So Mark, how's the weather in the Netherlands?

 

No I am not trying to pick a fight, it just bugs me as a professional engineer when someone makes a statement like "a fair amount of design margin". Especially when they are making what comes off as a condescending remark to another forum member who is very knowledgable and goes out of his way to help people out.

 

Spin is has helped countless members in countless ways, from doing work to sharing from his experience and knowledge. I would put that up against anyone's degree when it comes to making Corvettes go fast!
Maybe the remark wasn't meant to sound insulting but it did, that never helps anyone.

Thanks Spin!

 

imo if you plan on modding go LS3, if you plan on keeping it stock go 09 or higher ls7

 

You are the second guy this month to make some education level smart azz remark about engineering as if there was something you cant share here because we cant understand it. Why the offensive position? All I was asking was what is the design margin you speak so it can be discussed. I did nothing to insult you or otherwise to get your insult on education as if there is anything in your response that would be beyond me or my education level. Ring gaps? End play? Tensile strength?

As far as your engineering comment, I assure you I can teach most engineers more math than they see by their master's degree. I am a licensed math teacher in two states. My family owns an aircraft engine machine shop and can answer pretty much anything about engine engineering, design, and repair. I am completing a second masters here in Colorado this year.

You say you arent looking to pick a fight but you give a pretty good smack down when someone asks you to explain a statement so instead of telling people to take engineering classes, why not just answer the question without attacks?

 

Yes Sir, May I have another!



(Animal House reference...)

 

Maybe I should clarify my question....what were GM'S design margins that you speak of? If you just mean some arbitrary non-sense that they make it handle more than its tuned for then yeah....duh. Was there some specific thing you know of and can discuss or is it some fluff statement that it handles more than the 505hp for the LS7 and 430hp for the LS3? I would have respected something like 'the LS7 can handle 650rwhp before the pistions crack' (42% over stock) and 'the LS3 can handle 670rwhp too but its 74% over stock making the LS3 better for modded FI applications'.

Instead, the big tech info we need an engineering degree to understand is: LS7's break so the design margins are exceeded.

Insightful.

Exactly.

 

I 100% agree with you Mark. These arent mistakes I post on but rather limitations for people buying to later mod. The LS7 doesnt get any higher in power modded to justify its price tag as an engine to the guy that plans to mod and the OP never gave any indication that he was going to mod it. For the 650rwhp level, I would tell a guy to get the LS3 no matter what. I would feel fine with that as a daily driver power level on the smalle engine but not on the LS7. For someone planning 1000rwhp, the LS7 as it is set up in the Z06 has timing chain limits too. Why bring up modded applications when the OP didnt specify it? because we are in the tech section where most people do mod and people looking for info sometimes want to know such things. I would want to know what the weak link is. For the whole car; on the 1999 c5 it was the connecting rod bolt. On the 2004, its the fuel system. On the 2005 its the diff, on the LS7 its the pistons. The LS3 block handles more than the lS7 block. Its not a flaw but telling of the real world limitations.

As a bone stock car or even cammed, the LS7 is a great motor if you stay under that 600rwhp level.

They arent mistakes to have a weaker piston to have a 4" stroke but it could have been avoided. The thinner walls using the cylinder lining next to it to reinforce structual integrity isnt a prime move either. It was a gimmic to hit the magic 427ci level.

The LS9 is a tank and I'm not easily impressed. They did the ZR1 right from forged pistons to the dual disk clutch. I bet that motor can take a 300 shot in addition to the boost it has.

 

Which is why I went from a Z51 coupe to the Z06. Different cars in looks and obviously performance.

If the OP plan is to mod for big HP, buy the oldest out of warranty C6 that can be found -it'll save you some money, and mod away.

I'll just add this tidbit, Z06's on drag tires have run 10's in multiple instances. In the right/talented hands it's a low 11's high 10's capable car without anything more then a tire change.

How fast do you want to go? How much are you willing to sacrifice in stock driveability?

 

I agree too. When you say the LS7 is a great motor if you stay below 600 rwhp, is that because of the stock piston? I hear concerns about the block, since of the large c.i., but has any actually had a block failure not related to a rotating mass failure? I'm just wondering if that's really a real world concern.

I came to the same conclusion one recent saturday morning at the track. It was like a bolt of lightening hit me. A few hours later I was in a new Z06.

