2014 C7 Chevrolet Corvette

[WingsofWar]

Originally Posted by Dimman

The exercise here is about an optimized 5.X vs the 6.2. If bigger is better, there is no reason for them not to go to 7.0 for the base car. I think GM is approaching the limits on where they can go next with big OHV motors.

And besides cost is hardly an issue with the rest of the car.

As for the RX-7 weight distribution, I don't believe it. I've handled pretty much every single component of both a 12A and 13B. They are ridiculously tiny motors. Eccentric shaft on a 13B (equiv to crank on a real motor) probably weighs as much as an LSx's camshaft.

When we look at the efficiency gains that DOHC engines keep making compared to the OHV, I think GM is running out of displacement options and tech trickery to keep OHV relevant in the future. There is a point where they will not be able to just make bigger motors to suck in air.

Edit: Compact DOHC v8

well said dimmyboy! and yeah the weight distribution on the rx7 with LSx swap would be unchanged, but the CoG advantage loss over the rotary is pretty substantial. You would never really see the difference until you look at front tire wear after some mountain carving.

[sevi21]

o lawd, i do believe this looks amazing

[Dadhawk]

Originally Posted by Miniata

I like it. Not in love with it, but that may come with time. Not a huge fan of all of the black plastic and exposed CF bits on the red and silver cars, but they would virtually disappear on a black or dark gray car. Personally I'd go with a darker gray.

No surprise that I love it in red, and I love all the black trim.

I've wanted a 'Vette ever since the hot teacher at my high school drove an original Stingray with those beautiful side chrome exhausts. I have vowed to own one some day, and I think this is the one. I'll probably wait until I can get a gently used one for about 60% of the new cost though.

Two things you can count on with 'Vettes, they are daily driver supercars and their value drops like a rock after 5 years.

Olivia, we may have found your stable-mate.

[Dimman]

Getting back to the Vette, I think the choice of Stingray for it is starting to bug me.

Think of the original Stingrays. I can't think of any car that looks anything like them. But this one makes me think BRZ/599 from the front (good) but Camaro from the back (not so good). It's almost a GTA version generic supercar with un-subtle Chevy style cues.

Old Stingrays are anything but generic.

[White64Goat]

From what I read and heard today, the new Vette has an all new aluminum frame design, the option of a street or track interior seating and supposedly they really worked on upgrading the interior overall. Supposedly there are only 2 parts from the current car that carry over to the new one.

[Dark]

Man, that thing is ugly. GAWRRRRRRRR

I'm just kidding. The new Corvette is the best looking Corvette to date IMO. Every little detail is not just for look, but functionality as well. Hopefully, they improve the creature comfort that the previous gen lacks of. Though, it's really hard to beat Corvette for this price point.

[muffinman]

Kinda bugs me that they named the motor "lt1". Its weird. Its like if in 15 years they came out with a whole new motor and called it an "ls1".

[ZDan]

Originally Posted by serialk11r

A 5.7 can be designed to take up less space than a 6.2 if they want it to, the crank can be smaller if the stroke decreases and the block can be smaller either way. The engine was designed from the bottom up supposedly so this is something they could've done.

Figure if they kept the bore the same and designed around a 10% shorter stroke: 3.26" vs. the 6.2 liter's 3.62" stroke, in the interests of keeping the same valve area and keeping piston speed/acceleration reasonable at the required ~10% higher rpm levels. The resulting 5.6 liter engine would be the same length, about 1/4" shorter in height, and about 1/2" narrower vs. the 6.2 liter. Not bad... Weight savings would be pretty minimal, though. Everything other than the block itself would pretty much be the same weight as the 6.2. LS-series aluminum block weighs 116 lb. Weight-savings with the shorter deck would be less than 10%, i.e., less than 12 lb. lighter.

Long/short, yeah, a 10% smaller-displacement engine could be smaller and lighter, but not by a whole lot.

Max power is at 6000rpm, but max power is a weak 72.6hp/L at 6000rpm. My 15 year old Corolla engine with a lower rev limit, no direct injection, smaller cylinders (inherently lower efficiency at max load) does better than that at its 6000rpm power peak.

Power/liter isn't a true measure of the "goodness" of an engine. Power/weight is everything in a performance engine when you don't have limited displacement. I'll take the new LT1 over your "superior" '98 Corolla engine (which one makes more than 72 hp/L anyway?).

Furthermore, they were bragging about the torque from 1700rpm and up or something, another indication that the cams are very much low end focused. The power peak being at 6000 just tells you that the friction and combustion are better optimized so that the power doesn't drop as much as it traditionally does.

Peak power at 6000rpm says it is BREATHING well at 6000 rpm.

You're going to *complain* about having low end torque AND being able to breathe at (relatively) elevated rpm? You are so determined to hate on this engine that you tout positive features as big negatives. Strange to witness.

The point about the torque was that spinning the tires on dry pavement off the line means you have more low end torque than you can actually use. A 450hp 5.5 would be lower geared than the 6.2, but with the same power in the high rpm range it would improve acceleration in lower gears.

