2018 Chevrolet Corvette To Sport A 6.2L DOHC V8

Mmmm DOHC GM V8. Intriguing! 

It is coming about 2 years sooner than I expected.

With that we may see this in the ZR1 and Z/28?

Great choice for a high tech mid engine sports car.  It would have been a shame to offer a low revving pushrod V8 in something that demands high revving.  I will guess about 600hp.

Well here is the deal. This is needed for Emissions that need to be met. 

But like with DI there is advantages. 

The reality is there will be more than one version here. I expect a supercharged or Turbo to appear. The Zr1 will see 725-750 HP easy with the added down force. 

It is reported that the new Corvette was testing over 1000 Hp but the un named Corvette person said they would only use what they could put down. 

Now considering that private tuners are already hitting 1000 HP with the present engine emissions legal I tend to believe this to be true. Also the Corvette team has always given as much as they can use. They know large numbers mean little if you can't put them down. 

I also ponder will the Z/28 get this also is this a base for the coming DOHC Cadillac engine?

This would make an awesome CT6-V engine, or a retuned model for the Escalade

Finally GM entering modern times with a DOHC V8, but why so large?  Cadillac really could use a DOHC V8, but a 6.2 liter is going to get displacement taxed like crazy in other parts of the world.   You'd think there would have to be a turbo version too, I can't imagine any engine without a turbo by about 2022, save for base model 3 or 4 cylinders in sub $20,000 cars.  

2 minutes ago, smk4565 said:

Finally GM entering modern times with a DOHC V8

I HATE THIS ARGUMENT WITH A PASSION!!!!

From wiki: https://en.wikipedia.org/wiki/Overhead_camshaft

Quote

 

History

Early use

Among the first cars to utilize engines with single overhead camshafts were the Maudslay designed by Alexander Craig and introduced in 1902^[39] and the Marr Auto Car designed by Michigan native Walter Lorenzo Marr in 1903.^[40][41] The first DOHC car was the 1912 Peugeot which won the French Grand Prix at Dieppe that year. This car was powered by a straight-4 engine designed by Ernest Henry under the guidance of the technically knowledgeable racing drivers Paul Zuccarelli and Georges Boillot. Boillot, who drove the winning car that year, won the French Grand Prix for Peugeot again in 1913 but was beaten in 1914 by the SOHC Mercedes of Christian Lautenschlager.

 

 

From wiki: https://en.wikipedia.org/wiki/Overhead_valve_engine

Developments

The overhead valve internal combustion engine was invented in 1898, in Detroit, by bicycle manufacturer Walter Lorenzo Marr, who built a motor-trike that year with a one-cylinder OHV engine with a bore and stroke of 3 inches each.^[2] In 1900, Marr was hired as chief engineer at the Buick Auto-Vim and Power Company in Detroit, where he worked until 1902. Marr said he got the idea of overhead valves when making the small tricycle engine, because that was the only way he could get the valves to fit.^[3] Marr's engine employed pushrod-actuated rocker arms, which in turn pushed valves parallel to the pistons, and this is still in use today. This contrasts with previous designs which made use of side valves and sleeve valves. Marr left Buick briefly to start his own automobile company in 1902, the Marr Auto-Car, and made a handful of cars with overhead valve engines, before coming back to Buick in 1904. The OHV engine was patented in 1902 (awarded 1904) by Buick's second chief engineer Eugene Richard, at the Buick Manufacturing Company, precursor to the Buick Motor Company. The world's first production overhead valve engine was put into the first production Buick automobile, the 1904 Model B, which used a 2-cylinder Flat twin engine, with 2 valves in each head. The engine was of course designed by Marr.

 

Valve-In-Head engine, illustration from 1904 patent, Buick Manufacturing Company

Eugene Richard of the Buick Manufacturing Company was awarded US Patent #771,095 in 1904 for the valve in head engine. It included rocker arms and push rods, a water jacket for the head which communicated with the one in the cylinder block, and lifters pushed by a camshaft with a 2-to-1 gearing ratio to the crankshaft. Arthur Chevrolet was awarded US Patent #1,744,526 for an adapter that could be applied to an existing engine, thus transforming it into an Overhead Valve Engine.

In 1949, Oldsmobile introduced the Rocket V8. It was the first high-compression I-head design, and is the archetype for most modern pushrod engines. General Motors is the world's largest pushrod engine producer,^{[citation needed]} producing both I4, V6 and V8 pushrod engines.

 

MODERN?

What do you mean by modern?

This is such a tired argument.

Only non-car people are allowed to have that opinion of OHC engines being more  modern...

Leaving aside all the state of the art tech behind the GM V8s...I dont ever want to hear this argument from anybody in an automotive forum...EVER!

I know OHC has been around forever.  Perhaps then my argument would have been better said by saying Finally GM joining the rest of the world in offering a DOHC V8.  Because all the European and Japanese luxury car and performance car companies use DOHC.

