AWD in C7's Future?

[hyperv6]

Here is something going around on a Mule and speculation it may be a Vette? This is posted on autoblog.com.

Hot on the heels of discovering the next-gen Corvette could be offered with a dual-clutch transmission, word is now filtering out that General Motors may be working on adapting the Haldex-sourced XWD all-wheel-drive system currently available on the 2008 Saab 9-3 for use on Chevy's budget supercar. The Haldex XWD is a robust system, as it can send up to 85% of the engine's power to a single wheel.

Auto Motor and Sport in Sweden reports that GM engineers have been seen testing a mule with a wider rear track than any Saab currently available, which suggests the system is already in development for the next-gen Corvette. We're not sure whether to place this piece of news in the fact file or keep it on the rumor pile, as information surrounding the next-gen Corvette has been swirling since GM's contract with the UAW was leaked and revealed some juicy details. Will it switch to the smaller Kappa platform (production of the Pontiac Solstice and Saturn Sky is set to switch to the Corvette's facility in Bowling Green, KY in a few years). What about rumors of a mid-engine exotic Corvette to be built and sold alongside the traditional model? There's too much static to pick out fact from fiction, though the dual-clutch transmission seems like a definite lock since it was referenced in official documents. GM, of course, is silent on the subject.

I can not say much on the Kappa Vette merge but I do know Jim Queen has said that the new ZR1 has had problems on putting the power down to the ground. They have had to do some special things with a new traction control to make it all work with the 650 HP.

He was asked about 700 HP and he did say not in the first year and did not say there was no 700 HP in the future. AWD would save a lot of problems in putting the power down.

Also factor in that the SRS and CTS already has it an GM plans on more AWD offerings in various lines. It would be natural to offer it in the Vette.

[Drew Dowdell]

I still fear Haldex... they rely heavily on computers to make the whole system work right and it was apparently a nightmare on the Volvos with it.

[91z4me]

I don't know how a front engine, rear transmissioned car would be able to have an AWD system. It would need like 3 torque tubes or something insane.

[K.C.]

I would think that GM would want to reduce weight of the C7, so why add an option that would add weight? I don't think this will come to fruition.

[Joelill2]

The AWD in my mom's Volvo XC90 is pretty good.. no issues with it yet, or the car and it's got 50k on it. We've got faith in this car and will probably run it to about 150k or so without anything major hopefully.

Back to the topic, I don't think the C7 would go AWD, just seems out of character.

-Joe

[Newbiewar]

The AWD in my mom's Volvo XC90 is pretty good.. no issues with it yet, or the car and it's got 50k on it. We've got faith in this car and will probably run it to about 150k or so without anything major hopefully.

Back to the topic, I don't think the C7 would go AWD, just seems out of character.

-Joe

i was under the impression the ZR1 being rwd, is outperforming almost everything off the line... competing seriously with the bugadi and the enzo...

its under my impression that they learned something extremely important about rwd suspension to launch a 2wd rwd vehicle at a competative rate to a awd vehicle... so why switch to awd now?

[ZL-1]

I don't know how a front engine, rear transmissioned car would be able to have an AWD system. It would need like 3 torque tubes or something insane.

Perhaps the C7 will not have a rear-mounted transmission? We know very little about what's being considered engineering-wise.

[goblue1999]

I don't know how a front engine, rear transmissioned car would be able to have an AWD system. It would need like 3 torque tubes or something insane.

I believe that the next Vette is mid-engine.

[hyperv6]

Well I am not a big AWD fan but here are a few things to ponder.

GM has reached the limits of a 2WD system and the tires they have.

GM also now has power in the top line engine that can and will go over 700 HP in the near future.

Even with electronic aids the limits of the tires are hard to over come and even the Z06 is a hand full with the aids turned off.

Since this car is not driven by race drivers but average joes who can afford it and not always control it I can see them looking in this area for the top end car.

With over 700 HP plus in the future it can spare the 150 HP to run the front drivetrain and weight. All the power in the world is of no use if it does not get to the ground.

The new super vette is entering areas not seen in a Chevy since the Cerv I and II test car. Back then the AWD of the Cerv II had to give the ability to put the power to the ground that the two tires could not.

[ZL-1]

I believe that the next Vette is mid-engine.

I'm thinking the same, but I'm guessing front-mid-engine like the SLR, not rear-mid-engine like a F430.

[91z4me]

Perhaps the C7 will not have a rear-mounted transmission? We know very little about what's being considered engineering-wise.

I highly doubt that since rear mounted transmissions are acutally becoming more normal in the supercar league (AM for instance).

Also ZL-1 the current C6 and the C5 to boot were both front mid engined.

