What GM should do to improve the 2009 CTS-V before final release

[csp3000]

Originally Posted by CVP33

Here's video of Lutz addressing the CTS-V engineering team.

http://www.youtube.com/watch?v=TRDx5...eature=related

[dqw1]

Move the V emblem from the door to the fender where it belongs. Make the CTS embelm say CTS-V,(I know there's a V embelm on the other side of the trunk). I'd rather see the hood vented rather than the cheesy stamped vents. I see so many people putting fake Buick like vents on everything it's sickening.
Just wondering if that's a Corsa exhaust?

[Blackout]

A guy on another forum I am on actually builds pistons and he did extensive testing with hyper pistons and the results were not favorable. Anything over 6 psi netted BOOM and that was with 8.0:1 compression, although that was an iron block.

[Katshot]

Originally Posted by Blackout

A guy on another forum I am on actually builds pistons and he did extensive testing with hyper pistons and the results were not favorable. Anything over 6 psi netted BOOM and that was with 8.0:1 compression, although that was an iron block.

That's BS!
Not to say that they couldn't be made stronger by forging but the cast hyper-T's should be fine. I really don't see why so many people are getting so freaked out about this. You know how many cars have these pistons? More have them than don't. They're VERY commonly used these days. I really think the LAST thing you should be concerned about in this car is the engine.

[Me Wanna A V]

Originally Posted by Katshot

That's BS!
Not to say that they couldn't be made stronger by forging but the cast hyper-T's should be fine. I really don't see why so many people are getting so freaked out about this. You know how many cars have these pistons? More have them than don't. They're VERY commonly used these days. I really think the LAST thing you should be concerned about in this car is the engine.

How many "Forced Induction" cars have "these"?

Does AMG put hypers in there Kompressor or BiTurbo engines? NO!

Did Ford put hypers in the 03-04 Cobras? NO!

Is Ford putting them in the Shelby GT500? NO!

[Blackout]

Originally Posted by Katshot

That's BS!
Not to say that they couldn't be made stronger by forging but the cast hyper-T's should be fine. I really don't see why so many people are getting so freaked out about this. You know how many cars have these pistons? More have them than don't. They're VERY commonly used these days. I really think the LAST thing you should be concerned about in this car is the engine.

The biggest issue with these is that from what everybody has been talking about is that usually in F/I applications they usually use forged pistons instead because they know that they are more durable and that they can take more power. I'm sure these hyper pistons are used in non performance applications and whatnot but who knows. The car is just making its tour and sitting on a spinning platform at this point. Maybe GM will change some things around before its release

[Katshot]

Originally Posted by Me Wanna A V

How many "Forced Induction" cars have "these"?

Does AMG put hypers in there Kompressor or BiTurbo engines? NO!

Did Ford put hypers in the 03-04 Cobras? NO!

Is Ford putting them in the Shelby GT500? NO!

And you know this for a fact how? I think you're confusing the hyper pistons with whether they are cast or forged.

[Katshot]

Thought this was cute. I picked it up on a site that apparently has some piston manufacturers on it:

"...I think hypereutectic pistons got a bad name for the same reason that EFI did when it first came out.

A bunch of beer drinkin' old timers were sitting around sayin' "Why can't they just leave stuff alone? All this new stuff is confusing us. If it's confusing us, then it must be bad. So let's tell everyone how bad the new stuff is..."

[PSRmark]

Originally Posted by Katshot

Thought this was cute. I picked it up on a site that apparently has some piston manufacturers on it:

"...I think hypereutectic pistons got a bad name for the same reason that EFI did when it first came out.

A bunch of beer drinkin' old timers were sitting around sayin' "Why can't they just leave stuff alone? All this new stuff is confusing us. If it's confusing us, then it must be bad. So let's tell everyone how bad the new stuff is..."

Even GM knows that these pistons are not adequate...they have stated that since the combustion pressures are not that excessive that they can "GET BY" with the Hyper units...

Excuse me WHAT???

I expect ring land issues to arise after some miles have been put on them.

But I would love to be wrong.

[The Tony Show]

Originally Posted by d3mark

Even GM knows that these pistons are not adequate...they have stated that since the combustion pressures are not that excessive that they can "GET BY" with the Hyper units...

Source link or it didn't happen. This is how rumors get started.

[Silver Dollar]

Originally Posted by Katshot

....A bunch of beer drinkin' old timers were sitting around sayin' "Why can't they just leave stuff alone? All this new stuff is confusing us. If it's confusing us, then it must be bad. So let's tell everyone how bad the new stuff is..."[/i][/b]

Hey, that's me!

[Katshot]

Originally Posted by d3Mark

Even GM knows that these pistons are not adequate...they have stated that since the combustion pressures are not that excessive that they can "GET BY" with the Hyper units...

Excuse me WHAT???

I expect ring land issues to arise after some miles have been put on them.

But I would love to be wrong.

Again, I think you are confusing hypereutectic with cast vs. forged. Does ANYONE actually read the posts & links provided? People are obviously a little confused about what "hyper-eutectic" means. And likewise, I think people are a little too eager to jump on the "forged" bandwagon like it is synonymous with saying the parts (in this case pistons) are the ultimate choice. They aren't. Do some reading on pistons and you'll see that choosing forged pistons is not without it's draw-backs, and this is what factored into GM engineering's decision NOT to use them. People need to stop being taken in by marketing crap. The phrase "forged internals" is used so freely these days that many people quite naturally equate the phrase with being the best and strongest choice for engine parts but it's simply NOT true. They ARE the best for certain applications, but NOT all.

[CVP33]

So somebody break it down for me. As an "old timer" I'm use to forged crank, rods, pistons being the strongest period. So what was the reason GM chose hypereutectic pistons? I understand that these cast pistons have more silicon, have reduced wear, minimal expansion and allow for the compression ring to move farther up the piston. Thus you can have a lighter, shorter piston reducing reciprocating weight and allowing for a faster rev-ing engine. The downside is detonation, which a cast piston will not tolerate for long.

The forged piston has expansion issues, which could make for a noisy engine when started cold. They are also heavier, more expensive, etc. So it the bottom line cost? Is the issue that a modern V8 with a stock PCM shouldn't be allowing detonation of any kind anyway so forged internals are overkill? I gotta know GM, I gotta know!

[HiTechRV]

Pure guess here but NVH? We all love the lope and rough idle of a Z06 engine, but there are those who think it is unrefined.

[Katshot]

Originally Posted by CVP33

...I understand that these cast pistons have more silicon, have reduced wear, minimal expansion and allow for the compression ring to move farther up the piston...

Sorry to single you out but this is what I've been talking about. You say "cast" but you're actually describing "hypereutectic".
A hypereutectic piston can be either cast or forged. People are bashing GM and they aren't even sure about the technologies involved. Check out the link I posted earlier in this thread. It's very informative on the subject.