Supertrapp?

[Coyote]

Thanks for all the info. Hopefully I did not unduly interrupt Chewy's topic. Thanks to you all I can see now what I did not before. Didn't realize there were optional parts here. I guess I will try closed end first and see how it works after an FLTRI tune. Cheers.

Keith,
I believe this is good for this thread because it concerns the Supermeg and discs with open or closed end cap. Power-wise it is not a big change but the sound does change.
As I mentioned to you, get the sound you want first by trying open and closed end cap, then we'll tune.
Looking forward to it! 
Bob

Give me a week or so. Pipes are going on this week, then a 55k service, then we change both tires, then a trip to the Hayward area. How do you sniff the O2 with a closed end cap? Or tune each cyl separately? Got lots of questions I guess! LOL 

[Jeffd]

you have to drill a hole in the end cap.  I am sure most tuners have one already drilled.  the end caps are cheap.  It is pretty easy to manipulate the sniffer up each header from the end cap.

[FLTRI]

Jeff answered you question correctly. Either you drill a hole in the middle of the closed end cap or I can. You will not notice any difference in noise from the 5/16 hole.

I do tune each cylinder individually and can do that by using a sample tube about 4ft long, inserting it through the hole and guiding it into the front cylinder's header pipe. Then, after tuning the front, the tube is pulled back and reinserted into the rear header pipe.

Hopefully you can be present with me in the room while all this happens. I will explain the entire process from beginning to end  so you will know and understand how all this is done and the whys.

[Bagger]

NRHS V-Twin Performance - Supertrapp Dyno Test

http://www.nrhsperformance.com/tech_supertrapp.shtml

The Supertrapp is a popular exhaust system on Harley Big Twins and XL's alike. We offer Supertrapp systems and we've seen many examples of our customers getting great results when using them.

Often we get asked about how many discs to use. Every engine combination has the potential to be a little different, but we went to the trouble of dyno testing disc packs from 12 to 26 on our '04 Sportster, which is a typical mildly modified street bike. Here are the results of that testing:

http://www.nrhsperformance.com/tech_supertrapp.shtml

[FLTRI]

NRHS V-Twin Performance - Supertrapp Dyno Test

http://www.nrhsperformance.com/tech_supertrapp.shtml

The Supertrapp is a popular exhaust system on Harley Big Twins and XL's alike. We offer Supertrapp systems and we've seen many examples of our customers getting great results when using them.

Often we get asked about how many discs to use. Every engine combination has the potential to be a little different, but we went to the trouble of dyno testing disc packs from 12 to 26 on our '04 Sportster, which is a typical mildly modified street bike. Here are the results of that testing:

http://www.nrhsperformance.com/tech_supertrapp.shtml

Great comparison. IMO this is a proper, back to back test for the Supertrapp Supermeg, 2into1 for Sportsters. Nice job!
However the Big Twin (TC) has a very different power output, as noted on your sites dyno graphs.

What I mean by this is generally the XL engines put out more horsepower vs  torque and @ higher rpms (6500-7000) while the BT engines put out more torque vs horsepower and @ lower rpms (6000-6500). (this applies TC builds with street cams not all out racing engines using cams with high overlap).

That said, we find there is a point of no return with the amount of discs added to the stack, possibly due to lower peak power rpms compared the the XLs. ie: typically once 18 discs with closed end cap is exceeded the return is very little, if any, on top and below 3000 is affected, albeit not a lot.

This is a great pipe for 99% of the BT owners simply because he/she can first adjust the noise level/tone to his/her liking. Then take it to the tuner and dial the AFR/timing for best performance. IMO, best of both worlds. In the early days I would not/could not get my head around how a modified spark arrestor (originally developed for the forestry to keep sparks from exiting the exhaust and burning down the forrest) could be considered a performance exhaust system, but that was 1000's of happy customers ago and the dyno don't lie.