 

Boosted LS3 or LS2 cars give up nothing in driveability and still cost 20k less than a Z06. There is also the roof issue which some cant live without a removeable roof.

Mod for mod the LS3 Grand Sport is faster and more relible at 650HP until you go with a forged stroker, and by that time you can have a forged 427 without the limitations of the LS7's weak pistons and lack of ability to run a real timing chain. Widebody looks, warranty, removeable roof, and an A6 if you want it. A forged 427 in a Grand Sport still costs less than a Z06.

How fast do you want to go for stock, I'll agree with you. To me the Z06 represents a step in the wrong direction. All I see is a thin cyl wall engine with cast pistons. I'll take the base car and an LS3 stroker any day and I can easily afford a Z06.

 

Just save your money and buy an LS3 vette. Cam, headers and tune and your faster than a zo6 and sounds wayyyy better.

 

Funny, I used to say the exact same thing.

 

As with any build you have to considder application and mine is at 6800 feet elevation. Here a 427 maxxed N/A build nets you 450rwhp uncorrected due to the 28% correction factor so the only way to make power is forced induction. A 418 represents the strongest you can build unless you go with an insanely expensive block.

My cars will always be modded and nothing you can extract from a LS7 is anything near what my car does. You cant even regear the Z06. Once you forge, any advantage the Z06 had is out the window so to me the Grand Sport is the new flagship. Tires, brakes, gearing, and cost all favor this lS3 monster.

Guys with a calculator will add up what it costs to mod their car and since the resale value wont return modding costs, most people sleep better with the 80k Z06 bottom line. I do my own work and as such am happy with my car that to date is still under 60k at 800HP and it drives like stock with no bucking, surging, hard starts, nor is it loud.

I've tuned stock and cammed z06's and wouldnt go there. Anyone driving an FI car would also say its in a whole new class where high 10 sec passes arent enough. A cammed LS7 at this altitude runs about 11.8 to 12's at a DA of 7000 feet on the average day in Puebo.

Once you go with a blower, displacemnt means nothing if it comes with weak pistons.

 

Yes he's right , Its the rockers arms . But its all if you by a 2009 that will no more . But I put new my self . It was 200.17 $ for the new GM parts and that and it . I love the power of 427 I had a old Z06 2002 and loved the corvette . But this much better . A good woman is good but power is better ,

 

If i lived at high altitude, I'd agree with FI being the ONLY option to make power.

I owned a twin turbo GTO that ran 10's at over 133 mph, so I'm familar with what FI will do.

But since 99.99% of GS buyers will not FI their car, I don't see how it could be considered a flagship. And, of course, there's more to these cars than what engine they have and what ultimate potential each one has.

Even callaways GS 606hp car isn't really faster than a stock Z06, according to their own published times (I've yet to find anyone provide their own times from these cars).

 

Maybe I missed reading it, but isn't the ZR1 a 6.2? I don't know how much it has in common with LS3, but the displacement is the same.

Oh ya, for the record, I was too cheap, sorry frugal, to buy a Z06 in 2006, so I bought a base Z51 and am very happy. The brakes and suspension that make the Z06 special, outside of the engine, I upgraded, so I have a car with lower drag than a Z06, and will soon have more HP, so I am happy.

 

You shouldn't have missed reading it, as it's been pointed out several times in this thread.

Be happy, that's a good thing.

 

How do you plan on using the car? Street only? Autox?

 

The one thing that nobody can take away from you, is your model. When you go to sell your car, either you're going to say:
FS C6
or
FS C6 Z06

People don't care if your modded C6 has $30,000 worth of mods done. There's a guy on here trying to sell his 600+rwhp C6 for $37k. Imagine how much money went into that, and he isn't going to get it back. At the end of the day, I have a base C6. He has a base C6. Anyone with a base C6, has to sell it as a base C6. Just because you put a widebody on it, doesn't suddenly make it a Z06. Just because the GS comes with the widebody doesn't make it a Z06. So on that point, a base C6 will never be a true Z06, and a buyer will not be fooled when you try and say your convertible is a Z06.

Can you build the LS3 up further to be more powerful than what the LS7 is capable of? General consensus says yes.

Can you buy a Z06 and be happy with the stock performance? General consensus says yes.

But the OP, as far as I can tell, hasn't responded to this thread since his original post, so we don't know if he plans on modding or not.