LS7 information and speculation

[Cam]

While browsing this website, and a few other Corvette and GM related sites, I've come across some interesting information regarding the LS7 motor, which GM has officially announced as the power plant for the 2006 Z06 (specs to be released at the 2005 North American International Auto Show).

First, we recently saw a 6.4L/575HP GTO concept. This vehicle's engine is advertised as using all GM Gen IV engine parts. See the picture below. I want you to try to ignore the fancy dual-MAF Ram Air induction, and focus on the intake manifold. The runners aren't rounded like the LS1/6 or the LS2 intake manifold. This intake is something new entirely:
http://www.micro-op.com.au/execls1/cruise10.jpg

Now look at this intake:
http://www.tamparacing.com/gallery/data/500/10479DSCF0005-med.JPG

http://www.tamparacing.com/gallery/data/500/10479DSCF0002-med.JPG

It appears to be the same intake that's in the GTO concept!

The above intake is reportedly the LS7 intake manifold, although that hasn't been confirmed beyond a shadow of a doubt yet. Just a handful of "GM insiders" who insist it is; you know how that goes. One thing interesting to note is that this intake uses a four bolt pattern to connect it to a 90MM throttle body, just like the LS2.

Now consider the cam specs for the motor in the GTO concept. The duration @.050 is 232/272. :eek:

Why would they use a cam with so much duration on the exhaust side? The logical conclusion is that this cam was designed to take advantage of 3 valve heads. Since there are 2 intake valves and only one exhaust valve, you need a lot more exhaust duration to compensate.

The evidence is building that the GTO concept does indeed use the Gen IV LS7, the same motor destined for the 2006 Z06. My guess is that GM will use a more emissions friendly cam in the production version of the motor, and therefore will be closer to the rumored 500HP target for the C6 Z06... and I still believe it will be a 6.4L motor, rather than a 427 as the wishful thinkers insist. ;)

[green97racer]

interesting :D

[Chief Pontiac]

Well I am not a wishfull thinker just someone who with all the info believes it will be a 7.0.

By the way why would GM start putting the same HP engine in the Vettes as the GTO.If they did it would have to be rated with more hp than the GTO.Thats why I am going with the 427.

[Cam]

Originally posted by Chief Pontiac
Well I am not a wishfull thinker just someone who with all the info believes it will be a 7.0. Yeah yeah, I know. It would be cool if some of you guys who have this information would share where it comes from. If you check around the forums, you'll find plenty of people who claim to be working with this engine, and they all flat out deny that it's a 7.0L. But who knows, maybe it's a clever diversion to hide the truth. :shrug: ;)

By the way why would GM start putting the same HP engine in the Vettes as the GTO.If they did it would have to be rated with more hp than the GTO.Thats why I am going with the 427. Have you seen the stats on the 2005 GTO? Exact same motor, exact same HP as the 2005 C6. Why did they do it? Because the GTO is turning out to be a flop and they're trying to save it.

As for the 389ci GTO, that car is a concept rated at 575HP, not a production car rated at 500. Who knows what the final HP rating on the production version of the LS7 will be? Don't be shocked though if a limited edition version of the GTO sports the same LS7 that the 2006 Z06 has.

[Chief Pontiac]

Originally posted by ZO6Cam
Yeah yeah, I know. It would be cool if some of you guys who have this information would share where it comes from. If you check around the forums, you'll find plenty of people who claim to be working with this engine, and they all flat out deny that it's a 7.0L. But who knows, maybe it's a clever diversion to hide the truth. :shrug: ;)

Have you seen the stats on the 2005 GTO? Exact same motor, exact same HP as the 2005 C6. Why did they do it? Because the GTO is turning out to be a flop and they're trying to save it.

As for the 389ci GTO, that car is a concept rated at 575HP, not a production car rated at 500. Who knows what the final HP rating on the production version of the LS7 will be? Don't be shocked though if a limited edition version of the GTO sports the same LS7 that the 2006 Z06 has. I would believe that the 2005 GTO will have the same engine as the C6 but not have anything near the ZO6.The Vette is and allways will be the flagship for GM not a Pontiac GTO.If you remember the Trans Am beat the Corvette three times in its 32 year history and it wont happen again.

