G8 GT Tune Yields 353rwhp
12-19-2007, 11:24 PM
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G8 GT Tune Yields 353rwhp Holden Commodore SS-V/Pontiac G8 GT tuned, pushed out 353hp at the rear wheels.
From 312rwhp stock.
http://www.gmhightechperformance.com..._g8/index.html
G8 GT-L76 6.0L V-8
If you've read this magazine for any measurable length of time, you've undoubtedly heard us bantering about the L76 intake paired with L92 cylinder heads. Oddly enough, up until now we didn't even have a vehicle in the United States that used this particular manifold. The good news is that not only do we finally get this mystical intake, we also get cylinder heads that fit the smaller bore-but with the same benefits of the L92-style heads, including the rectangular LS7-style intake ports.
In basic terms, the L76 is a natural extension of the LS2. They share a similar bore (101.6mm LS2, 101.3mm L76), and the same 92mm stroke, but there are also many differences that should be noted. First up is the addition of "Active Fuel Management," or Displacement on Demand, as it was originally termed. This system allows the deactivation of four specially provisioned cylinders through the use of particular lifters, oil channels, and tolerances on the camshaft lobes of those four cylinders. The L76 can thus transition from a V-8 to a V-4 and back again, with nearly seamless precision all but unnoticed by the driver. Additionally, this system increases fuel economy under low-load, low-throttle situations such as highway driving, but doesn't play a large role in city fuel economy. Currently, Holden does not have this feature activated on their L76s; however, the Pontiac model will reportedly have Active Fuel Management.
Next up is the option of variable cam-phasing. While the L76 currently in use in the Holden Commodore does not have the ability to change cam timing, the L76 truck variant here in the US does, which means we are likely to see it in the car relatively soon. This system works by metering the oil flow to the cam phaser, effectively physically advancing or retarding camshaft timing. Couple that with Active Fuel Management, and we have a V-8 that can not only pass upcoming stricter emissions standards, but also get incredible fuel economy.
Speaking of fuel, the L76 in the G8 is calibrated to unleash an astounding 362 hp on regular fuel. This is a dream come true for tuners, who will likely be able to wring over 40 hp by simply tweaking the fueling and spark to use high-test premium gasoline. Tuning, of course, leads us to another topic: the engine controller. As of press time, it appears the G8 will be sporting the relatively new Delphi E67 controller. This faster processor allows control of the Displacement on Demand and cam-phasing (if equipped) simultaneously, and adds a few needed input and output drivers, as well.
From 312rwhp stock.
http://www.gmhightechperformance.com..._g8/index.html
G8 GT-L76 6.0L V-8
If you've read this magazine for any measurable length of time, you've undoubtedly heard us bantering about the L76 intake paired with L92 cylinder heads. Oddly enough, up until now we didn't even have a vehicle in the United States that used this particular manifold. The good news is that not only do we finally get this mystical intake, we also get cylinder heads that fit the smaller bore-but with the same benefits of the L92-style heads, including the rectangular LS7-style intake ports.
In basic terms, the L76 is a natural extension of the LS2. They share a similar bore (101.6mm LS2, 101.3mm L76), and the same 92mm stroke, but there are also many differences that should be noted. First up is the addition of "Active Fuel Management," or Displacement on Demand, as it was originally termed. This system allows the deactivation of four specially provisioned cylinders through the use of particular lifters, oil channels, and tolerances on the camshaft lobes of those four cylinders. The L76 can thus transition from a V-8 to a V-4 and back again, with nearly seamless precision all but unnoticed by the driver. Additionally, this system increases fuel economy under low-load, low-throttle situations such as highway driving, but doesn't play a large role in city fuel economy. Currently, Holden does not have this feature activated on their L76s; however, the Pontiac model will reportedly have Active Fuel Management.
Next up is the option of variable cam-phasing. While the L76 currently in use in the Holden Commodore does not have the ability to change cam timing, the L76 truck variant here in the US does, which means we are likely to see it in the car relatively soon. This system works by metering the oil flow to the cam phaser, effectively physically advancing or retarding camshaft timing. Couple that with Active Fuel Management, and we have a V-8 that can not only pass upcoming stricter emissions standards, but also get incredible fuel economy.
Speaking of fuel, the L76 in the G8 is calibrated to unleash an astounding 362 hp on regular fuel. This is a dream come true for tuners, who will likely be able to wring over 40 hp by simply tweaking the fueling and spark to use high-test premium gasoline. Tuning, of course, leads us to another topic: the engine controller. As of press time, it appears the G8 will be sporting the relatively new Delphi E67 controller. This faster processor allows control of the Displacement on Demand and cam-phasing (if equipped) simultaneously, and adds a few needed input and output drivers, as well.
12-20-2007, 05:22 PM
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12-20-2007, 06:40 PM
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You need to get even more excited because the straight conversion from 263 rear wheel kilowatts to 353 rear wheel horsepower is different to what a US Dyno would actually read.
A stock 400hp LS2 car generally puts out about 225 rear wheel kilowatts on a Dyno Dynamics in Australia. Straight conversion for 225rwkw is 301rwhp.
Yet if you dyno a stock 400hp LS2 car (05-06 GTO) on a US Dyno (Dynojet) the figures claimed are usually about 340rwhp.
So what I'm saying is if you are excited about 353 rwhp......this same car on your Dynojet would read closer to 390rwhp.
A stock 400hp LS2 car generally puts out about 225 rear wheel kilowatts on a Dyno Dynamics in Australia. Straight conversion for 225rwkw is 301rwhp.
Yet if you dyno a stock 400hp LS2 car (05-06 GTO) on a US Dyno (Dynojet) the figures claimed are usually about 340rwhp.
So what I'm saying is if you are excited about 353 rwhp......this same car on your Dynojet would read closer to 390rwhp.
