Genaris: This is actually a WONDERFUL outcome.
Note that your torque cruve reaches maximum by 4000 rpm but also does not begin falling off until 5700 rpm! That is EXCELLENT breathing - gaood enough that I am surprised to see that you did not list ported or cleaned up heads in your mods.
450 rwhp on Reese's dyno is excellent, as Reese does not inflate his numbers via dyno technique to satisfy a client's ego. These are what you call honest numbers. If you see better than 450 rwhp with the mods you have done, I would suspect an optimistic dyno.
I am impressed that this engine can handle 0.612 valve lift. Are the pistons flattop or do they have clearance cutouts for the valves? I think it is the valve lift that is giving this very fine torque curve.
I know you are probably wondering why the torque curve, and therefore hp curve, fall off so much at low rpm. This is, I am almost certain, a result of moment of intertia and hi stall torque converter effects.
On an inertia type dyno, which Reese's Dynojet is, the powertrain accelerates up VERY quickly during the dyno run, and a LOT of powewr is diverted to spinning up heavy rotating components. On the dyno in 3rd gear, the entire run probably took maybe 4 to 5 seconds. On the street in 3rd gear, it would take much longer.
The hi stall torque converter burns up a lot of power into HEAT at rpm below its stall point. And, with your engine combo being as strong as it is, that stall point is almost surely no longer the 2600 to 2800 it was designed for.
Some people "lock" the torque converter for dyno runs, but I think that could be pretty hard on the lockup surfaces, and would also tend to promote detonation at lower rpm.
All in all, if I were you, I would be very proud of this outcome. It's darn good. Now, put a set of really free breathing heads on there, and watch the results skyrocket again at high rpm. Your pistons and rods are forged, and I am surely assuming you chnaged to high quality rod bolts in the process, so this combo is pretty robust.
Nice engine.
Jim G
