2015 Camaro SS - slight performance decrease

[moogle4u]

Hey everyone,

I wanted to do some baseline testing at the track yesterday for my stock car and decided to do a few passes with the built-in "Diablo" tune and actually saw a slight loss in top end.

Track conditions were clear, early evening, temperature ~55 and dropped to ~50 by my last pass, humidity ~20%, track is 253ft above sea level, and the track was solid and cars were running good.

I brought my stock 2015 Camaro SS - 2SS, Convertible, Auto, 3100 mi on the ticker - made no changes to the car and let the transmission shift on its own in the "sport" mode for consistency, TCS/Stabilitrack off (not in "competitive sport", fully turned off)

I had 1/2 tank of good ol' Sunoco, 93 Octane

I had no issues with traction, the p-zeros did a great job keeping the car hooked to the track and overall the car ran great!

First three passes were very consistent:
2.017/2.019/2.019 60ft
8.77/8.74/8.79 1/8mi
81.17/80.94/80.90 mph
13.55/13.52/13.61 1/4mi
102.81/101.79/101.93 mph

Passes were ~30 min apart, same lane

Installed the "Diablo" ECM tune and the "hard" TCM tune, left the track and drove ~50 miles and came back to make the next three passes (and put a few more gallons of Sunoco to get me back to 1/2 tank)

2.13/2.11/2.10 60ft
9.07/8.97/9.12 1/8mi
79.68/80.16/78.97 mph
13.91/13.79/xxxx 1/4mi
100.51/100.68/xxxx mph

(They went to 1/8mi on the last pass)

Passes were ~30 min apart, same lane as first 3 passes

Any thoughts on why the tune would be slightly slower?

Not an issue at all, I will be tuning it on the dyno once I install the engine mods, I just pulled the Diablo tuner out of my Silverado for curiosity.

On the fun side there were some disappointed EVO, Mustang, and Trans Am drivers that ended up on the line with me --- all the mods in the world don't help if you can't get off the line and be consistent!

[mikel]

Well, clearly the tune seemed to lead to a slight loss of traction, which doesnt help, but the MPH is down at the 1/8th and 1/4 mile, which is odd for sure.
My guess would be knock related, would be great top see a log of a pull on the tune and the stock tune.

[moogle4u]

Mike,

I have a log from one of the tuned passes, I didn't know if it would be much help or if I even did the logging correctly, I was trying to figure out how to start the logging process while in the staging lanes was not the best place to try, thus only one pass got logged.

-Fred