I personaly NEVER ride my bike at the lower 1/2 of my power so i want as much on top as i can get.

[Vealmonkey]

I have a harley davidson, and companies have made straight pipes for years. Dyno tests have proven that straight through pipes, no muffler or back pressure of any kind was bad for performance. Dyno tests have shown that a certain amount of back pressure was better for performance. An old trick was if you took a bolt and drilled 2 holes in an exhaust pipe, and you welded a washer onto the bolt inside the pipe, you could turn the bolt with the washer until you had the desired back pressure and than you put nuts on the bolt and tightened them down to lock the washer into position. The best performance was determined while running on a dyno and slowly turning the bolt with a washer and taking the dyno readings.

[xman23]

yea im gonna try her out tonight without the endcap, i have a bigger jet for it already, do you think going from a 120 to a 138 will be fine or dont ya think it will work

[xman23]

i have idea, if i take out all the disks, drill a big hole in the endcap and have someone weld the endcap on becuase my friends is a really good welder, and ideas on that

[NOS_350X]

I have a harley davidson, and companies have made straight pipes for years. Dyno tests have proven that straight through pipes, no muffler or back pressure of any kind was bad for performance. Dyno tests have shown that a certain amount of back pressure was better for performance. An old trick was if you took a bolt and drilled 2 holes in an exhaust pipe, and you welded a washer onto the bolt inside the pipe, you could turn the bolt with the washer until you had the desired back pressure and than you put nuts on the bolt and tightened them down to lock the washer into position. The best performance was determined while running on a dyno and slowly turning the bolt with a washer and taking the dyno readings.

Have you looked at any of the race bikes recently? No high hp bike will have anykind of endcap on them. In hp the name of the game is getting as much air through the engine as you can. Straight out is the best way to do that.

[xman23]

alright im gonna try that then sounds like it will help, and i dont use bottom end very much, i have my trike geared for as much top end as possible so that should help out, any other commets about no endcap?

[xman23]

have any of you guys taken off the cap

[Huffa]

Honestly, they are WAAAAAAAY too loud with no end cap. I'm against it for sure.

Do you have neighbors right around where you plan on riding it like that?

I don't care about performance as much as I care about controlling the sound output. Even if I didn't live close to anyone I wouldn't want one with no end cap. I think they sound like crap that way. Yea, go ahead, try it and form your own opinion as I'm anxious see if you can stand it that loud.

[leprogle]

I've got 18 discs in mine, it said on a pamphlet that came with the pipe, that Supertrapp's R&D dyno tested that with 18 discs, and sufficient intake and jetting modifications, that 18 discs provide max HP for racing applications. I would never run mine without discs. No back pressure would turn your nice Supertrapp into a Cobra or DikGobbler. AKA valve eater. Put lots of discs in it, that'll give you your flow.

[NOS_350X]

I've got 18 discs in mine, it said on a pamphlet that came with the pipe, that Supertrapp's R&D dyno tested that with 18 discs, and sufficient intake and jetting modifications, that 18 discs provide max HP for racing applications. I would never run mine without discs. No back pressure would turn your nice Supertrapp into a Cobra or DikGobbler. AKA valve eater. Put lots of discs in it, that'll give you your flow.


Have you looked into any of the performance exhaust for any of the new quads or bikes??? they are almost all striaght through. Very few arnt. Ive ran bikes with no exhast just a headpipe and valves are A-OK.

And yes it is loud and some sound like crap. BUT it gives you much more top end power. My banshee has more on the mid and bottom than my 350x. Thats just the way i built the engine on my 350x.