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View Full Version : 3" Internal Discs vs 4" Fat Shots for FLH



warwick
09-22-2009, 12:58 AM
Hi. I´m new to this forum.

1) What are the differences in terms of torque/hp and sound level adjustability of the Fat Shots compared with the 3" 2+2 Internal Disc mufflers?

2. Can you get the fat Shots with a BLACK closed end cap?

3. Since there is no end cap covering the discs, I wonder if there is a potential sooting problem?

4. Since discs and screws are exposed to rain and dirt, is there any corrosion problem?

Thanks for your answers

bschultz
09-22-2009, 07:15 AM
Hi. I´m new to this forum.

1) What are the differences in terms of torque/hp and sound level adjustability of the Fat Shots compared with the 3" 2+2 Internal Disc mufflers?
On a stock machine torque/hp gains will differ little; however the Fat shots have more potential for gains as modifications are introduced. In most cases the 3" units will be slightly quieter on the same machine due to the size of the discs and the cosmetic end cap.

2. Can you get the fat Shots with a BLACK closed end cap?
Yes, as an additonal optional accessory.

3. Since there is no end cap covering the discs, I wonder if there is a potential sooting problem?
There is an end cap on both units; however exhaust sooting is usually an indication of rich running condition or a potential internal engine problem.

4. Since discs and screws are exposed to rain and dirt, is there any corrosion problem?
All disc assembly components are made of stainless steel.

Thanks for your answers

************************************************** ********

warwick
09-22-2009, 07:45 AM
Thanks for your replies.

What are the main differences between the HD SE Fat Shots and the ST version?

bschultz
09-22-2009, 08:27 AM
The Disc Assembly (screws/number of discs/end caps).

warwick
09-22-2009, 02:48 PM
Would you please elaborate?

bschultz
09-23-2009, 07:24 AM
Screws, security (HD) vs. allen head (SuperTrapp)

10 discs per muffler assembled on HD "FATSHOTZ" vs. 24 disc included w/SuperTrapp "FatShots".

Open end cap HD FATSHOTZ vs. Closed end cap w/SuperTrapp FatShots

Black coated aluminum trim ring HD FATSHOTZ vs. Polished aluminum trim ring w/SuperTrapp FatShots

and of course the the logo's, SceaminEagle vs. SuperTrapp, on the muffler body

fgizzo
10-21-2009, 02:05 PM
I understand the fatshotz will not work on older touring bikes since the right and left mufflers flow differently. Can anyone confirm that. I would like to put these on my 2004 CVO 103" Electra Glide.

Thanks

bschultz
10-21-2009, 03:21 PM
The Screaming Eagle FatShotz and the SuperTrapp Fatshots will fit earlier models. There are NO differences in the core/baffle assemblies between the left and right sides. The Screaming Eagle FatShotz will provide MORE sound on an earlier bike due to the "open" end-cap vs the "closed" end-cap supplied with the SuperTrapp FatShots.

fgizzo
10-21-2009, 03:44 PM
Thanks for the quick info, if I try these it will be my 7th set of mufflers on this 103" with Vance and Hines Dresser Dual head pipes.

V+H ovals ( Too Loud )
V+H Monster Ovals ( Great sound but too ugly )
SE 65115-98b's ( Sounds like making popcorn on the bike)
Kuryakyn Crushers ( Nice Idle and Cruise but tinny sounding on easy throttle),
Klock Werks WFB's ( Too loud and weird decel sound )
Rinehart slip ons ( Way too loud )

bschultz
10-22-2009, 07:18 AM
If sound is an issue, the SuperTrapp units may be a better choice. If you find them too quiet you could always swap to the "open" end cap.

fgizzo
11-19-2009, 04:33 PM
I have decided against the fatshotz and have ordered a set of fatshots with the closed end cap. On a 2004 Screamin Eagle Electra Glide with a 103" engine with Vance and Hines Dresser Dual headpipes and high flow AC, so how many discs do you think would be good to start with.

Also I will be looking to find a comparable power commander map for these mufflers. Any suggestion on what to compare these mufflers to for map selection.

Thanks

bschultz
11-20-2009, 09:08 AM
You should be able to start tuning with 8-10 disc; however you may want to purchase an extra pack of discs, depending on how aggressive you want to get.
Like wise the following maps should work well, depending on the aggressiveness;
M807-240, 237, 228, 194

fgizzo
11-20-2009, 10:29 AM
Thats interesting - I am running the M807-240 map with my Klock Werks WFB Mufflers. Great map - bike runs amazing - my gas mileage has dropped to around 30mpg from 37mpg. I am a little concerned that I am running too rich.

Will adding more disks increase sound or decrease sound.