[ZL-1]

Also ZL-1 the current C6 and the C5 to boot were both front mid engined.

I had an idea that it was close to being front-mid-engined but that the front of the engine was placed above the front wheels. My bad then.

[smk4565]

Front engine, rear drive has worked for 50 years, I say stick with it. All wheel drive will add weight, and the Corvette's main advantage over it's competition is it's low weight. The ZR1 will has more than enough power, if they can make that work with rear drive then they are good. I think rear drive only will give them the best handling.

Really the Vette doesn't need over 500 hp, it is plenty fast in Z06 form. Doing the ZR1 as a low production bragging rights thing is good for image, but I don't think they need to focus on the 500-700 hp range for the Vette and then adding all wheel to control it. Porsche still uses the 3.6 liter engine and doesn't need tons of power to make a fast car. The C7 should focus on increased gas mileage, handling, braking and interior.

Edited October 4, 2007 by smk4565

[bobf]

Really the Vette doesn't need over 500 hp, it is plenty fast in Z06 form.

Sacrilege!!!! Who ever heard of such a thing.

Granted, going over 500 with only the rear wheels is wasting power, but if a strong - lightweight AWD system were available, I'd be on it in a heartbeat. RWD is at the limits with the power being produced today. Plenty of supercars have AWD and IMO, the penalty you get in weight is made up by the amount of power you can dump in and the extra grip AWD offers.

[quantum110]

Porsche still uses the 3.6 liter engine and doesn't need tons of power to make a fast car. The C7 should focus on increased gas mileage, handling, braking and interior.

Yes, but they sure do need AWD.

911 Turbo: ~3500lbs, AWD, 0-60 in 3.4s, and still a decent street car.

911 GT3 RS: ~3000lbs, RWD, 0-60 in 4.0s, may handle better, but not great for the streets (I'm willing to bet the ZR1 out performs it too)

I see no problem in adding a AWD Vette to the line up. It will be a killer street car (imagine actually being able to launch a Vette without the rear coming around on you). The should also keep around the ZR1 for the track hungry folks.

[hyperv6]

I see the vette staying mid front engine.

I see AWD as a drive train offered on the high end vetts like the Z06 and ZR1 but the base will do with a rear transaxle and a duel clutch that is in the works.

A mid engine Vette is a nioce idea but not what Vette buyers want as the engine in front of the driver is a badge of honnor with them.

Keep in mind many of the new Ferraris have also returned to Front mid layouts.

As for the AWD with the hight HP it is viable as it has some power to give and traction to gain. The 32 Ford we have at work has a Syclone front drive and ZR rear. It is good for 3 sec 0-60 times but the front drive limits the 1/4 mile to 12 sec. The front drive pulles 150 HP to drive it.

With out the drive shaft to the front it will run 10's. This is with an engine just under 600 HP Linginfelter SBC on the dyno.

It is not real important for the new ZR1 to run way over 200 MPH but it is important for lap times to pull through and out of corners. The Z06 is already struggleing with that now as traction is limited.

All the power in the world is no good with out being able to put it down.

[avro206]

NO! NO! NO! DSG fine....AWD NO!!! Totally out of caracter fort he Corvette. Doesn't belong! NO!!!

[bobf]

The 32 Ford we have at work has a Syclone front drive and ZR rear. It is good for 3 sec 0-60 times but the front drive limits the 1/4 mile to 12 sec. The front drive pulles 150 HP to drive it.

With out the drive shaft to the front it will run 10's. This is with an engine just under 600 HP Linginfelter SBC on the dyno.

I don't understand the logic behind this. I can run my Tahoe at the track in 2wd drive Vs 4wd and see almost identical times. I can run my Jeep SRT the same way and get similar results with the exception of limited traction in 2wd so it would actually be slower in 2wd.

Many cars have awd and don't get a performance hit (especially of 2 seconds). And it certainly doesen't "steal" 150 horsepower form anywhere. If anything, it allows you to put all 600 horsepower to the ground.

Sorry, I just had to comment on this when I saw it.

[91z4me]

I don't understand the logic behind this. I can run my Tahoe at the track in 2wd drive Vs 4wd and see almost identical times. I can run my Jeep SRT the same way and get similar results with the exception of limited traction in 2wd so it would actually be slower in 2wd.

Many cars have awd and don't get a performance hit (especially of 2 seconds). And it certainly doesen't "steal" 150 horsepower form anywhere. If anything, it allows you to put all 600 horsepower to the ground.

Sorry, I just had to comment on this when I saw it.

Your missing the point that both of those vehicles still have the awd system on them, hence more weight vs a 2wd version.

