I've often wondered what are the limits of performance for the stock muffler, reason being is that reading about the Porsche Salzburg rally beetles they had the standard muffler as well as the southern cross rally cars of 1967.
What sought of things can be done to increase the performance of the standard muffler, and has anyone used one for a decent output motor, from specs on the aforementioned cars they put out about 100-125hp with the muffler, running either 32 or 35.5mm exhaust valves.
Cheers
Shaun
sander288 ·