GM Shows 2009 Changes!

[1G6]

Sorry for the commotion, just sticking up for a fellow Caddy fan.

I've always enjoyed DuSpinnst's posts. He's one of the good guys.

[ogg vorbis]

Originally Posted by b4z

ogg_vorbis,

Great Post!

Nice to be able to cut through all the cr** you read on here with a post that has actual facts.

thank you!

i really love the 2v ohv architecture...i don't think much of 3v. it strikes me as odd that gm has developed one of the best v8 period...and nobody cares about the v6.

the epa has asked mfg to stop the hp wars...which opens the doors for torque - large ohv, and diesels. if honda couldn't make the great peak hp, their engines wouldn't be worth anything.

the 4.3 is based on a 20 yr old design. how can gm perpetuate a design that shares no parts or technology with any other engine, be it v6 or v8? either it will be updated, or replaced with the 3.9 (i give it until 2010). the top of the line ridgeline has a 3.5. mercedes just developed a 90° v6, so nvh isn't an issue with that architecture.

gm appears to be squeezing out the 4.8 too (no aluminum versions), or it's made the 5.3 aluminum to justify the small power difference, and separate them in cost. imho, they can rework the heads (ls3 style) and get 345+ hp/ 360 lb-ft from the 5.3.

as far as cars, i didn't see the 3.5 in the line up. it's being replaced by the 2.4. the 3800 stops production in the next month or so. the 3.9 lives on in the lucerne for now. again, it's strange that buick gets a dohc v8 when cadillac won't. afaik the ultra is cancelled.

[ogg vorbis]

Originally Posted by 88ls1blazer

the LS1 block was ALWAYS over priced. an LS2 block is usually ~800 new, and an iron ~500-600 brand new, 2-300 isn't much more.

I have NO idea where you get your HP figures from but LS* guys went bottom 8's 4+ years ago on stock cranks and a stock aluminum block. I am pretty sure in a 3400+ lb F-car it takes more then 1000hp to do so. As far as a C5r block, you would be insane to spend that much for what you got.

please explain to me how NVH is better on iron? Iron is a denser material then aluminum, automatically making it a more efficient transmitter of vibrations.

So in your mind (just to clarify) this is how aluminum looks:

300% more expensive then Iron (because companies LOVE to spend obscene money on parts used to production when a cheaper alternative is available)

Iron is stonger (yes, durability on engines is at an all time high, the use of cast iron is at an all time low... connection anyone?)

an Iron liner is difficult to deal with (companies like to make their workers LESS productive right?)

the aluminum barely helps with heat because it still has an iron liner (even though the iron liner is thin enough to rapidly dissipate heat into the aluminum which then cools at an even faster rate)

And aluminum engines lose combustion efficiency (even though increasing compression ratio with less heat adds efficency when compared to a lower cylinder pressure with more heat)

Am I understanding you logic correctly?

check the gm parts catalog for hp ratings. i accept that they're conservative...so the lsx is conservatively rated at 2500 hp. whatever an ls2 can withstand for 8.xx seconds, and lsx can handle many times more, and endure much longer. how often do those engines run and last?

the high cost of first run ls1 blocks demonstrates the difficulty in making it. ls3 heads cost $800 new, while gm's own cnc ls2 heads are $2000. lowering mfg costs account for the ls1 vs ls2 price difference. and the difference you quoted is still 50-60%. when mfg will work to cut pennies, $300 is not insignificant.

you obviously have no concept of design vs materials. engines today are designed much better captain obvious. and 99% of aluminum blocks use iron liners - you suggest that aluminum makes it durable. steel has a higher fatigue strength than aluminum - it will last infinite cycles below ~50% yield stress. aluminum will continually lower its yield stress and fail at a predictable number of cycles. high stress parts are still steel - rods, main caps, fasteners, valvesprings etc. they use aluminum when they can get away with it. will cars today last as long as older cars?

all the ribbing designed into aluminum parts to increase strength and diffuse noise. mfg use coolant to dampen combustion noise. the lighter the part, the more noise it radiates. you'll sometimes find steel weights on suspension arms to dampen resonances. i was talking to a quiet steel rep recently, and he admitted that while the elastomer dampens high frequency noise, you still need mass to dampen low frequency noise.

the movement to aluminum in cars is a direct result of increasing minimum creature comforts, 'safety' devices, economy and size. the aluminum lobbies have a lot to do with it, as well as consumer perception.

so in my automotive engineering mind, from a material standpoint cast iron is just as viable as aluminum...just as i believe 2v are better than dohc in street cars. even aston martin says that 2v are an advantage in racing, and the ls7r wins motorsports engine of the year. a cast iron block ohv v6 imo is on par with a dohc aluminum v6.

c'mon, this is sophomore thermodynamics. even high schoolers learn that temperature and pressure are related - boyle's law. a thin section of material will conduct and transfer heat SLOWER than a thick section. and the boundary impedes heat again. compression ratios above 10.1 DO lower mechanical efficiency, but can be compensated with thermal efficiency. do you understand the distinction?

