View Full Version : Thunder Trapp...

11-05-2007, 07:27 PM
The Thunderheader on my bagger got too loud so I removed the muffler and put on a ss Supermeg Elite from Summit racing...
I have a closed end cap with 18 discs...
The build...Deweys pro st heads shaved .030 w .030 com. head gasket, And 37 gear drives, 95" Weisco flat tops, Ness BS2...
I had it dynoed and the tq. was 94ft lbs from 2500 to 5000 rpm...flat as a pancake...
We really didn't play with the discs on the dyno...Does it sound like we have the right amount of discs...thanks

11-05-2007, 07:38 PM
This set up also got rid of the famous Thunderheader torque dip....

11-06-2007, 08:15 AM
You may want to experiment with a couple more discs, you may get to a point where power curve is no longer consistent. I would think the torque curve, the way it is, would make it a great ride. Unless your unhappy with the results and want to go back to the Dyno. If that's the case I would say add 6 discs and have your tuner concentrate on the fuel/air ratio you want to be at.

11-06-2007, 11:16 AM
Thanks for the reply...This is one happy bagger now...
Liked it so much... I cut the Thunderheader muf. off my 06 St Bob and welded
a S/C 4" muffler on. It is a 103" and I am running 18 and closed cap...
Here are some before pics...I will take some after pics soon...

11-06-2007, 03:16 PM
Looking forward to the after pictures.

11-06-2007, 06:41 PM
I have some time off this week so I will buy some extra discs to experiment and take some new pics...thanks for the forum

11-21-2007, 01:59 PM
Sorry it took so long to get pics up...I got a fancy camera that won't upload to my PC due software problems...

12-09-2007, 01:24 PM
the guts fell out of the St. Bob muffler....Hhmmmm....:mad

04-07-2008, 03:10 PM
Summit racing got me a replacement for the 'guts' I lost under warranty...I now run 21 and closed end cap...97hp 105 ft lbs...
I put a piece of safety wire on to make sure I don't lose this one...