I have read in this forum that subtracting disks makes the engine run richer which confuses me since I thought only a fuel management system can accomplishe that.

bschultz
11-23-2009, 07:37 AM
Adding discs will increase exhaust flow and sound.

Removing discs restricts exhaust flow and increases back pressure. This can richen the A/F ratio in a carbureted or "open loop" FI system. Changes in exhaust/intake flow are monitored in a "closed loop" FI system and adjustments made to meet the A/F parameters of the ECM settings.

fgizzo
11-24-2009, 06:42 AM
Well,

I have decided to stick with my Klock Werks so this is probably not the correct place to post this but I am selling a set of Supertrapp Fatshots for 95+ with less than 5 miles on them. You can email me at fgizzo2@comcast.net if you are interested. $275 plus shipping

jwells
11-25-2009, 09:35 AM
Your right, this isn't the place to post that-wow.

baggermanmcp
11-25-2009, 05:37 PM
Adding discs will increase exhaust flow and sound.

Removing discs restricts exhaust flow and increases back pressure. This can richen the A/F ratio in a carbureted or "open loop" FI system. Changes in exhaust/intake flow are monitored in a "closed loop" FI system and adjustments made to meet the A/F parameters of the ECM settings.

So, BS - with my 2007 103" w/255 cams shall I run with the fatshots and adjust with more discs for sound or SE's and limit the performance I might otherwise maximize with the fatshots?

jwells
11-27-2009, 11:42 AM
BS is enjoying his holiday. Yes the Fatshots would be the better performance choice.

baggermanmcp
11-27-2009, 02:52 PM
Can you tell me where I should start with regard to how many discs to run. On a 2007 FLHTCU I'm running a 103 stage II with the 255 cams like those in the CVO SE Ultras. I'm currently getting 101 foot pounds of torque but don't recall the hp number. This bike is relatively new to me. The SE CVO mufflers are oh, so quiet and the Bassani's before that were both very loud and popped at let off no matter how rich we ran it.

My previous experience with Kerkers 128-78020 ran very well on my 95" 2002 FLH and with some extra fiberglass quieted a bit more so I'm gonna give these Fat Shots a go.

Any additional comments on searching for that right combination of torque and exhaust note would be much appreciated.

Thanks - baggermanmcp

baggermanmcp
11-27-2009, 05:14 PM
So when someone answers the tuning question, if I start with lets say 10 discs, what about fuel management. I forgot to state that I have a SE Race Tuner on this 103 with 255 cams. It's currently mapped pretty rich; any thoughts here? thanks

bschultz
11-30-2009, 07:19 AM
Leave the fuel management alone and start with 10 discs. Have an additional 6 pack of discs available to add (2 at a time) if needed.

baggermanmcp
12-04-2009, 09:30 PM
So adding discs 2 at a time how do I know when I'm at the right point or will I know when the popping stops on decel?

Thanks for this great tech support - By the way I love the way these fat shots look - non-traditional!

bschultz
12-07-2009, 08:01 AM
The touring models popped on decel out of the factory; however it's not very noticeable due to the quiet OEM mufflers. On an "open loop" FI or carburated model, reomoving disc may richen the A/F ratio and in turn reduce decel popping. Fuel management is a better tool for clearing up decel popping on a "closed loop" FI model.

baggermanmcp
12-08-2009, 02:05 PM
Should I expect to add the same number of discs to both sides with the stock header pipe on this 2007-103" w/255 cams w/HD-SERT big air box or will I need to do some kind of balancing act? I purchased a 6-pack of xtra 4" discs so I'm ready to go.

bschultz
12-08-2009, 02:21 PM
Putting the same amount on the left won't hurt; however a 2:1 ratio (twice as many on the right) is a good rule of thumb.

Jeepwatchman
02-18-2010, 03:13 PM
2. Can you get the fat Shots with a BLACK closed end cap?


Careful with the black endcaps. I ordered 2 for my fatshots and after awhile, the black started to come off of them, so I had to take them off.

Just my .02

king of the road
02-21-2010, 04:19 PM
I got a 06' Road King only got hi flow filter and screamin eagle 2 pipes. I want about the same sound maybe better performance. I was considering the Fatshots, but not really sure if gonna any big mods in future.

bschultz
02-22-2010, 08:17 AM
You most likely will not gain performance with your present set up; however may benefit with additional mods.

king of the road
02-22-2010, 11:00 AM
what type of mods can I still do within a small budget. Which pipe would you suggest with my current set up S/E supertrapp, kerker, or fatshots

bschultz
02-22-2010, 12:39 PM
I think you are fine with what you have. You may be able to squeeze a littlle more out out of her with a good fuel management system. Going inside the motor would follow, cam, headwork etc.

king of the road
02-22-2010, 02:21 PM
is there anything I can do with the carb. What type of exhaust..