We pulled out the .074 jets in the primaries and screwed in some .072 jets and took the rear down to .076 from .080. We also went with a 10.5 powervalve to help smooth throttle tip-in.
We also noticed the QFT carbs come with jet extensions in the rear float bowl; these ensure your carb doesn’t get fuel starved during hard launches.
With the 750-cfm carb, 35-degrees of timing, and fresh oil, our 385ci belted out 506 hp and 495 lb-ft of torque. From here, we decided to try the larger 950-cfm carburetor.
The 950-cfm QFT carb (PN BDQ-950) features a larger throttle bore and venturis for greater airflow. We were curious to see how the 950 performed at the low rpm, since we were told it may be too large for cruising. At this point we added a degree of timing as well, for a total of 36-degrees.
With a fresh tank of 91 octane and the engine well broken-in, Brulé made a couple more pulls with the 950-cfm piece and glimpsed a stellar “518.9hp and 496.7 lb-ft” flash on the screen. We even observed a pretty smooth low rpm throttle tip-in with the bigger carburetor, as well.
A full, 10-pound nitrous bottle was hooked up to our potent powerplant. Brule’ made sure to keep our pressure at an ideal 950 psi.
The nitrous system we chose is Nitrous Oxide System’s Big Shot Plate Kit (PN 02101NOS). This is a simple, effective power adder that can increase power output (to the wheels) up to 300 hp!
This kit comes with high-flow "Cheater" solenoids, 88-hole spray bar, and a 10-pound bottle with brackets.
With 100 octane Rocket Brand racing fuel in the tank, and two degrees of timing taken out, we unleashed the laughing gas, making sure to purge the air out at the solenoid before making the final pulls. We only plan to run the base “190hp” tune on this engine (0.073 nitrous jet with a 0.067 fuel jet) since our piston’s ring lands are fairly close to the top of the crown and too much heat in the chamber could potentially lead to meltdown if you’re not careful.
With a mighty roar, the 385ci tossed flames out of the collectors and we saw the power output spike well over 700 hp, and that was way before redline. It appeared we shocked the dyno brake on this pull too. After a few adjustments to the dyno, Brule’ made additional pulls on the sauce, all in the 730 hp range, which is more than enough power to get our project running in the nines … and possibly quicker after the chassis is sorted out.
With 519 hp on pump gas and more than 730 hp on nitrous, we were ravenous to get the engine into our early Nova. Back at the Source Interlink Tech Center in Irvine, California, the real thrash begins. In the next few issues we plan to show off assembly of the interior and engine bay, it won’t be long now until we’re doing burnouts and busting wheelies.
Dyno Results Naturally Aspirated
Fuel: Pump gas, 91 octane
Peak horsepower & torque: 518/496
Average horsepower & torque: 409/471
Dyno Results on Nitrous Oxide
Fuel: Rocket Brand, 100 octane
Peak horsepower & torque: 734/740
Average horsepower & torque: 535/481
Plate Jetting: 73 nitrous jet, 67 fuel jet