Just because everyone else is doing it doesn't mean GM has to. I like their pushrod V8s, I have no problem with them offering both.  Pushrod has some distinct advantages over DOHC for packaging.   Yes, DOHC may get more horsepower per liter, but pushrod can stuff a lot more liters in there.... and with GM's technology of being able to shut off cylinders, they can get a lot of the efficiency of those smaller displacement engines as well. 

This DOHC 6.2 sounds like it will be great, but that doesn't change the fact that anywhere this engine fits, a S/C pushrod 7.5 - 8 liter would also fit.

This is obviously going to go into a mid-engine Corvette. 

The ZR1 is far too along for it to be receiving this engine. It just doesn't make sense. That said, I do wonder if they would put this in anything other than  a Corvette. I can't see it going in the Z/28 due to cost, but I could see Caddy getting this in a few models.

sweet

2 hours ago, Frisky Dingo said:

This is obviously going to go into a mid-engine Corvette. 

The ZR1 is far too along for it to be receiving this engine. It just doesn't make sense. That said, I do wonder if they would put this in anything other than  a Corvette. I can't see it going in the Z/28 due to cost, but I could see Caddy getting this in a few models.

Priced a Z/28?

Coul be under the zr1 hood now. Have you heard one?

This is not a case of doing this beuse everyone else is. This is a case of if you want to meet future emissions you will have to do this.

The flexibility of the timing and extra valves make for more power and  better emissions. 

Vette deserves this, and maybe a big Cadillac eventually too.  Not sure a CT6 will accept it, seeing as how this engine is probably twice as big as the 3.0L currently.  They may have planned for it though. But a bespoke engine that will sound and feel far different than any other currently offered by GM, is a welcome addition and I bet many customers are probably craving it.  There simply is no V8 sound as good as a DOHC.  

The agree it has more to do emissions, economy and power delivery than it does packaging.  A lot of cars have excess space under the hood anyway.   If packaging was the main priority they could put a 3 liter V6 that revs to 8,000 rpm or something that was more power dense.  Plus you have Lambos and Ferraris with V12s, I don't think space is a big concern.

29 minutes ago, smk4565 said:

The agree it has more to do emissions, economy and power delivery than it does packaging.  A lot of cars have excess space under the hood anyway.   If packaging was the main priority they could put a 3 liter V6 that revs to 8,000 rpm or something that was more power dense.  Plus you have Lambos and Ferraris with V12s, I don't think space is a big concern.

Having DOHC grows it a bit in width and very slightly vertically.  No problem at all for a mid mount that does not have to worry about hood clearances.  The more I think about this, the more impressed I am with GM's decision.  

4 hours ago, Wings4Life said:

Vette deserves this, and maybe a big Cadillac eventually too.  Not sure a CT6 will accept it, seeing as how this engine is probably twice as big as the 3.0L currently.  They may have planned for it though. But a bespoke engine that will sound and feel far different than any other currently offered by GM, is a welcome addition and I bet many customers are probably craving it.  There simply is no V8 sound as good as a DOHC.  

The CT6 already is slated to have a twin-turbo dohc V8 of around 4 to 5 liters. I doubt getting it to 6.2 without a turbo would be that hard.

You don't need 6.2 liters though, if you can't get 500 hp from 4 liters you are doing something wrong.   You can get 600 hp from 4 liters, even.  If one were so inclined they could get 1,000 hp from a 1.6 liter V6 hybrid.

I get 300 HP from 2.0 liters and it still has more room to grow.

8 hours ago, smk4565 said:

You don't need 6.2 liters though, if you can't get 500 hp from 4 liters you are doing something wrong.   You can get 600 hp from 4 liters, even.  If one were so inclined they could get 1,000 hp from a 1.6 liter V6 hybrid.

Sure, if you spin it to 18,000 rpm, but you still have no torque.

And no one is getting 500hp from 4 liters unless there is some forced breathing going on, so as soon as you do that you have additional complications and weight. 

A 6.2 liter will have awesome torque off the line while a turbo 4 liter is still waiting to spool up.

Expect the new DOHC to easily exceed 750HP. There is ZERO reason to push one out that doesn't considering the cost. The current LT4 can hit 700 with changes made by a shade tree mechanic.

The Caddy DOHC engine will probably be in the 550HP 

GM should completely bias this engine for hp, not torque.  I think that is why they are switching to a high revving valve train that can handle it, without going with ridiculously expensive titanium rods.  Now I am not saying it does not need torque, but as light as the vette is, it certainly don't need more than say.....550ftlbs.  It needs to breathe and spin to about 7500rpm's, and a realistic hp of about 650.  Sorry casa, no way will it hit 750hp, and still be an easy car to live with daily and manage decent fuel economy.  And yes, all that matters.

3 minutes ago, Wings4Life said:

GM should completely bias this engine for hp, not torque.  I think that is why they are switching to a high revving valve train that can handle it, without going with ridiculously expensive titanium rods.  Now I am not saying it does not need torque, but as light as the vette is, it certainly don't need more than say.....550ftlbs.  It needs to breathe and spin to about 7500rpm's, and a realistic hp of about 650.  Sorry casa, no way will it hit 750hp, and still be an easy car to live with daily and manage decent fuel economy.  And yes, all that matters.