[PA Dweller]

Originally Posted by nsap

The Epsilon II G6 is due out in 2011 MY (so 2010 launch). I can't see GM spending money to refresh the G6. I suspect GM has about maxed out their intended investment of Epsilon I.

Do you have any idea or at least a theory on how the Pontiac will be different from the Aura, Malibu, and LaCrosse? Will it drive differently?

[44 mpg by 2010]

If GM is serious about fuel economy, why not a NOx abated version of one (or both) of the following Astra turbo diesels:

MY2008 5 Door Estate 1.7CDTi 16v 100PS with 15" wheel at 47 http://www.vcacarfueldata.org.uk/search/vehicleDetails.asp?id=20284

MY2008 5 Door Estate 1.9CDTi 8v 120PS, A6 at 33.6 mpg(US) combined cycle http://www.vcacarfueldata.org.uk/sea...s.asp?id=20292

Heck ... who knows ... the Astra diesel drive train might just work in a lot of different vehicles.

[nsap]

Originally Posted by PA Dweller

Do you have any idea or at least a theory on how the Pontiac will be different from the Aura, Malibu, and LaCrosse? Will it drive differently?

GM has been swearing that all of the Epsilon II vehicles will be very different.

[PA Dweller]

Originally Posted by nsap

GM has been swearing that all of the Epsilon II vehicles will be very different.

I hope they give it a more sporty ride compared to the rest.

[CadiEldo67]

Is Epsilon II AWD capable? If so, the I think the G6 should be standard with AWD. And when it and if it migrates to Alpha, it should feature a Saab inspired XWD system, that is RWD biased along with a RWD version.

[airglow]

Originally Posted by 44 mpg by 2010

If GM is serious about fuel economy, why not a NOx abated version of one (or both) of the following Astra turbo diesels:

MY2008 5 Door Estate 1.7CDTi 16v 100PS with 15" wheel at 47 http://www.vcacarfueldata.org.uk/search/vehicleDetails.asp?id=20284

MY2008 5 Door Estate 1.9CDTi 8v 120PS, A6 at 33.6 mpg(US) combined cycle http://www.vcacarfueldata.org.uk/sea...s.asp?id=20292

Heck ... who knows ... the Astra diesel drive train might just work in a lot of different vehicles.

Have you looked at US diesel prices lately? Virtually all of diesel vehicles improved MPG is eaten up by the price of the fuel. Add in the $3-5K price premium and I fail to see an economic argument for diesel. I won't even talk about the apparently unsolvable small particulate problem (Asthma anyone?) diesels still have.

[SierraGS]

Originally Posted by ogg vorbis

check the gm parts catalog for hp ratings. i accept that they're conservative...so the lsx is conservatively rated at 2500 hp. whatever an ls2 can withstand for 8.xx seconds, and lsx can handle many times more, and endure much longer. how often do those engines run and last?

the high cost of first run ls1 blocks demonstrates the difficulty in making it. ls3 heads cost $800 new, while gm's own cnc ls2 heads are $2000. lowering mfg costs account for the ls1 vs ls2 price difference. and the difference you quoted is still 50-60%. when mfg will work to cut pennies, $300 is not insignificant.

you obviously have no concept of design vs materials. engines today are designed much better captain obvious. and 99% of aluminum blocks use iron liners - you suggest that aluminum makes it durable. steel has a higher fatigue strength than aluminum - it will last infinite cycles below ~50% yield stress. aluminum will continually lower its yield stress and fail at a predictable number of cycles. high stress parts are still steel - rods, main caps, fasteners, valvesprings etc. they use aluminum when they can get away with it. will cars today last as long as older cars?

all the ribbing designed into aluminum parts to increase strength and diffuse noise. mfg use coolant to dampen combustion noise. the lighter the part, the more noise it radiates. you'll sometimes find steel weights on suspension arms to dampen resonances. i was talking to a quiet steel rep recently, and he admitted that while the elastomer dampens high frequency noise, you still need mass to dampen low frequency noise.

the movement to aluminum in cars is a direct result of increasing minimum creature comforts, 'safety' devices, economy and size. the aluminum lobbies have a lot to do with it, as well as consumer perception.

so in my automotive engineering mind, from a material standpoint cast iron is just as viable as aluminum...just as i believe 2v are better than dohc in street cars. even aston martin says that 2v are an advantage in racing, and the ls7r wins motorsports engine of the year. a cast iron block ohv v6 imo is on par with a dohc aluminum v6.

c'mon, this is sophomore thermodynamics. even high schoolers learn that temperature and pressure are related - boyle's law. a thin section of material will conduct and transfer heat SLOWER than a thick section. and the boundary impedes heat again. compression ratios above 10.1 DO lower mechanical efficiency, but can be compensated with thermal efficiency. do you understand the distinction?

Excellent overview of Aluminum vs. Cast Iron.

One point you should mention that 2V OHV V6-V8's are lighter than DOHC counterparts and an all cast iron engine has better emissions performance due to higher thermal efficiency, although "start-up" problems remain.

These facts are illustrated with the 3800 BIN 5 and SULEV 2008 emission ratings and there is not that much difference in a LS Aluminum or Iron V8 and even the Iron block LS V8 weighs less than many V6's.