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Hi everyone, my first thread, hope you all find it a good one.

Seems that Dodge plan to hook an 8 speed auto into the 2012 Challenger. Apart from getting better fuel economy is this a good move? With such a flat torque band on the 392 I'm interested to hear if folks think that an 8-speed is needed. The more gears you have the more the computer will change gear and in some cases change multiple times to find the optimal one. Plus the time loss between gear changes.
When I test drove the 6 speed auto Camaro, when you came out of a turn and floored it on the exit the tranny took a few attempts to find the right gear, then a second later was the slam in the back when it dropped it into 2nd from 5th. Was horrible. Will an 8 speed be worse with closer ratios?
 

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The 8 speed is only mating with the V6 for the moment (2012).
 

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That will probably the most effective place for it, unless we are to see hemi's with 7000/8000/9000 rpm redlines anytime soon.
 

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I think the new 8speed will be awesome. We could see better acceleration and better gas mileage
 

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I think you'll find that even if it did come to the v-8's and could handle the torque, that the 5-speed would still dominate at the track...someone correct me if I'm wrong.
 

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All things being equal an 8 speed would keep the engine in the meat of the power curve better, as long as the shifts are fast. I would still want Autostick with the 8 spd.
 

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That is only effective if it can be substantiated that the engine could not keep in the meat of the power curve, in the first place, with the 5-spd. If there was already enough gears to do so, then adding more is just splitting down the fine hairs.
 

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It's following some pretty big footprints............the "MB" 5speed is a TANK in about every way.

Seems like you can beat them to death with a Hemi, but can't hardly kill them!

I guess time will tell.
 

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Ok, I don't mean to sound dumb. Can someone give me a quick class on why an 8 speed transmission would be better? Faster?
 

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Near as I can tell, a higher number of gears makes people feel better about their purchase (keeping up with the Jones' mentality).
 

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Near as I can tell, a higher number of gears makes people feel better about their purchase (keeping up with the Jones' mentality).
What is it about too much seeming just like enough?

 

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I think it's more on the lines that with 8 gears you can have lower gearing than what the 5speed does on it's first 4gears (giving better acceleration, kinda like having 3.73s put in an auto instead of the 3.06s)..then for last few gears, you can have taller gears to keep the rpms down on the highway in hopes of getting better mileage.
or atleast that's the way I see it. It's not like you'd go through all 8 gears in a 1/4mile anyway
 

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I wouldn't be expecting the 8spd to be quicker in the quarter mile, i'm pretty positive it is designed to increase fuel mileage on the highway so that it can compete with some of the other cars in fuel efficiency. More than likely it will act more like a 5spd with a couple overdrive gears.
 

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My wife's Enclave has a 6 speed automatic and the thing is constantly shifting up and down trying to find the right gear. Granted it is a smooth shift and is hardly noticeable but it is still there. I cannot imagine how much a 8 speed would hunt for a gear during normal city or country driving (rolling hills). To get to my parents house we need to go up a long hill and the Enclave is always shifting to keep the speed. The Challenger never changes gear on the hill. If my Challenger had the same transmission I would be in the hospital with a broken neck from the whiplash of downshifting when making small speed increases. The only good thing I can see and 8 speed for is highway driving where you are at a set speed for long periods of time.

I wonder how that would affect the MDS - would the engine keep adding and dropping cylinders with the RPM changes?
 

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A really interesting tranmission to look at is a CVT.
CVTs come in many cars today and have No set "gears". If you have ever driven on of these, you will notice that they keep the rpms at about max torque rpm as the car speeds up, then once you reach you desired speed, it drops the rpm down to get max mpgs.

Some people do not like the sound of this and then select a mode on the transmission that makes it feel like it has 6 speeds by selecting 6 predetirmined ratios.

Here is a better explanation:

Continuously variable transmission - Wikipedia, the free encyclopedia


So far no one has developed a CVT that can handle large amounts of torque. Ferrari started working on one but I think they gave up.
 

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Ok, I don't mean to sound dumb. Can someone give me a quick class on why an 8 speed transmission would be better? Faster?
It's all about keeping rpms in the most optimal, narrow, portion of the power band. Ever hear an F1 car screaming through the 7 gears? Barely any drop off between gears, it stay pegged in its most optimal power band.

Also, having 8 gears, the last couple can be dedicated to an "overdrive" of sorts, maximizing fuel economy while cruising. The best of both worlds so to speak. However, most old school drag racers with big v8s only want a few gears, in theory the result is a stronger transmission with less moving parts. Like the old powerglide 2 speed, lol. Not sure if that is still a relevant concern...

But I doubt a hemi with the 8 speed will accelerate down the 1/4 much quicker than the 5 speed. The torque curve is pretty broad. Might be a different story on a smaller, peakier engine.
 

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I think that is a poignant example to bring up...that the day we are running around with engines tuned to the very edge like an F1 car is the day that 7-gear transmissions will actually make engineering sense, rather than just catering to "marketing sense".

The 6-spd manual is already at the limit for justification of gear numbers. It's got not only 1 but 2 overdrive gears, rather than even bothering with taking the obvious performance perk of utilizing a default 5-gear spread for gear reduction. Clearly the engineers thought that 4-gears was quite sufficient to do the job of leveraging the hemi when taken to the dragstrip.
 
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