theboom

Everyone has been talking about the new c7 zr1 that is supposed to be announced any day now as well as the high possibility of the mid engine corvette (or mid engine gm product although I hope its a corvette, I don't want the price spike of it being a Cadillac on an already expensive car). I know some things about this but I don't have a complete grasp on this yet. How much of a performance benefit would going mid engine have? Because we don't know how the c7 zr1 will perform, we can only use the z06 as a base line. The z06 posted a 1:33.05 on Laguna Seca, a 1:25.00 at willow springs, both quoted by Motor Trend. What would a mid engine car, using the exact same equipment of the z06, be able to run on these 2 tracks (and others if you care to guess). I am talking same downforce, same tires, same suspension setup, same amount of power, same weight.

I am not against a mid engine corvette, I just want to know actually how much more its going to get you. One way or another, the corvette is truely becoming a world class, bang for your buck, supercar killer

SBC_and_a_stick

Ok, first I have to say that "same weight" is not fair. Mid engine cars will weigh a bit less all things equal. The front of the car would be much smaller, while the back will be about the same with a huge loss in storage space. The torque tube will be eliminated and the front wheels/tires can be downsized. The car will have lower drag as well. I'd say mid engine is almost for sure lighter with a lower drag coefficient. It's inherent in the design.

I think you will gain about a second to a second and a half. However, the steering response is much better and you get less tramlining.

Same power is also not fair. The same engine in a mid engine orientation can be made to breathe much better. Think of the flexibility you have to build a proper multi stage intake manifold, a large diameter TVS inlet, or heat exchanger bricks. The header design could also be improved since there is more engine bay width. The rear wheels don't have to steer.

Vernon

The first part of my opinion is that any of these cars - Z06, ZR1, and mid-engine - have performance capacities beyond my 10/10ths racing ability so regardless of layout, I'd probably turn similar lap times. The second part of my opinion is that my purchase preferences are very much influenced by visual design appeal and driving comfort preferences. I have a visual preference for the proportions of the front engine vehicle ('lusted' for E type and C2 coupe body proportions since before I could drive) and driving experience with the front engine rear drive, and front engine all wheel drive so my driving comfort lies with these two layouts.
If I were to have driving experience with mid-engine, I would learn how to address it's driving characteristics, ie. understeer/oversteer/spin through trial and error. I would then have the driving comfort with all three drive layouts (presuming mid-engine rear drive) and believe I'd have similar lap times with all three.
Some may suggest a desire for the 'exotic' allure of a mid-engine design. If it's a high performing car that I believe is 'eye candy', that's what would sway my decision for the purchase...if I could afford it.
Hmmm...New Ford GT...can't afford it.

So, my rookie driving ability for cars at this level will be the biggest influence on performance.

stevebz06

To see the difference just watch a Formula 1 race or an Indy Car race and see where the front engines cars finish.

There aren't any front engines cars in those series? Gee, I wonder why?

Glenn Quagmire

I will say that as an owner of both a McLaren and Z07, power delivery and driveability are certainly very different. The vette is a fair bit larger (both size and weight), which can definitely be felt. Hence, the McLaren is much more nimble and has far better sightlines. But, when cornering at speed, the vette feels more planted. Braking is also a bit better with the vette.

Throttle response is better in the McLaren and it pulls quicker, but the vette pulls harder.

The magnetic ride ride control and braking of the vette could make a mid-engine configuration very compelling...especially if the balance is right and the weight is kept down. I've got deposits on both the yet to be confirmed mid-engine vette and the yet to be revealed McLaren 720S. If the ME vette is 700+ hp and $200K or less, it will be a major win for the general. In contrast the 720S spider with 710 hp will be closer to $400K. So, a ME exotic vette with a giant dealer network could be a game changer...

Deslok

Weight distribution is a major advantage of mid-engine cars. On acceleration, engine weight transfers to load rear tires better for traction. On braking, mid-engine car tends to put less weight on front tires and keeps more on the rear tires for braking grip.

Also, as mentioned, mid-engine tends to give more freedom in engine layout for intakes, DOHC designs, etc.

SBC_and_a_stick

OK, but Porsche did basically make something like this (exotic rear engine with a giant dealer network) for a long long time. I know the 911 is rear engine technically, but it's 99.9% ME.

The only way it's a game changer is if it's less than GT3 prices by a lot.

I'm surprised to hear you say the turbo has better throttle response. GM messed up the throttle mapping for sure. No reason to have a supercharged car lag ... in lag...

MacManInfi

Agreed with this. I've had two mid engine cars and they both hooked like crazy from a standstill. 0-60 times would be improved and more consistent. As powerful as the Z06 is, it struggles out of the hole (at least on the street.)

Higgs Boson

I drive all cars all the time (not simultaneously though). Today I drove a 2015 Cayman S (PDK), 2016 Range Rover Full Size, 2016 Range Sport Diesel, 2014 CLS550, and my 16 Z06.

They all lagged, most notably when transitioning from off throttle decel, like coasting up to a yield sign and then rolling back in to accelerate, they all did not respond immediately. The MB and the two Ranges felt like turbo lag. The Cayman S would respond better if I shifted manually and kept the revs up. The Z06 only lag I could feel was from having a torque converter based automatic and it had to choose a gear to downshift into.

It's the new way of the world, IMO. Given that they all had the most issue with the decel/reaccel situation I would say it is the torque based electronic throttle causing the issue.

When I have some time I will play with the Driver Demand table in my Z06 and see if I can pinpoint it. Like the Cayman, if I manually downshift my Z06 into a higher RPM range the lag is gone or at least less apparent.

