Our feature was shot at Robin's home track during Steve Barcak's Pontiac Heaven event this past April. Pulling the front wheels on launch is a given for this T/A.
A Bullet solid roller cam specs out at 276/293-degrees duration at .050 and .765/.742 lift thanks to the 1.60 roller rockers of the T&D shaft system. The lobe separation angle is a wide 116 degrees. Robin explained, "I asked the cam manufacturer to give us the widest LSA possible once the other specs were set to help bleed off some cylinder pressure. The cam was installed straight up for the same reason. It costs torque, but reducing the propensity for detonation is more important. Sure, we could bring the power in earlier with a tighter LSA and run 14:1 compression, but that would make a lot of cylinder pressure at mid range where detonation occurs. We'd make more power but would probably break running pump gas."
He and his friend, Justin Hart, have over 100 hours of porting in the Edelbrock wide-port cylinder heads with a resulting flow of 375/236 cfm at 28 inches of pressure. The exhaust-to-intake flow ratio is 63 percent. Robin wanted over 70 percent but couldn't get it with porting.
Surprise! The T/A has a full interior up front, right down to the console. The transbrake button is on the steering wheel.
Machine work on the heads was handled by WFO, where the chambers were opened up to 80 ccs and polished (as were the pistons) to reduce the chance of detonation. SI stainless 2.25-inch intake and Inconel 1.75-inch exhaust valves were employed. The latter are more resistant to heat, for durability's sake, while also reducing the chance of the exhaust valve becoming a hot spot in the chamber that could promote detonation. Pushrods from Smith Bros. measure 5/16 inch and have a .116 wall thickness. Comp Cams valvesprings provide a seat pressure of 300 pounds and 780 pounds open.
The Victor Junior intake manifold received 40 hours of porting to match the capabilities of the heads. Except for a change in air bleeds for a smoother idle, a 1,200 cfm Pro Systems Dominator was perfect out of the box, Robin said. Jetting is #95 square.
Robin's instructions are dialed into an NOS Progressive Controller mounted on the side of the console. On top of the console, one toggle switch controls the bottle heaters, and the other controls the second cooling fan.
A 15-gallon RCI cell holds the fuel and -10 line runs from the MagnaFuel ProStar 500 pump to an Aeromotive regulator set to 6.5 psi with -6 line carrying the petrol to the carb. Two Holley regulators are employed for the nitrous systems, each set to 6 psi with -6 line to the nitrous fuel solenoids.
BOP's beltdrive connects the cam to the crank, and a crank trigger, front-mounted distributor, coil, Digital 6 with digital retard, and wires, all from MSD, put the current through Autolite 32 platinum plugs. Timing is 35 degrees with no mechanical advance. When the nitrous is activated, the digital two-stage retard pulls 8 degrees of timing out with the first system and an additional 6 degrees with the second system so that the engine will live on pump gas.
The actions of the Moser rear are controlled by a Chassisworks four-link setup that features an extended panhard bar to keep the rear centered and CE coilovers set on the #3 position. To improve 60-foot times, Robin moved the instant center further back in the car. Would you believe this T/A actually has 50/50 weight distribution with the bottles full, a full fuel cell, and the driver in the seat? Stock was 59/41 percent.
Exhausting the monster motor is a set of Hedman headers with 2-inch primaries that were modified to step-up to 2.125-inches just before the turn to the 3.5-inch collector. A set of 3.5-inch pipes dump into twin Borla mufflers with turndowns just ahead of the rear axle.
Drivetrain
With all that engine prep, you can rest assured that the remainder of the drivetrain received the same attention. A 10-inch converter with 3,800 rpm stall, which bolts to a CSR flex-plate, is listed as a Fuel & Blown unit by ATI, meaning it has the highest torque capacity of all the models the company sells. After toasting four converters, Robin is satisfied with this one.
As you may imagine, the Turbo 400 was completely upgraded, highlighted by a Vasco input shaft, reverse manual valvebody, and a Griner transbrake. A B&M SuperCooler keeps temps down. The trans does, however, retain its stock gear ratios.
Made from chrome-moly, a 3.5-inch Denny's Driveshaft with HD U-joints connects the trans to a Moser 9-inch based housing, which contains 3.50 gears, a spool, and 33-spline axles.