[hyperv6]

I don't understand the logic behind this. I can run my Tahoe at the track in 2wd drive Vs 4wd and see almost identical times. I can run my Jeep SRT the same way and get similar results with the exception of limited traction in 2wd so it would actually be slower in 2wd.

Many cars have awd and don't get a performance hit (especially of 2 seconds). And it certainly doesen't "steal" 150 horsepower form anywhere. If anything, it allows you to put all 600 horsepower to the ground.

Sorry, I just had to comment on this when I saw it.

The point is your 4x4 is not traction limited on dry payvment coming out of a tight turn. 4x4 and AWD performance cars have different needs for traction.

The Vette is one of the fastest cars at the Ring in Germany but a less powerful 911 can run nearly as fast times in AWD as it can take and come though then out of the corners much faster. The Vette makes most of it's time on the several long straights.

If the Vette had AWD it not only would have straight line speed but it would also be faster in the corners so it would have massive gains in usable performance.

I used the 150 HP penalty as a mark that I know was true on a car we built. It did use some stock performance drivelines from the 80's so I would expect some of the new computer active systems today to much rob less power.

Lets face it the new ZR1 will not show all it has as it will not be able to put it down in stock street trim. Using 4 tires vs just two would give it performance never seen in a Chevy since the Cerv II, Duntovs AWD Can Am Corvette Prototype.

I was never a big AWD fan till I saw the Vette was going over 600 HP and know the performance gains in acceleration and braking are more important to this car than going 220 MPH.

[CaddyXLR-V]

It doesn't need AWD. It needs to be mid-engine, as in, engine behind the driver. The fastest cars around a track, are still mid-engine-RWD cars. Mclaren F1 and Koenigsegg CCR don't have AWD, but still beat every AWD car around the track. Put more weight over the rear wheels, and you get more traction, without the weight penalty, and parasitic losses of AWD. Like anything mechanical, AWD drains power because there are more moving parts and more weight to be turned. It's the same reason you would choose a lightweight driveshaft as opposed to a heavier driveshaft.

[bobf]

I used the 150 HP penalty as a mark that I know was true on a car we built. It did use some stock performance drivelines from the 80's so I would expect some of the new computer active systems today to much rob less power.

AWD fan till I saw the Vette was going over 600 HP and know the performance gains in acceleration and braking are more important to this car than going 220 MPH.

I realize all of the benefits of AWD and I'm a huge fan of it. The only think I couldn't wrap my mind around is you said your car had a 150hp penalty by having AWD. Which I still don't really get. Especially to the tune of a 2 second deficit in the 1/4. Besides, if you went RWD on it, you'd need slicks to get it to hook up anyway.

[CaddyXLR-V]

I realize all of the benefits of AWD and I'm a huge fan of it. The only think I couldn't wrap my mind around is you said your car had a 150hp penalty by having AWD. Which I still don't really get. Especially to the tune of a 2 second deficit in the 1/4. Besides, if you went RWD on it, you'd need slicks to get it to hook up anyway.

AWD takes power to run it. For example, lets say you have a car with 500hp at the engine. That's about 425hp at the wheels with 15% loss.

AWD would be more like 20-25% loss to the wheels. That would result in 375hp-400hp to the wheels, meaning a 25-50hp loss.

So AWD increases weight, and decreases the amount of power put to the ground.

Edited October 6, 2007 by CaddyXLR-V

[eldiablobanshee]

The only thing the C7 will need an AWD option for is to let its buyers make it an all season car. If you want to know what GM will do to get the C7 to put down all that power just look at its main competition, the Ferrari 599 gtb fiorano F1 , 612 bhp 448 lb-ft 3700 lb curb weight, 0-60 in 3.2, 1/4 mile in 11.2 at 129.3. This car handles better and is quicker than a rear mid engine enzo and has a DSG style gear box, using this $280,000.00 car as a template GM should have no problem figuring out what to do to get the lighter more powerful C7 to unleash its potential.

[Z-06]

The only thing the C7 will need an AWD option for is to let its buyers make it an all season car. If you want to know what GM will do to get the C7 to put down all that power just look at its main competition, the Ferrari 599 gtb fiorano F1 , 612 bhp 448 lb-ft 3700 lb curb weight, 0-60 in 3.2, 1/4 mile in 11.2 at 129.3. This car handles better and is quicker than a rear mid engine enzo and has a DSG style gear box, using this $280,000.00 car as a template GM should have no problem figuring out what to do to get the lighter more powerful C7 to unleash its potential.

Have you been watching Jeremy Clackson? Because he compared the Z06 with the 575 Maranello. I hope when you said benchmarking the 599GTB is to actually surpass it.