For the mid engine car, absolutely, should be geared towards HP... But I'd like to see a torquer version, lower top rpm but thicker torque band that starts lower, for use in the Escalade and possibly the CT6.

1 hour ago, Drew Dowdell said:

For the mid engine car, absolutely, should be geared towards HP... But I'd like to see a torquer version, lower top rpm but thicker torque band that starts lower, for use in the Escalade and possibly the CT6.

Although OHV absolutely does not mean more torque than OHC, I just don't see bothering with a high revving DOHC in a low revving truck application that is all about torque down low. There should be some bespoke-ness to it as well.  Start throwing it into everything, and you optimize it for nothing.

21 hours ago, Wings4Life said:

There simply is no V8 sound as good as a DOHC.  

1. Let me first wish you Merry Xmas in Greek.

2. Im quite neutral with what you have said, In agreement even with 99.99% of what you wrote, but you know me, I MUST find something you said to pick on!!! Yes, even on XMAS day...even when I have a house full of family and friends!

That quote up above....

THIS ONE:

Quote

There simply is no V8 sound as good as a DOHC.  

UMMMM....NO!!!!

Although DOHC V8s do sound good....you my dear friend...you come from Detroit even. You my friend, even has a MOPAR...

Let me demonstrate:

So....

Whether a DOHC V8 sounds better or a Pushrod V8 sounds better is just the difference between Vanilla cake with Chocolate icing or Chocolate cake with vanilla icing.. 

They are two different kinds of great. I love both. 

43 minutes ago, Drew Dowdell said:

Whether a DOHC V8 sounds better or a Pushrod V8 sounds better is just the difference between Vanilla cake with Chocolate icing or Chocolate cake with vanilla icing.. 

They are two different kinds of great. I love both. 

Me too.

I LOVE both....I mean....who doesnt love a Ferrari V8 wailing?

Ill throw a bone to Wings as I think this DOHC V8 sounds BETTER than a Ferrari DOHC V8..and I LOVE Ferrari V8 sounds!

Ill demonstrate:

I love the sound of the Hemi and the GM small blocks under full throttle.

The sound is more cylinder count and the degree of the block.

Some combos sound better than others. 

My eco sound like a fart can but has power and torque.

My 2.8 V6 sounds like a 308 Ferrari but has little power. 

Even an old 318 with thrush side pipes sounded killer but had no power. My buddy used to get challenged all the time but he has to tell then it was just a stock 2bl Dart Sport.

Another buddy with a first year Viper said it sounded like school bus with the V10.

Olds.

you're the best.. Love you like a Greek brother man.  I swear we are far more alike than you think. And that's not the 7 Star Metaxa talking either, haha.  I too hosted Christmas dinner, and everyone is gone home now and my feet are up, watching Sulley that I just rented and coffee black and hot beside me.  

Now lets talk shop......

Nobody appreciates and loves Detroit iron more than me, no how, no way.  My dad built Cadillac's in the 60's and 70's and he did all his own repairs and I was right there by his side long before I found girls interesting. I have busted my own knuckles on enough of them as well,  restoring them or just hot rodding them.  So I can certainly appreciate the sound of a 426 hemi, or Boss 302, or just  healthy SBC.

But let's compare apples to apples. Any V8 sounds great with big pipes and low restriction deep base exhaust.  Assuming you can live with the droning, it is music to my ears too, both OHV and OHC. Take a minute and listen to the end of this video where they add a simple 3" cat back system and Magnaflow mufflers.  Fast forward to the end, and you will see what I mean.  A DOHC sounds good revving, but it really needs to be heard under load.  It is a mechanical symphony. Obviously it is a subjective statement, but come on man.....it is glorious.  And that is not even with a G350 5.2L, just an everyday coyote.  

Now compare to a cat back Camaro SS.  Let me know if you still feel the same way.  

I love a good sounding pushrod V8, but nothing beats a high-revving DOHC one. Ferrari's, Maserati's, and Aston's in particular sound spectacular.

DOHC has a distinctive sound.

So does high compression ratio engines.

So does big displacement.

I think the combination of all the above will make the new engine incredible sounding.

On 12/25/2016 at 9:22 AM, Drew Dowdell said:

Sure, if you spin it to 18,000 rpm, but you still have no torque.

And no one is getting 500hp from 4 liters unless there is some forced breathing going on, so as soon as you do that you have additional complications and weight. 

A 6.2 liter will have awesome torque off the line while a turbo 4 liter is still waiting to spool up.

Turbo engines make better torque than NA, and really what car of the future won't have a turbo engine unless it has an electric one.  A turbo will be as common as ABS brakes by 2025, you are seeing turbos on things like a Cruze and Equinox on almost every trim level, and the biggest engine downsizing hasn't even hit yet.  