[Cam]

It does seem like the rumblings about a 7L Corvette are building.

Much of the following are reposts from other forums. Reposts appear in quotes; my comments are between the quote boxes.

From Wardsauto.com(posted at Z06Vette.com)
The new 6-speed automatic is expected in late 2005, for the ’06 model year. That is about when the Corvette joins the supercar ranks with the launch of a 500-hp, 7L Z06 version of the new model, which is scheduled to debut at the 2005 Detroit auto show. A new LS7 V-8 replaces the old 5.7L 405-hp LS6 as the highest-performance Corvette engine. Top speed jumps from the standard ’Vette’s 186 mph (299 km/h) to more than 200 mph (322 km/h)......'A German competitor (BMW AG) has just launched a complicated V-10', Lutz says, 'Our overhead-valve V-8 has the same power and performance, and only revs to 6,500 rpm.'

While Bob Lutz himself isn't quoted as saying the LS7 is 7L, Wardsauto is considered a very reputible and reliable source.

Originally posted by 427l (at Z06Vette.com)

C6 ZO6 News from Carlisle

--------------------------------------------------------------------------------

I talked with several engineers from the GM corvette team and here's what I found out:

The car will be unvailed in January and put on sale in august. The engine will be a 7.0L but they would not say what the horsepower would be. I did talk with Dave Hill briefly and although he was very careful about his remarks to my questions I asked him about any potential 3 valve per cylinder head for the corvette. He said that although GM had researched and testing many different engine packages they did not see anything wrong with their current setup of a 16 valve pushrod V8. I was also told (by another engineer) that the exterior of the z06 would be significantly different than the current C6. The engineer continued to say that althought the current c5 coupe could easily be made to look like a c5 z06, the new c6 coupe will not be able to be transformed into the z06 very easily, he said it would look much different. I was also told the new engine will be an LS7. Just thought you all might like to know.

Like most rumors, this is secondhand information, which is not to say it's not true, just less reliable than firsthand sources.

What I found interesting about this post is that 7.0L is again confirmed, and the fact that Dave Hill seems to imply that they are sticking to a 16 valve (2 valve/cylinder) head design. Perhaps they decided against the 3 valve setup?

That actually jives with the following quote that I found on LS1Tech, when someone asked about the pic of the LS7 intake that I posted earlier in this thread:
Originally posted by Chris@AP-Engineering
That intake is a LS7, for the big cubic inch corvette that will be coming out in a few years. Nice manifold and makes good power. When I worked at Katech we were doing the initial tests on that manifold. If you think the manifold is nice wait till you guy's see the heads it bolts on to. They are going to be a cross between the current heads and the C5R heads. I have flowed a few sets and they have all flowed right around 370cfm. Can't wait till they come out!!
Since the current heads and the C5R heads are both 2 valve heads, the implication is pretty clear that the LS7 heads are in fact a 2 valve/cylinder design, versus a 3 valve design as all previous speculation has suggested.

If GM decided on a 7L setup, IMO this would have eliminated the need for a fancy and complex 3 valve head, since 500HP shouldn't be too tough to achieve with 7L of displacement.

One more, from Z06Vette.com:
Originally posted by Zlicious
I guess some news were spilled out from GM on the corvetteforum by a GM employer and was deleted by mods asap.

"Guys the forum took it off so no one gets in trouble. I respect that 100%. The story was wrote by automotive news there web site is www.autonews.com If you know somone signed up you r set. Otherwise there is a fee. If you sign up go to ...GM unfinished business lutz ............ect. story. This is the same thing that I posted before. Trust me it is 7.0 500.hp And I know better than to post somethig that would get me fired!!!!!!"