[eldiablobanshee]

Have you been watching Jeremy Clackson? Because he compared the Z06 with the 575 Maranello. I hope when you said benchmarking the 599GTB is to actually surpass it.

I am just showing that everyone is wrong when they are saying a front engine rear drive car can not put down over 600bhp cleanly. With more power and more torque the C7 should smoke the 599GTB and even if they style it up with a deluxe lether interior it will be lighter and handle better.

[hyperv6]

I realize all of the benefits of AWD and I'm a huge fan of it. The only think I couldn't wrap my mind around is you said your car had a 150hp penalty by having AWD. Which I still don't really get. Especially to the tune of a 2 second deficit in the 1/4. Besides, if you went RWD on it, you'd need slicks to get it to hook up anyway.

The performance was improved 0-60 even with the 150 HP being lost to the drivetrain. But on the other hand the 1/4 mile was killed by 2 seconds as we used slicks and traction is not much of a factor over 50 MPH. Yje lost HP was felt at the higher speeds.

I don't have a problem with AWD on a high HP Vette but the standard Vette needs a diet. You can gain more performance with less mass than anything.

As for todays car mId engine is so over rated in a street car. It may have some more edgy performance but few will ever use it to find it. The truth is balance of a car is more important. If the cars mass is ballanced correctly it does not know where the engine is.

I own a mid engine car today and it is good and will pull a 1G but it will drop throttle over steer on you in a second if your not on top of it during Autocross. How many drivers today would know to get back on the throttle to keep from spinning out. I think that is why so many Enzo's bit the dust anymore. Even stability control has its limits.

Front engine is a badge of honnor to most Vette owners. To take that away is to losse it greatest trade mark and to gain very litte more than a marketing point with just a little performance gain.

Get the car lighter or get the traction to the ground is where it is at. Doing 220 MPH is worthless and doing 0-100-0 is going to be more of a guage that real people will see vs magazine test. Besides it would lower lap times at the ring.

Most of us only dream of Ferraris where many of us either ownm have owed or will own a Vette. You have to keep the dream alive. Y

ou make a cheap midengine you just have a MR2 fighter amd Ford already proved it is very hard to make a affordable super car that is out of the norm.

[91z4me]

I don't have a problem with AWD on a high HP Vette but the standard Vette needs a diet. You can gain more performance with less mass than anything.

Wait a minute...

Did I read that right? You think the C6 coupe is to heavy? Try comparing it to any other high powered sports coupe (and remember it is lighter than almost any 2 seater except the kappa triplets or Miata).

[eldiablobanshee]

I think he is just trying to say that you can gain just as much performance by lowering mass as you would by increasing bhp. So if you made an all aluminum and carbon fiber Zo6 that weighed about 2600lb and left the engine alone it would probably perform close to a 650bhp 3200lb Zo6. Anther benefit of weight reduction is also handling.

[91z4me]

I think he is just trying to say that you can gain just as much performance by lowering mass as you would by increasing bhp. So if you made an all aluminum and carbon fiber Zo6 that weighed about 2600lb and left the engine alone it would probably perform close to a 650bhp 3200lb Zo6. Anther benefit of weight reduction is also handling.

But the current Z06 uses an extremely light weight, high strength aluminum chassis and has at least some CF body panels. Sure the BD will get more CF but there isn't all that much weight to be rung out of the chassis, without compromising the integrity of said chassis.

[hyperv6]

But the current Z06 uses an extremely light weight, high strength aluminum chassis and has at least some CF body panels. Sure the BD will get more CF but there isn't all that much weight to be rung out of the chassis, without compromising the integrity of said chassis.

I am not saying the Vette is too heavy but Chevy it's self is looking at everything to lower weght just. They struly would love to get the car down to 2700 LBS but cost climbs as you add expensive metals and Carbon Fiber.

The point is most cars today are too heavy because of safety and cost but here is what is gained in lighter weight.

Better controll of the car in

Shorter stopping

Faster acceleration

Better handling

better gas milage [yes this is a factor for todays sports cars]

All of this is gained just with weight loss and nothing touched on the engine.

The only negitives are as mentioned is cost or durability as noted in some past Lotus.

Lotus is a extreem example of light weight but it is to the point where in the past they have paid a price of durability so I agree there is some limits but GM still has room to work.

I see with the increase use of composites the price fill fall and we will see Vettes om the 2700 pound range and Kappas with 2400 pound range being a reality.

He who controls the mass better wins in lap times and over all performance.

There is a heck of a lot more to this than just more power and sticking the engine in the back.

In GM's case money is an object with Vette buyers as well as tradition that has to be considered.

[ctsls7]

COULDN'T AGREE MORE LEAVE IT AS A OPTIONS