davepl

Oh, I don't know. The people that open their mouths before their eyes are pretty blind too.

The LT4 isn't a "peaky" motor by any meaningful definition. Explaining it slowly or quickly doesn't make a difference. Enjoy your superior understanding like an alien on Star Trek, I'll just muddle down here with the humans where the torque curve is within 30ftlbs, or 5%, of PERFECTLY FLAT in my "peaky" motor.

I wish I had another 2 gears. Instead of dropping 18 ftlbs on that last shift maybe it would have only been 17.5! Could you imagine!

Good luck to you. I hope you get your CVT and turbo.

jvp

Dave, here's my opinion for what little it may be worth to you: generally, if you're arguing with glass slipper, you're wrong. The simple fact that you responded to his long but factual post with a "too long, didn't read" is evident that you're the one who doesn't get it.

Bear in mind that I've nominated GS for a "tech contributor" title on Corvette Forum numerous times. I can assure you that you're never going to get that nomination from me. Whether that means anything to you or not is of little consequence to me. But you might note my title before you respond.

davepl

Go look up the definition of torque. Here is your error. You're welcome:

"as in 550 pounds lifted one foot in one second."

https://www.roushperformance.com/blo...er-and-torque/

BWFitz

When will the Z06 get the new 10 speed automatic from the ZL1?

Never.

davepl

I assume if I was wrong my Moriarty would have pointed it out, so I take the absence of a flame as a great praise :-)

But why never? Because it's not worth it to accommodate the special physical packaging requirements of the rear transaxle when they already have a perfectly good A8, or what's your rationale?

glass slipper

The LT4 is the epitome of a "peaky" engine.



The HP curve goes straight up to its power peak at 6400 RPM and then redline comes in at 6500 RPM. A "peaky" engine is one that has a sharp climb to peak power immediately followed by a sharp drop over a narrow RPM band. The LT4 doesn't even have the sharp drop after peak power because red line immediately follows peak power...the only reason the LT4 doesn't define a peaky engine is because it's technically worse than a "peaky" engine. The close ratio M7 keeps the LT4 from falling too far off its power peak thus preserving the performance. If the Z06 had a CVT, its performance would be phenomenal on a road race track...but they don't make a CVT that'll handle 650 HP.

glass slipper

Good grief, 550 pounds lifted one foot per second is the definition of HP...go click on the Britannica link in my post you didn't read.

The article in the Roush link is littered with mistakes, go read an actual physics book. At this point, I'm feeling very embarrassed...for you and Roush. I have to believe you're making these incorrect statements on purpose, nobody can be as smart as you claim to be yet make such ridiculously wrong statements. I prefer to think you're just trolling me and aren't really that ignorant.

davepl

Welcome to my ignore list. You crossed the line. Bye! Me and Roush and the rest of the qualified engineers will just have to live without your Internet ramblings. Horsepower is peaky because it is DEFINED that way, with RPM and the scalar constant 5252 right in it. Utterly meaningless semantics. Torque turns the output shaft.

All you've been saying all day is that if you graph a quantity THAT IS A FUNCTION OF RPM that it GOES UP WITH RPM. No kidding. I keep hoping you'll suddenly "get it" and apologize, but you wore out your welcome with your bad attitude.

LT4 is a "peaky" engine with a pool-table flat torque curve. Good one. I actually can't wait to get to work on Monday to tell everyone else what happened to me on the Internet this weekend, they'll enjoy it.

glass slipper

Now I get it, the optimist in me just wanted to believe...

C7 x 2

Attended the local Corvette club meeting this week. A member attended the Bash and had a one-on-one with some of those engineer types and asked them this question directly. Their answer was the C7 will not get the A10 simply because it will not physically fit. They also said the Z06 is not being built until September because they have so many GS orders to fill and a surplus of '16 Z06's that they delayed producing any more Z06's and are concentrating primarily on building GS's. Don't know personally but he said that is what he was told.

glass slipper

Interesting...the A10 is not physically larger than the A8 so there's no reason why the A10 will not physically fit. So much for that rumor...

Busa Dave

As reported at the Corvette Bash last month and confirmed by GM it is slightly longer because of the 2 extra gears so.....

jvp

That's comedy gold, right there...

glass slipper

The A10 will have 2 extra gear ratios, not two extra gears. Planetary gear sets are the least understood gears we have on our cars and adds to the "mystique" of automatic transmissions. The thing that puzzles a lot of people is how multiple gear ratios are available from one planetary gear set but that's not really too difficult. You can hold the ring gear and rotate the sun gear to make the planet carrier rotate at a slower speed, hold the ring gear and rotate the planet carrier to make the sun gear turn faster, hold the sun gear and rotate the planet carrier to make the ring gear turn slower, hold the sun gear and rotate the ring gear to make the planet carrier rotate at a faster speed, hold the planet carrier and turn the sun gear to make the ring gear rotate slower in the opposite direction, or hold the planet carrier and rotate the ring gear to make the sun gear rotate faster in the opposite direction. You can also lock any of the two elements together and get a 1:1 ratio as the whole gear set rotates at input speed. Some of those combinations aren't practical to use, for example the two reverse gears. But what puzzles people the most is how you can get even larger combinations of gear ratios when you have multiple planetary gear sets because you can combine the ratios of different planetary gear sets. For example, aftermarket companies take the 4-speed 4L80E and turn it into a 6-speed with the only modifications being to the valve body to change the combination/numbers of clutches/brake/sprag engaged.
http://www.transmissioncenter.net/4l80e.htm
Scroll down to see the 4-speed 4L80 and continue to see the 6-speed 4L80.

