dyno time!
Our test bike is a rat bike and is used for test purposes. Dyno's are hard on motors and tires. Always the the possibility of catastrophes.
Dyno's and exhaust gas analyzers are expensive tools but tools are needed to diagnose and perfectly tune the internal combustion engine.
Because we are the manufactures of the twin carburetor system for SOHC Honda's we are always looking to improve our products.
We selected MAC drag pipes for several reasons:
Many people use drag pipes.
Suspicious about the horse power they develop.
We could probe each cylinder individually with the gas analyzer.
Here is what we found:
Drag pipes are inconsistent and you can expect a decrease in horsepower over 4 into 1 exhaust systems. ( read exhaust tech article for details )
Commonly, middle cylinders run somewhat hotter on air cooled motors. Of course, richer mixtures help.
We designed the intake manifolds and are aware that the middle cylinders get a little more fuel when using straight intake rubbers.
Buy moving the carburetors inward or out, the fuel can be directed as needed.
Direct the carburetor straight at the spilt off point for 1&2 cylinders (Then 3&4 of course) The
exhaust gas analyzer shows the carburetors will deliver fuel & air equally to all four cylinders.
To get the carburetors pointing towards the manifold split, grind or cut the intake rubbers on a angle ( 7 degrees is a good start )
Or simply look down the throat of the carb.
We have found some super high quality angle boots if you are uncomfortable modifying your existing rubbers.
If you mess up your rubbers or need new ones contact your local NAPA store.
Head to manifold reinforced rubbers are NAPA part # 607 (1 3/8)
Carb to manifold reinforced rubbers are NAPA part # 610 (1 5/8)
High quality angle boots are $ 26.00 each ( expensive, I know)
