Holeshot Headers with Stock Cans

[UselessPickles]

I recently had fun installing Holeshot headers on my GenII (2007) bike with stock cans. The following info may help others decide whether to go with this combination:

• The stock mufflers won't fit on the Holeshot header unless you get the flange expanded slightly. Just take the headers and the mufflers to a muffler shop and ask nicely. A Midas shop allowed me to pay one of the employees cash ($15) to do the job.
• The header gaskets that are sold on the Holeshot website are the same as the stock header gaskets, so you can purchase them from whatever source is convenient for you (but it is not recommended to re-use the originals).
• There are mounting points near the center stand that are used to mount the stock headers. These mounting points are not used by the Holeshot headers. On a GenII bike, these mounting points touch the Holeshot Headers (and scrape the pipes). I chose to just cut these mounting points off with a Dremel + cutoff wheel.
• After getting the mounting points near the center stand out of the way, the center stand mounting bolt heads are the next thing in the way. One of the bolt heads must be ground down a bit (a Dremel works...). The contact between the bolt and the pipe is not obvious. Test fit the right header on the bike then stick your head under the bike to look up and see which part of which bolt must be ground down. If you don't fix this, you'll suffer from an annoying metallic buzzing sound at higher RPMs when the pipe vibrates against the bolt head.
• The service manual calls for removing tons of stuff from the bike (including gas tank and radiator) to take the headers off. It can be done by removing only the lower fairings and unbolting the lower mount of the radiator. The radiator can then be pulled away from the engine slightly and held by a second person or a couple zip-ties around the front wheel. A universal joint and extension for your ratchet will be needed to reach the header nuts.
• I took my bike in to get a custom PCIII fuel map tuned. With all the complexities and catalytic converters in the stock mufflers, they could not feed a tube deep into the exhaust system to analyze the exhaust for A/F ratio measurements. The shop would not tune my bike because they felt they would be wasting my time and money by doing so without a reliable exhaust analysis. Maybe it could be done if rivnuts were installed on the headers?
• The bike sounds like
  with Holeshot headers and stock mufflers*
• I will not attempt to comment on power gains, as I have not had the bike on a dyno. I won't even speculate.
• There is noticeably less heat coming up from below the bike when in slow traffic or stopped at lights on a hot day (I actually haven't noticed any heat in such conditions since I installed them, but I also wasn't consciously looking for it).

*Note: my bike also has a modded airbox, which may affect the sound a bit.

I'm happy with the reduced heat and change in sound. The sound isn't fully captured in those videos. The difference was enough that wife commented on the improved sound when she heard me start it up (she was in the house and not caring about what I was doing to my bike).

I am a bit uncomfortable not having a custom tuned fuel map, but the tuner told me that the stock mufflers are probably restrictive enough to limit airflow improvements of the new headers to the point that a fuel map for stock exhaust should be close enough (not as smooth or powerful as it could be, but also no danger of damaging the engine). I plan to save up some money and watch out for anyone selling used slip-ons so that I can install them and get the bike properly tuned. I think I'm leaning toward Remus Hexacones; now I just need to win the lotto.

 

[ponyfool]

If you aren't using the lower header mounts, what's holding all of it together? The allen bolts at the engine and the muffler mounts by the rear pegs? That's it?

 

[UselessPickles]

If you aren't using the lower header mounts, what's holding all of it together? The allen bolts at the engine and the muffler mounts by the rear pegs? That's it?

That's correct. I seem to remember Dale Walker posting an explanation for his decision to not use the lower mounts, saying that the new headers are much lighter and don't really need the extra support.

 

[v65]

If you aren't using the lower header mounts, what's holding all of it together? The allen bolts at the engine and the muffler mounts by the rear pegs? That's it?

That's correct. I seem to remember Dale Walker posting an explanation for his decision to not use the lower mounts, saying that the new headers are much lighter and don't really need the extra support.

I haven't mounted mine yet. I wonder how these will work when it comes time to jack the bike?

 

[jordylad]

Thanks for the excellent report.

Just wondering, why don't you like the Holeshot cans to go with your headers?

 

[radman]

Have been running the header with stock muffs almost 2 years now, I have one of the originals. The Holeshot muffs combined with the header can get tiring over time, like a trip-the stock muffs on the other hand, combined with the header give the most perfect sound, quiet at speed but a nice mellow rumble below 3000 rpm. Tunnels sound great..... No issues raising the front of the bike multiple times with the header. PM me with your email addy for a nice map, Gen I, dyno style, header and stock muffs. Ponyfool-the system is strong enough once assembled to never be a problem concerning the missing center mounts.

 

[UselessPickles]

Just wondering, why don't you like the Holeshot cans to go with your headers?

I prefer the looks of the stock cans (although I'm beginning to like the Remus Hexacones) and also don't want something that's too loud. A limited budget is also forcing me to add upgrades in small steps. I'll have plenty of time to decide on which slip-ons to get before I have the funds to cover the slip-ons and dyno tuning .

