In a message dated 11/2/2010 5:17:23 P.M. Eastern Daylight Time,
msteitle@gmail.com writes:
Lynn,
I've been thinking for a while now that going with a tangential muffler
wasn't the best choice for a p-port motor. It definitely produces more
HP than the side port, but not as much as I had expected. Maybe the
exhaust system is the problem. Good thing that I can tig weld.
;-)
Based on what you've just said, I suppose the p-port isn't the best motor
for turbo-charging?
Not much of a problem when there is some boost available. Off idle would be
very short on torque.
Most factory looking turbo manifolds are dreadful looking boxes. Unequal
runner lengths. Cast iron and so-on. You just want a few pounds of boost and the
major advantage will be the lack of noise. Most could have had short
runners moving the assembly to a more advantageous location.
Looks like I need to get busy ordering some inconel tubing. The
problem will be fitting it under the cowl. As I recall, ideal exhaust
runner length is 31". Is this for a specific narrow rpm range or will
this work from 4500 rpm - 7500 rpm? Would I need a different runner
length for 6500 rpm? What diameter tubing works
best?
A national champions engine man told me to look for multiples of 11" for a
12A between 7500 and 10,000 RPM. I used 24" primaries in 1 7/8" ID tubing. Maybe
2" ID for a 13B but that is very big. Once you have equal length headers, the
length becomes less important, and tuning returns to the intake runner length.
I would make up test systems in thick walled mild steel tubing. Just order
180s and cut up whatever it takes.
Measure for matching length with a flex hose similar to a small shop vac.
Once you have what you want, then start cutting the expensive stuff.
Lynn
E. Hanover