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Discussion Starter #1
Requires reprogramming for best result.
Too much torque management?
Shift points ideal?
Stall speed too low?
Can it be reprogrammed?
Downshift quickly?
etc.etc/

I ask because one would think the A8s should ET much quicker than the older autos.
 

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It is about 0.3-0.5 seconds faster depending on the driver from reading the threads
and magazines.
 

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2016 Hellcat
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Requires reprogramming for best result.
Too much torque management?
Shift points ideal?
Stall speed too low?
Can it be reprogrammed?
Downshift quickly?
etc.etc/

I ask because one would think the A8s should ET much quicker than the older autos.

The A8 is a beast and way better than the old past autos. The manual guys hate to admit it but these new autos have surpassed the manuals in performance now.
 

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Best automatic that I've ever owned.


Hooked up with a 392, and it's just real "street fighter". LOL Nothing more needed IMO.
 

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2015 Dodge Challenger R/T Scat Pack
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Best automatic trans I've ever driven. In Sport Mode on the Scat Pack it is perfect. Upshifts, downshifts, etc. You can't beat it at the track. I loved my old M6 R/T but this new A8 is a monster. It's a total beast at the track.

As far as I know there is no TCM programming available yet. You can reduce torque management via a canned or custom tune. You can also buy a Tazer to unlock SRT features in a Scat Pack to utilize Track Mode which shifts even harder/faster than Sport mode (I average about .1 off my 0-60 time compared to Sport Mode).

The new Scat Packs seem to be at least a few tenths quicker than the older SRT's and SRT Cores (maybe more). Part of that is due to the 15hp gain over the prior 392 but the A8 trans likely has a lot to do with that.
 

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381 Posts
The new A8 with 1st gear being 4.71 is putting out more torque to the wheels than the old NAG1 5 speed with 3.92 rear gears!! That is some torque these new 8 speeds are putting out and explains why there is a 0.4 second difference in the 0-60 as reported by C&D.

Not taking any loss into account. Torque to the wheels is transmission ratio X engine torque X the rear end ratio

The A8: 4.71 (1st gear) x 400 (Torque) x 3.09 (Rear gear ratio) = 5821

The old Nag1 with 3.92 rear: 3.59 x 400 x 3.92 = 5629

Every other gear is also putting out more torque than the old 5 speed with a 3.92 rear end.

IMO this is the reason many car magazine writers are stating that the scat pack and SRT feels almost as good as the Hellcat at lower speeds.
 

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The A8 is measurably faster, but where it's much faster is in 1/4 to 1/2 throttle acceleration. It makes torque almost accidently, like a turbo diesel truck. Really fun to drive around.
 

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I just want to throw my thoughts in here. I'm a manual guy, I love my TR-6060 and I haven't owned an 8 speed auto...BUT...I work a dealership, I've driven the 8 speed in pretty much every Dodge/Chrysler/Jeep/Ram in all it's variations (Not getting into the BMWs and Bentleys that also use a ZF box). I have to say that it works great across the board. Even in a truck it seems to be in the right gear all the time. I believe Dodge has programmed this transmission very well, to the point where it doesn't detract from an enjoyable driving experience. We've sold a ton of them, mostly in trucks and Jeeps, and they've been rock solid. Only seen one fail, which was a just an isolated fluke. They have an excellent track record and they're built to work.

My verdict: Excellent
 

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Requires reprogramming for best result.
Too much torque management?
Shift points ideal?
Stall speed too low?
Can it be reprogrammed?
Downshift quickly?
etc.etc/

I ask because one would think the A8s should ET much quicker than the older autos.
The A8 is a ZF design licensed to FCA and built in Kokomo, IN.
 

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2015 Dodge Challenger R/T Scat Pack
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Yep, that super steep first gear in the A8 helps get this big tanks moving quick off the line. I've hit 1.69 60ft time before at the track on the stock tune with essentially just drag radials and a couple other minor mods. That's insane considering the car weighs probably 4300lbs with me in it and it's basically stock with sticky tires. When you kick it down from a roll the car just pins you back and you're gone!

The M6 is a great trans as well, but a completely different experience. Any stick shift car you'll feel more connected to the car and more involved in the driving experience simply because you are. But this automatic is not your typical mushy slushbox trans, it flat out rips!
 

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I will be putting in a 4k stall in my a8 this winter from paramount. Here is a little more A8 info for you as well from paramount.

