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-   -   SE Fatshotz vs Supertrapp Fatshots (https://www.hdforums.com/forum/touring-models/770364-se-fatshotz-vs-supertrapp-fatshots.html)

fj1200 05-26-2012 04:14 PM


Originally Posted by 0ldhippie (Post 9853110)
A allen head with a pin in the middle. All ya need is "Security " allen bit/key. Got mine at ACE. guess ya could dremel the pin out of there too? The security screw is also too short to add discs so ya will need a longer allen screw to do any tuning.

I got a set of bits and a handle at Home Depot (Husky brand). Supertrapp sells the tool as part of their HD upgrade kit. Supertrapp disks fit the HD exhausts.

DeneFXDWG 05-28-2012 09:57 PM

Running SE Fatshotz
 
Just a quick update with my opinions to all those who have helped and responed to my OP. To recap I had Jackpots, Rush True Duals, SE 204 cams and a Ness intake. The sound was tinny and far from deep and horrid on the freeway. I spent a lot on this project over the winter and was worried about dropping more into it to get the deep touring friendly sound I thought I'd have. Well I rolled the dice and after 500 miles the SE Fatshotz, (got them over the Monster Ovals), provide just the sound I was after. I somehow think that the power suffered but keep in mind that I'm not comparing a loud racket with power and low noise with a guttless bike. Time to do another phone call to Supertrapp to find out if the discs are different before I order a whole bunch, (like someone else mentioned), and if there is any point in getting a closed end cap if I think it's already quiet enough, (backpressure / torque issues). Nice muffler system.

flattracker60 03-25-2013 11:17 AM

Anyone know if the two pipes (SE fatshotz and Supertrapp Fatshots) are different internally?

Or are they the same?

0ldhippie 03-25-2013 11:24 AM

While they come with different caps and # of discs, Supertrapp says they are the same internally. I have no reason not to believe them?

'05Train 07-06-2013 10:13 PM

Holy thread resurrection Batman!


Supertrapp says that their version and the Harley version are identical internally. The difference is the name on the side and the EPA stamp. I got a pair of the S/E versions and bought the tuning kit. I'm at 14 discs and a closed end cap, and the bike runs great and quietly. I may be giving up a little on the top end, but so what? The bike makes great power where I am most of the time, and it's crazy quiet - which is what I want.

These are freaking awesome mufflers.

mkguitar 07-07-2013 03:26 AM

I use an internal closed end cap ( painted black) inside the open cone:

http://i367.photobucket.com/albums/o...g/P1030943.jpg

and dummy discs on the left side so the stacks are equal length.

9 discs left, 15 right

2009 , no cat header, 96"

Been using Supertrapps on my Harleys since 1990


mike

'05Train 07-07-2013 09:01 AM

Gotta ask, why would you restrict the flow on the side with less flow? Everything I've read from Supertrapp and elsewhere says to have the disc count the same on either side with a 2:1:2 exhaust.

mkguitar 07-07-2013 10:21 AM

to control exhaust gas velocity.

the left side flows less exhaust than the right

having a wide open muffler would give lower velocity.

high(er velocity) can be used to help scavenging.

I try to get similar velocity from each side.




some mufflers sets are sold with different flow capabilities left and right




mike

'05Train 07-07-2013 11:20 AM

You're never going to get the same velocity or volume from each side given the design of the exhaust. In fact, if you're restricting the flow out of the left muffler, you're further reducing volume, since the exhaust gasses are going to follow the path of least resistance.

With the disc design and the closed endcaps, you've basically eliminated any chance for reversion, and the mufflers are designed to dramatically improve scavenging. Respectfully, I think you're doing the opposite of what you want.

'05Train 07-07-2013 03:56 PM

I wanted to expand on my prior post, and please be assured that I'm not talking down to you, I just want to explain my thought process.....

The new frame uses a 2:1:2 setup. Exhaust gasses will exit the mufflers via the path of least resistance. Right off the bat, on a stock bike, you've got three major bottlenecks; the additional length to the left muffler, the right angle where the crossover goes under the frame, and the crossover itself (which is flattened out). So a stock bike will have less volume of exhaust gasses exiting the left muffler. It would follow that the crimped crossover would increase the velocity a bit, but probably not enough to make it equal between mufflers.

Further restricting the flow of the left muffler creates another bottleneck. While that may also increase velocity, it's going to decrease volume, and at the same time increase both the volume and the velocity of the right muffler.

To make matters worse, IIRC you're running a stock headpipe with the converter removed. So rather than the X-pipe/merge collector that the aftermarket pieces have, you've essentially just got a large plenum with both of the O2 sensors in it, and the exhaust gasses from the cylinders commingling. So when you come off the throttle and vacuum is created, you have the tendency to suck the unburned gasses back into the cylinder(s), not to mention the fact that your two O2 sensors aren't reading the individual cylinders, rather they're getting a composite of the two.

And worst of all, with the additional resistance to flow on the left, you're actually hurting your scavenging by increasing the required pressure for the gasses to pass through.

Even on my bike, with a full-sized crossover, there's going to be greater flow through the right muffler since it's essentially a straight shot.

Velocity seems like a poor choice to make, since volume is more crucial to proper scavenging....Not to mention all the other negative effects of plugging up the left side of the system.


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