 

[UselessPickles]

Updated original post with info about grinding down a center stand mounting bolt to avoid annoying metallic buzzing sounds at high RPMs from the pipe vibrating against the bolt.

 

[Fairlaner]

Hexacones will not fit on a the Holeshot headers.

r

 

[ctfjr]

Updated original post with info about grinding down a center stand mounting bolt to avoid annoying metallic buzzing sounds at high RPMs from the pipe vibrating against the bolt.

Great write up UselessPickles, thanks. Do you think not grinding down the bolt but rather filling the space between the bolt & pipe with high temp silicone would accomplish the same thing? ie eliminate the contact & buzzing.

 

[UselessPickles]

Great write up UselessPickles, thanks. Do you think not grinding down the bolt but rather filling the space between the bolt & pipe with high temp silicone would accomplish the same thing? ie eliminate the contact & buzzing.

For one of the bolts, there is no space between the bolt and the pipe. Maybe the best solution would be to grind it down a little to make some space that can then be filled with the silicone. .

 

[Geezer]

If I read your post correctly, you used the gaskets between the header and mufflers and had to have the muffler ends expanded a little to make them fit. So, if you chose to leave out the gaskets, then do you still need to expand the muffler ends?

I am running the full Muzzy 4-2-1 system and there is no gasket where the muffler attaches to the header. Seems to work fine.

 

[radman]

No way the stock muffs will fit using the gaskets-header designed to eliminate them. He's talking about the header to head gaskets.

 

[double_entendre]

I recently had fun installing Holeshot headers on my GenII (2007) bike with stock cans. The following info may help others decide whether to go with this combination:
<SNIP>

[*]I will not attempt to comment on power gains, as I have not had the bike on a dyno. I won't even speculate.

[*]There is noticeably less heat coming up from below the bike when in slow traffic or stopped at lights on a hot day (I actually haven't noticed any heat in such conditions since I installed them, but I also wasn't consciously looking for it).

*Note: my bike also has a modded airbox, which may affect the sound a bit.

I'm happy with the reduced heat and change in sound. The sound isn't fully captured in those videos. The difference was enough that wife commented on the improved sound when she heard me start it up (she was in the house and not caring about what I was doing to my bike).

<snip>

So you've got headers but still have the stock catalytic converter and mufflers? I'm confused. Where would the heat reduction come from? And why would the bike be any quieter or louder if the mufflers were unchanged? I wouldn't think that the headers would make a difference in sound level on their own....

Rancho

 

[UselessPickles]

So you've got headers but still have the stock catalytic converter and mufflers? I'm confused. Where would the heat reduction come from? And why would the bike be any quieter or louder if the mufflers were unchanged? I wouldn't think that the headers would make a difference in sound level on their own....
Rancho

The stock headers contain catalytic converters (underneathe the bike, in the perfect position to heat up your feet/ankles when stopped at a traffic light). Those catalytic converters do not exist in the Holeshot header. There are still catalytic converters in the stock mufflers, but those are not really in a position to radiate heat onto the rider.

As for the sound, there is a noticable difference. Part of it could be due to the larger header pipes (I believe they are 1/8" larger in diameter than stock). Part of it may be due to the 4-into-2 design rather than the 4-into-2-into-1-into-2 design of the stock headers (plus the stock header has a connector pipe between the header pipes for cylinders 2 and 3). Part of it could be due to the less restrictive airflow through the headers due to the gentler curves and lack of catalytic converter. The mufflers muffle the sound that comes out of the headers. If you change the sound that goes into the mufflers, then the sound coming out of the mufflers will be different.

 

[SkooterG]

There are NO CATALYTIC CONVERTERS in the FJR's mufflers. Only in the header.

 

[UselessPickles]

There are NO CATALYTIC CONVERTERS in the FJR's mufflers. Only in the header.

I guess there must just be quite a mess of metal structure at the front end of the mufflers (at the pipe end, not the exit hole end) for muffling purposes that could be mis-identified as a catalytic converter. The guy at the dyno shop said there was a catalytic converter in there after inspecting the muffler to see if he could somehow drill a small hole through it to get an exhaust analyzer all the way through and into the header pipes.

 

[Fairlaner]

There are NO CATALYTIC CONVERTERS in the FJR's mufflers. Only in the header.

I guess there must just be quite a mess of metal structure at the front end of the mufflers (at the pipe end, not the exit hole end) for muffling purposes that could be mis-identified as a catalytic converter. The guy at the dyno shop said there was a catalytic converter in there after inspecting the muffler to see if he could somehow drill a small hole through it to get an exhaust analyzer all the way through and into the header pipes.

Sounds kinda strange to me.....

As far as the header bracket under the bike goes all i did was bend it out of the way with a **** offfff hammer then had no trouble. When i reinstalled the stock header last week i just bent it back into place and Bobs your uncle.

R

 

[FJR919]

There are NO CATALYTIC CONVERTERS in the FJR's mufflers. Only in the header.

I beg to differ. It's my understanding that the Gen II added a cat in each muffler for a total of four.