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CVO Technical => Intake/Exhaust/ECM => Topic started by: Jbbrown73 on October 04, 2018, 10:00:04 AM
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My ‘17 Road King with the 107 has a Fulsac head pipe and K&N breather. Dyno tuned by Jason at C&S in metro east STL. Bike runs great, no issues. I had CFR’s and it had a very noticeable dip in the 2,000-3,000 RPM range. Noticeable in both the dyno graph and the butt dyno. I went with 2” Fulsac cores in the stock muffler housings and that torque dip is definitely gone. However, the sound is very anemic. The sound is just about like stock. I have respectfully named the bike a Yamahog. With that said, is there a muffler set out there that has enough back pressure to keep the torque in the low rpm band and make it actually sound like a Harley?
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My ‘17 Road King with the 107 has a Fulsac head pipe and K&N breather. Dyno tuned by Jason at C&S in metro east STL. Bike runs great, no issues. I had CFR’s and it had a very noticeable dip in the 2,000-3,000 RPM range. Noticeable in both the dyno graph and the butt dyno. I went with 2” Fulsac cores in the stock muffler housings and that torque dip is definitely gone. However, the sound is very anemic. The sound is just about like stock. I have respectfully named the bike a Yamahog. With that said, is there a muffler set out there that has enough back pressure to keep the torque in the low rpm band and make it actually sound like a Harley?
IMO the SE Street Cannon's are often overlooked
I'd ask Jason,, he's a pro at what he does.... MKE 8's are exhaust finicky :-\
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I had the RC Components on mine when I bought it new. Then added the RC Components Tormentor head pipe. I really like the looks of it. But it REALLY made the slip ons loud! So I purchased and installed the SE Street Cannons. For me it is the perfect combo of power and exhaust note. JMHO.
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My ‘17 Road King with the 107 has a Fulsac head pipe and K&N breather. Dyno tuned by Jason at C&S in metro east STL. Bike runs great, no issues. I had CFR’s and it had a very noticeable dip in the 2,000-3,000 RPM range. Noticeable in both the dyno graph and the butt dyno. I went with 2” Fulsac cores in the stock muffler housings and that torque dip is definitely gone. However, the sound is very anemic. The sound is just about like stock. I have respectfully named the bike a Yamahog. With that said, is there a muffler set out there that has enough back pressure to keep the torque in the low rpm band and make it actually sound like a Harley?
The low-end TQ dip with the FS header and CFRs was caused by the lack of restriction (resulting in a lack of "back pressure") in that setup. Of course, it also gives plenty of volume, like racing pipes.
Now, with the non-cat FS header and the 2" baffles, you still have a low-restriction header but a semi-restrictive muffler. It gives enough restriction to maintain TQ at the low end, but naturally it loses volume.
The upshot: the laws of physics require a certain amount of restriction to keep the low-end TQ, either in the header and/or the mufflers. Since the mufflers are designed specifically to reduce sound volume, the solution is to get a more-restrictive header and a muffler designed to "tune" the sound and not reduce the volume so much. A good setup would be the stock header paired with the CFRs (or any megaphone type muffler; mine only cost $185--enough restriction to keep low-end TQ, with mufflers that have good quality sound and high volume. This will get you much closer to what you want, although it won't be as loud as the FS header with CFRs.
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The low-end TQ dip with the FS header and CFRs was caused by the lack of restriction (resulting in a lack of "back pressure") in that setup. Of course, it also gives plenty of volume, like racing pipes.
Now, with the non-cat FS header and the 2" baffles, you still have a low-restriction header but a semi-restrictive muffler. It gives enough restriction to maintain TQ at the low end, but naturally it loses volume.
The upshot: the laws of physics require a certain amount of restriction to keep the low-end TQ, either in the header and/or the mufflers. Since the mufflers are designed specifically to reduce sound volume, the solution is to get a more-restrictive header and a muffler designed to "tune" the sound and not reduce the volume so much. A good setup would be the stock header paired with the CFRs (or any megaphone type muffler; mine only cost $185--enough restriction to keep low-end TQ, with mufflers that have good quality sound and high volume. This will get you much closer to what you want, although it won't be as loud as the FS header with CFRs.
I was going to replace the head pipe, mufflers, and add a tuner. But, i'm thinking now I just may leave the stock head pipe and put SVT BoneShakers on my bike.
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I was going to replace the head pipe, mufflers, and add a tuner. But, i'm thinking now I just may leave the stock head pipe and put SVT BoneShakers on my bike.
will you be able to use stock heat shields with that? I have the same questions as you
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100%. I have pics of the install on my exact bike w/SVT's.
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Kuryakyn crushers gave me a torque curve that comes straight up off of idle and stays extremely flat through the power curve. Just dont get the crusher maverick's Steve with GMR Performance recommended them a few years ago.
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100%. I have pics of the install on my exact bike w/SVT's.
Can you post those pics please?
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Can you post those pics please?
Here you go:
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Thanks!
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Hey, peeps, I know its 11:45 for this thread, but.....JB, what I've done on every set of FULLSAC baffles I've owned is cut off the portion of pipe that continues past the rear flange of the baffle. This makes a nice echo chamber out of your 4" endcap and gives it a "big boom" sound in MHO. YMMV, but worth a thought
Laters...and happy thanksgiving everyone!
Bobby
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IMO the SE Street Cannon's are often overlooked
I'm getting ready to purchase an '19' SERG, previous owner put the SE Street cannon's on, i have Fullsac on my 12 SESG and love them, but you have me thinking now..are you happy with the cannons?
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IMO the SE Street Cannon's are often overlooked
I'm getting ready to purchase an '19' SERG, previous owner put the SE Street cannon's on, i have Fullsac on my 12 SESG and love them, but you have me thinking now..are you happy with the cannons?
My experience with the SE Street Cannons: On my M8 107", I added the Stage 3 kit, so it's 114" with 11:1 pistons (higher compression makes more sound). I kept the stock header and put on M8 Street Cannons. Terrible sound, barely louder than stock mufflers (although they look better than stock), and a real waste of money. So I ditched the Cannons and put on a set of $185 generic megaphones (similar to CFRs). Result: Big improvement in sound. Note, though: generic megaphones aren't "tuned" for sound quality the way CFRs, V&H, etc. are...so you do get better sound results for the extra $500 to $600 cost.