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watchmanuk
07-30-2009, 04:15 AM
hi just built an s&s 95 inch tc. 79cc superstock heads pop up pistons 570g cams super e carb 10:4:1 compression ignition to match s/eagle supertrapp 2:1 with 20 discs to fit , want to fit open end cap how many discs approx do i need to start with please help many thanks watchmanuk :-)

jwells
07-30-2009, 08:00 AM
10 and the open end cap.

watchmanuk
07-30-2009, 09:15 AM
hi thanks for that is that baseline ? or will i need more after trying ?

jwells
07-30-2009, 10:08 AM
Should be fairly spot on, try it and see, may need to add or remove one or two?

thinkpt1
07-30-2009, 05:07 PM
I had a 1986 FXR and a 2003 FXWG both had supertrapp 2-1 with 11 discs with open end cap. The fxwg was a 95" with pretty much the same cam etc ran like a raped ape........

The 86 fxr was my wheelie bike, the guy I sold it to still has the supertrapp on the bike, he told me he took it off for a short while but put it back on....

My current bike is a 103 FLHX with 22000 miles, jonny sachs did the heads andrews cams etc..just ordered a new 2-1 supermeg will be installing next week...I will post some pics.......great forum here...

hugger
08-03-2009, 11:10 PM
hi just built an s&s 95 inch tc. 79cc superstock heads pop up pistons 570g cams super e carb 10:4:1 compression ignition to match s/eagle supertrapp 2:1 with 20 discs to fit , want to fit open end cap how many discs approx do i need to start with please help many thanks watchmanuk :-)

To use the open endcap and keep the performance that you have with the 20 discs and the closed endcap you will need to take off 8 discs and the closed endcap and put the open endcap on. So 12 discs and the open endcap.

watchmanuk
08-15-2009, 09:50 AM
thanks for all the help guys went with 12 discs and open end cap bang on tweeked the carb and pulls like a train all the way to the limiter and far more low down than the ar3 pipes it replaced ace :) once again thanks :)

jwells
08-17-2009, 09:11 AM
Right on!!!

Thank you for the update.

mortbike
08-23-2009, 11:05 PM
I have a sest tune on my XR1200 2009 sportster with supertrapp racing muffler(2.5"dia). and 2-1 remus headers using 18 discs and closed end cap. runs great except I get a pop when I reopen the throttle at 3,000 to 3,500 rpm after decel. No popping during decel, just when I re-crack the throttle open in low gears after a high rpm decel and only when the engine is hot.
Any ideas?
also- I wanted to experiment with changing the sound. If I use the open end cap and reduce discs to 10 from 18, do I need to re-SEST the bike again? What effect would this have on performance-torque curve, low end torque, etc.plus vs minus for 18 discs closed cap vs 10 discs open cap?
thanks for your help-Mort

jwells
08-24-2009, 12:20 PM
Give it a try with fewer discs and the open cap and see how it runs. Should be right in the ball park if it was tuned properly before with 18.

You popping is probably more accossiated with cam/cam timing on that bike? But obviously we never tested with another brand headpipe and a universal muffler so it is only speculation.