The E63 S makes 627 lb-ft at 2,500 rpm, that is much lower than the GM supercharged 6.2 liter, and no NA engine from anyone makes peak torque at 2500 rpm.  Audi engines are even a better example, an S8 could probably beat a CTS-V 0-60 despite being larger and down 120 hp because of the all wheel drive and low rpm torque from that turbo V8, which is also a 4 liter.  Although I was thinking of the 2015 S8, with 520 hp, the just realized the new one has 605 hp and does 0-60 in 3.3 seconds.

8 minutes ago, smk4565 said:

Turbo engines make better torque than NA, and really what car of the future won't have a turbo engine unless it has an electric one.  A turbo will be as common as ABS brakes by 2025, you are seeing turbos on things like a Cruze and Equinox on almost every trim level, and the biggest engine downsizing hasn't even hit yet.  

The E63 S makes 627 lb-ft at 2,500 rpm, that is much lower than the GM supercharged 6.2 liter, and no NA engine from anyone makes peak torque at 2500 rpm.  Audi engines are even a better example, an S8 could probably beat a CTS-V 0-60 despite being larger and down 120 hp because of the all wheel drive and low rpm torque from that turbo V8, which is also a 4 liter.  Although I was thinking of the 2015 S8, with 520 hp, the just realized the new one has 605 hp and does 0-60 in 3.3 seconds.

Not everyone wants a turbo and plenty of torque can be made without it.  If GM can make more than enough power without it, good for them and good for customers.

On 12/25/2016 at 10:29 AM, Drew Dowdell said:

For the mid engine car, absolutely, should be geared towards HP... But I'd like to see a torquer version, lower top rpm but thicker torque band that starts lower, for use in the Escalade and possibly the CT6.

The CTS v-sport engine makes 430 lb-ft @ 3,500 rpm, while the Escalade V8 makes 460 lb-ft at 4,100 rpm.  Both make 420 hp at around 5600-5700 rpm.  So really you could have an Escalade with a 3.6 liter V6 and it would be perfectly adequate, especially for a base model.  A DOHC V8 could be the optional engine in the Escalade, gives people a good reason to up for a Platinum or V-sport trim.

1 minute ago, smk4565 said:

The CTS v-sport engine makes 430 lb-ft @ 3,500 rpm, while the Escalade V8 makes 460 lb-ft at 4,100 rpm.  Both make 420 hp at around 5600-5700 rpm.  So really you could have an Escalade with a 3.6 liter V6 and it would be perfectly adequate, especially for a base model.  A DOHC V8 could be the optional engine in the Escalade, gives people a good reason to up for a Platinum or V-sport trim.

Peak HP is largely irrelevant because it is only obtained at full throttle. No one drives like that even 5% of the time. The Escalade feels smarter off the line because it has more grunt at 1/3 throttle. 1/3 throttle on a turbo charged car isn't going to get you the kind of thrust you are talking about because the boost hasn't kicked in yet, even at 3,500rpm.

Further muddying the waters is dynamic throttle response dictated by the computer.

12 hours ago, Drew Dowdell said:

Peak HP is largely irrelevant because it is only obtained at full throttle. No one drives like that even 5% of the time. The Escalade feels smarter off the line because it has more grunt at 1/3 throttle. 1/3 throttle on a turbo charged car isn't going to get you the kind of thrust you are talking about because the boost hasn't kicked in yet, even at 3,500rpm.

Further muddying the waters is dynamic throttle response dictated by the computer.

I hate to disagree on the turbo engine and RPM.

With today's engine and DOHC combined wit a turbo torque can be had low and held all the way up.

My 2.0 hits max torque at 1800 and holds it to 5300. I can hit 23 psi before it hits second gear with a automatic in drive. The real issueit traction as you can lose it even with launch control on an pop the waste gate. The last Engine to give me torque like this was a 428 Pontiac. Even then the curve was not that flat and over that much RPM.

When you toss 9.5 compression in with 23 psi, variable valve timing and direct injection things are possible that were only dreamed about before.

Most engines will not all do this as they are tuned for mpg in a mall cross over so the torque is left for more rpm.

Much of this can also be done on a dohc v8 too with vvt also much to do with much higher compression and did to cool the cylinder all with out a turbo.

These engines are not like the old and we are just now tapping into what they can do via yeh performance markets. 

The superchargers are just to get more air in as the two valves only can suck so much in. 

It is only a matter of tuning to what you want and the regulations that have to be met.

At how much throttle? You're not hitting 23 psi at 1/3 - 1/2 throttle where most people drive.  Even on my boat anchor 307, half throttle off of a red light will put me into the back of a Camry.