Here is what the Automotive news article said:

"The re-engineered and re-styled 2005 Corvette packs a 400-hp V-8.
Corvette: The restyled and re-engineered 2005 Corvette is being launched this summer; a convertible arrives this fall. A 6.0-liter V-8 engine producing 400 hp is standard. The Z06 model with a 7.0-liter, 500-hp V-8 and a fastback roofline is on tap for the 2006 model year."

There's more and more of this kind of stuff popping up almost daily, and it's getting to the point that even I am starting to believe. I guess if you're gonna be wrong, it's better to underestimate and be pleasantly surprised than to overestimate and be disappointed.
:beer:

[-=boM=-]

From WardsAuto.com, Aug 26 2004

"The new 6-speed automatic is expected in late 2005, for the ’06 model year. That is about when the Corvette joins the supercar ranks with the launch of a 500-hp, 7L Z06 version of the new model, which is scheduled to debut at the 2005 Detroit auto show. A new LS7 V-8 replaces the old 5.7L 405-hp LS6 as the highest-performance Corvette engine. Top speed jumps from the standard ’Vette’s 186 mph (299 km/h) to more than 200 mph (322 km/h)......'A German competitor (BMW AG) has just launched a complicated V-10', Lutz says, 'Our overhead-valve V-8 has the same power and performance, and only revs to 6,500 rpm.'

That is just too good to be true..and too hard to believe.

a 427 ci, 500 HP, 200+ mph car for 65K..I dont beleive it!!

There was also some talk about a tiptronic drivetrain soon to come out in late 05.

[Chief Pontiac]

Whats hard to believe,GM is finally making a Corvette with world class status.Hey if Ford and Dodge can do it and GM does it for alot less just enjoy and quite being a pessimist.:D

[Cam]

What's got me pessimistic now is speculation about the price. Doesn't sound like I'll be able to afford a new Z06 anytime soon.
:(

[Chief Pontiac]

Originally posted by ZO6Cam
What's got me pessimistic now is speculation about the price. Doesn't sound like I'll be able to afford a new Z06 anytime soon.
:( I agree but well will have to wait and see.Who knows maybe the monetary damage wont be so bad.

[Cam]

Originally posted by Chief Pontiac
I agree but well will have to wait and see.Who knows maybe the monetary damage wont be so bad. Maybe. I would personally rather see a $60K Z06 with 450HP than a 500HP Z06 for $70K+.

I respect what GM is trying to do, but IMHO they should keep the car within reach of their current customer base.

[cm_ls1]

Im gonna say its a toned down version of the motor thats in the "judge concept"

the manifold is visual proof, an authentic RPO sheet that was posted last year names the ls2(6,0) and Ls7(6.4) and i'm gonna stick with it,

it listed the GTO body as GM280x , it listed the ssr 5.4L as Ls4 i think ? and all have turned out correct.

[Cam]

Originally posted by cm_ls1
Im gonna say its a toned down version of the motor thats in the "judge concept"

the manifold is visual proof, an authentic RPO sheet that was posted last year names the ls2(6,0) and Ls7(6.4) and i'm gonna stick with it,

it listed the GTO body as GM280x , it listed the ssr 5.4L as Ls4 i think ? and all have turned out correct. I was leaning towards the 6.4 until just a day or two ago. The stuff on Wards Auto, as well as a bunch of GM employees (and friends of employees) stating that GM decided on 7L of displacement, really has me wondering.

The intake is visual proof that the GTO motor has a LS7 intake. It doesn't prove anything about the displacement of the LS7.

Rumor has it that they couldn't quite get the performance they wanted out of 6.4L in an emissions friendly package, so they bumped the displacement up to 7L.

Either way, we'll know in just over 3 months, maybe sooner if more solid info leaks out!

[02redhawk]

Here's a fact. LS7 heads have casting numbers 8452. Bank it.


BTW, the decision was made long ago of 7L vs. 6.4L, as all performance and safety testing is well underway. Especially for safety, there needs to be weight, size, and distribution representative hardware installed otherwise all crash tests are worthless.