Ron78Z&01SS

I agree with most everything Guy has posted (so far ), but a few thoughts on weight and the comment of "We need to take the time to actually check things out before using them as an example." which I assume was directed towards me.

I wasn't using the C6 Z06 as an example.

My post was obviosly mis-read as I was talking weight reduction on the C5 Z06. Even though it didn't have the magnesium engine cradle and aluminum frame (both started with C6 Z06), it still managed to come in at 3,118 lbs compared to 3,246 lbs for the "base" Vette.

True, the weight spread isn't as dramatic on the C6 Z06 (i've read anywhere from only 37 lbs to 50 lbs) even though it has the magnesiun eng cradle and aluminum frame. Why? Don't know for sure .....but like I said, I wasn't using the C6 as an example.

Ron78Z&01SS

If I'm wrong, please tell me otherwise, but I can't see ONLY a cam swap (no heads, no exhaust etc) giving that much of an increase and still be emissions legal.

The LG site has what they call a "G6XE or “Executive Cam”" which they claim will "maintain stock drivability and idle" but doesn't say anything about emissions legal.

HAZ-Matt

Which is why you should be looking at something more like the L92 with a performance designed cam instead of an LS3 with a cam.

BigBlueCruiser

The LS7 is 7 liters aka 427ci. The LS3 is 6.2L. That's where your cheap and easy 53 hp comes from.

I do like the titanium exhaust idea. What's that worth 15lbs for another $1K bucks?

Ron78Z&01SS

Not sure how much more expensive it was, but by going titanium aft of the cats saved 18lbs.

Here's some info from 2001 on it: http://www.corvettemuseum.com/specs/2001/exhaust.htm

BigBlueCruiser

The LS7 is simply a sleeved LS block with external plumbing to go dry sump and special crankshank with a longer snout to drive it. There are plenty of guys(no pun intended) running wet sump LS7 blocks with an LS2 oil pump and pan and standard LS2 cranks, rods and aftermarket pistons.

http://www.ls1tech.com/forums/showthread.php?t=986036

There is nothing that precludes GM from building an easy 475hp assembly line LS7 without the ported heads and the fancy Ti valvetrain and rods for the same price as an LS3.

You may want to keep believing that GM hasn't done it because they can't. But the actual reason is that it wasn't part of the plan. The Z/28 was going to be a fat overweight SCed beast to go toe-to-toe with the Shelby GT500. And probably because they wanted to to keep the 7.0 exclusive to the Z06.

Well guess what? Plans change. I bet they didn't plan on their stock price going to $8 either.

guionM

Wasn't directed especially at you. I should have emphasized that others have used the C6 Z06 as an example as well as yourself. There's also plenty of people who don't have a full understanding that Carbon Fiber isn't a miracle cure-all for weight savings and that taking weight out of most all components means taking out durability.

However, I will direct the C5 weight issue your way.

You are using the wrong "base" Corvette.

The C5 Z06 weighed 3115. The Corvette hardtop it was based on was 3153. Again, the weight savings on the Z06 was a scant 38 pounds.

You mistakenly used the Corvette hatchback as the jumpoff point for the Z06. The hatchback was about 100 pounds heavier than the Corvette coupe. Perfectly understandable.... most people have already forgotten that the C5 Corvette was offered in a hardtop.

Like the C6 Z06, emphasis was on keeping weight down to make up for the added weight of higher performance hardware.

The C5 Z06 had thinner glass, lighter rims, fixed anntenna, less soundproofing, and that titanium exhaust. This made way for the addition of underside body panels to improve airflow, the active suspension system, and the upgraded transmission.

What I posted on the C6 Z06 also holds true for the C5 version. It all ties in with the idea many have that the Z06 is this wundercar of weight savings. It isn't.

Alot of expense went into saving a small amount of weight to make up for heavier performance hardware. The car was going to retail for some serious cash over the regular Corvette anyway.

Those thinking there's some magic way to make a lightweight, highpowered Camaro those 4 words still apply......There's no free rides.

Although I've read about people using LS7 blocks the way you described, I seriously disagree with you on your points and Corvette conspiracy theory, and I think the facts bear me out here.

First, GM looks at things as: "What's the cheapest, highest volume way to go where we can cheat the fuel economy tests?".

Because of that, I don't believe there was some dark conspiracy to not produce a "cheap" LS7 because they want to keep it exclusive to Corvette. I know that GM at least looked into an LS7 Camaro & decided against it (which I suspect will be in that Camaro book headed to press soon). But for cost, durability, EPA testing cycles, and power output, GM decided that a supercharged LSa was a superior choice.

