LS3 and other engines/transmissions

[TAG UR IT]

GMHTP give us a little snippit of info on page 10 saying:

In mid-November, two LS3 crate engines-the LS376/485 (EFI) and LS376/500 (carbed)-will be available. These are LS3's with cam upgrades; both will run around $7,000.

...with that being said, this UPGRADED LS3 engine is going for less than half of an LS7. Now, add that up in the price of the Camaro and I don't think we are going to go through the roof here. I think that is good news that an upgraded LS3 is 7k.

[Mr. Wyndham]

That's really, REALLY,REALLYgood to know nice find...

LS3 it is!

[Mr. Wyndham]

Hey, I know some of you were wondering about the Active Fuel Management system in the LS3. Well, I found a picture that better demonstrates what I was going on about...

That is the "thing" that "disconnects" the Pushrods from the Camshaft...just thought you'd all like to know

[TAG UR IT]

^Nice find!

[TFord]

so if the base corvette LS2 got 28 miles to the gallon, and LS7 got 25 both without DOD, what will this LS3 get with DOD?

[DGthe3]

Originally Posted by TFord

so if the base corvette LS2 got 28 miles to the gallon, and LS7 got 25 both without DOD, what will this LS3 get with DOD?

depends (as always) on how hard you stomp on the gas. I think I have heard 30-ish as the target for a v-8 camaro. makes sense, somewhat heavier car but a more efficient system. The two should at least ballance off and give numbers like the LS2 corvette. When driven conservatively

[AirGoya]

Originally Posted by DGthe3

depends (as always) on how hard you stomp on the gas. I think I have heard 30-ish as the target for a v-8 camaro. makes sense, somewhat heavier car but a more efficient system. The two should at least ballance off and give numbers like the LS2 corvette. When driven conservatively

Ofcourse we are talking about highway mpg right? So that would mean low 20s on city mpg.

Ive mentioned my dads 06 Impala SS with cylinder deactiviation alot but on the highway he gets with trunk and full car 30 mpg and with just a driver in the car he gets 21 mpg. Just my lil 2 cents about V8 fuel mileage

[TAG UR IT]

GM hopes to get 30+ as they have said in many interviews. It could be a possibility w/ all the DOD, ACD, AFM, and whatever else they want to call it or switch the names to. Basically, there are a few different things they could do to the engine, if I am correct. Add these into the equation and 30+ (I would only have to assume HWY) wouldn't be so far fetched. 30 is still better than the 24 I'm getting in my SS now. That works for me!

[Mr. Wyndham]

I like to put it into perspective for some of my friends here...of course I assume (when I'm with them) that Camaro is getting the LS3:

430hp...

okay?...

now...

30+ mpg hwy...

Let that sink in


And now we're talking Camaro!

[Rock36]

Did I miss something? Will future variations of the LS3 have DOD?

All the current reviews for the new LS3 Vette are showing 16/26 mpg.

[Mindz]

The camaro is rumored to have DoD. I don't know about the current vette running the LS3 though.

[bcannan354]

IMO: Horse Power rating have always been advertised lower that actual, and MPG have always been advertised higher than actual. Just my 2.5 cents, but I have never had a car hit the MPG range that was posted on the window. Example: My 2004 Tahoe average today is 14.6 MPG. ouch:eek:

[Mr. Wyndham]

Originally Posted by Mindz

The camaro is rumored to have DoD. I don't know about the current vette running the LS3 though.

I thought for sure the LS3 had DoD...turns out I'm wrong, of 5 articles I found about this article - motortrend, edmunds...etc. - not one of them even mentioned DoD. However, one of them (I forget which) said something about VVT...

The mentioned 16/26 mpg rating is true as far as I can tell. But keep in mind, this is under the new EPA testing procedures, so it estimates more acurately the Fuel economy. 16/26 is probably the "equivalant" of 17-18/28-30 mpg under the old ratings...still pretty good especially for no DoD.

Here's one of the better articles I've found so far:

http://blogs.automotive.com/6209025/...ent/index.html

The changes involve everything from an all-new, larger and more powerful V-8 engine to refinements in driving characteristics that solidify the Corvette's position as the preeminent American sports car -- and further the argument that it is one of the world's best. There are also a host of exterior and interior refinements that raise the Corvette's luxury status and enhance the feeling of craftsmanship.

"Corvette is an uncompromising sports car that rewards its owners with impeccable performance and great comfort," said Ed Peper, Chevrolet general manager. "The changes and enhancements to the 2008 Corvette reflect continual improvements that speak to Chevrolet's unflagging commitment to building the best sports car -- and with nearly 55 years of experience, the Corvette just keeps getting better and better."

Also back again for '08 is the 505-horsepower Corvette Z06, an American super car that has won over enthusiasts, journalists and racers around the world for its balance of racetrack-bred performance, daily-driving civility and value.

