Just bought a new 09 Jeep SRT8 a few months ago and I have noticed a major loss in performance over the last few months. As I drive mostly on the streets my 0-60 times have gone from 4.8 seconds when I first bought it (3 months ago) to 5.4 seconds now. Just wondering if anyone else here in Phoenix also noticed the same drop in performance or if its just me. The dealer blamed the heat, but I don't know how much it would effect it.

Just bought a Volant CAI to help a little bit and a predator to make some adjustments.

The heat does alot put the volant on and get a 180 tsat and with the predator u lower the fan settings

You have to remember that altitude will effect times. Heat is bad but low humidity is good. When you get the preditor and pick a canned tune watch out on the adjustments you make in the timing and fule curve as it will affect the a/f. Heat,humidity and pressure will all change the altitude up or down.

I live in Phoenix and a performance drop due to our summer temperatures is definitely noticeable. Plus the past few weeks have been above 110F which is miserably hot. Keep in mind, all cars will be affected so you should still be able to kick most cars in the butt.
Regards,
Ed

It's called heat soak and for that reason I can't wait until winter!

you should see how these things perform up here when it's -50C. We call it the super cold air mod!!!

I bought my 09 in April. It was running 4.3s 0-60 mph and now is at 4.7s according to the in dash timer. Heat definetly affects the performance, so I just went to a 180 F thermostat to help a little. I was running up over 230 F after a couple red light races. Still running hot, but I'm maxing at 215 F now. My tires have a little more give to them now and chirp pretty good now off the line which is worth a tenth or so. Watch your digital temp gauge and try a few runs at different temps to see if that's it.

I slowed down .06 hunderdths and 1/2 mph going from 1475 ft to 2489 ft so its not really that bad IN 1000 FT but more than 1000ft it gets worse. The humidity hurts my jeep more than the heat but i never raced in that 110 degree heat either. THE DIFF IN THIS ALTITUDE AND WHAT I RAN AT 2489 FT, I WOULD OF LOST .63 HUNDREDTHS AND 5.5 MPH. So this will give you a little idea on heat and humidity on how it will affect your times. Heres the readings at SPEEDWORLD RACEWAY IN AZ LAST NITE AT ITS HOTTEST TEMP.

Based on: 7/25/09 5:29PM
Temp: 106.1°
Humidity: 22%
Track Altitude: 1600 feet
Pressure: 29.70 in.
Density Altitude = 5350 feet (NOTE THIS DA ALTITUDE LOL)
Uncorrected N/A @ N/A
Corrected 0 @ 0

Living in Saudi Arabia, I can tell you the differences in temps is huge. The lowest temps I have drag raced or Auto X'd was in the 80's. I can't give you the time difference other than 80* and at 105*. At 80* my average 1/4 mile is 13.2secs. At 105* the average is 13.7 secs.

Altitude+heat= no bueno.

Winter time+vacation in California= increased 0-60 times and an excuse to hang with the guys out here in Cali...

I'm just sayin'.

I just got back from a trip to Monterey, CA, where it never gets hotter than 75* - back in AZ...in this heat, I can definately notice a difference as well. I'd suggest the 180* t-stat + Predator as well, but be careful with the adjustments!