Report: Next Chevy Corvette to offer small-displacement turbo V8

[GEEo]

High Revving V8's!!

And Finally the Seats looks better.

[Apex Motorsports]

Originally Posted by DGthe3

Unless they change to a different architecture for that small V8 (which is unlikely, since they're pushing to consolidate their V8 lines not diverge them), its gunna weigh more than a large displacement pushrod V8. No matter the displacement on current production small blocks, the bore spacing is 4.4" and the deck height is 9.025" (IIRC). Overhead cams add weight. Turbos & intercoolers add weight. Building a small engine for forced induction (so stuff doesn't break) adds weight.

Where is the weight savings going to come from? Boring a smaller hole into the block? Wouldn't that end up adding (a little) weight too? Could go with a shorter stroke, but conversely that leads to longer connecting rods ... again, adding (a little) weight. The higher RPMs, plus forced induction mean that internals would have to be incredibly strong. Not that they can't do it but unless they've discovered unobtanium strength = weight.

I see this as little more than a fishing trip by the Corvette team and it sounds like they got a few, hook line and sinker.

This is all 100% speculation at this point, but I have to disagree. The only way something like this would make sense would be for it to be a completely new engine program with implications for the entire GM product line. I find all of it highly unlikely since this is the first anyone has heard about it, but a boy can dream.

[8cd03gro]

Originally Posted by syr74

I love the concept, but I think DG3 hit it square on the head with this one. A stand alone, small displacement, OHC V-8 engine program that is going to debut in a car that isn't too far off in the future and we've heard nada about it thus far. It would be a real coup, particularly if GM used such a design to replace their current large V-6 engines. (What would you rather have in your LaCrosse, a 3.6L V-6 or a 3.6L V-8?) But, if this is a program it is very difficult to believe it will be done in time for a next gen Vette.

I agree with almost everything, but the comment about not being too far off. The fact that the c7 is coming moderately soon does not mean that all of it's drivetrain offerings will. The gen 4 LS9 wasn't released until 4 years after the c6 hit the streets.

[a_Username]

DO IT! Talk about bang for your buck in the aftermarket!

[2010-1SS-IBM]

I think a TT makes sense for 2 reasons:

1) Torque is starting to get out of hand in some of the high performance cars, and our cars are getting more high-performance every year. We all have torque management/launch control, etc... to keep us from roasting our tires up while easing into/out of a parking space or pulling out of the office. Turbo gives GM another avenue to control torque (through boost options) while continuing to push performance.

2) Gas mileage. CAFE requirements and gas guzzler taxes create economic incentives for manufacturers to increase gas mileage, even in performance cars. Having a "Daily Driver" setting via boost controls that keeps the boost low while below a certain number of RPM's could increase the gas mileage significantly, without sacrificing the performance the car is capable of doing.

[Sax1031]

So the new Corvette will be a low displacement OHC turbo car. Otherwise known as a ricer.

[ShnOmac]

Originally Posted by Sax1031

So the new Corvette will be a low displacement OHC turbo car. Otherwise known as a ricer.

I think saying those words counts as sinning.......

[8cd03gro]

Originally Posted by Sax1031

So the new Corvette will be a low displacement OHC turbo car. Otherwise known as a ricer.

So the ferrari f40 is a ricer?



Name one turbo v8, "ricer." One. Turbo = displacement on demand. With modern turbo technology, you can make peak torque EARLIER than a comparable n/a engine, make more power, better gas mileage. . . For example, the cobalt ss turbocharged makes 260 lb ft @ 2,000rpm out of a 2.0l I4. Look at all the big aftermarket shops. How many of their top cars aren't turbo now? Hennessey, linginfelter, heffner, etc.

[Sax1031]

I was just joking. lol

It is just funny. When the mustang went OHC it was omg ricer engine. Then when the Cobra went supercharged it was OMG they had to use a power adder to make power.

Just like to laugh about it now. Follow the leader and all.

[DGthe3]

Originally Posted by 8cd03gro

So the ferrari f40 is a ricer?



