2009 Corvette ZR1 LS9 Engine

[baddabang]

This thread is definitely Legen


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dary.

[bruxell]

are you sitting down ?
Coz I concur ..... now THAT's a shock given the company

Jeepers! I can’t remember the last time you and I were on the same side of something…

You do have crazy cars though.

[Slicks]

Where did kigango123 go?

[kigango123]

I have two graphs depicting Volumetric efficiency and thus Boost of a turbocharger and a supercharger, The supercharger's efficiency peaks at 90% but efficiency only peaks at a very narrow RPM band, The turbo however peaks at 70% but retains efficiency throughout most of the rpm band. This is how it is with most superchargers unless you get it to where it has two pulley ratios or something of that nature


Even if the Z06 redline really is 7K, There is no real usable torque and power past 6.5 K. That is why the Dyno's from The Lingery-Feller's supercharged corvette don't go past that!

If now i Say that the corvette has a Narrow powerband,I do not see how i can be wrong. The supercharged ZR1 or whatever you call it will likely not be revved past 6K, and It's supercharger Pulleys will most likely be geared for peak efficiency at about 4k at most which in all probability will lead to a narrow powerband.


Edit: Quick facts

1. C6 redline = 6.5k--not 7K, go to wikipedia and read ;
____________Z06= 7k redline while C6= 6.5k redline

2. short gearing =/ Close gearing (Which the C6 has)

[culver]

I have two graphs depicting Volumetric efficiency and thus Boost of a turbocharger and a supercharger, The supercharger's efficiency peaks at 90% but efficiency only peaks at a very narrow RPM band, The turbo however peaks at 70% but retains efficiency throughout most of the rpm band. This is how it is with most superchargers unless you get it to where it has two pullers or something of that nature


Even if the Z06 redline really is 7K, There is no real usable torque and power past 6.5 K. that is why the Dyno's from The Lingery-Feller's supercharged corvette don't go past that!

If now i Say that the corvette has a Narrow powerband,I do not see how i can be wrong. A supercharged will likely not be revved past 6K, and It's supercharger Pulleys will most likely be geared for peak efficiency at about 4k at most

I think you seem to be confusing the LS7 and the LS9. The LS7 is normally aspirated, redlines at 7k and has a power peak at 6200RPM. Compared to my 1.8L Miata's PEAK torque the LS7 has "useful" power at 800RPM.

Yes, the LS9 will have a lower redline. I still don't see how you can think this car will have a "narrow" powerband. Flat? Maybe not as flat as others but hardly narrow.

A while back I drove a C6. It was below freezing when I first drove the car. You couldn't use full gas in 2nd gear because the tires would light. Not just due to a hard shift. I'm talking 2000 RPM rolling into the throttle, no drive line power spikes. The 400hp version is silly powerful. The LS7 has 25% more power.

[kigango123]

I think you seem to be confusing the LS7 and the LS9. The LS7 is normally aspirated, redlines at 7k and has a power peak at 6200RPM. Compared to my 1.8L Miata's PEAK torque the LS7 has "useful" power at 800RPM.

800 RPM!, Maybe in first gear you could launch with it or something but if you are in third gear or fourth gear , 800 rpm is not a place to be in a suprcharged Z06,

If you Meant to say 7k as in There is power at high rpm in the LS7, you are wrong.
Posted by Monarocountry, this is the other supercharged Z06, as you can see power at 6.5k is already at about 420, even though the supercharger was clearly geared to produce maximum torque at the same rpm.

Yes, the LS9 will have a lower redline. I still don't see how you can think this car will have a "narrow" powerband. Flat? Maybe not as flat as others but hardly narrow.

Again I wil say this, The Supercharged Corvette Engine (LSwhatever) Will most likely be tuned to receive maximum Supercharger efficiency at about 3.5K-4K. And what do you have in the rest of the RPM range?

