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  #13  
Old 05-04-2011, 04:01 PM
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Re: New transmission to have 9 speeds?

Why don't they just engineer a CVT that can take the torque and be done with it. All those shift points would be annoying if felt, as posted above for the Audi.
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  #14  
Old 05-05-2011, 09:01 AM
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Re: New transmission to have 9 speeds?

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Originally Posted by Jim Hef View Post
Why don't they just engineer a CVT that can take the torque and be done with it. All those shift points would be annoying if felt, as posted above for the Audi.
My thought exactly - there comes a point when there are too many gears.
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  #15  
Old 05-05-2011, 09:01 AM
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Re: New transmission to have 9 speeds?

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I was discussing the 545RFE transmission (comes with the Hemi) with an old engineering friend. He emphatically stated that with the existing three planetary gear sets in the 545FRE, Chrysler should be able to get eight (8) forward ratios from it through programming.
I have a 1973 Ford 4000 tractor that has a "Select-O-Speed" transmission that has 3 planetary gear sets, and it has 10 forward speeds and 2 reverse speeds.
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  #16  
Old 05-05-2011, 11:24 AM
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Re: New transmission to have 9 speeds?

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Originally Posted by Nouveau Redneck View Post
I have a 1973 Ford 4000 tractor that has a "Select-O-Speed" transmission that has 3 planetary gear sets, and it has 10 forward speeds and 2 reverse speeds.

Have you attempted to use that transmission in your Jeep?
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  #17  
Old 05-05-2011, 11:44 AM
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Re: New transmission to have 9 speeds?

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Originally Posted by Jim Hef View Post
Why don't they just engineer a CVT that can take the torque and be done with it. All those shift points would be annoying if felt, as posted above for the Audi.

A couple reasons:

1) Not everybody likes the dynamics of a CVT. They have some advantages, but they also have some disadvantages. For example, they take a bit longer to figure out what you want to do- when you floor it, there's about half a beat before it sorts things out and pours on the power.

2) The nature of a CVT means it doesn't handle torque very well. They've been getting better at it, but the pulleys and belts are fairly vulnerable and it's easy to burn the things up or snap them entirely.

The thing is, no transmission is going to make a large displacement engine efficient. Not going to happen; they can make incremental improvements here and there, but there's no box o' cogs they can bolt on that's going to deliver great mileage. Increasing numbers of gears help, but as you say, then you're shifting a lot.

I'm expecting the real answer to be something more along the lines of what Ford has done- switch to a smaller displacement overhead cam design to generate the same amount of power. GM is still flogging their small block, but even its days are numbered. I don't see Chrysler hanging on to the 5.7L Hemi indefinitely... in fact, I fully expect that in some basement they're working on it's eventual replacement right now, and it will probably be smaller by a fair margin.
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  #18  
Old 05-06-2011, 07:53 AM
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Re: New transmission to have 9 speeds?

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Originally Posted by Technosavant View Post
...I fully expect that in some basement they're working on it's eventual replacement right now....
Agreed, and it's the trend that everyone else seems to be following right now. The Explorer no longer offers a V8 option, although I haven't driven one with the new V6 to see if it compares favorably to past performance. I would have thought that the Pentastar V6 would have been tuned for greater output, but perhaps it wasn't giving the longevity that they were shooting for.
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Old 05-06-2011, 09:04 PM
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Re: New transmission to have 9 speeds?

I'm not displeased with the Pentastar; its output is in the ballpark of competing V-6 engines, and there's still a couple tricks left to play (like direct injection).

I find it interesting that even as engines are being downsized, we're still in the middle of one of the most ruthless horsepower wars we've ever seen, and in many cases the vehicles are getting mid 20mpg combined (for sedans) even while getting somewhere in the neighborhood of 300HP. The amount of firepower the average family sedan is getting out of a middling size engine is absolutely astounding. We may miss the large displacement super-torquey mills, but it is not a bad time to be driving.
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Old 05-07-2011, 09:57 AM
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Re: New transmission to have 9 speeds?

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Originally Posted by Milous View Post
New 6-speed will be the "65RFE".
Milous,

Do you know the individual gear ratios for the 65RFE compared to the 545RFE?
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Old 05-08-2011, 10:05 PM
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Re: New transmission to have 9 speeds?

I prefer CVT but I'm also crazy so nevermind
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Old 05-09-2011, 09:22 AM
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Re: New transmission to have 9 speeds?

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Originally Posted by Tony007 View Post
Milous,

Do you know the individual gear ratios for the 65RFE compared to the 545RFE?
Exactly the same as the 545. It's the same transmission. They're just counting the alternate 2nd in their marketing literature.
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  #23  
Old 10-04-2012, 08:22 AM
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Re: New transmission to have 9 speeds?

Chrysler has been known to be working on a nine-speed for some time and Hyundai, according to AutoGuide, is also working on a 10-speed. Aside from these two automakers, General Motors and Ford have also paired up to joint-develop nine- and 10-speed transmission. Other car makers are coming up with similar transmissions.



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