Paramount ZF8HP trans.
Bought a 2015 SRT8 Jeep and outfitted the 8 speed trans with our Racepak hooked up (drilled and tapped the case and valve body)to all the clutch packs, converter and lockup clutches to give our 8 speed customers a premium product that will shift correctly and not burn up under increased power.
What we have achieved as seen in the attached Data log is a ZF8HP trans (70 or 90 series) that I have modified the valve body to achieve a quicker shift (eliminate the large "stair step" that occurs during your WOT shift). In "auto mode" the trans still shifts very calmly, but in "Sport" or "Track" mode at WOT HOLD ON! Damn thing shifts RIGHT NOW:) You can see also where I raised the clutch pressure once it is in gear, again to help the clutch life. No check engine light or codes thrown.
Pretty happy with the mods.
We now also have the ability to program a TCM (located on the valve body) to your VIN so we can send a ZF8HP off the shelf to you and you don't need to take it to a dealer and have them program the TCM.
Next project is the TCM. My 1st goal is to turn off the Torque Limit in the TCM which you can see with your WiTech or Snap on scanner. Hitting the Torque limit results in the timing being reduced to -12 degrees and if that is not enough, it will close your throttle.
2nd goal will be to raise the shift points, we are leaving a TON of power on the table. I feel the tuner suppliers are not giving much priority to helping us Mopar guys with any TCM support. Yeah, I hear about Beta testing from tuner suppliers....we can't wait!!!!!!
 

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Even though my car didn't perform that well at the track the 8 spd operation was a high point. Quick shifts, smooth and the fuel economy benefit is a plus. I have taken one of these units apart and reassembled it and I can see why they are so tough; clutch to clutch shifts(no bands), high pinion planateries and large diameter clutch discs and plates. The TCM is part of the valvebody and not separate so the whole valve body must be changed if there is a failure here. The HP90 in the Hellcat is essentially a mildly beefed up version of the HP70 in the 5.7/6.4 cars to say something of the strength of these transmissions. Light years ahead of the old 3 speeds.
 

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Even though my car didn't perform that well at the track the 8 spd operation was a high point. Quick shifts, smooth and the fuel economy benefit is a plus. I have taken one of these units apart and reassembled it and I can see why they are so tough; clutch to clutch shifts(no bands), high pinion planateries and large diameter clutch discs and plates. The TCM is part of the valvebody and not separate so the whole valve body must be changed if there is a failure here. The HP90 in the Hellcat is essentially a mildly beefed up version of the HP70 in the 5.7/6.4 cars to say something of the strength of these transmissions. Light years ahead of the old 3 speeds.
Too bad they are computer controlled sounds like they would be awesome behind an old 426 or 440 or even a built Small block with a reworked tunnel in an old Retro Rod.
 

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Too bad they are computer controlled sounds like they would be awesome behind an old 426 or 440 or even a built Small block with a reworked tunnel in an old Retro Rod.
Frank, that could happen with a stand alone controller that would operate the TCM. Dimensionally and weight wise this transmission could be swapped. The transmission is 198lbs and is amazingly compact considering you have 8 spds. The issue is just having a way to control it in an old carb vehicle.
 

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Frank, that could happen with a stand alone controller that would operate the TCM. Dimensionally and weight wise this transmission could be swapped. The transmission is 198lbs and is amazingly compact considering you have 8 spds. The issue is just having a way to control it in an old carb vehicle.
Hmmm just had an idea. Re-body an old B Body onto my R/T, let the bank repo the left over parts :D Joke....
 

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The new A8 with 1st gear being 4.71 is putting out more torque to the wheels than the old NAG1 5 speed with 3.92 rear gears!! That is some torque these new 8 speeds are putting out and explains why there is a 0.4 second difference in the 0-60 as reported by C&D.

Not taking any loss into account. Torque to the wheels is transmission ratio X engine torque X the rear end ratio

The A8: 4.71 (1st gear) x 400 (Torque) x 3.09 (Rear gear ratio) = 5821

The old Nag1 with 3.92 rear: 3.59 x 400 x 3.92 = 5629

Every other gear is also putting out more torque than the old 5 speed with a 3.92 rear end.

IMO this is the reason many car magazine writers are stating that the scat pack and SRT feels almost as good as the Hellcat at lower speeds.
The M6 has the 3.92 rear gear, the A5 has the 3.09.
 
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