Power Drain (from Supercharger), And hot air going into your engine(from Supercharger).
which i equate to narrow powerband

A while back I drove a C6. It was below freezing when I first drove the car. You couldn't use full gas in 2nd gear because the tires would light. Not just due to a hard shift. I'm talking 2000 RPM rolling into the throttle, no drive line power spikes. The 400hp version is silly powerful. The LS7 has 25% more power.

Beacuse second gear in a corvette is almost the same as first (close gearing!) and a narrow powerband

[The_Canuck]

800 RPM!, Maybe in first gear you could launch with it or something but if you are in third gear or fourth gear , 800 rpm is not a place to be in a suprcharged Z06,

If you Meant to say 7k as in There is power at high rpm in the LS7, you are wrong.
Posted by Monarocountry, this is the other supercharged Z06, as you can see power at 6.5k is already at about 420, even though the supercharger was cleary geared to produce maximum torque at the same rpm.



Again I wil say this, The Supercharged Corvette Engine (LSwhatever) Will most likely be tuned to receive maximum Supercharger efficiency at about 3.5K-4K. And what do you have in the rest of the RPM range?

Power Drain (from Supercharger), And hot air going into your engine(from Supercharger).

After all this you still sound foolish and you're lacking a point.

BTW do you know what a redline is?

[culver]

800 RPM!, Maybe in first gear you could launch with it or something but if you are in third gear or fourth gear , 800 rpm is not a place to be in a suprcharged Z06,

If you Meant to say 7k as in There is power at high rpm in the LS7, you are wrong.
Posted by Monarocountry, this is the other supercharged Z06, as you can see power at 6.5k is already at about 420, even though the supercharger was cleary geared to produce maximum torque at the same rpm.



Again I wil say this, The Supercharged Corvette Engine (LSwhatever) Will most likely be tuned to receive maximum Supercharger efficiency at about 3.5K-4K. And what do you have in the rest of the RPM range?

Power Drain (from Supercharger), And hot air going into your engine(from Supercharger).



Beacuse second gear in a corvette is almost the same as first and a narrow powerband

GM has never made a factory Corvette with FI. Any dyno charts you produce showing as much aren't relevant to what the stock car can do. In 4th gear 800 RPM isn't the place to be in just about any car. However, even if the power has fallen off, the Corvette has a lot of power even down low.

How GM ends up tuning the engine is still unknown to people outside GM... including you. Odds are it will have plenty of power at all revs and should be able to (just barely) top 150

[bruxell]

800 RPM!, Maybe in first gear you could launch with it or something but if you are in third gear or fourth gear , 800 rpm is not a place to be in a suprcharged Z06,

Have you seen the Top Gear Episode where Clarkson launches the Z06 in fifth, from a stand-still, and then accelerates to 160? This car does not have a narrow power-band. And do you really think that a supercharger, being opperated off the crank, producing boost right off the bottom end, and with a high-efficnecy charge-cooler, is going to make the engine less flexible???

Read your own posts, they don't make sense.

[kigango123]

GM has never made a factory Corvette with FI. Any dyno charts you produce showing as much aren't relevant to what the stock car can do. In 4th gear 800 RPM isn't the place to be in just about any car. However, even if the power has fallen off, the Corvette has a lot of power even down low.

How GM ends up tuning the engine is still unknown to people outside GM... including you. Odds are it will have plenty of power at all revs and should be able to (just barely) top 150

I'll admit, I do not know anything about GM tuning, But just as odds are that they will try and "flatten" out the powerband. Odds also are that they will use the same tuning methodology that all Tuners use when dealing with root type superchargers which as i said is --> Adjust blower pulleys to give you peak efficiency where you want (By you, I mean Target audience of the LS9)and The Target Audience of The LS9 are turkey necks who simply want one thing. Something that can beat the new Dodge Viper on the strip that is made by Chevy. Nothing more!