But there's a big, huge, massive, glairing, 800-pound-gorilla-in-the-room, obvious point I feel you may have completely missed in all this:

The LS7 puts out 505 horsepower and 475 lbs/ft of torque.

The LSa puts out 556 horsepower and 550 lbs/ft of torque.



I suspect that alone puts any notion of this latest Corvette conspiracy to rest.
If not, then these might:

The LSa is cheaper to produce than the LS7.

The LSa offered inhuman power output next to a comparatively detuned, "mass produced" LS7.

The LSa can be programed to bypass the supercharger at key times during the EPA test cycle and the CAFE rating tests.

Also, the LS3 already has 436 horsepower in the Corvette and easily has factory capability in excess of 450 if they chose to up the power.

No dark conspiracy.

No "Corvette protecting".

Just a decision that gave the most powerful engine possible with the best fuel economy possible at the lowest cost possible.

I wouldn't hold my breath waiting for GM's plans to change and make a "cheap" LS7. It simply is not going to happen. Power and fuel economy boosting direct injection is far more likely the next step.

Gripenfelter

Replace all body panels with carbon fibre and all suspension and mechanical parts with titanium.

JakeRobb

Yes. And the fact that the LG Motorsports cam isn't "emissions legal" is purely because it's aftermarket. If GM wanted, they could put that cam in a car and sell it, and it would be perfectly legal. Problem is, even though LG says it maintains stock drivability, that's just not quite true. Close to true, but there are differences.

I'm not familiar with the specifics of the LG cam, but if it's anything like the other popular LS* cams, you wouldn't want to cruise in 6th gear at 1000 rpm on the LG cam -- it would bog. The stock cam handles that just fine. Differences like that improve the EPA highway rating of the car, because it allows the car to perform the test in 6th instead of 5th.

Long story short, an aggressive cam like that isn't up to GM's requirements, but it is very much possible to attain those power levels in a cam-only LS3.

The problem isn't that they can't, or that it wasn't part of the plan. It doesn't make business sense!

I see your point, but keep in mind that for every model year where the C5 Z06 was available, there was no such thing as a non-Z06 fixed-roof coupe. This basically means that the Z06 gets to include the fixed roof as a weight-saving measure as compared to its non-Z06 siblings.

txturbo

20lbs lighter than the stock aluminum hood?

jg95z28

FWIW, GM Performance Parts already offers a crate engine hot cam version of the LS3 (LS376/480) that puts out 480hp.

Why not simply use that in a theoretical Z/28?

guionM

Which further makes the case that an upgraded LS3 makes more sense than blowing cash (which everyone knows GM doesn't have) on a redone "mass produced" LS7. For serious power, the LSa is pretty much the superior choice.



Going back to the original subject of the post, as is being made clear once again, there is no free rides, no magic pixie dust, no miracle material or wundermetal that's going to miraculously both cut meaningful weight and handle additional horsepower and torque while at the same time keeping costs compatable with a standard SS. If there was, it would have been done.

The Camaro SS weighs 3860 w/ manual. The LS3 is capable of power excess of 450 horsepower. The whole package costs just under $30,000.

My advice is buy yourself a Camaro SS, run it with no more than a half tank of gas (savings about 100 pounds) and wait till the warranty runs out and tweak your engine (450-480 hp) and buy yourself a set of Z28 emblems and stick on your car. You may then send me $6,000. You don't even need a 7L engine, and GM doesn't need to waste money making one.

There.... you have your 475HP, 3760lb, $36,000 Z28.

AdioSS

I have an answer to that...
You want 475-480hp AND good torque AND good fuel economy?
Take the tricks used on the LSa and apply them to a 5.3L engine. (Be sure to keep AFM functioning and maybe add in variable cam timing.)

Or for a more efficient engine, take the tricks used on the LS9 and apply them on a 4.8L engine to get just over 500hp. If you don't want to spin it over 6000RPM (but with a stroke of only 3.28" I don't see why not), then integrate SIDI into the package.

Either engine should get greatly improved fuel economy numbers while off boost and would still have the ***** to get a heavy Camaro (or maybe even a truck?) going.

We already know that GM has already planned to use a supercharged V8 in the Camaro and in the trucks. Show me one problem with reducing the displacement of the engine underneath that blower?

Pruettfan

You could do that but then of course not many could afford that car now could they? This is essentially what GM did to some extent with the ZR1 and 115k it is a pretty expensive car. Since all versions of the Camaro have to be afordable and competitive with the Mustang and Challanger it does not seem likely that GM would follow your example.

JakeRobb

Gas weighs about six pounds per gallon. To save 100 pounds, you'd have to remove ~16.6 gallons of gas.

Something tells me that "half a tank" won't cut it.