Video: Corvette C8.R Lapping Road America, Flat Plane V8 Available In Street Car
As I reported last week, Chevrolet surprised journalists at the C8 convertible debut by unveiling the C8.R race car. They stated more information would be coming this weekend at the Petit. Another bombshell dropped, this time involving the power plant for the race car and also a road going version.
The C8.R will be powered by a 5.5 liter flat plane crank V8, producing approximately 500 horsepower and 480 pounds feet of torque. Mated to a 6 speed sequential transmission, this engine will feature dual over head camshafts, a first for Corvette racing and the first use of DOHC in a Corvette since the limited production C4 ZR-1. If the 5.5 liter displacement sounds odd, it is due to the regulations set by IMSA and FIA for naturally aspirated engines.
A more significant regulation states that any engine eligible for racing must have 300 examples in street cars. Chevrolet did not confirm that it would be in a C8 Z06, but stated that it was “a future production based engine.” If you read the writing on the wall, it just makes sense that this engine will be the Z06 power plant. It is a possibility that the displacement could be increased for the street car engine, as Chevrolet would most likely want the horsepower and torque ratings to meet or exceed the 650hp/650tq numbers for the C7 Z06. This engine is a completely new engine from the ground up and will not share any components with the current pushrod LT series. It also is not related to the Cadillac 4.2 liter DOHC V8 engine.
The C8.R was shown off during some hot laps at the Petit LeMans at Road America. Blacked out windows hid any interior details, but the sights and sounds of the C8.R more than made up for that. The C8.R will debut at the Rolex 24 at Daytona in January.
For a FPC 90° V8 I would guess that 5.5L would be the maximum for vehicles that are mass produced and include a substantial warranty, but the longitivity needed for a Corvette isn’t needed in low production cars; 5.9L for SSC and 5.8L for Zenvo. A naturally aspirated 5.5L FPC DOHC V8 with direct fuel injection if built properly and having a well built transmission can produce 690 SAE HP/BHP(approximately 125 HP per liter) at 8500 rpm or 825 SAE HP/BHP(150 HP per liter) at 8000 rpm with forced induction and passing emmisions. Having .1 liter more displacement, 10 less SAE HP/BHP and a shorter stroke(if based on the Ford’s 5.2L DOHC FPC V8 because of 100mm bore spacing) than Brabham’s BT62 making passing emmisions easier.
It sounded awesome from Spectator Hill!