After spending about 40 years building round track and tractor pulling engines, and actually testing the output on real dynamometers, not computer programs, I have a little difficulty accepting rear wheel horsepower figures like the ones you're quoting. I'd like to see the dyno printouts on your Charger, corrected for atmospheric pressure and wet-bulb humidity factors. A very extensively worked-over 440 magnum pulling engine with a roller cam, one 4-barrel, and 106 octane racing gas produced 714 horsepower at 6500 RPM, with all the atmospheric corrections dialed in. A 426 hemi, bored and stroked to 547 cubic inches, produced a calculated HP of 1,350 on alcohol and nitromethane. Since we built it as a dry-block engine, it was impossible to do a bellhousing dyno pull on that one. When the owner got greedy and put his 40% overdrive blower on it without dropping the compression ratio, he made it about 2/3 of a 300-foot pull, and blew the crankshaft out the bottom of the engine. From its performance up to the 200-foot mark where it scattered, I'd guess he was making 2,000 HP, minimum!
The 350 Chevy based round track engines I build live about half a season, 800 to 1,000 laps around a high-banked 5/8 mile paved oval, at around 650 crankshaft HP. Putting more than 450 to the ground on a chassis dyno is a challenge, mostly due to wheelspin. If the car is chained down tight to the dyno rollers to minimize wheelspin, and super-soft gum rubber tires are used, it's possible to record a little more HP, but there's no way to stick the car down that well on the track. BTW, those tires are illegal for street use, they would need to be changed every 500 miles or so, and would be utterly worthless in any sort of rain event. The only place those engines produce maximum HP is above 7,000 RPM, something you rarely, if ever get to do on the street. Why have it if you can't use it? The average cost of one of those 600+ HP small blocks is around $15,000.00. How many of them can I build for you? The 38-lb. King crankshaft, with the corresponding rods and pistons will run just over $5,000.00 of that amount, BTW.
Jerry
Last edited by Hotrod Lincoln; 05/20/2010 4:49 PM.
Please educate me to all this. I have always liked old classics and muscle cars and thought that it would be nice to take the truck to points its never seen in its life. I guess I am more familiar with mynew model charger which is not uncommon for someone to put close to put 450 RWHP easy. Please educate me is this something to do with the car being old, is it uncommon to have 450 to ground and if so what is a reasonable rwhp on these vehiclesand how do i get there