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Discussion Starter #1 (Edited)
Track times - RT Predator vs. Stock Tunes

Here are the results of my comparison between the DS Predator 91 oct tune and a DS modified stock tune. My car is a 2009 RT with Corsa catbacks, DS Predator tune, catch can and CAI. Michelin Pilot 255/55/18s on rear, stock 18s on front. I am a beginner at this racing thing (obviously)

These time slips are from 15 April of this year at Firebird Raceway, Chandler, AZ. Elevation is 1243 ft above sea level. I ran 10 runs: 5 with a modified stock tune and 5 with the 91 oct CAI canned tune (9r28 crom). Modified stock tune had fans set for Jet 180 t-stat, firmer shifting, MDS off, throttle control set at "0". Engine temps prior to each run were approx 190-194 degrees, outdoor temp around 70-80 degrees. First run was at 6:11 pm, last at 9:52 pm. Car has never broken 100 mph with DS 91 oct tune.

Modified Stock:



91 oct CAI tune:



I've also attached a link to my times from a week previous, racing my wife in her 2010 GT. Wife drove a 2010 GT Premium with CAI (built in) and DS Predator. She's in car 270, I'm in 271. She's new at this too.
http://www.challengertalk.com/forums/f37/took-rt-track-1st-time-not-happy-55862/

All runs were with trac control OFF and I reduced the rear tire pressure to 28 psi. We only get 91 oct gas around here and I've been told octane booster isn't so great for your car, so I simply use the 91 tune/gas. I did find that the tires (street) hooked up better at 28 psi than the previous week at 36 psi.

Launching: I quit power braking and raising the rpm's. While this may work with slicks or drag radials, it does not with street tires. Instead, I simply went straight from the brake to the accelerator and tried not to floor it so quickly. I "rapidly" eased into it so to speak. I drove around the water and not through it (quit doing the burnouts).

I also learned (for me) to stage (stop) right when the 2nd staging light came on. When the countdown began, I would release the brake and begin accelerating when the 2nd yellow came on (I figured that out on my last two runs - see the R/T times drop).

In all honesty, I believe that by applying what I've learned to driving the GT, the GT will be the consistently faster car.
 

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Discussion Starter #2
All: I'm a bit surprised at the lack of comments on this thread as I believe the majority of members here use the Predator. Granted, the time/speed results are not earth shattering, however, to make it a little easier to get the point of the time slips is this: I averaged the times and speeds of my runs with the DS 91 oct tune vs those of the modified stock tune. I had 9 runs using the 91 oct tune (over 2 different days) and 5 runs (one day) using the modified stock tune. I cooled the engine to somewhere between 190-194 degrees between runs. All Predator settings for each tune were the same - fan settings, firmer shifting, MDS off, tire sizes, etc.


The thing that really shocked me was the difference in performance between the two:

DS 91 oct tune speed/time average: 96.17 mph @ 14.55 secs (9 runs)

DS modified stock tune speed/time average: 100.26 mph @ 14.23 secs (5 runs)

The modified stock tune was 4.9 mph and .32 secs faster on average!

For those interested in approx DA info: Density Altitude: 3089 feet, Relative Density: 91.27 %

Again, I'm not trying to bash the DS Predator - it's a great tool. I did however expect to get better results using the 91 oct tune and frankly, I'm surprised. I realize these are not a lot of runs to make judgements, however, there are enough to see there is a substantial difference. While I'm going to continue with this little experiment, I would appreciate it if anyone can shed some light on these results!
 

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Well it looks like the tune did on the whole, improve your 60' times... top end of the track... not so much.
I'll be watching this thread to see if anyone can shed some light on the results of the 2nd 1/8th mile, and especially the last 320'
You would think it should have been a tad cooler at 9pm too.
 

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Ok I have a 100% stock RT. My Buddy has more or less what you have with the Predator tune. Our cars are both 6 speeds; he can't catch me.

No 1/4 runs, no time slips, no BS, fat-out can't catch me, I pull on him from the start and he's behind me the entire time. Perhaps its driver who knows, next time we'll switch cars see how it goes.
 

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since you adjusted the predator so for the stock tune did you make the same adjustments in the canned tunes? i have seen the HP inmrovment on the dyno with my car.. mostly in the middle range on my 93 tune.. I have also heard guys getting better results on the 91 than the 93...

Truthfully a lot of us diablo guys have a custom tune.. It will make a world of difference on the track over the stock or the canned tune
 

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Discussion Starter #6
since you adjusted the predator so for the stock tune did you make the same adjustments in the canned tunes? i have seen the HP inmrovment on the dyno with my car.. mostly in the middle range on my 93 tune.. I have also heard guys getting better results on the 91 than the 93...

Truthfully a lot of us diablo guys have a custom tune.. It will make a world of difference on the track over the stock or the canned tune
All the setting were the same for both tunes. I've been looking into a custom tune myself.
 

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are you auto or speed , the 6 speeds get almost nothing out of a predator as far as i have read here, i have an auto and the very first stock 1/4 ever was a 14.1 @104.1 mph. going to the track this month and expect 13.5 with the pred, some stock cars do that now. maybe better.
ps 14.xx with a pred stinks.

watch out hemiwoman can almost hit those numbers with her SE. just sayin.
 

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I went to the track a few weeks ago and did the same thing. Guess what, the car ran the same times no matter what tune was in the car. Mine is bone stock. I was running 13.20's @ 105 with ALL THE TUNES. Nothing changed. The car drives better and shifts better with the Diablo tunes but it was not any faster. Mine is an Auto car by the way. The Predator has been off of the car ever since. Ill let it collect dust for a while until I figure out what Im gonna do.
 

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Discussion Starter #10
are you auto or speed , the 6 speeds get almost nothing out of a predator as far as i have read here, i have an auto and the very first stock 1/4 ever was a 14.1 @104.1 mph. going to the track this month and expect 13.5 with the pred, some stock cars do that now. maybe better.
ps 14.xx with a pred stinks.

watch out hemiwoman can almost hit those numbers with her SE. just sayin.
I have an auto and yes, I know a 14.xx with a pred stinks. A 14.xx without a pred stinks just as bad. What's your point?
 

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Discussion Starter #11
The only good tune is a custom CMR software dyno tune.canned tunes are just guessing games
Seems so. I guess I expected the times to at least remain the same.
 
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