vanzen@rockerboxer.com wrote:According to Dr. Curve,
What works for air-head RR,
Megaphone specs: 6º taper, 2" reverse at 45º, outlet 50% of inlet diameter.
These will be megaphone specs for a road-racing airhead with an engine built as prescribed by Dr. Curve.
vanzen@rockerboxer.com wrote:Team Incomplete built an excellent 2-into-1 engineered specifically for the TI boxer engine
using specs provided by Craig Hanson (Hanson Racing Technology).
The design has been much copied ...
While in NY a few years back, I had the opportunity to measure the TI bike exhaust system:
Primary 29", Y 3.25", collector 18", Universal (& tunable) Supertrapp 17.5"
These will be the 2-into-1 specs provided by Craig Hanson and used by TI –
and
specific to the TI Boxer engine.
mattcfish wrote: I'm getting very interested in exhaust tuning on a 2 into 1. Please forgive my ignorance, I need some elaboration....so the outlet at the muffler should be 50% smaller(or bigger) than the inlet? Y=3.25" diameter after collector? 18" of single pipe between collector and muffler?
As my previous posts have attempted to clarify –
any performance exhaust system will need to be engine and (desired) performance specific.
What does "this and that" as promoted in the advertising or as fitted to certain machine
will likely (to a greater or lesser extent) yield different results on
your MC.
Again, if you were to replicate the TI system, put that system on your bike,
the system will NOT be right
UNLESS your engine is built just as TI has built theirs,
and your performance use expectations are defined as TI has defined theirs.
And the TI Boxer is essentially a track bike.
Jon Lars posted a similar message – his exhaust system, though similar in appearance to the TI system
uses Hanson specs that were specified and are appropriate to that engine in the Jon Lars R80GS
to provide those performance / use expectations of Jon Lars.
Sorry, with or without the expertise of Craig Hanson to crunch the numbers,
this will be how the job must be done if the results are to work so well –
There will be no magic bullet or "one size fits all" formula
in spite of popular and pervasive advertising hype.
The details of any worthwhile performance exhaust system
will always begin with consideration of valve sizes, cam profile ...
the specific engine in question.
And then be tailored to provide a planned performance expectation of
torque peak RPM and desired torque delivery throughout the RPM range ...