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2012 Charger Pursuit
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Discussion Starter #1
I don't personally spend any time at the drag strip trying to achieve the lowest Elapsed Time possible, but I know there are those of you that do. Further, I also know that some of y'all can spend an awful lot of time and money trying to drop a couple of tenths of a second off your E.T., and you do so with no guarantee the mod will actually do what it's supposed to - lower your car's E.T.

If you find yourself in this group of gear-heads then listen up, I am about to either inform you or remind you of something simple that you may not know (or may have forgot): the quicker your transmission shifts its gears, the lower your E.T. will be.

Before you roll your eyes and move onto the next thread, allow me to present a couple screen shots from a recent datalog to illustrate my point.

988433


988434


The two datalog screen shots pasted above show the engine RPM and throttle position during a recent WOT run in my car. (For <reasons> I actually had my TranZformer disabled during this run and the AutoStick mode was NOT engaged. So my transmission was commanding its shifts from its default mode/settings.) The areas circled in the screen shots are the points at which the shift either begins or ends and the corresponding time of that event.

If we take those times and do some fancy math on them, we get this:

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0.659 seconds, i.e. over 6 tenths of a second were spent shifting a gear there. With my TranZformer turned on and dialed in, it will complete that shift in about 0.3 seconds, or over 3 tenths of a second quicker!

And that is just one gear (2-3)! Imagine how long, cumulatively speaking, the average car spends shifting gears in a quarter mile run!!

Now, I will qualify this with the information that my transmission is the venerable NAG1 A5, not the newer and likely snappier-shifting ZF A8. So some of you who are interested in this topic are already ahead of the curve if your car is a 2015+ with the A8, as I understand their shifts are already quicker by default than the old A5s.

My point still stands though - if you want lower E.T.'s and have the ability to firm up your transmission shifts, you should do it, as there is definitely some time left on the table in many scenarios...possibly as much as 0.3 of a second per shift!

Please use this information for good instead of evil.
Nuke, OUT!!
 

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Boosted Stroked 2014 Shaker M6
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Pondering how your enlightenment could lead me to Nirvana with my Tremec. Now that I'm done pondering, I'll remain with the tried and true one hundred pounds equals one tenth of a second...
 

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2012 Charger Pursuit
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Discussion Starter #3
Pondering how your enlightenment could lead me to Nirvana with my Tremec. Now that I'm done pondering, I'll remain with the tried and true one hundred pounds equals one tenth of a second...
I would submit that the rule still applies!

Row those gears faster for a lower E.T., right?!?

Besides, isn’t a quicker shift the main reason for getting one of the Barton shifters installed a Challenger in place of the factory one?
 

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Boosted Stroked 2014 Shaker M6
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I would submit that the rule still applies!

Row those gears faster for a lower E.T., right?!?

Besides, isn’t a quicker shift the main reason for getting one of the Barton shifters installed a Challenger in place of the factory one?
You're exactly right.
 

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2018 Scat Pack Charger 11.995 first time out stock tune
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So on an A8....stock is about 4-6 tenths in duration, at best. Now modified I have seen the best of .200 with most being .240. If I could post the screen shots I would. So again that makes the quarter mile distance eat quicker too. Racing season soon. 2 cars in my so called team. Both running similar setups. No long tubes, for these 392 A8 models, but that too would allow "Flow" for the air pump better, ex quicker revving through the rpm range.

Both 392 equipment include an underdrive Slp/ Powerbond crankshaft pulley.
Tj
 

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So on an A8....stock is about 4-6 tenths in duration, at best. Now modified I have seen the best of .200 with most being .240. If I could post the screen shots I would. So again that makes the quarter mile distance eat quicker too. Racing season soon. 2 cars in my so called team. Both running similar setups. No long tubes, for these 392 A8 models, but that too would allow "Flow" for the air pump better, ex quicker revving through the rpm range.

Both 392 equipment include an underdrive Slp/ Powerbond crankshaft pulley.
Tj
Can't find my source but the shift speed of the A8 is much quicker than 4 to 6 tenths of a second. My memory is it is just under 3 tenths of a second.
 

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2016 Jazz Blue A8 Scat
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Or less.

Keep in mind that the vehicle is still moving forward during the shift and generally the clutches doing a "hand-off" during this time so even during the shift time, the vehicle speed is increasing. So while the shift may take upwards of 1/2 a second, the reduction in ET from the shift time is not actually the time it takes for the shift to complete.
 

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2018 Scat Pack Charger 11.995 first time out stock tune
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Plus the shift time shall all depend on "Tune"and which mode its in, ex. Track sport street.
 

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So on an A8....stock is about 4-6 tenths in duration, at best. Now modified I have seen the best of .200 with most being .240. If I could post the screen shots I would. So again that makes the quarter mile distance eat quicker too. Racing season soon. 2 cars in my so called team. Both running similar setups. No long tubes, for these 392 A8 models, but that too would allow "Flow" for the air pump better, ex quicker revving through the rpm range.

Both 392 equipment include an underdrive Slp/ Powerbond crankshaft pulley.
Tj
We had 2 of the fastest gen 2 5.7 hemi cars back in the day also.
 
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