No, 450hp is 450hp. Both geared appropriately, your 5.5-5.7 will accelerate the same as the 6.2 liter one.

They could keep the gears the same and just reduce the torque delivered to the wheels, reduce spinning the tires, and keep the top end acceleration.

They could just gear the current car taller for the exact same effect.

You do bring up a good point about being able to run in 4 cylinder mode more often. I still don't think it's very clear cut how much that affects fuel economy though, because half of 5.5L is still over 2.7L.

It's not very clear cut, but a bunch of engineers with a lot more experience and knowledge decided to stick with 6.2 liters for the reason of keeping it in 4-cylinder mode more.

Even though they have monstrously tall gearing, and taking into account the fact that the OEM would want to run in 4 cylinder mode *less* of the time for emissions reduction,

So they should have developed cylinder deactivation in a way such that they don't use it?
Pretty sure they knew what they were doing, and at least part of the reason for sticking with 6.2 was more time in 4-cylinder mode.

You have to remember that with cylinder deactivation, you gain efficiency from pumping loss reduction and a higher combustion temperature, but friction is not improved upon at all (probably made even worse), and friction is the primary culprit for poor efficiency at low load.

The engineers who developed this engine probably had a lot of good ideas on how to best achieve 450hp while improving fuel economy. They apparently didn't find any compelling reasons to go to a smaller-displacement engine.

[n2oinferno]

Originally Posted by Dadhawk

No surprise that I love it in red, and I love all the black trim.

I've wanted a 'Vette ever since the hot teacher at my high school drove an original Stingray with those beautiful side chrome exhausts. I have vowed to own one some day, and I think this is the one. I'll probably wait until I can get a gently used one for about 60% of the new cost though.

Two things you can count on with 'Vettes, they are daily driver supercars and their value drops like a rock after 5 years.

Olivia, we may have found your stable-mate.

I look forward to pictures of your garage five or six years from now.

[Purdue FR-S]

Got around to seeing the new Corvette today and was thoroughly disappointed.

Christ how many vents can they fit on the damn thing?

Theres just way too much going on in my opinion, and although I would suspect that there is some major functionality to all that riff-raff ... I would appreciate a little more subtlety

[Dimman]

@ZDan If you look at the first part of your post, you can maybe see the constraints that GM has built for themselves with the size of the motor. They can't make it longitudinally shorter, since the single intake valve's flow limits are related to the bore. Going with bigger and bigger stroke increases the height of the motor, plus limits how low they can mount it (dry sumps on the Vette are no coincidence) as well as how fast they can spin it due to increasing piston speeds. So they seem to be at the practical limit of displacement in the 7.0L range. So they may hit a wall (barring expensive NASCAR level guts) when it comes to airflow (power) vs physical size. This is no good when we're dealing with under 75hp/L.

[serialk11r]

@ZDan, I know hp/L isn't important per se, but the issue is that no, 6000rpm peak does not mean it is breathing well. A power peak is just a power peak, but specific torque tells you where it's breathing well. Knowing hp/L at some rpm lets you compare specific torque, as I did to my 1ZZ turd pile. The fact is, 450hp at 6000rpm on a modern 6.2L engine means it is NOT breathing well at 6000rpm. Knowing that the specific torque on this LT1 motor is very good until like 4000 or whatever only adds to the evidence.

Any performance metric alone is pretty useless (except maybe peak power), it's how it fits into the whole picture that matters, and the picture is very clear in this case.

You say power to weight is important, and I completely agree. What I'm saying is, they put the wrong cams in there for power/weight ratio, because that motor has just stupid high torque. These changes are all small, 10% lower displacement means 10% less torque, maybe 5% better fuel economy, maybe 5% off the total engine mass, when I'm talking cams I am talking like "stage 1" intake cam only. I just think this makes more sense for a passenger car, while keeping with the big displacement, high power/weight ratio tradition. There is absolutely no reason those motors can't be putting out 80hp/L with that rev limit and stroke.

[Sasquachulator]

Originally Posted by Gixxersixxerman

Some people that care about tradition, a lot of enthusiast claim Chevy ruined the camaro when they swapped the front end from recessed lights to bubble things they put out... Traditional camaro owners hated it.. And sales dropped so much after that, they stopped the whole line years later.. Some cars just need to keep to tradition

Theres only so much you can do with one design.
Look at Porsche, all their cars look very much the same since the beginning of time.....

Besides the double round taillights is like in everything nowadays (GTR, various ferarris, Lotus, Vettes)... I think Chevy has been squaring their taillights since the Camaro came out....

And between the C5 and C6, the rear end looks almost exactly the same, only the C5 taillights were more oval shaped. What else could they do to the back end without making it look like the old one?

[BlaineWasHere]

There's nothing really wrong with it, but there's nothing really right with it either.

I see tons of ill placed vents and GT-R in the side profile.