Here's a look at the new and enhanced features for '08 Corvette models:

Engine -- A new, 6.2L LS3 small-block V-8 is the standard engine in Coupe and Convertible models. It is rated at 430 horsepower (321 kW)* and 424 lb.-ft. of torque (586 Nm)* with the standard exhaust system; with the new, optional two-mode exhaust system, power ratings increase to 436 horses / 325 kW and 428 lb.-ft. / 592 Nm. As a result, the standard Corvette is true supercar, capable of 190 mph. The LS3 with the six-speed paddle-shift automatic is the fastest automatic-equipped Corvette ever, with 0-60 mph capability of 4.3 seconds.

This new iteration of the storied small-block family features a revised, larger-bore cylinder block ? 4.06-inch / 103.25 mm vs. the previous 6.0L?s 4.00-inch / 101.62 mm bores -- high-flow, LS7/L92-style cylinder heads; larger-diameter pistons; revised camshaft and camshaft timing; revised valvetrain with offset intake rocker arms; high-flow intake manifold; high-flow fuel injectors from the Z06's LS7 engine; and a new engine beauty cover.

The LS3 features an aluminum cylinder block with cast iron cylinder liners. In addition to its larger bores, which help create a 376-cubic-inch displacement, the block casting also features revisions and machining in the bulkheads that enhance its strength and improved bay to bay breathing. But while the bore of the 6.2L engine is increased when compared with the previous 6.0L engine, the engine's stroke remains at 3.62 inches (92 mm). The pistons for the larger 6.2L engine also are new and are designed for its high-rpm performance capability.

Breathing for the new 6.2L engine is accomplished via new, high-flow cylinder heads. They're based on the large port/large valve design found on the LS7 engine and other GM L92 engines, with larger-capacity, straighter intake ports. The design optimizes intake flow to the combustion chamber and the exhaust ports are also designed for better flow.

Complementing the larger-port design of the heads are commensurately sized valves. The intake valve size alone increases from 2.00 inches (50.8 mm) to 2.16 inches (55 mm) -- an increase of nearly 9 percent. The intake valves feature lightweight hollow stems, which enable the engine's 6,600-rpm capability. The exhaust valves also are large, measuring 1.60 inches (40.4 mm) in diameter.

To accommodate the engine's large valves and enable more direct intake port flow, the intake-side rocker arms are offset 6 mm between the valve tip and the push rod. Actuating the valves is a new camshaft, with intake-side lobes providing more than a 5-percent percent in increase in lift, from 0.521-inch to 0.551-inch (13.25 mm to 14 mm). Exhaust-valve lift remains unchanged from the LS2. The camshaft timing was revised to optimize performance with the higher-lift intake cam profile.

Ensuring the cylinder heads receive all the air they can handles falls to a new, acoustically tuned intake manifold. The composite design is manufactured with a "lost core" process that improves runner to runner variation and reduces airflow losses. An acoustic foam material is used to reduce radiated engine noise; it is sandwiched between the outer top of the manifold and an additional "skull cap" acoustic shell. Also new beauty covers atop the engine shield the rocker covers and also feature a noise-reducing, acoustically tuned insert to provide a more refined engine sound.

Exhaust system -- Optional on '08 Coupe and Convertible models is a new, two-mode performance exhaust system. Similar in design and function to the system used on the Z06, the dual-mode exhaust uses vacuum-actuated outlet valves, which control engine noise during low-load operation, but open for maximum performance during high-load operation. It is not identical to the Z06 system; the Coupe/Convertible uses a 2.5-inch-diameter exhaust, while the Z06 uses a three-inch system.

With the new, dual-mode performance exhaust, power output for Coupe/Convertible rises from 430 horsepower (321 kW) and 424 lb.-ft. of torque (575 Nm) to 436 horses (325 kW) and 428 lb.-ft. (580 Nm). This system gives the Corvette a more aggressive exhaust sound character that will appeal to performance enthusiasts.

Transmissions and axle ratios -- The shifting efforts for both the six-speed manual transmission and paddle-shift six-speed automatic transmissions have been improved in '08 Corvette models. The manual transmission shifting improvements include a more positive and direct feel during gear changes, with better gate-to-gate location.

The six-speed paddle-shift automatic transmission on Coupe and Convertible is improved with new hardware and a new controller calibration that deliver quicker shifts. This change bolsters the feeling of performance and driver control when using the shifting paddles.

Also new for '08 models is the availability of the 2.73 performance axle ratio with the automatic transmission. It is included with the Z51 package.

I don't know, boys(and girls)...I know the LS3 is a great engine...but that L76 is looking more and more probable to me. What with the fuel economy crap and all...The LS3 doesn't have DoD, or VVT (based on the above article only), The L76 on the other hand, has BOTH - and although it gets a (new rating) of 16/26 mpg...is that enough for the Camaro in GM's eyes? Personally I hope not...just my $0.02....

[JeepinMatt]

The L76 is a great engine, but whether or not they come from the factory with them, I'm putting an LS3 between the fenders of mine