Points to consider:
1) It is not the "sound" everyone likes. ie: Can not wake the dead like a Thunderheader or straight pipes and never will unless, of course, you remove the discs and baffle making it an obnoxiously loud, nonperformance POS.
2) It does not produce the absolute (2-3) highest "peak" numbers in the industry. ie: Thunderheader will outperform it in "peak" tq and hp.
3) It does not come with a "false" left side pipe to balance the "look" on baggers.

IMO, the Supermeg is by far the best compromise in looks, power, and most importantly adjustability. Especially as applied to baggers.

Disclaimer: I only use Thunderheader as an example due to its accepted, longstanding, "King of Peak Power" reputation. There are other systems that also outperform the Supermeg in "peak" numbers.

HTH,
Bob

[Bagger]

NRHS V-Twin Performance - Supertrapp Dyno Test

http://www.nrhsperformance.com/tech_supertrapp.shtml

The Supertrapp is a popular exhaust system on Harley Big Twins and XL's alike. We offer Supertrapp systems and we've seen many examples of our customers getting great results when using them.

Often we get asked about how many discs to use. Every engine combination has the potential to be a little different, but we went to the trouble of dyno testing disc packs from 12 to 26 on our '04 Sportster, which is a typical mildly modified street bike. Here are the results of that testing:

http://www.nrhsperformance.com/tech_supertrapp.shtml

Great comparison. IMO this is a proper, back to back test for the Supertrapp Supermeg, 2into1 for Sportsters. Nice job!
However the Big Twin (TC) has a very different power output, as noted on your sites dyno graphs.

HTH,
Bob

Hey Bob

This web link was not to my site, I have no affiliation with NRHS Performance - I just ran across the testing on their site.

[FLTRI]

Bagger,
Oop, sorry I was fooled by the statement you included in your post:

"Often we get asked about how many discs to use. Every engine combination has the potential to be a little different, but we went to the trouble of dyno testing disc packs from 12 to 26 on our '04 Sportster, which is a typical mildly modified street bike."

I know Brian Nalin and his company, NRHS but with your "Bagger" handle I didn't but if you might be an employee or something. Sure wish we could use first names. Guess I don't really understand forums that well, which is prolly why I only do this and some V-twin occationally.
Thanks for the clarification, and Happy New Year,
Bob (aka FLTRI)

[Bagger]

Bagger,
Oop, sorry I was fooled by the statement you included in your post:

"Often we get asked about how many discs to use. Every engine combination has the potential to be a little different, but we went to the trouble of dyno testing disc packs from 12 to 26 on our '04 Sportster, which is a typical mildly modified street bike."

I know Brian Nalin and his company, NRHS but with your "Bagger" handle I didn't but if you might be an employee or something. Sure wish we could use first names. Guess I don't really understand forums that well, which is prolly why I only do this and some V-twin occationally.
Thanks for the clarification, and Happy New Year,
Bob (aka FLTRI)

I'd like to have my own shop like NRHS with a dyno.......

[FLTRI]

Brian is a very knowlegable and talented guy who, in my opinion has talken an unwarranted big hit over the Revolution cylinders and some defective plating from outside sourcing.
Just go over to the otherr v-twin forum site and search on revolution performance. 

[Bagger]

Brian is a very knowlegable and talented guy who, in my opinion has talken an unwarranted big hit over the Revolution cylinders and some defective plating from outside sourcing.
Just go over to the otherr v-twin forum site and search on revolution performance. 

Bob, I don't believe the two sites are the same.  I believe Brian Nallin left NRHS and now does Revolution Performance.

Revolution Performance:  http://www.revperf.com/TwinCam/twinCamPerformKits.html

NHRS:  http://www.nrhsperformance.com/ekittc.shtml

[Bagger]

Just some more info FWIW I have on file - was considering the Supertrapp myself at one time a couple years ago.

Here's a couple of tidbits I found in regards to the Supertrapp, as I too having been looking for quiet performance.