At those throttle positions, you're getting little to no boost. People don't drive around at full throttle 23psi boost more than 5% of the time. Turbo is an attempt to replace displacement. So most of the time a 4.0tt is really just a 4.5 - 5.0 at 1/3 throttle, while a 6.2 is still a 6.2 no matter where the throttle is. (Ignoring AFM for now)

TUrbo engines have a lot to do with tuning and turbo size when it comes to how it feels.  The Fusion my brother had for a while had excellent torque and low end without having to go anywhere near WOT.  My 2.0T VW and even his old A5 both suffered turbo lag but certainly have a more stout top end and mid range feel than the 2.0EB in the Fusion. 

9 hours ago, Drew Dowdell said:

At how much throttle? You're not hitting 23 psi at 1/3 - 1/2 throttle where most people drive.  Even on my boat anchor 307, half throttle off of a red light will put me into the back of a Camry.

At those throttle positions, you're getting little to no boost. People don't drive around at full throttle 23psi boost more than 5% of the time. Turbo is an attempt to replace displacement. So most of the time a 4.0tt is really just a 4.5 - 5.0 at 1/3 throttle, while a 6.2 is still a 6.2 no matter where the throttle is. (Ignoring AFM for now)

Drew the boost is based on how much throttle. 

Now the difference is much like this. I can give full throttle in the 2.0 and reach full torque from 1800 RPM to 5300 RPM at 315 FT LBS. 

Now my 3.6 V6 it does not reach max torque till just over 3000 RPM to around 6000 RPM. Same for the 3.0 V6. Both are more tuned for MPG as with other 2.0 engines that make torque higher up. 

As for a Chevy V8 it depends on the cam and timing. Most build in a steady actual Curve that starts around 2300 RPM and will peak around 4700-5000 RPM with most cams. They have limited timing and limited air due to the size of the valves. 

The reality is not all DOHC engines have to make high end power they are just tuned there. It was the same on my Chevelle built with a Tunnel Ram where the cam and intake did not make power till 3500 RPM and carried it to 7000 RPM. 

The timing and phasing of the cam can deliver the power where ever you want it. My 2.0 is tuned more for power and it is a flat curve where the power is available at about any level.

The Turbo side of it is just added cubic inches. The Compression side is something Turbo engines lacked in the past as with any forced induction the compression was relieved to make it so the Supercharger or Turbo had room to work. Today with VVT timing and Direct Injection they can do 9.5 to 1 or even higher now with the added boost and make more power.

It is about power on demand. No I do not do 23 PSI all the time but neither is a LT V8 putting out more than a minimum amount of power most of the time to just keep the car rolling.

The Turbo is a replacement for displacement but it is a variable displacement unlike a fixed displacement NA engine.  While a NA V8 has a specific displacement they are fixed to where you can neither decrease or increase the volume of air at a specific throttle position. With a Turbo You can decrease the engine size by just going on displacement but you can increase it also with added throttle and boost. Same is being done on the Z06 now. 

The fact is before we had improved Turbo chargers and super chargers. Before we had the inclusion of Direct injection and variable valve timing you were limited on the control of the engine. Today these options along with advanced sensors open the door to many more options and the ability to do much more with forced induction. 

They can so much better control fuel and air now that it gives them the ability to do things never possible before with any engine. 

Years ago you chose an engines tune when you built it with the choice of size, Cam and Compression. Today all this is no longer fixed and can be tuned as you go down the road. More air can be added.  Timing can be changed on the fly. More fuel can be precisely added to cool  the engine and to prevent it from going lean but yet still pass emissions. Timing can be maxed with knock sensors. 

The days of the Turbo engines with great amounts of lag are gone. The days  of DOHC meaning they only can make power at high RPM are gone. The days of engines that are not as tune-able are coming to a close just to meet emissions and MPG.  Yes they will still make some of the engines with these traits as it adds to the MPG and they are not in performance applications where they need to pull a tree stump out. 

The reality is We have a lot of good engines and how the testing for emission is done dictate what we get anymore. Also the taxes in many countries are based on size of engine so that has driven the smaller engine market.  

Companies if they could would all be doing two valve large engines if they could. It is much cheaper and easier to package. Many are envious of the Chevy V8 because of the size but there are limits on how far they can go as things keep closing in on them. Sad but true. Gm has stated they would have to make the change at some point. 

I see the future of the Corvette mostly being a transition from the present car to a Mid Engine line with various engines and prices. Just because the engine is in back does not say the car has to be $200K. I expect we will see a line from $69K to $200K once they are done. It will not all be done at once either. We will see various V8 engines of both DOHC and two value used. I suspect a V6 will show up at come point with more than enough power too. A hybrid will be in the mix some place too. The Stingray will remain for a while as the first ME will be high end models and as they price them down they will be replaced with ME coupe and convertible. 

45 minutes ago, Stew said:

TUrbo engines have a lot to do with tuning and turbo size when it comes to how it feels.  The Fusion my brother had for a while had excellent torque and low end without having to go anywhere near WOT.  My 2.0T VW and even his old A5 both suffered turbo lag but certainly have a more stout top end and mid range feel than the 2.0EB in the Fusion. 

Yes on mine I can easily smoke the tires at 35 MPG rolling with half throttle. 

