i did the 3/8" 6 holes and like it but wonder if 8 1/2" holes would be better. Any opinions

 

probably wouldnt hurt, but would it be worth taking it back apart and rewelding again? probably not worth the trouble. Im not for sure if its the same on these bikes but with most engines there is a point where you start to loose torque, it might help HP at 6500+ rpms. Torque is what you feel (seat of the pants) HP is a result of torque brought higher up the RPM range. So the best running engines are going to have a very smooth steady torque curve. I would much rather have an engine with say 100lbs of torque with a steady dyno curve than one that went straight up to 150LBs then fell back off. Sorry about the rant. This might not even apply to your application. Im sure someone has tried it.

 

wildrides, mine is like what you want. I have eight 1/2" holes drilled and the spark arrestor removed. Mine is a little louder than nyrocs but not as loud as an HMF. I think it sounds great.

Also, I have tons of torque, nyroc watched me today on a wet paved road just blimp the throttle in high range and the front wheels come off the road a couple of feet with ease. What Im saying is you wont loose torque with the eight 1/2" holes.

Im just needeing mid/top to topend power now. I know the plan I have will work though, just need to impliment it.

wildrides, before I did my cold air intake on a new 03 air filter and rejetted, nyroc was just as fast if not faster than me. So, if you like a little extra noise do it my way, if you would like a quiter pipe do it nyrocs way.

Ill tell you what you can do that I did. After cutting the end cap off with a portable band saw I had the spark arrestor cut out at that time. After I had drilled six 1/2" holes I held the endcap back on and started the P650 and listened to it run. You can do the same thing to determine how loud you like it.

 

Wildrides, 12 ....... 1/2 inch holes!!!

 

The pipe mod will be louder and if you cut out baffle at end,it will not be legal to ride on forest service land. I was just putting trying no to be noisy and was lucky not to get checked with no spark arrester. I went with the hmf eco series ,not as loud. power seemed better.

 

Travelor,
FYI: I did the Nyroc mod, but I also added a home-made spark arrestor screen to the inside of the end cap piece. Of course, this spark arrestor is not U.S. Forest Approved, but it gives me a little more piece of mind (in addition, it keeps sticks, rocks, etc. from going into my muffler and getting stuck there.). Just food for thought.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Hey KOD,whats nyrocs way,with the spark arrestor in??Do you have to re-jet?

 

Pretty sure nyroc did the 3/8" holes not the 1/2" holes and maybe 6 like I did. with the end opened up.

Look at his site.

you will probably have to rejet if you add a better air filter with the muffler mod.

 

Thats right, nyroc did six 3/8" holes and I did eight 1/2" holes. As far as rejetting goes, Im not sure if you "need" to or not. That would depend on many things, most importantly how its running.

I did the mod to be able to rejet and flow more air, I also went with the DG snorkel.

 

After I did my mufler mod ,I was worried about fires. I would sugest using a spark arrester.