catbox wrote:we dyno tested about every sbc stock exhaust manifold available on a 355, 9-1, 2 barrell stock cast intake w/modified plenum and port matched ,2-G sean smith carb, 455 lift cam, steel crank, forged piston, 2 into 1 exhaust set up on a limited motor a couple years ago,..these were the exhaust manifolds we tested,..LT1, rams horn 2 1/2, truck log, 90's camaro over the port manifolds, tube type 1 ton truck manifolds,...
the tube 1 ton truck manifolds were the best with the LT1 & rams horn about the same,...everything else was way off the mark,...our conclusion as to why the LT1 worked as well as the 2 1/4 rams horns was the design,...and both the LT1''s and the rams horns had alot more torque from 3500-6000 rpm than the tube truck manifolds,..from 5500 on to a max of 6700 the large tube truck manifolds were superior...
340 hp max @ 5500 rpm
the tests were done with 3 different rochester 2-g carbs as well,..so every manifold had at least 3 runs..
so maybe flow isnt everything?...considering the very restricted motor we tested them on it seems to be the case..
Key here is your testing was on a 340hp 5500 rpm engine. My stuff was a 390-400hp 420-440-tq and 6600 rpm engine with 2101 intake and a 4412 carb, 450 lift hyd cam 10to1 comp. The more power and higher up you rev it the more it will show up.