So Odds are that this will turn out to be nothing more than a drag racing spectacle with a Narrow powerband and close gearing and as an added bonus- i bet chevy will install a totally uncomfortable butt killing suspension so that the corvette can at least take corners.

[Slicks]

Even if the Z06 redline really is 7K, There is no real usable torque and power past 6.5 K. that is why the Dyno's from The Lingery-Feller's supercharged corvette don't go past that!

You know, at the very least you could have gone to GM's site and looked up this information. Honestly where are you getting all this BS???
This is a dyno graph of the LS7 directly from GM:
http://media.gm.com/us/powertrain/en...7/2008_LS7.pdf
So ~350ft.lbs+ of torque is "unusable"?

If now i Say that the corvette has a Narrow powerband,I do not see how i can be wrong. The supercharged ZR1 or whatever you call it will likely not be revved past 6K, and It's supercharger Pulleys will most likely be geared for peak efficiency at about 4k at most which in all probability will lead to a narrow powerband.

The graph above shows you are 100% wrong. The torque curve is table top flat. Something like this is a narrow powerband:
http://www.turbo-kits.com/images/rev...e_III_dyno.jpg
Thats peaky as hell.

Edit: Quick facts

C6 redline = 6.5k--not 7K
short gearing =/ Close gearing (Which the C6 has)

[/quote]
Quick facts:
LS2 redline : 6500RPMs
LS7 redline : 7000RPMs.

[Slicks]

I'll admit, I do not know anything about GM tuning, But just as odds are that they will try and "flatten" out the powerband. Odds also are that they will use the same tuning methodology that all Tuners use when dealing with root type superchargers which as i said is --> Adjust blower pulleys to give you peak efficiency where you want (By you, I mean Target audience of the LS9)and The Target Audience of The LS9 are turkey necks who simply want one thing. Something that can beat the new Dodge Viper on the strip that is made by Chevy. Nothing more!

It seems more like you no nothing about any cars, not just GM.
GM was testing the ZR1 well before Dodge announced the 600hp Viper.

So Odds are that this will turn out to be nothing more than a drag racing spectacle with a Narrow powerband and close gearing and as an added bonus- i bet chevy will install a totally uncomfortable butt killing suspension so that the corvette can at least take corners.

Odds are you couldn't be more wrong.
This cars purpose is to be the top of the line track Corvette. Its going to be lighter, more aerodynamic, bigger brakes, more tuned suspension, etc etc.
Supercharged engines has LARGE powerbands, they are at boost off idle.
Show me exactly what your talking about with "close gearing" please.

[bruxell]

[QUOTE=kigango123;766414]I'll admit, I do not know anything about GM tuning, But just as odds are that they will try and "flatten" out the powerband. Odds also are that they will use the same tuning methodology that all Tuners use when dealing with root type superchargers which as i said is --> Adjust blower pulleys to give you peak efficiency where you want (By you, I mean Target audience of the LS9)and The Target Audience of The LS9 are turkey necks who simply want one thing. Something that can beat the new Dodge Viper on the strip that is made by Chevy. Nothing more! [QUOTE]

Wow… Your technical knowledge is matched only by your insight to the market…

By the way, did you notice the part where Chevy has already gone a slightly different tack, by combining the intercooler with the intake manifold to decrease both the length of the intake tract, and the temperature of the incoming air??? That would seem to bode well for throttle response, and detonation resistance at high revs.

So Odds are that this will turn out to be nothing more than a drag racing spectacle with a Narrow powerband and close gearing and as an added bonus- i bet chevy will install a totally uncomfortable butt killing suspension so that the corvette can at least take corners.

I’ll agree that I don’t think this Corvette is setting out to be as complete a sportscar as the Z06. Still, I don’t remember the last time anything capable of 200mph could be said to have “close gearing” in the accepted sense. It really would need to have a high first great, and a pretty tall fifth, as I don’t think even this engine is going to hit its torque-peak in the Corvettes over-long sixth.

