PacerX

...use the CAST pistons that the CTS-V LSA uses in a LSA powered Z28.

They better be FORGED, or this is a failure precisely in line with the glass-jaw 10 bolts we got in the F4s. GM had better have learned that damned lesson or there is NO HOPE.

DO NOT, DO NOT, DO NOT use cast pistons in that motor or I swear to God you people are dumb as a box of hammers and Z28 owners will be SCREAMING about them for the next 20 years while GT500 owners giggle their blue-ovaled asses off.

twocamaros

yeah it be a good idea.. id rather pay a couple hundred more then not get them an be laughed at..

Z284ever

I'm not sure why the LSA has cast pistons, but it does.

The question is, is it reasonable to expect the Z/28 to have higher content than the V, but also cost $10-$12K less?

SSbaby

The Z/28 will be modified to race, therefore, it needs the forged pistons.

The CTS-V is probably more likely the boulevard cruiser than strip weapon.

Horses for courses.

IREngineer

I think we've known for a while that they were gong to be cast. You will not see stock bottom end LSA's with 900hp like the Shelby.

Big Als Z

Yeah...GM didnt spend the money to remove things out of the Camaro.
They are going to spend the money to ADD more things to it?

Cast pistions FTL. Yet another reason why cutting 150lbs out of it and throwing a bigger cam would have been a better solution.

QATransAm

Good thread

The LSA using hypereutectic pistons from the start is a slap in the face.

I can't imagine GM being dumb enough to do it with this car....they have to know there will be a lot more modded Z/28's running around than Caddys.

We'll see if they hand the Ford yet another advantage

PacerX

No, it's more reasonable to expect GM to quit panty-waisting around about the noise issue with forged slugs in the CTS-V, FIX THE NOISE ISSUE, and put forged slugs in both.

Instead, we get the typical GM-speak:

"It's unpossible."

No, it's not unpossible. They may make noise, but if the customer doesn't HEAR the noise, it's not an issue. On a Z28, my bet is that customers would WANT to hear the noise as long as it isn't the same sound as the piston-slap issue was.


The Z28 gets hyper-u-explode-its, or any other measure of weak bottom end gear, and you can mark my words that it'll be talked about for a decade as yet another GM bone-headed move.


Simple rule:
Performance cars get performance parts.

2010_5thgen

why would they change the pistons for the z28 motor and leave the same pistons in the cts-v which has the same motor as the camaro "z28"????? doesnt make sense.

PacerX

The only reason that the CTS-V should get cast is NVH. "Should" is the wrong word... "We're too lazy/brain-dead/cheap to figure out the NVH issue" or "we don't believe anybody is going to mod a CTS-V" would be a better way to put it...

However, from my understanding, CTS-V LSA's are already grenading their bottom ends because of weak components.



There is no reason to give a Z28 cast pistons, beyond epic stupidity. The noise issue, unless the thing sounds like a diesel, is a non-issue. The solution, even if it does sound like a diesel, is forged pistons and fix/mask the noise issue. You had better believe that Z28's are going to get modded...



This is the perfect example of a bone-headed GM business case... i.e. letting the accountants decide that putting the proper parts for proper reliability in a performance car (10-bolt anybody?) is too expensive to justify. Make no mistake, it isn't about NVH for the cast pistons, just like it wasn't about weight for the 12-bolt in the F4's...

It was about MONEY and bad engineering.

Good engineers find solutions for NVH and weight issues, good management pays for them with hard work with the suppliers in other parts of the car (for the 10 vs. 12 bolt, find the weight elsewhere, pay for it with VA/VE). Bad engineers and bad managers listen to accountants about critical reliability items.

2010_5thgen

wow. you get very hostil over a car that isnt even made yet. look at it from a business perspective. why would they change the motor for the z28 when they are already being produced for the cts v? they wouldnt, because that involses more R&D and design changes = $. also do you really think gm is concerned about the people who mod these cars? not really because they see it as you voiding the warranty. therefore being your own responsability if something goes wrong. they dont make cars thinking that everyone is going to mod them. majority of people will keep a cars warranty.

PacerX

Yeah I'm hostile. It's stupid.

Ford figured it out, and the GT-500 has a forged bottom end.

GM can't???



Furthermore, your explanation is nonsense. The cars WILL get modded. Ford gives theirs a solid bottom end, GM doesn't. Then we get to hear about GM's glass-jaw motors, while the Ford guys have the added value of a forged bottom end.

Just like the 10-bolt, all over again.


Ford likes a reliable powertrain, GM likes a cheap one. Wonderful.

The definition of insanity is doing the same thing over and over again and expecting a different result.

2010_5thgen

like i said. there is no need to get so worked up over a car that you know 100% of NOTHING about.

Gold_Rush

Definitely agree with pacer, but i don't think GM will go through with it and the Lsa will most likely carryover to the z28 unchanged.

If you're going to benchmark the GT500 and use a boosted v8, then take note of the 5.4's tough construction. I believe there are examples putting out 1,000+rwhp with the stock longblock.

Z284ever

Oh, no way. I hear the LSA is already near it's max limit for reliable power.