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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter #1
For those of you with the 8 speed auto and Pentastar combo, when you execute a 0-60 mph run in your car:

1. What gear is the trans in when the car gets to 60 mph?
(I am assuming 3rd gear, is that correct?)

2. Which rear-end does your car have?
(Should either be 2.65 or 3.06, with regular SXTs having 2.65 and Plus, etc. having 3.06 IIRC.)

3a. Do you have a DiabloSport tuner?

3b. If so, could you datalog a 0-60 run and post it up or PM it to me?
(I'm only interested in the Engine Speed/RPM PID BTW)

Many thanks,
nuke
 

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2016 SXT Plus Blacktop
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3rd gear yes. 3.07 Rear gear. No Diablo ;) Best recorder 5.9

A Guy
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter #3
Breakin' the Law, Breaking' the Law...

3rd gear yes. 3.07 Rear gear. No Diablo ;) Best recorder 5.9

A Guy
Most interesting...5.9 seconds with 2 shifts...I do wish you could datalog one of those runs, I am very curious to know long it takes the A8 to actually shift a gear.

Unmolested, the NAG1 (A5) can take right at 0.5 seconds to shift a gear. Which means with you can molest them with something like the TranZformer or a set of blue-tops to get the shifts down to around 0.2 seconds, and BAM, you just shaved 0.3 seconds off your 0-60 time, assuming a one-shift(1st to 2nd) 0-60 run. :eek:hyeah:

I'm guessing the A8s probably tightened up their shifts, so I doubt they take 0.5 seconds, but what if they still took 0.35-0.40 seconds. Assuming you could find something like the TranZformer to firm those puppies up to around 0.2 seconds...times 2, that'd knock 0.3 - 0.4 seconds off the top and get you down to 5.5 or 5.6 seconds for the 0-60 mph runs without breaking a sweat. :icon_biggrin:

But let us not forget, doing 0-anything with a 2.xx rear-end and less than 300 ft/lb of TQ is a fool's errand. That's not where the car should be, nor where it wants to be!

Where it wants to be...where it thrives..where it's funner'n a sack full of monkeys to drive is much higher up in the RPM spectrum. Think 35-105 mph runs, or even better, how about a 40-120 mph run?!?! :redblob:

Although, I gotta say, make sure you've taken your nitro glycerin pill if you've got a bad ticker, because you never know when you'll crest a hill, see some flashing red & blues (~0:53), assume they're waiting for you, and have a full on heart attack!!


Luckily, they were after a completely different outlaw tonight >:)
 

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Super Moderator
2016 SXT Plus Blacktop
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Not great videos, but these were 6.1 runs, hard to concentrate on 0-60 when your holding an iPad to record. Give you some idea on timing, 1st video I tried to video instruments



A Guy
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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6,180 Posts
Discussion Starter #5
Not great videos, but these were 6.1 runs, hard to concentrate on 0-60 when your holding an iPad to record. Give you some idea on timing, 1st video I tried to video instruments

IMG 2920 - YouTube

IMG 2921 - YouTube

A Guy
Damn those A8s do wind that Pentastar up quick...I wish I would have had one with my Pentastar :crying:

So how do you have the trans during your 0-60 runs, in regular Drive?

Try it in Auto-Stick 1st gear and let the auto-upshift shift the gears when you get to redline. There may not be much difference, but I know in my A5 with the 2.65 rear-end, it was good for an extra 0.1 or so during a 0-60 run.

Also, depending on how the lock-up does with the A8s converter, you might be able to knock a tenth of a second off by power braking the car right up to it breaking loose on you (was approximately 2100 RPMs in my A5) to try to get a better launch. The NAG1's lockup was such that it would dump RPMs as soon as you let off the brake, so that wasn't good for my Pentastar. But the A8 might be different, definitely worth a try!
 

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2016 SXT Plus Blacktop
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That's sports mode, traction control off. Left foot on brake, mash gas pedal while releasing brake at same time. I have tried power braking, but it will spin the rear wheel(s), and that slows it down. Never tried autostick. You say if you put it in 1st and just floor it, it will still upshift itself?

A Guy
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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6,180 Posts
Discussion Starter #7
That's sports mode, traction control off. Left foot on brake, mash gas pedal while releasing brake at same time. I have tried power braking, but it will spin the rear wheel(s), and that slows it down. Never tried autostick. You say if you put it in 1st and just floor it, it will still upshift itself?

A Guy
Yep, auto-stick will automatically upshift at redline (or whatever RPM it is programmed to, which in stock form is redline for the engine) if you do not manually command a shift yourself.

Seeing as the Pentastar makes its max HP at redline, getting to it means you're pumping out as much GO as you possibly can. But leaving it in Drive won't always wait until redline to shift...sometimes it does, but sometimes it does not. Leaving it in Auto-Stick will guarantee it will.

Keep in mind, it will only auto-upshift if you hit redline...so if you're doing a 0-60 run, it'll shift for you twice, but then when you hit 60 and let off the gas, it will just stay in 3rd gear, all wound up and such. You'll have to either shift it yourself into 4th or disengage Auto-Stick by holding it for 2 seconds when you're past 60mph
 

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Premium Member
The Bacon Hauler (‘12 Cop Charger)
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6,180 Posts
Discussion Starter #9
Or paddle shift it? The A8 paddles are very responsive.
You'd have little chance of shifting at the right time though, most likely you would shift too early. The Pentastar makes max HP at red line and that's coincidently when the autoupshift is programmed to take place, so shifting before that would mean losing out on some power.
 
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