Why the 6 speeds are slower than the auto (datalogging info too)

[neidan]

I realize the auto was a second / third shift verses the 1 to 2 on the manual, but it would be interesting to see the MPH graph slope on both from a dead start through say 90 mph. The auto is sure very very smooth at this point in the run...

Another interesting thing on the auto chart is we are monitoring throttle position which does not change, however I think the ECU actually cuts fuel for the shift....

Lots of good stuff toofart Thanks for the posting...

[Speedy!]

More good data toofart. Keep up the good work.

I still love shifting gears personally, even if a tad slower.

Could the ability to run the gear out longer compensate for the slower shift time and make this a wash?

[neidan]

when everting is figured out, and maximized, my guess wold be:
a) correct shift point will minimize the tendency for the car to slow between shifts. (inertia)

b) the shift times can likely be reduced with practice & or a different shifter.

c) power shifting will add tq going into the next gear and give some make up.

d) lower drive train loss will give some gains...

That siad a properly tuned automatic tx will likely gain much of the above back soooooo...

In the end it will require more of a driver to beat the auto, and with everything else being equal a properly tuned auto will have the edge...

[DETOUR]

Originally Posted by Hemi Orange

Not too surprising results. Nowadays, you just can't compare to the fast shifting and efficient five speed Mercedes autos that the Challenger comes with, especially with Predator tune. Mine shifts so hard it will throw the car sideways if I want it to.

Are you talking about "AutoStick" mode or just jamming the pedal to the floor?

[toofart]

Next time I'm at the track (and it doesn't suck bawls) I'll try a few runs powershifting to see the difference. The (relative) sloppiness stock shifter doesn't inspire me, though.

The moral of the story is that, unless you're shifting like this dude, the 6 speeds will always be behind the auto at the track.

YouTube - How to shift an 06 GT

I know the TR-6060 is a stout unit, but does anyone think it can take the abuse of powershifting at the track?

[neidan]

I've not had mine on the track yet... almost a 5 hr drive... BUT I there is an old runway not far from where I live and I've power shifted there (and a few other places) quite a bit. I haven't had issues with the TR-6060 yet. But I haven't missed a shift yet either...

As I say sometimes I do think I'll pull the shifter out by the way it feels....

Don't forget your going to spin up so you may need to adjust your shift point to avoid red-line...

I'm not totally satisfied with my shift points yet, and the ideal will change for every gear, but I shoot for 200 rpm before that to allow for my reaction time to hit it..

Good luck... If I get a good day I may run out to the airport and log just to see what mine look like... If so I'll post em up....

[Valley]

Shift speed is paramount in any racing but I believe you have overstated the impact upon your runs. The only ET loss due to "coasting" is the delta to how fast you would have been going if power had been reapplied sooner. For example, shifting slow from 1st to second costs more ET because you are coasting at a slower speed (and for a longer time in your example). Shifting slow from third to fourth costs much less ET as you are coasting faster at shift time and accelerating at a slower mph gain rate.

It's been 40 yrs since I was a weekend warrior but unless I've misinterpreted your logic don't count on reducing your ET via .4 sec with a little quicker technique.

Leave her wide open, bang her in second with confidence at your optimum RPM and use conservatism if need be for second to third !! I've missed third once out of I'd guess 40-50 occurrences and it was only due to a distraction (she has been told to watch only !). The second to third gate does work well. Practice will allow you to trust it and the faster you will go.

Valley

[brian70809]

An Auto is impossible to beat for consistency.. But there are some that can be that way with a manual..

Ronnie Sox was one of them.. Look him up.. He was a legendary Hemi racer... There are many articles written about his shifting ability.

Ronnie Sox Memorial Website

Click on the NHRA Article Link.. it talks about his shifting.

[raVenX]

Originally Posted by toofart

Why the 6 speeds are slower than the auto (datalogging info too)

Interesting data results. Thanx for posting it up.

Do you think some kind of short throw shifter with a shift gate would make for a faster shift if you knew you could slam it home into only one slot? Just curious. I know the Pantera we used to race had this, although we modified it a bit, and we were able to hit the mark rather fast. Here's a pic of an unmodified one on a Pantera with a rather tall shifter but you'll get the idea.

[neidan]

Speaking of short through my Hurst apparently shipped last night.... yea!!! I let you know what I think....