Exhaust System Comparison (in progress)
Pipes are being posted as I collect data.  Click on links below...
I am working my way through a comparison of various exhaust systems on my XR1200.  So far the pipes I have data available to post results on are:
  • Drilled Stock Exhaust - Stock XR1200 vs Ported and Cammed XR1200 (coming...)
  • Torque Hammer Exhaust - Stock XR1200 vs Ported and Cammed XR1200 (coming...)
Several of these pipes have been lent to me for this testing, and I will run additional pipes if they become available.
Here are some notes on what I have looked at so far...


The following dyno graph gives a baseline for comparison of exhaust systems on the XR1200 with a modified 1200 cc engine.  This build includes Zippers' Redshift 575XR cams, Zippers CNC ported heads, and Wiseco pistons to keep about a 10.2 CR. 
The pipe used in the two runs on the ported and cammed engine is a combination of the header pipe for the D&D 2-into-1 Concentric Baffle exhaust system,with a special exhaust can.  This modified D&D exhaust system produced much more TQ throughout low and mid-range RPM than the production version of the system.  This was an initial baseline for the optimum TQ available for the build.  (One other pipe combo - the D&D header with a more open exhaust can - did produce slightly more TQ and HP on this build, but the noise level was nasty and far too high for the average person to use on a daily basis.)
Just to take a look at the consistency of the build, the below is a graph of the above configuration done during September of 2010 and again on the same dyno during May of 2011.  (This is compared to the stock engine with drilled stock pipes and a Mastertune tuned HD ECM in GREEN.)   In between the runs of the built the engine, I  had a fluke warranty problem and  replaced the motor.  The top of the old build was installed on the new engine. So, these two builds show the effects of the cams, heads and pistons on two different engines. The Red lines are the original build, and the Blue lines are the current build.  The engine tune in the Thundermax ECM was also changed, and quite a bit of the mid-range loss in the later dyno run is due to the AFR going lean at the beginning of the run, and then very rich in the middle.  While I adjusted this prior to running later pipes to get a flatter AFR at about 13.0, these two runs did not have any special AFR or timing tuning - just the autoadjustment of the fuel offsets by the TMax.  Both of these runs and particularly the current 2011 baseline (Blue lines) could show better performance with a bit of fine tuning on the AFR targets.  Still, they give a comparison starting point for the pipes I am about to run on the XR...
So, here is the XR1200 as dyno'd in September of 2010 (RED) and again on the same dyno in May of 2011 (BLUE), with the main changes being the bottom end of the engine and the TMax mapping.  I'll use the lower BLUE lines as the comparison starting point.  (The Stock motor with drilled stock pipes and a tuned HD ECM is in GREEN.)

XR1200 with 575XR cams and CNC heads vs Stock
D&D Header with Special Exhaust can vs. Drilled Stock Exhaust

Some Exhaust Comparisons

The below graph shows the difference in power output of my engine when changing from the modified D&D 2-into-1 header with special exhaust can, to the Termignoni 2-1-2, and to the Torque Hammer 2-into-1 system (without silencer).
You can see the tradeoffs between the modified D&D exhaust combo (RED), the Termignoni exhaust system (without silencer) (BLUE),  the Torque Hammer exhaust system (with silencer) (GREEN), and the drilled OEM exhaust (PINK).
As a reference, the BLACK line is the stock engine before any work, tuned with a drilled OEM exhaust.
These HP graphs are from a fairly conservative dyno, with the Thundermax ECM set to deliver about a 13.0 AFR.

XR1200 with 575XR cams, CNC heads, and pistons
D&D vs Termignoni vs Torque Hammer vs OEM

Alternately, here are the Torque curves for the same pipes (with the same color codes).

Torque Comparison for 575 build with different exhaust systesms

While the modified D&D combo did not produce the highest peak horsepower, it had a very strong torque curve and at the time of the build was the overall strongest running pipe.  (Other production pipes have since been manufactured which are lighter, quieter, easier to install, and produce equal to better performance than the D&D configuration used here.)
The Termignoni 2-1-2 has produced some of the highest peak HP numbers with this build.  It builds power quickly at the low end, but for some reason has a flat spot from about 3000 to 4000 rpm.  Varying AFR did not seem to affect this significantly.  Later efforts at tuning the pipe could not substantially improve the mid-range power.
The Torque Hammer does have a bit more mid-range torque than the OEM exhaust and the Termignoni.  The Torque Hammer is also about 25 lbs lighter than the stock exhaust when installed.  The Torque Hammer is also significantly less expensive than the Termignoni.
I dyno'd the V&H 2-into-1 Widow (in its black street and stainless race versions) later.  Although not initially available to me at the time of this build, the V&H stainless steel race pipe has become my favorite pipe overall, in terms of composite perfrormance, durability, and ease of installation.  Click here for some data on it.
NOTE:  As a reminder, all of the above runs for the 575 build above were done with the 38/57 primary gearing and a 29 tooth transmission pulley.  The run with the stock engine was done with the stock 34/57 primary gearing and the stock 28 tooth transmission pulley.

Noise Comparison Summary


1,000 RPM

3,000 RPM

Exhaust System

dB @ 1 meter

dB @ 2 meters

dB @ 1 meter

dB @ 2 meters

Stock (OEM)

91 dB

87 dB

98 dB

94 dB

Drilled Stock

93 dB

90 dB

100 dB

96 dB

D&D 2-into-1 header with prototype exhaust can


98 dB


109 dB

Termignoni 2-1-2 without silencer

102 dB

98 dB


Torque Hammer w/silencer

96 dB

92 dB

111 dB

107 dB

Torque Hammer without silencer

100 dB

96 dB

114 dB

110 dB

Vance and Hines 2-1-2 Widow

102 dB

98 dB

112 dB

108 dB

NOTE:  The abve measurements give relative comparisons of noise levels with different exhaust systems.  The numbers were measured with a digital noise meter.  However, the sound intensity at a give RPM varies somewhat as the engine warms up, and it is difficult to get the RPM exactly stable during measurements.  The dB numbers are very close and should reflect a good comparison of the relative differences between pipes.

The following links show information on the individual pipes...

The Pipes

HD XR1200 Exhaust - drilled stock

Torque Hammer (standard header)

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