As for my lag the engine has enough compression that initial tip in is fine and the Turbo duel scroll comes in pretty fast. To be honest the transmission kick down has more lag.

The one real side affect from the Turbo is the power can hit pretty fast and hard with the torque on tap in a wide range. I have have seen the traction control light come on up to 55 MPH before and the Watergate popped with the loss of traction.  The power is more smooth and uniform with a NA engine but that is due to the less ability for the engine to adjust to demands and it makes it's changes more slowly. 

All I know is that a N/A 6.2 liter feels more energetic and effortless than a 3.6TT in normal driving.... and that's just a pushrod 6.2... or as SMK calls it, a "truck engine"

(comparing a Corvette Stingray Convertible to an ATS-V Coupe)

1 hour ago, Drew Dowdell said:

All I know is that a N/A 6.2 liter feels more energetic and effortless than a 3.6TT in normal driving.... and that's just a pushrod 6.2... or as SMK calls it, a "truck engine"

(comparing a Corvette Stingray Convertible to an ATS-V Coupe)

Different situations. As much as the VSeries is about performance.. even in the CTS.. the ATS still has to be geared towards some bit of civility for fuel economy.. the Vette has a little more lee way. I believe that E-Throttle mapping has to do with this.. I'm betting that a quick tune involving the throttle would give the LF4 a nice bit of wake up. 

I always find it interesting the plethora of overlap that GM has in the powertrain category. I have ZERO understanding of why the LGW is not the replacement engine for the LF3 and the LFX thru basic tuning.

The "wake up" you are referring to is just spinning the engine faster to get the turbo spooled up.  You don't need a tuner for that, just hit the sport mode button to get the remappings and the lower gear holding. The point is, that I don't need to "wake up" the 6.2 liter, I've got all 6.2 liters working for me at 1/4 - 1/2 throttle... no need to wait for a turbo to spool, no need to goose the RPM to get that kind to torque.   It's a case of nearly equivalent specs on paper leading to different driving feel in the real world. 

Another example is the first Regal GS tuned to 270hp/295 lb-ft on the 2.0T/6-speed auto. The GS, while a fantastic road car, simply does not feel the same as the pull of an old LD8 4.6 Northstar / 4-speed auto with roughly the same power specs (275hp/300 lb-ft).  The Regal GS may be a better car in every other way, but a Lucerne CXS just feels like it has more pull when poking around town even though it is heavier than the Regal.  On the track, I'm sure it would be no contest the other way. Even the current Lacrosse with less torque but the same transmission feels like it has more pull in normal driving. 

Another is the Mazda CX-9 v. GMC Acadia V6.  The Mazda has substantially more torque than the Acadia, the the Acadia feels more powerful in regular driving. I drove the Acadia, CX-9, and XT5 nearly back to back... and the GM V6 is the winner here in feel every day of the week even though the Mazda out torques it on paper. 

The examples I have in my head where I've driven two vehicles back to back with equal power on paper, but different types of engines is long... and I could really go on for days. 

The only counter example I have to date is the Volvo S90 T6 AWD 2.0, but that one is supercharged AND turbocharged. It really does have the feel of a larger V6 when rolling around town and absolutely smashed a Kia Cadenza 3.3 in acceleration. I was in the Kia following a colleague in the S90 and lost every single acceleration run.... badly. 

A lot of this is a disconnect between car enthusiasts/ media, and non-enthusiasts. Car enthusiasts/media spend too much time looking at numbers only during peak performance driving levels and not enough at how it feels when a vehicle is driven normally like non-enthusiasts do.  Again, a counter example: It's why my Encore is rated as "way too slow on 0-60" by just about everyone in enthusiast and media land, but in normal city driving it feels acceptable... with the sales numbers to back it up.  I'm an enthusiast, so I'd like more power, but I've got to admit that for my partner who doesn't care about cars, he thinks it is plenty fast enough. 

5 hours ago, Drew Dowdell said:

All I know is that a N/A 6.2 liter feels more energetic and effortless than a 3.6TT in normal driving.... and that's just a pushrod 6.2... or as SMK calls it, a "truck engine"

(comparing a Corvette Stingray Convertible to an ATS-V Coupe)

Because the two engines are tuned differently. 

The Corvette engine is tuned for more low end grunt. It has some timing variation but is limited due to just one cam. 

The 3.6 can be tuned for lower end but it is more efficient higher RPM. In a Terrain it is tuned to be efficient. Now GM could easily tune it for more bottom end and to make up for the lack of CID they could add a Turbo. Now with a larger V8 the engine should be able to do anything the present engine can do and even more. 

The added technology and the fact most DOHC engines are mostly here for more MPG and less emissions they are not for performance applications in most cars.

Now the thing is you give a Chevy V8 more ability to breath. You give it more cams to handle the low end and high end and you can toss more compression or even a super charger or turbo for more air.

As I know you already know engines are air pumps and the more air in the more fuel and the more cylinder pressure the more power.

