Why hasn't Chevy gone to the Direct Injection for the LS3? Doesn't DI improve gas mileage a good bit? Wouldn't that have been a good idea for this car? Or is DI too expensive, difficult, etc...?

 

Pretty sure that one is on the way...

Might take a while, but they've gotta be working on it.




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I don't know that’s a good question but direct injection engines been around for over 50 years. I think they were more focus on AFM on the LS3 because that was the cheaper route, but I am puzzled on how a LS3 engine with AFM only getting 23mpg. So do that mean if you would of remove the AFM part of the engine it will be getting around 19-20 mpg highway?

 

Probably. Look at the SRT8, it only gets 18 hwy.

 

DI would probably elevate the power to near 500hp like the test mule did.
DI will come with the Gen V's. There is talk of decreased displacement, while maintaing power levels.
So we could see a 420hp 5.3 V8 instead of 6.2 with increased fuel economy, as well as lower emissions.
DI 6.2 would be a great engine for the Z06 and Z28 as well as CTS-V.
And Id love tos ee a DI LS7. LS9's power without the blower.

 

Is there any idea n how long until GM has the DI V8's out there? Or are they waiting for the C7 to debut it? Heck give me a Turbo DI V6 in my Camaro and I'll be a happy camper.

 

LT1: 1992 (Gen2)
LS1: 1997 (Gen3)
LS2: 2005 (Gen4)

Gen5 engines are rumored to have both direct injection and variable valve timing. I think it's reasonable to guess that we'll start seeing them in the 2011-2012 range, and that they'll be available in Camaro and the trucks no more than a year after their initial debut (which I'm guessing will be with Corvette).

 

They said they would like to unveil the Gen V's in a high visibily product, such as Camaro or Corvette.
Z28 could be that high visibily car...so would the C7.

 

Funny, I was thinking the same thing, why no DI V8? Then I remembered that the 1993 4th Gen LT1 was the oddball of the LT1 family. Seems like GM likes to hold out a little in the engine area for a car's first year. Probably because the current engine is proven and they want as few problems as possible the first year.

 

Well now that it's going to have the normal LS3, GM can't put a new engine in for a few years or risk the GTO screwup all over again.

I guess they are having issues, otherwise a V8 that can get 6 cylinder or better mileage, hells yea!

FYI: LS3 does not get AFM. That's on the L99's only.

 

Here's one possible analysis of GM's V8 engine options for the fifth gen:
Should we:
(1) try to "graft" DI onto an LS3 ? (not sure if that's even possible, and even if it is, it would obviously involve the COMPLETE, ground-up redesign of the intake and heads, in addition to the fuel system)
Pros: If you can make a DI top end work with the pushrod bottom end, you would still get away with the light weight of the LS3. The LS3 obviously has plenty of fans, particularly in the enthusiast community.
Cons: Cost. Magazine writers complaining that "it's still a pushrod design, no matter how you dress it up."

-or-

(2) use the 3.6 DI design but essentially add two more cylinders to it.
Pros: A big chunk of your engineering has already been done, although it is still a big project. The new V8 would become your new "corporate" V8 in various states of tune. DI means higher compression without detonation, and better fuel economy. 400 HP in a 4.8-liter package.
Cons: Higher weight (uh-oh, here we go...). DOHC doesn't come without a penalty. Public perception that your engine isn't as big as the competition's, and that it lacks torque. Outrage from the enthusiast community that the car weighs over 4,000 pounds, is less mod-friendly, and doesn't make the low-end power of the LS1 in the 4th gen. And again, cost... At least in comparison with the third option.

-or-

(3) Use the LS3 from the 'Vette, which has only been out for a year anyway, and essentially leave it alone.
Pros: 422 HP in a ~415-pound package. R&D is 95% done for you already, so relatively minimal cost involved as compared to options #1 and #2. Class-leading (class-destroying?) power and torque. Happy enthusiasts.
Cons: Fuel economy not as high (but you can make up for some of that on the EPA Highway calculation by using a taller 6th gear, since you have more torque). Your need for a new "corporate" V8 is still there, just delayed (but with GM in a cash crunch, that delay may not be a bad thing). Magazine writers complaining about the "antiquated" pushrod design (but other magazine writers--see the Car & Driver editors--pointing out that the pushrod design works fine and is lighter than its DOHC competition).

Seems to me that GM made the right choice.

 

I thought it was stated that the Gen 5 V8 program was on hold because of GM's financial situation?

At any rate, a direct injected LS3 would make a fabulous power plant for a proper Z28.

 

I have no doubt that a direct injected V8 will be hitting the street soon. When is the C7 due? The C6 came out as an 05 model. The 09s are being built now. I'm guessing 2011-12. It will then migrate over to the Camaro and trucks increasing CAFE across the board as the 2020 deadline gets closer.

I want to see a DI LS9 But for my own personal transportation, a DI 5.3L backed by a 6L80E in a Colorado.

 

Why? Because there is no such thing as a DI LS3.

Probably the first Gen V SBC will have DI and it is more than likely it would debut in Corvette.

 

That's a stretch when the Hemi's been out for a while now making the same power.