Jetting for Power Up w/stock tip


9 replies to this topic
  • PBR_StreetGang

Posted May 10, 2005 - 08:03 PM

#1

Maybe I'm looking in the wrong place, but I'm looking for jetting suggestions for a dual sport ride coming up. I bought the bike completely uncorked and re-jetted including HRC exhaust tip and drilled sideplate. It runs great, but I need to pop in the stock exhaust tip to keep the noise down for the D/S ride, which should make my jetting too rich. What should I be using for jetting so it isn't impossible to start when hot with the stock tip?
Thanks

  • SaltyWalrus

Posted May 11, 2005 - 03:08 AM

#2

Instead of throwing on the stock tip, you might consider inserting a 90 degree downspout into your HRC tip. I think it would give you the noise reduction you are looking for without the need to change your jetting.

  • needsprayer

Posted May 11, 2005 - 04:59 AM

#3

Like this

Exhaust tip

  • TimBrp

Posted May 11, 2005 - 05:51 AM

#4

That's a nice setup needsprayer. I see you have the subframe ext. too. Nice. However, that insert looks smaller in diameter than the HRC tip. Think it restricts flow any???

  • needsprayer

Posted May 11, 2005 - 06:13 AM

#5

TimBrp,

It's a pretty close fit (within 1.5 mm all the way around) with a little JB Weld between the two walls. So allowing for the thickness of the pipe the inside diameter has probably been reduced about 5-6 mm. I didn't notice any difference in power delivery and I am happy about the sound being directed towards the ground.

NP

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  • TimBrp

Posted May 11, 2005 - 06:30 AM

#6

Nice. I'm going to work on something this weekend for it. I bet it would help with sound testing for sure. Thanks N.S.!

  • Roll_it_on

Posted May 11, 2005 - 12:03 PM

#7

Needsprayer,

Can you tell a difference in the perceived sound level after you made the mod? Have you ever had it sound checked the way you currently have it set up? I have been thinking about doing the same thing and I was curious as to your results.

  • needsprayer

Posted May 11, 2005 - 04:10 PM

#8

Roll_it_on,

I have not had a sound check but I can say that the sound has less bark and more rumble. If you stand behind an HRC exhaust (about 3 feet back) the exhaust POUNDS you in the chest. With the downtube the exhaust pounds the ground and the sound energy is absorbed quicker by the ground than it is by the air.

  • PBR_StreetGang

Posted May 11, 2005 - 06:08 PM

#9

I like that downturn outlet. I have seen aftermarket ones for around $100 that claim 96dB if I remember correctly. One of the reasons I hadn't pursued that was that the PO cut out the spark arrestor screen from the hi flow tip and I didn't want to throw more money at a half-assed solution that wouldn't work on ORV areas. But now that I think about it, it says it is an S/A on the outside and there's no way to get a rod past the 90 degree bend!!!!!

  • Roll_it_on

Posted May 11, 2005 - 09:14 PM

#10

Roll_it_on,

I have not had a sound check but I can say that the sound has less bark and more rumble. If you stand behind an HRC exhaust (about 3 feet back) the exhaust POUNDS you in the chest. With the downtube the exhaust pounds the ground and the sound energy is absorbed quicker by the ground than it is by the air.


Thanks for the info. I think I will give it a try :)





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