Name one turbo v8, "ricer." One. Turbo = displacement on demand. With modern turbo technology, you can make peak torque EARLIER than a comparable n/a engine, make more power, better gas mileage. . . For example, the cobalt ss turbocharged makes 260 lb ft @ 2,000rpm out of a 2.0l I4. Look at all the big aftermarket shops. How many of their top cars aren't turbo now? Hennessey, linginfelter, heffner, etc.

and here I thought displacement on demand = active fuel management ... where the displacement of the engine actually changes in response to the power demand

[8cd03gro]

Originally Posted by DGthe3

and here I thought displacement on demand = active fuel management ... where the displacement of the engine actually changes in response to the power demand

Cylinder activation/deactivation doesn't change displacement at all if you are taking it literally, which it seems you are, using the #cylinders x bore^2 x stroke x π/4 formula for displacement. The pistons are still sweeping from tdc to bdc, so the displacement doesn't change. You are effectively (sorry, is that better?) increasing displacement with forced induction as the volume of air/fuel fit in each cylinder is increased beyond maximum efficiency possible with an n/a engine. If you think active fuel management changes displacement by altering air/fuel delivery to specific cylinders, then forced induction under the exact same principal also alters displacement by increasing air/fuel delivery to all cylinders.

[DGthe3]

Originally Posted by 8cd03gro

Cylinder activation/deactivation doesn't change displacement at all if you are taking it literally, which it seems you are, using the #cylinders x bore^2 x stroke x π/4 formula for displacement. The pistons are still sweeping from tdc to bdc, so the displacement doesn't change. You are effectively (sorry, is that better?) increasing displacement with forced induction as the volume of air/fuel fit in each cylinder is increased beyond maximum efficiency possible with an n/a engine. If you think active fuel management changes displacement by altering air/fuel delivery to specific cylinders, then forced induction under the exact same principal also alters displacement by increasing air/fuel delivery to all cylinders.

Yes, that is the formula, but when 4 cylinders are closed off they aren't drawing in any air or pushing any out so they don't really count towards the effective displacement of the engine.

If you want to go forced induction to increase the theoretical displacement, you would need to go with a positive displacement supercharger not a turbo. Otherwise, your argument is just as shaky as mine

[8cd03gro]

Originally Posted by DGthe3

Yes, that is the formula, but when 4 cylinders are closed off they aren't drawing in any air or pushing any out so they don't really count towards the effective displacement of the engine.

If you want to go forced induction to increase the theoretical displacement, you would need to go with a positive displacement supercharger not a turbo. Otherwise, your argument is just as shaky as mine

Ah, and welcome to my trap. So decreasing air/fuel volume changes displacement, but increasing it doesn't? My point is, turbocharging is one of the most effective ways, if not the most effective way to increase power output while maintaining efficiency all around. Almost nill parasitic loss, other than minor changes from back pressure, great power potential, n/a gas mileage when the bpv is open and with modern turbos almost immediate response. You got caught up in the semantics because I used the word displacement and latched onto probably the least important part of my post, but when you hit peak boost before 2k rpm, it is just as much positive displacement as any PD blower.

[DGthe3]

Originally Posted by 8cd03gro

Ah, and welcome to my trap. So decreasing air/fuel volume changes displacement, but increasing it doesn't? My point is, turbocharging is one of the most effective ways, if not the most effective way to increase power output while maintaining efficiency all around. Almost nill parasitic loss, other than minor changes from back pressure, great power potential, n/a gas mileage when the bpv is open and with modern turbos almost immediate response. You got caught up in the semantics because I used the word displacement and latched onto probably the least important part of my post, but when you hit peak boost before 2k rpm, it is just as much positive displacement as any PD blower.

Are you saying that you're anti-semantic?

Seriously though, I'm just having a bit of fun in an amusing thread, that is all. For all the advantages of what is proposed to be in this mythical engine, the reality is that anything that it might be able to do, a large displacement naturally aspirated gen V small block will probably do it better for less money. Arguing the details about how turbos are or are not displacement on demand in comparison to the technology that actually used that term seems just as relevant to the C7 Corvette as anything specific to this engine.