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Discussion Starter #1 (Edited)
I thought I'd do a few runs pre/post Predator tune to see what kind of difference there was. The car is a 2006 Charger SRT8, just a Mopar CAI and a 180 'stat. Runs were done on a flat deserted area near the bay, in both directions to negate possible slope or windage. Full tank of gas for each set. In short, as well-controlled as I could make it. The GTech measures acceleration in multiple axes; it has been tested to be quite accurate when compared to the traps at the track. Using this device, 0-60 times will suffer if there's wheelspin... unlike the EVIC timer.

I ran seven times under each tune and analyzed the data using GTech PASS RR 2.0 software, with a 12" rollout as per Road & Track and Car & Driver. I tried a variety of launch RPMs on brakestands, with ESP "single press" disabled. Below are the three best 0-60 times for each tune:

Stock tune:
4.889 sec
5.121 sec
4.974 sec
Average: 4.99 sec

Predator 91 CAI tune:
4.778 sec
4.823 sec
4.802 sec
Average: 4.80 sec

I think the data are pretty tight, and I'd say dropping 0.2 sec is both reasonable and worthwhile. I'm working with a friend that has a dyno to see if he will add the Mopar CMR software to his license from Diablosport... if so, we will do a custom tune and see if anything better can be achieved on this (mostly) stock car.

As previously mentioned, the Predator tune is making the car quicker at the 1-2 shift. Check out the HP in this plot:



You can see the 1-2 shift very clearly; the red and black traces are from the Predator runs, while the green and blue are from stock runs. The Gtech computes the HP from actual vehicle weight (input by driver) and g-forces measured. Rolling resistance and aerodynamic drag cause this number to be lower than that seen on a dyno.

So there you have it.
 

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GREAT WORK

Convinced me to go get both
 

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excellent data, thanks for posting the facts. the only thing missing was weather, but it never changes there anyway, right :D
 

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Discussion Starter #4
I'm curious as to what's happening with the Predator tune from 0.1 to 1.0 sec, and with both tunes at about 1.2 sec.

Unfortunately, the GTech will not capture RPMs on these cars, so I can't analyze TQ or plot vs. RPM. Still useful, though.
 

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Nice job........I still wonder about the mid 3 sec claims with the EVIC timer........I should be getting my Gtech soon....good work!!!!
 

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Discussion Starter #6 (Edited)
Just to update: I thought you guys might like to see the gTech results now that the car has a custom CMR tune. I used the same testing method as before, same location, weather was almost identical (hey, it's California, after all).

Best three runs:
4.695
4.644
4.697

Stats: Average 4.679, StdDev 0.03

So it drops another tenth, at least. Here's the power graph (blue trace is the canned Predator 91/CAI tune):



Thanks to Ravi @ Speed Freaks in Tracy, CA... his Mustang dyno showed more power and it translates to a quicker car out on the real pavement. More importantly, AFR is now happy across the entire rpm band at WOT.
 

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Great work, and thanks for the useful info!
Question; I noticed in the colored boxes above the graphs it says the shift points are set at 5900? Is that correct? If so, I thought SRTs shifted at 6200 stock, and 6400 when using the Predators "raised shift points" option?
Also, what were your settings with the "91 Oct CAI" tune? Anything cheanged?
Lastly, could you give more "before and after" detail (unless it's in another thread I missed) about you tune/dyno session?
Thanks again.
 

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Discussion Starter #8
The shift points shown in the colored boxes are from the gTech itself; the unit allows you to set a shiftlight feature to any desired rpm. The car itself shifts at 6400 in the CMR tune.

The "91 Oct CAI" tune is one of the standard canned tunes supplied with the Predator.

And here is the thread for the CMR tuning session:

http://www.chargerforums.com/forums/showthread.php?t=73045
 
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