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View Full Version : Maps for internal 4" Supertrapp on Buell X1



Tadek
12-16-2009, 01:54 PM
Hi!

I hoped that you might be able to help me with the following question.
The normal Buell X1 hardware (air cleaner with Helmholtz resonator and the standard exhaust) causes a torque dip between 3500 and 4000 rpm which is rather annoying.
Buell also offered a race setup which eliminated this torque dip.
As you probably know, the race hardware consists of an semi-open K&N ham can style air cleaner, race exhaust and ECU with mapping tuned for the other hardware components. The race hardware does remove the torque "bump" between 3500 and 4000 rpm, which I believe is mainly thanks to the race exhaust. The race exhaust consists of a longer header (seperate pipes are longer) with a transition pipe below the engine and a 2,5 inch absorption muffler. It also is rather loud.

I upgraded my Buell X1 exhaust header from the European 2" to the US 2.5" variant (with the original short primary pipes, not the long race ones!) and also have an original 2.5" Buell muffler and a 4" internal disc Supertrapp muffler fitting the 2.5" header. The Supertrapp muffler is quite loud for my taste and especially too load for German authorities, therfore I sometimes use the original muffler and sometimes the Supertrapp muffler (for track days etc.).

I also have the ham can style race air cleaner and the ECU maps for US and race setup

When using the Supertrapp muffler, how many discs should I try and what maps should be considered adequate for the muffler? Should I go with the US maps, race maps or try some custom mapping. I do have the ECMspy tool to tune the maps and I also have a wideband O2 sensor, but I do not have a second bung for the front cylinder, so that tuning could be only optimized for the rear cylinder and estimated for the front.

What do you recommend how to start.

Best regards,

Tadek

bschultz
12-16-2009, 03:48 PM
Our testing on the X1 was in stock configuration and the best performance was achieved with 12-14 discs. Additional discs can be added for more flow; however we did not test with a fuel management sytem or remapping of the ECM.