Express Checkout: Infiniti’s G7 Coupe
This is the first application of the VQ37 engine with Variable Valve Event and Lift (VVEL).The increase of 200 cc comes via the stroke changing from 81.4 mm to 86 mm.Compression ratio is increased from 10.6:1 to 11.0:1.Nissan claims VVEL improves performance and fuel economy, and reduces emissions.
Automotive Design & Production
This is the first application of the VQ37 engine with Variable Valve Event and Lift (VVEL).
- The increase of 200 cc comes via the stroke changing from 81.4 mm to 86 mm.
- Compression ratio is increased from 10.6:1 to 11.0:1.
- Nissan claims VVEL improves performance and fuel economy, and reduces emissions. Hydrocarbon production is reduced about 40%, fuel economy (adjusted to 2008 EPA methodology) is up almost 10%, and power output is 330 hp @ 7,000 rpm and 270 lb-ft @ 5,200 rpm.
Two transmissions are offered, a five-speed automatic and a six-speed manual.
- Randy Fior, Infiniti’s senior manager, Product Planning, expects 70% of buyers to order an automatic. Sport models come standard with magnesium paddle shifters.
- The DS mode has higher shifts points, and Automatic Shift Control uses a lateral g-force sensor to prevent the transmission from shifting mid-corner.
- Torque converter lock-up on the automatic has been expanded, and the ECU automatically matches engine revs on downshifts.
- To reduce NVH levels the manual gearbox has a revised dynamic damper, modified shift linkage, and a revised shifter isolator.
As expected, the braking and suspension systems also have been upgraded from the G35 Coupe’s specification.
- Sport models receive 14-in. front and 13.8-in. rear rotors with opposed-piston calipers (four pistons front, two pistons rear). Base cars use sliding calipers and have 13-in. calipers front and rear from the G35 sedan.
- Electronic brake force distribution, brake assist, vehicle dynamic control, and ABS are standard on all models.
- Lateral stiffness of the double wishbone front and multi-link rear suspensions are up 45% despite an increase in front and rear tracks.
- Four-wheel active steering (4WAS) is optional on the Sport model and uses an actuator between the rear spring perches to add 1? of steering—in-phase with the front wheels—at about 40 mph. The addition of a front steering actuator to this system gives an effective dynamic steering ratio of 12-20:1.
- “The idea,” says Fior, “is to decrease effort at low speeds, increase nimbleness in the midrange, and slow the ratio down for greater stability at high speeds.”
- Chassis stiffness has been increased 36%.—CAS
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