You can be for sure what they come out with will be as powerful or more powerful than what we have and will have a much wider RPM range of torque.

With the large displacement I have a hunch it will be a NA engine and it may hold as much or more power than the present LT4.

Cadillac may be going small and T Turbo but the Chevy may be all CID. Then if they want more they can Turbo or SC it. 

I know the reports of over 1.000 HP testing are legit. I know even the old ZR1 engine passed all the test for Emissions and Warranty at 725 HP with no issues. 

Chevy will pack as much power into this car as they can and at a price few can come close to. We know they benchmarked the Ferrari and Mclaren so that gives you an idea of the starting point and you know it will be cheaper than it. 

Even the Ford GT in all its glory will be down on power to what I expect is coming and for less than half the price. 

The supercar  segment is going to get get busy in the $150K - $400K as more companies are now building less expensive models that are still mega fast. The Exotic class is the Million dollar cars but the super cars have created a notch below half a million that will give you nearly the same performance for much less and Corvette will play here and also still cover the under $100K segment. 

3 hours ago, Drew Dowdell said:

The "wake up" you are referring to is just spinning the engine faster to get the turbo spooled up.  You don't need a tuner for that, just hit the sport mode button to get the remappings and the lower gear holding. The point is, that I don't need to "wake up" the 6.2 liter, I've got all 6.2 liters working for me at 1/4 - 1/2 throttle... no need to wait for a turbo to spool, no need to goose the RPM to get that kind to torque.   It's a case of nearly equivalent specs on paper leading to different driving feel in the real world. 

Another example is the first Regal GS tuned to 270hp/295 lb-ft on the 2.0T/6-speed auto. The GS, while a fantastic road car, simply does not feel the same as the pull of an old LD8 4.6 Northstar / 4-speed auto with roughly the same power specs (275hp/300 lb-ft).  The Regal GS may be a better car in every other way, but a Lucerne CXS just feels like it has more pull when poking around town even though it is heavier than the Regal.  On the track, I'm sure it would be no contest the other way. Even the current Lacrosse with less torque but the same transmission feels like it has more pull in normal driving. 

Another is the Mazda CX-9 v. GMC Acadia V6.  The Mazda has substantially more torque than the Acadia, the the Acadia feels more powerful in regular driving. I drove the Acadia, CX-9, and XT5 nearly back to back... and the GM V6 is the winner here in feel every day of the week even though the Mazda out torques it on paper. 

The examples I have in my head where I've driven two vehicles back to back with equal power on paper, but different types of engines is long... and I could really go on for days. 

The only counter example I have to date is the Volvo S90 T6 AWD 2.0, but that one is supercharged AND turbocharged. It really does have the feel of a larger V6 when rolling around town and absolutely smashed a Kia Cadenza 3.3 in acceleration. I was in the Kia following a colleague in the S90 and lost every single acceleration run.... badly. 

A lot of this is a disconnect between car enthusiasts/ media, and non-enthusiasts. Car enthusiasts/media spend too much time looking at numbers only during peak performance driving levels and not enough at how it feels when a vehicle is driven normally like non-enthusiasts do.  Again, a counter example: It's why my Encore is rated as "way too slow on 0-60" by just about everyone in enthusiast and media land, but in normal city driving it feels acceptable... with the sales numbers to back it up.  I'm an enthusiast, so I'd like more power, but I've got to admit that for my partner who doesn't care about cars, he thinks it is plenty fast enough. 

Note drive a Solstice with the GM Tune and you will know what I have been trying to explain. The other cars are all tuned mild. 

My SS was pretty much the Regal with just FWD. Same feel good but nothing special. Now adding the GM tune it is like night and day the feel. I have owned many muscle cars over the years and some of these do not even have the feel I have here. To be honest the real sin is the FWD as it has no traction. Contrary to popular belief FWD traction sucks due to the transfer of weight upon launch. 

I improved the traction with better tires than the factory pilots yet it is still difficult to get it to hook up. Yet the Solstice people still have the same issues as they have 340 FT LBS of torque low down available from 1800-5300 and all they need to do to get it at any RPM in this range is step on it. 

The feel is very much like the old 428 Pontiac that stock has 390 FT LBS and we would toss in a Ram Air IV cam to add a little bit more. 

Like I stated most GM 2.0 are in mild tune even the GS as they are tuned for Premium recommended and not required. You can take these engines to 400 HP with the stock parts before you need to change anything. 

This 6.2 liter NA DOHC V8 sports car idea has been done before and it was killed off mainly for emissions and fuel economy reasons, but also because they could get more power and torque with turbos.

5 hours ago, hyperv6 said:

Note drive a Solstice with the GM Tune and you will know what I have been trying to explain. The other cars are all tuned mild. 

My SS was pretty much the Regal with just FWD. Same feel good but nothing special. Now adding the GM tune it is like night and day the feel. I have owned many muscle cars over the years and some of these do not even have the feel I have here. To be honest the real sin is the FWD as it has no traction. Contrary to popular belief FWD traction sucks due to the transfer of weight upon launch. 

