poor results at the 1/4... does this seem right?

My dad and I went to KCIR and ran the 1/4 mile the other night. He brought his 06 GT and I brought my 88 2.3l.

It was a quite hot day, around 90F and the track is at 800ft elevation. Using an online calculator, the alititude density was ~3500ft.

The car is an 06 mustang GT, automatic, with less than 15K miles. The only major change is GT500 wheels and tires, which I can imagine are a little heavier. His best run was a 14.649 at 95.05 mph. This seems WELL short of what one would expect since magazines have tested stock GTs to as quick as 13.6@102mph. His 60' times were around 2.2s, which seems a bit sad too.

Shouldn't the car be a lot faster than this, even in hot conditons? Even if you correct the 3500ft altidude density to sea level using NHRA correction factors, it's still only 14.02@99mph. He had absolutely no wheel spin. Does the stock wheel/tire combo allow a bit of wheel spin to get the rpms up faster? The traction control and AC were off. He would stomp it from the line and get no wheel spin at all.


Bottom line: is this right or is something terribly wrong? Do these car's really roll over dead like this in hot conditions?

On a good note, I improved my best times a lot, running 13.73@99mph with a 4cyl in the heat. hehehe

cowtown said:

We'd need to know more about the runs too. I found my best times were always with OD off and running the car up against the stall converter has mentioned above, easily a tenth or more just in the launch.

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At first, he was just stomping the gas on the 3rd yellow. He later tried reving the engine against the torque converter, but I'm not sure how much, probably just enough to get the rpms up instead of loading the driveline hard. I'd guess he left the OD on and of course let the transmission do the shifting.

ski said:

Another thing to be aware of with these cars is the stock tune pulls timing when the ambient air temperature gets hot in order to prevent pinging.

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I was wondering about this, but really 30hp worth of timing?! The other thing I was wondering... does it have a knock sensor? Maybe it was detecting knock and pulling timing, but I would think the runs wouldn't be so consistent then.


He bought the 'power pack', but didn't install it yet. Obviously, if it is down 30hp, then we should figure that out before putting on mods I would think.

ski said:

It's not 30 hp worth of timing, but when combined with a lesser amount of oxygen per cubic foot of inlet air at higher ambient temperatures(and at high relative humidity levels), then the engine's power output will be noticeably reduced.
The engine has 2 knock sensors. However, it's the MAF sensor that detects the ambient air temperature, and sends a signal to the ECM, which then pulls timing if the ambient air temperature exceeds a specific level. This happens before any pinging occurs.
Also, a hot engine compartment will slow down these cars for the same reason. Did your Dad open the hood and turn off the engine for at least 15-20 min before each race?

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Nope, he left the hood down the whole night. You really gain that much from opening the hood and letting the engine compartment cool down? I thought these cars sucked in air from the inner fenders instead of from underhood from the factory? Sounds like next time, there are a lot of little tricks to do, and combined with cooler temperatures should produce the expected results. On searching, it still seems a lot of people are getting only 2.2 60' times... I figured these cars would do 2.0s from the factory.