Close

Activity Stream

Filter
Sort By Time Show
Recent Recent Popular Popular Anytime Anytime Last 24 Hours Last 24 Hours Last 7 Days Last 7 Days Last 30 Days Last 30 Days All All Photos Photos Forum Forums Articles Articles
Filter by: Articles Last 30 Days Clear All
  • Sticky's Avatar
    Yesterday, 10:45 PM
    The C6 ZR1 and C7 Z06 have engines have some similarities. They both have the same 6.2 liter displacement and both are supercharged V8 engines. The similarities pretty much end there though as they are two different generations of GM supercharged V8's. The LT4 of course incorporates direct injection which allows higher compression at 10.0:1 compared to the 9.1:1 of the LS9. The LT4 also has a smaller 1.7 liter supercharged compared to the LS9 2.3 liter unit. It is quite a bit smaller but also 20 pounds lighter. They both have the same 6600 rpm redline. Let's break down each motor with GM's own details: LT4 6.2L supercharged engine specifications Displacement (cu in / cc): 376 / 6162 Bore & stroke (in / mm): 4.06 x 3.62 / 103.25 x 92 Block material: cast aluminum Crankshaft: 1538MV steel Connecting rod (in / mm): 6.125 / 155.5 powder-metal steel Piston: forged aluminum with internal ribs; flat-top crown Cylinder head material: A356-T6 rotocast aluminum Induction system: 1.7L supercharger 9.4 psi / 0.65 bar max boost Valvetrain: overhead valve, two valves per cylinder Valve type (intake / exhaust): 54mm solid titanium / 40.4mm sodium-filled Camshaft type: hydraulic roller Intake valve lift (in / mm): 0.492 / 12.5 Exhaust valve lift (in / mm): 0.551 / 14 Duration @ 0.050-in. tappet lift (crank angle degrees, intake / exhaust): 189 / 223 Camshaft lobe separation angle (degrees: 120 Fuel delivery: direct injection Fuel injectors: 25cc/second (1.5L/min) Engine-driven fuel pump (psi / MPa): 2900 / 20 Lubrication system: dry sump, incl. oil-spray piston cooling Compression ratio: 10:1 Horsepower (hp / kW @ rpm): 650 / 485 @ 6400 SAE certified Torque (lb-ft / Nm @ rpm): 650/ 881 @ 3600 SAE certified Max. engine speed (rpm): 6600 Recommended fuel: premium required LS9 6.2L supercharged engine specifications The LT4 is rather at 650 horsepower and 650 lb-ft of torque despite the smaller blower. The LS9 is rated at 638 horsepower and 604 lb-ft of torque. The difference between the two in practice at the wheels is even greater than the crank ratings on paper: 49 wheel horsepower and 84 lb-ft of torque at the wheels difference in favor of the LT4 over the LS9. These numbers really make one wonder why the C7 Z06 is not putting up better performance numbers.
    2 replies | 22 view(s)
  • Sticky's Avatar
    Yesterday, 08:32 PM
    Cadillac has leaked out that they will debut the next generation CTS-V at the Detroit Auto Show taking place next month or more accurately in just over three weeks. Considering how powerful Cadillac's European competition is they need to pack some serious heat. They intend to as the C7 Z06 LT4 6.2 liter supercharged direct injection V8 is expected under the hood. This raises the question as to whether the CTS-V will get the exact same LT4 or if there will be changes much like the previous generation CTS-V saw to its LSA V8 compared to the LS9 it was based on which saw use in the ZR-1 Corvette. Let's think positively for a moment that the CTS-V will not be detuned. That means 587 rear wheel horsepower for the CTS-V or in other words more than any of its competition. It will likely be mated to the 8L90 automatic transmission which offers incredibly quick gear changes meaning GM is likely to have the fastest luxury performance sedan in the world if they manage to keep the weight from ballooning. We will know more next month but let's hope GM gives the CTS-V the LT4 without any changes and if they do make any changes they only do so to give it more, not less, power and torque.
    2 replies | 30 view(s)
More Activity