The LS1 Camaro uses a bone...
The LS1 Camaro uses a bone stock 4L60E automatic transmission that has been computer tuned to shift into Second gear, and stay there, when the car reaches 12 mph.
Work began on the car and one of the first areas the group addressed was safety. One argument against electronic fuel injection that is often brought up is the fact that in the event of an accident, the motor will keep pumping fuel because of the electric fuel pump. In a properly designed engine, this is a fallacy and Rippamonti and his crew designed it properly.
The car's fuel system has a rollover switch, which shuts off the fuel flow in the event the car gets upside down. It also has an inertia switch, which will cut the fuel flow based on a pre-determined g-force in the event of a hard impact. Many of these switches can be adjusted to a setting that suits the particular application.
Finally, there is a fuel cutoff switch that is linked to the engine's oil pressure. In the event that the oil pressure drops below a certain psi, the switch will cut the fuel to the engine, shutting the whole thing off. This is not only an excellent safety measure but it can save vital internal engine components and prevent a blown motor. Apart from those three switches, the car has all the standard safety equipment you'd come to expect-a full 'cage, a racing seat, a fuel cell, and so on.
Here, you can see part of...
Here, you can see part of the wiring harness. It's a stock unit that was gutted down to the bare bones. Only those wires needed to make the engine and transmission run were kept.
Using an LS1 in a dirt Street Stock is actually a pretty logical step, if you can get your local track to approve it, which these guys did for one simple reason: cost.
"We were trying to make something as inexpensive as possible, a cheap alternative to something that is becoming harder and harder to find-the small-block Chevrolet," said Rippamonti. "We've got less than $2,000 in the whole car; that's the car, safety equipment, the motor, and the transmission."
A race-ready Street Stock for less than $2,000? Awesome.
As we mentioned, the car sits on a '78 Camaro chassis. It has Performance Bodies skins, but the bumper and the hood are straight off of an '02 Camaro. "It looks interesting to say the least," jokes Rippamonti.
Rippamonti kept the stock...
Rippamonti kept the stock instrument cluster. The only thing that doesn't work is the fuel gauge. Racers who have driven the car reportedly got a kick out of looking at the speedometer as they made laps.
The engine is the 4.8-liter LS1 that found its way into many a GM truck throughout the '90s. At 293 cubic inches the guys are giving up a lot of cubes, 57 to be exact, to racers running the 350 Chevy, but this exercise was about more than just making raw power. The boys mated that LS1 to a 4L60E automatic transmission with overdrive and a stock converter! Rippamonti proudly reports that they picked up the motor and the transmission for $200.
To get everything running, they basically gutted a stock LS1 wiring harness to the bare bones. If they didn't need it to run the engine and trans, they didn't keep it. With the engine running, they began the tweaking process. "We robbed some valvesprings off of a 5.3-liter LS1 motor that was blown up just so we could get the rpms up a little bit," says Rippamonti. Then they set the rev limiter at 7,000 rpm.
Early testing revealed that the engine would run hot, but after a little investigating the team found that water in the water pump would cavitate above 5,500 rpm. Their solution was to put a 25-percent underdrive pulley on the engine. The underdrive pulley essentially moves the pump slower than the motor, down in the range of 5,200 rpm so that the water in the pump would behave and flow smoothly, thus eliminating the overheating issue. With the addition of the underdrive pulley at $200, they doubled the cost of their engine, but $400 for a little Saturday night power is still a bargain.