I improved the traction with better tires than the factory pilots yet it is still difficult to get it to hook up. Yet the Solstice people still have the same issues as they have 340 FT LBS of torque low down available from 1800-5300 and all they need to do to get it at any RPM in this range is step on it. 

The feel is very much like the old 428 Pontiac that stock has 390 FT LBS and we would toss in a Ram Air IV cam to add a little bit more. 

Like I stated most GM 2.0 are in mild tune even the GS as they are tuned for Premium recommended and not required. You can take these engines to 400 HP with the stock parts before you need to change anything. 

The base Northstar is a mild tune also, it got a 50hp jump in other iterations.

It doesn't matter what these engines can do if they are never sold that way.... And don't try and tell me an ATS-V Coupe loaded to the gills with every performance option is tuned for economy and a base Stingray isn't.  Again, I've driven these cars back to back and the ATS-V feels softer. The only way the ATS-V starts to have the same kind of pull is in track mode, but again, that's cheating because it just forces the RPM higher, the Corvette can do the same trick.

The Solctice Turbo guys do NOT have 340 lb-ft at 1800 rpm with the throttle 3/4 closed. At 1/4 throttle you're driving a plane old GM 2 liter 4cylinder with no boost and maybe 100 lb-ft of torque. There is no displacement being replaced. Yet at 1/4 throttle in a Northstar, you're getting all 4.6 liters working for you. If you do step into it on the turbo, then you've just negated the whole reason for downsizing engines in the first place... The fuel economy. 

Even the fuel economy argument seems to largely be a farce as well. The Regal and Lacrosse get roughly the same fuel economy on the highway. The heavy LX cars that you like to bash get excellent fuel economy. The fusion 2.0t, Accord V6, 300c V6, Regal 2.0t, 2017 Lacrosse V6, and Altima V6 all get right around the same fuel economy when you account for weight difference. 20 - 23 city and 29 - 34 highway... And the V6es in all of these (where available) are more pleasurable to drive than the 4Ts (again, where available) in NORMAL driving.  The Lacrosse is getting 31 mpg and has 310hp on regular fuel even ... And that's in grandma tune.

Hyper, you keep talking about these peak numbers. I am talking about non-peak. There is simply more effortless glide from larger displacement engines and seemingly no fuel economy penalty.

I also want to point out that I am not against turbo-charging when there is no way to put a larger engine in... I realize I'll never get a 3.6 liter into an Encore.... but if I have a choice between displacement and turbo with peak power outputs being equal.... I'll go with displacement every time. 

5 hours ago, smk4565 said:

This 6.2 liter NA DOHC V8 sports car idea has been done before and it was killed off mainly for emissions and fuel economy reasons, but also because they could get more power and torque with turbos.

 

Just because Mercedes failed at it doesn't mean GM will. 

Drew your argument thst at part throttle that the 2.0 does not have said power or torque applies to any engine, 

What count is what it can do when called upon at 1800 to 5300.

46 minutes ago, hyperv6 said:

Drew your argument thst at part throttle that the 2.0 does not have said power or torque applies to any engine, 

What count is what it can do when called upon at 1800 to 5300.

Again, that is not how people drive. No one drives at full throttle all the time.

I'm not coming to this position rashly.... 4 - 5 years ago I thought Turbo-4s were the bees knees and would likely replace most V6es (the latter still likely to be true, to my dismay).  Heck, I've even argued with @smk4565 about a Turbo-4 being the base engine in the CT6 because 0-60 times looked comparable to larger displacement naturally aspirated cars. I even argued that Ford should have kept the Crown Vic / Town Car in production just for Cab/Limo duty but swapped in the 2.0T since it makes the same or better horsepower anyway.  All of the above is true at max throttle, but in partial throttle situations, the story changes. 

Take two engines, one 2.0T and one 4.6 N/A, both the same horsepower and torque peak ratings. Open both throttles to 1/4... and the net result is that one engine is a V8 and the other engine is a naturally aspirated 4-cylinder because there is little to no boost happening at that throttle position. And in that situation, the 4.6 will be putting out more torque than a 4-cylinder of less than half the displacement.  This is where a Regal or Fusion will feel labored and the driver will goose the throttle more, while grandpa in the DTS isn't even trying and is just effortlessly gliding along. 1800 RPM in a 2.0T at 1/4 throttle and you're getting maybe 100 lb-ft. if you've got a little boost going on... 1800 rpm in a Northstar at 1/4 throttle and you're getting 150 or better. It's why even my boat anchor 5.0 Olds with 145hp feels effortless (before it runs out of gears and breath) compared to my 138hp 1.4T Buick.

The only time the extra displacement is a disadvantage is in the city when idling and highway cruising when lower power is needed.... but the availability of cylinder deactivation, auto-stop, and possible coming of skip-fire largely negate that disadvantage. 

What I'm saying is... there is still no replacement for displacement...