Pay freakin’ attention! There are lots of bad things about Corvettes if all you want to do is bash one them. You’ve just picked the one thing that isn’t wrong and chosen to harp on it. It makes you look a little ignorant.

[kigango123]

It seems more like you no nothing about any cars, not just GM.
GM was testing the ZR1 well before Dodge announced the 600hp Viper.

OHHH, Cmon now! , You cant tell me they began testing the ZR1 all the way before Dodge announced that they were going to be skipping a model year for the Viper.

This cars purpose is to be the top of the line track Corvette. Its going to be lighter, more aerodynamic, bigger brakes, more tuned suspension, etc etc.
Supercharged engines has LARGE powerbands, they are at boost off idle.
Show me exactly what your talking about with "close gearing" please.

Track corvette - my ass! ,

They have not improve any aerodynamics except for the addition of a hood scoop,if you think that will help """" . Neither have they lightened it and there is no way to know right now because of the obscurity of the car.


Edit: I meant to put a frowny face, In the quotations!

[culver]

I'll admit, I do not know anything about GM tuning

We’ll just leave that quote up top.

Funny how much you seem to “know” about the Corvette yet you profess to not knowing about the car. Have you ever seen one in person? Have you ever driven one?

The Target Audience of The LS9 are turkey necks who simply want one thing. Something that can beat the new Dodge Viper on the strip that is made by Chevy. Nothing more!

Certainly Z-06 and ZR-1 buyers are looking for some extra power however your categorization speaks of a narrow minded author rather than insight. Would you say the same thing when Toyota offers both a V6 and an I4 in the same chassis? Would you say the same when Ariel offers a more powerful motor for the Atom? Do you think the 911 Turbo is simply a 911 for those who don’t understand how to turn a normal 911? Why is it so with the Corvette?

Your narrow power band idea is laughable. What do you consider a broad power band? This is a car who’s reputation seems to be built on power. You just said the car was good for nothing else! How could the car develop a reputation for power if the power band were S2000 narrow?

i bet chevy will install a totally uncomfortable butt killing suspension

How would you know? I’ve driven a Corvette on the frost bitten roads of the Midwest. It rides better than my Miata by a fair margin. Helps that the chassis is much stiffer so the shocks can do more of the work.

Perhaps you should watch 5th Gear’s review of the Z-06. Very positive. Nedell said the ride was quite acceptable. I’m sure you know better… wait, I just looked at that quote of yours.
YouTube - 5th gear z06

They have not improve any aerodynamics except for the addition of a hood scoop,if you think that will help """" . Neither have they lightened it and there is no way to know right now because of the obscurity of the car.

Well we don’t know what they are going to do with the ZR-1 because the car isn’t released. That means you don’t know what they will or will not do. It’s possible they will do nothing. But I have heard talk of a carbon fiber roof panel.

Lets also consider history. When the Z06 came out GM did a lot to reduce the car’s weight. The went as far as switching the chassis from steal to aluminum! Also, since you know more about what GM has done than GM I suppose they didn’t actually change the aero on the Z06 despite what GM has said. They didn’t add the splitters I see in front of the wheels. That’s just my imagination. They didn’t change the fenders. The didn’t change the spoiler. I guess GM was just making all that up. Made up just like the weight the car shed.

Now you might think I’m just a blind Corvette junkie who thinks GM can do no wrong. Well you would be very wrong. I like my Miata because you have to work hard to make it go at all fast. That doesn’t mean I don’t respect the Vette for what it is. I will not claim it’s the best sports car. I don’t know that the “best” sports car even exists. I don’t know that I would pick one over a Cayman. Heck I suspect I wouldn’t but I wouldn’t be unhappy with a Corvette. I have driven one and it was very good. Perhaps you would get your head out of your exhaust if you drove one.

One last thing, you know what’s really funny about all this… the forum unity. You actually got members who almost NEVER agree to actually agree that you were wrong. That takes real talent.