The point of all of this is the 8L90 has 4 planetary gear sets and so does the A10...there are no more "gears" added. There is one additional clutch added for a total of 4 clutches and two brakes but two of the clutches are nested and the two brakes are nested to "compact" the transmission and make room for the extra clutch.

You can read more about it here:

http://gmauthority.com/blog/2015/01/...the-internets/

From the GM Authority link above:
"There are 4 simple planetary gear sets, just like the ZF 8HP and the GM 8L transmission families.
There are six shift elements (as compared to 5 for the ZF 8HP and the GM 8L).
2 brakes (A and B) that are nested (one shift element is packaged inside the other)
4 clutches (B, C, D, and E), two of the clutches (D and F) are nested as well."

"The nesting of shift elements means that the overall package size will be pretty similar to the 8 speed transmission designs."

I can see the case possibly being slightly wider/taller but I see no reason for the transmission to be longer, the package size will be pretty similar as stated in the quote above.

GM is famous for down playing automatic transmissions with more gears, they did it in the first year of the C6 and again in the first year of the C7 saying there's no reason for more than 4 gears and then 6 gears. Maybe they needed a different excuse this time. The Camaro engineers love the A10 because the RPM drops are so much smaller than the 8L90 which keeps the LT4 closer to its peak power after the shift. I've seen a preliminary chart of the gear ratios and can say the large RPM drop between 4th and 5th is gone...25% in the 8L90 vs 14.5% in the A10. The gear ratio selection is very good in terms of RPM drop and performance for every gear, roll races and road race tracks would see a huge difference. 9th to 10th looks like around 7.5% which is only 150 RPM drop at 2000 RPM in 9th. 1st gear is slightly higher numerically and 10th gear is slightly lower numerically than 8th in the 8L90... they're close enough to be the same, especially 10th/8th. The focus seems to have been on minimizing RPM drop between gears.

I'm not saying the A10 will ever show up in the C7, just saying there doesn't appear to be an issue with "fitment". Performance would definitely be increased above 70 MPH.

davepl

This is the fundamental cause of our disagreement, I believe. We're talking past one another because we're agreeing about the physics but we've selected different definitions of what makes a "peaky" engine, and why.

I defined a peaky engine as one with a narrow torque window which causes you to need to shift often like a small four cylinder turbo. I think that's a more useful definition. I, of course, think it makes far more sense.

An engine that is able to make the same torque nearly off idle as it does at redline is (to me) the antithesis of "peaky". We call that "flat". Who's we? Me and the professional engine builders I deal with on a daily basis where I learned that notion. That's where I learned likely 25% of what I know about engines, and I'm not shy to admit it.

It's not an important distinction, and other than I think 2 more ratios won't help our engine much, not interesting to me to pursue.

Your ultimate failing was that you cannot communicate.

You ranted. You reaved. You were rude. You got personal. You repeatedly attempted to insult my intelligence and various other things about me all because you were losing an argument on the Internet. Then your little buddy jumped in too. I hope it's not a reflection of how you act in the real world.

And I think you owe me apology for the way you conducted yourself, but I'm not going to grow old waiting.

You acted like the lowest form of Telephone Tough Guy.

JustinStrife

Someday you'll look back at this thread, and see how you conducted yourself. At least one will hope so.

But I'm not going to grow old waiting for that day.

davepl

I will, and with pride, because I only spoke of the matter at hand. Right or wrong on the facts (and I still argue right), I didn't make it into a d*ck measuring contest about credentials, I didn't say anyone else was stupid, I didn't call anyone ignorant, and so on.

Anyone who wants can read the whole thread, it's right there. If you think being adamant about the issue and NOT making it personal is a defect, I'll live with it.

JerriVette

Sorry guys...didn't mean for this thread to cause such an issue.

Just shooting the breeze.

We will find out in July about 2017

Lipstic

That is what a few engineers and a tech told me, it will not fit

Lavender

What do you expect them to tell you? Yes we will have the A10 in the C7 for '17 or '18 MY...in the mean time don't buy what we have to offer at the moment. Oh wait...

Keeping their mouths shut today will help sell another A8 Corvette tomorrow. Which could be traded on a A10 Corvette in the near future..