Pontiac 455 Dyno
.030 Over 455 , 10:1 forged rotating assembly, 4 bolt mains, e-heads. Full Roller motor. 475hp/560ft lbs@ 5000 rpm.
Sehr Performance Machine / Randi's 400 Pontiac
Randi came to us with a 400 Pontiac project for his 1968 Firebird. He didn't want to go crazy on the build but he wanted something that would give him performance that is better than original. With that goal in mind Scott did some custom porting on his heads, upgraded his valve train and went with a Custom COMP cam and lifters and aluminum roller rockers. We maintained his complete original rotating assembly but had to re-balance his crankshaft, it had been poorly balanced sometime in the past and was out by 127 grams on one end and 181 grams on the other. A single plane intake with a 780 Quick Fuel carb got it breathing and the fire is lit with a Flamethrower ignition package. Custom cut and fitted 8mm plug wires are standard equipment here at Sehr. Headman custom coated headers will be added at installation time. The results were a satisfying 543.5 Hp @ 5500rpm and torque reading of 519.8 @ 5400rpm. Corrected to sea level the numbers are 577 Hp and 551 Tq with nearly 400 lb of torque at 3500rpm.
PONTIAC GTO Judge (1971 455cid, the differences basic supertuning can make)
Those who know me well, know that I always beat "SUPERTUNING" "SUPERTUNING" "SUPERTUNING" into the ground. This video shows the difference minor tuning can do (This is minor because a 1971 GTO's fuel/ign calibrations are already geared for performance, so there's not as much improvement you can make like you'd be able to on say - a late 70s smogger). But on larger scales, HUGE differences can be made, as much difference as adding performance parts alone. The more the car is severely out of tune/adjust------which happens more with the more mods you make, then the more you'll gain by supertuning it. There's another vid on YT where an Olds 455 was built with performance parts to be totally streetable but achieve 1hp per cubic inch. After they got the recipe of perfect parts all together they were disappointed when she only Dynoed at 320hp. But luckily they did not give up! After the proper ign-curve/timing & carb adjusts were made, the engine jumped from 320 up to 455hp!! No doubt all the new cam/intake/head mods put the old fuel/spark adjustments badly out of calibration for the NEW BREATHING ABILITY. Also with things like dual quads (especially to engines not originally equipped wit them), your adjustments are most likely going to be way off and need calibration even more. There's lots of dual quad cars out there not running well for this reason, however the few that have been calibrated perfectly (EVERY adjustment set for the best "stop watch" time, etc) truly do run like a bat out of hell!