Joe Minton: http://www.americanrider.com/output.cfm?id=1054045

The SuperTrapp 2-into-1 system we used to get our best results is probably the best all-around exhaust available for Harleys today. It combines large volume flow with good wave dynamics. Its closed end cap sends a strong pressure wave back up the pipes to help stop intake-charge loss when the rpm is too low for the closing angle of the exhaust valves. This accounts for the pipe's strong showing below 3,000 rpm. At the same time, its multiple-plate outlet provides high-volume flow for operation at high rpm.

Sound bite: http://s85.photobucket.com/albums/k69/JABMIKE/?action=view¤t=SUPERTRAPP.flv

Disc number testing:
http://www.nrhsperformance.com/tech_supertrapp.shtml

End Caps
http://store.summitracing.com/egnsearch.asp?N=400410+304765+115&Nao=0&autoview=sku#rstop

Forum discussions on Supertrapp:

From: MaineUltraClassic Sent: 2/12/2007 10:20 PM
Closed endcap/17 discs gives 99% flow
Open endcap/9 discs gives 99% flow

http://www.v-twinforum.com/forums/showthread.php?t=100256

When I was on the dyno, we got the rest results with the open endcap/9 discs combo. Great low-end torque, and it still revs up on the top end. The open endcap also makes the exhaust a bit louder, enough to be heard in traffic. The closed endcap is almost too quiet, and the throttle response is not as quick. On the dyno it didn't produce the good low-end power, and the top end suffered too.

Pick up an open endcap and try it out..............it's the way to go for good overall performance.

Steve

http://www.v-twinforum.com/forums/showthread.php?t=93543&highlight=Supertrapp

http://www.v-twinforum.com/forums/showthread.php?t=64386&highlight=ohiomotoxer+supertrapp

http://www.v-twinforum.com/forums/showthread.php?t=91249&highlight=supertrapp

http://www.v-twinforum.com/forums/showthread.php?t=88860&highlight=supertrapp

[Blackbaggr]

I just put mine on today...20 disks/closed end cap...





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[Sonny S.]

I just put mine on today...20 disks/closed end cap...

Whadda ya think ?  Did you fire it ? Gonna take it for a putt before you pull it back off 

edit :   Never mind..... I just realized you prolly didn't put the 02 sensors in yet being as you have to take the pipe back off for....... your new cams !!!!

[14Frisco]

I really like the Supermegs on my 94 FLHR too.

One thing for Supermeg newcomers to watch out for, though, is the transmission clamp.  After you put on your new shiny SuperTrapps, keep an eye on that clamp since there is a chance it will break.  Many of us has replaced it with a beefier clamp.

[Blackbaggr]

I just put mine on today...20 disks/closed end cap...

Whadda ya think ?  Did you fire it ? Gonna take it for a putt before you pull it back off 

edit :   Never mind..... I just realized you prolly didn't put the 02 sensors in yet being as you have to take the pipe back off for....... your new cams !!!!

No didn't ride it....mostly for the reasons you stated. I like it...cleans it up ALOT ! Fits real nice....although the rear heat shield could be a hair longer...maybe I have to "f' with it more. Otherwise a real nice set up...no regrets.

[Blackbaggr]

One more from a different angle...

[attachment removed after 60 days by system]

[FLTRI]

Brian is a very knowlegable and talented guy who, in my opinion has talken an unwarranted big hit over the Revolution cylinders and some defective plating from outside sourcing.
Just go over to the otherr v-twin forum site and search on revolution performance. 

Bob, I don't believe the two sites are the same.  I believe Brian Nallin left NRHS and now does Revolution Performance.

Revolution Performance:  http://www.revperf.com/TwinCam/twinCamPerformKits.html

NHRS:  http://www.nrhsperformance.com/ekittc.shtml

The N of NRHS stands for Nalin as in Brian Nalin. But maybe he sold the "NRHS" letters to someone. I haven't spoke to Brian in a few years.
He is definitely RevPerf.