Raitzi

It is not the number of gears what matters, it is rev matching and shift speed. If automatic C7 is not faster than manual, we can call it a failure.

Parker Corvette

DRC--- A person can post a message very clearly and yet it seems people don't read it or don't understand it. In my post #9 I clearly said that me Z4 runs at 2,000 to 2,300 at 70 MPH. I do not drive a Honda S2000. My Z4 does not operate at 8 or 9,000 RPM. My Z4 is in storage at this time, but I will check my rpm's at 70 MPH the next time I get it out.

Why is it that GM seems to be one of the few without an 8 speed auto tarns? Most premium brands have an 8 speed auto. GM's Cadillac XTS does not. Everything else in the XTS is new and very nice. GM just simply didn't get it done. The mags are bringing up the lack of an 8 speed.

BeaZt

So what exactly are they not getting done?

Parker Corvette

My old (traded it off) 2009 C6 and the wifes currect 2008 C6 both got 28 to 29 mpg. Where is the improvement?

Raitzi

Ford is developing the 10 gear automatic for GM and Ford 2wd cars: http://www.autoblog.com/2012/10/01/f...eed-gearboxes/

Kappa

I told you this already, none of those companies makes their own transmission. Most, if not all of them are using ZF and Aisin transmissions. The cost/benefit ratio obviously did not impress the Corvette team enough to buy one of those transmissions and try to fit it in a rear transaxle car.

A lot of programs got put on hold or canceled during GM's reconstruction. The 8 speed auto was one of them. That being said, I'll be surprised if its not in the new CTS coming out this spring.

Parker Corvette

When you don't have an improved transmission to offer on your brand new car, you tap dance.

I Bin Therbefor

The trans for the Corvette mounts to the front of the rear axel. What is needed is a transmission, in production, that can handle the torque and that can be mounted in that position. From "All Corvettes are Red" you'll learn that a transmission that is designed for four wheel drive meets the mounting requirement with minor mods. So, GM needs to have a four wheel drive automatic transmission in production that can handle 450 lbs of torque and better that the Vett team can modify for Corvette use. The RPM range of the transmission must also meet the LS1 needs. I keep saying in production because the Corvette can not afford to develop a unique transmission. I am not aware of any such four wheel drive intended automatic transmission that GM has in production or coming. Perhaps the transmission wars that he mentions will lead to such a development.

chiromed0

Yes! At least my tranny isn't out of date! Just my car.

Seriously, 99% of my driving could be done in just 2nd gear. They could have a direct drive and I wouldn't even notice.

I noticed in the 7 spd DCT it tends to jump all over the place. You can't feel it but man it must wear out parts quicker with so much going on.

BeaZt

There's tons of other improvements and we don't know for a fact what the MPG will be until real users get them on the road.....and great MPG in a Corvette is just "low hanging fruit" if you will...IMO all other performance aspects take precedence. It would be odd to hear that someone bought a Corvette only because it got great gas mileage.

BeaZt

While still beating you to the finish line

jimmyb

I agree. You can't brag about the NEW 7 speed manual and 2 minutes later say there's an "marketing arms war" in regards to the number of ratios. That said, I think the A6 is plenty for an engine with the LT1's torque curve.

I do wish he would just say what we all KNOW, that the GM 8 speed auto isn't ready yet.

In the end, I will order a manual (like always), but the automotive press sure didn't do him any favors with the Aisin 8 speed auto rumor, since almost 3/4ths of Corvettes are ordered with automatics.

Jimmy

Raitzi

According to the link I posted the next one will have 10 gears not 8.

BlueOx

When your car is a weak kneed 4 banger your wife made you buy, you whine about 8 spds.

Bill17601

With big torque you do not need more gears. The drag racing Corvettes use the 4 speed automatic. My C5 equipped with 3:15 gears, an LS3 and four speed automatic has not lost to a 6 speed automatic Vet. But I have not raced yours so I concede yours is faster before you tell me that. I run on the street heads up for money so your not going to get me to tell you my et. Great interview thanks to all who brought it to this thread.

DRC

I understood your point, and I also made a little joke, no bad intentions.

But, Tadge was quite clear I thought, said an 8 speed is heavier, costlier, and in testing suggested the 6 speed held up better, said with a wide band of torque the 6 speed did the job well.

GM just simply did not get it done? Good Lord buddy, aluminum frame, carbon fiber hood / roof, all info suggests the most fuel effecient 450 HP (maybe more) engine in the world, launch control, take it to the drag track of road race track, beat the crap out of it and your 100,000 mile warranty is in tact, probably costs in the mid 50's, etc., etc.

Get a piece of paper and a pencil and make a list of all the cars on the planet that accomplish the above. Hint: You won't need a very big piece of paper.

BeaZt

The Chevelle still has a power glide...so do Top Fuel Dragsters..lol..don't need any stinking extra gears..hey is that a gas station over there? LOL

DRLC5

It is out there already and if they mass produced it the cost would go way down. Actually it is not much more than the current trans if we has a buyer had to go out and buy. Redline just installed one in a 700rwhp ZR1?

JoesC5

That's odd. When I do the math on a 2005 C6 with 285/35ZR-19 rear tires and the A4 with .7:1 overdrive 4th gear and the base 2.73:1 differential gear I come up with 1675 RPM at 70 MPH.

The optional 3.15:1 ring gear and pinion in a 20 equates to 1930 RPM at 70 MPH.

The 2006 A6 with it's .67:1 6th gear overdrive and standard 2.56 rear gear sees 1500 RPM at 70 MPH.

1450 RPM in a 2005 C6 with the A4 and base 2.73 rear gear equates to 60 MPH.

I sometimes wonder if you really do have a Corvette, or just pull crap off the Internet to post.

You can bet that a 8 speed auto will run at lower RPM at a given speed then your A4 or the newer C6's A6, while delivering better gas mileage.

My 505 HP 7L C6 will equal your 400 HP 6L C6 in highway gas mileage. But then I have a 6 speed with a higher final gear ratio(1.71:1) then your C6(1.91:1 or 2.45:1).

That's what a 8 speed auto will bring to the table over a 4 or 6 speed auto, plus the lower gears in 1 thru 5, will give better performance.

BlueOx

Hmmm, never found that link yet huh?

I have a 6 speed manual 3.42. I was making a point about torque and the relative lack of need for an 8 spd, even in my old LS2. So what rpm will the LT1 in the C7 run at 70 mph with the 7 speed manual? How about the 6 speed auto? The 8 speed auto?

Mr.z4 runs at 2200rpm with his 8 speed at 70. I consider that high.