So here's the story, I bought a turbo system from c & s which included 2 turbos, 2 Wastegates, BOV, pro carb hat and a blow thru carb. These guys were very secretive regarding turbo sizing. All of this is on a bbc 565 8.5 to 1 with Brodix bb2 extra heads that are untouched. Straub ground the cam Brodix single plane manifold as well. When I showed up at the dyno the first thing they said was those turbos look small. The only numbers c and s ever gave up were they were 78/65 turbos.
When the dyno ran the motor made 1000 ft torque by 3400 rpm and the best we got out of the engine was 981 at 6300. No need to go higher as it was falling off. The dyno graph looks like a hump and when adjusting from 10 to 18 pounds of boost we only gained 40 hp. I told c and s I was looking for 1200 hp out of this motor and I figured it would be doable with 15 to 20 pounds of boost. With all this said I'm sure the turbos are way too small on the exhaust size and need some good recommendations on a pair of replacements. Thanks
Thanks to Jose at Forced Inductions he set me up with a couple of Borg Warner turbos. They are 75/102 - 92/82 turbines t4 with a 1.10 A/R. What a difference in performance. At 13 psi of boost it made just under 1100 and at 23 psi it made over 1400 HP. Here are pics of the dyno sheets. The first ones are with C & S Chinese turbos that made 963 at 23 psi of boost. The new Borg Warner turbos made over 1400 HP at under 23 psi.