Glenn Quagmire

The problem 911's have is that unless one understands the nuances between models, generations and sub-generations it can be hard to differentiate one from another. So, while straight-line runs from a 991.2 TTS iare amazing, both the GT3 and GT3RS are better better performers and hold MUCH better resales. Plus, 911's are really for purists as opposed to those seeking exotic styling. Corvette isn't really structured the same in that regard. Thus I think a halo performer from America's #1 sports car brand certainly has a lot of upside. Not unlike the new FGT, technology can be launched in the halo car and trickle down to lesser expensive platforms.

Bear in mind that unlike Mustangs, Camaros simply aren't selling. A lot of that has to do with the popularity of the vette and the relatively close price point. Personally, I believe that GM will make both FE and ME platforms, before phasing out the FE and making the Camaro a bigger player. But, what the hell do I know...?

theboom

Thanks for the response but quick question. I get the eliminating of the torque tube would make it lighter and with a mid engine design, it can be more aerodynamic. But any shortening of the front, do you not have to extend the back the same amount so you can fit the engine between the rear of the cabin and the rear axle? Otherwise it's rear engine and not mid engine right? Because I'm pretty sure there is nowhere near enough room in the stingray from the seats to the rear axle, just enough for the transmission.

How much wheight do you thing it would save? z06 weighs about 3,550lbs. What are you guessing it would be?

Bill Dearborn

The bread and butter sales of Pony cars is to people who don't buy the performance models of those cars. They buy the base engine and use the vehicle as stylish basic transportation. When those people look at the Mustang and the Camaro they may actually want the Camaro but will buy the Mustang because the Mustang has more rear seat leg room and the rear seat is somewhat usable. GM has been refusing to recognize this problem for the last 25+ years. You see a fair proportion of young women driving Mustangs but you don't see the same in the Camaro since it doesn't pass the usability test.

Bill

stevebz06

I don't think there is going to be much transferred from the C7 to the C8. It should be an all-new car. Don't worry about there not being enough room for the engine and gearbox. The proportions of the car will change.

As for the weight, it just depends on how big a priority they place on it. The C7 could be much lighter than it is but the decision was made to make it a luxury sports car to the detriment of weight. A big factor there is wheels and tires. They keep getting bigger and heavier for the only purpose of style and the penalty is expense, aerodynamics, slower acceleration, reduced fuel economy, difficulty in mounting new tires, etc, etc.

A lot or maybe all of the weight savings could be squandered if they keep bolting on bigger wheels and cramming more equipment into the car.

Glenn Quagmire

Agreed. I recognize the prices are dramatically different, but for comparison purposes, the new McLaren 720S (aka P14) has a reported weight of under 2,900 lbs...with no sacrifices made to equipment or interior quality. Of course, the CF monocoque certainly helps to reduce weight.

I would love to see the ME vette come in under 3,200 lbs. with their first go at the configuration...with reductions to come as lessons are learned.

JoesC5

How much lighter will the Mid Engine Corvette be it you eliminate the carbon fiber torque tube and the carbon fiber prop shaft? Shortening the two exhaust pipes approximately 6 feet would save how many pounds? How many pounds will be added by increasing the length of the two radiator hoses by 6 feet?

What other items will be lighter going from the present front engine architecture to the mid engine architecture?

I don't believe the new NSX mid engine is that low on weight at 3876 pounds. I doubt that the NSX would drop 352 pounds, to 3524, by eliminating the electric motors and then adding 2 more cylinders.

SBC_and_a_stick

Honestly, you are simplifying this too much and you know it. With a mid engine that is adding strength to the chassis you can build a frame that's much lighter all things equal. Start there. Then you can make a more compact frame with far shorter overhangs, stiffer, and far more aerodynamic without compromising any mechanical grip. I think GM can shave as much as 250 lbs without giving any mechanical grip that the C7 Z has.

You speak as though powertrain components are suspended in mid air and there is no weight for auxiliary attachment points, no weight added to strengthen the frame to cope or anything else. With a mid engine design you don't have to suspend feet and feet of dual runs of pipe. It's everything hanger supports, rubber bushing, heat shielding, the frame built to house it, the extra stiffening that has to be added around housings etc.

How about you start with the NA NSX from the 90s and add the weight of two more pistons Joe?

phantasms

I can't see the mid engined vette not having a CF "frame". Prices have come way down and production capabilities way up on that kind of thing. Think i3 and 4C. The stiffness and weight savings would be huge.

JoesC5

250 pounds savings in the frame design, you say.

Even if you could eliminate the aluminum space frame completely from the C7 you would eliminate approximately 309 pounds.

Do you really believe you can design a mid engine Corvette with an aluminum space frame that weighs 59 pounds with the torsional rigidity that it currently has, by relocating the engine to behind the cockpit?

GM better hire you quick.

Poor-sha

Based on my limited experience driving mid engine cars hard on the street or on track (986 Boxster S with a 3.8L Carrera S motor and an Audi R8) here is what I've noticed. First, the ME cars are much easier to control when they rotate. They seem to rotate more slowly and are much easier to catch at higher degrees of rotation than the vette. As others have said it comes down to polar moment of inertia.

The other thing is that while the ME cars do have great front end feel they also seem to have less front end grip than the vette. With less weight over the front wheels you need to use more trail braking to get down to the apex. It's not that it's better or worse but it's definitely a different driving style.

From what I've read about Porsche's move to a true ME for the 911 RSR it was more about tire wear than anything. Having all the weight over the rear wheels resulted in quicker rear tire wear. On our vettes we tend to burn up the fronts long before the rears on the road course. I suspect that a true ME vette would have much better tire wear all around on track and wouldn't overheat them as quickly as the C7Z does.

SBC_and_a_stick

Obviously not from the frame alone. The entire car.