Some folks who have tested balance pipes obtained different results depending on the resistance in the muffler - with a street legal muffler a balance pipe improved power around 5% across the board, with a free flowing Production racing system which already gave 10 % more ponies than the street system there was no difference.
And the position of the balance pipe made no difference to where the power was produced, contrary to the testers expectations.
But that was only Doug Hele and his Bonnie racers and road bikes,and what would he know about developing production engines.
But is sort of adds to the point I made in an earlier post - no one that know of was ever able to repeat the results that Doug got, either with balance pipes or production race engines, everyone seems to claim different results from pretty much the same changes so I would just try what you fancy and see how it works out - there is a good chance you wont get the same results as everyone else either !
For what it is worth, my 1000 cc G/S reaches the same speed at the top of our test hill as my mates one owner original GSXR 750R, and these were "100HP" bikes which inertia dyno'd at around 83 HP at the rear wheel, so I dont have much faith in rear wheel dyno figures as an indicator of actual real world performance.
System on the G/S was full Staintune 800cc G/S system, with a balance pipe, small G/S style collector and the Staintune copy of the stock G/S muffler, which was claimed to flow a bit more freely than the stock muffler.
Jetting is stock 800 G/S, 135/2.66, with SU slide springs , foam filter, no snorkels and carbs set a bit back with Bonnie Amal Mk 2 intake rubbers blended to carbs and head.
Head and valves stock 800cc, BMW low comp 1000cc pistons with squish as close to 50 thou as we could get, and a bit of light work on the intakes, valves combustion chamber, rods and pistons buy an ex race mechanic, who has spannered for a speedway world champ and knows a bit about 500 cc air cooled two valve motors.
Boyer twin plug system set by road test around 25 degrees BTDC , I think, as I cant see the timing mark.
Most folks will tell you an 800 exhaust system doesn't work on a 1000 cc bike, but not many will tell you the actual set up they have tried it with, and anything other than a stock air box is reputed to kill the mid range, but I get just about the opposite results.
Go figure.
