2012GT

Of course hot air depletes your car's power, but this past week it seems these hot days have taken a toll on the Stang's horsepower more so than other cars I've owned. I'm just wondering if there's something that I can do to improve flow towards my cai to minimize the heat that seems to be hurting my car pretty bad. Heat hasn't seemed to have such a negative effect on my other cars ( ls1, 347 stoker fox body).

karman

High ambient temps will hurt you no matter what.
You could try a hood like my white car has:

There is a direct flow to the CAI from the hood scoops.
http://www.stage3motorsports.com/pro...enom-Hood.html

Fat Boss

Massive loss of power on mine when it is hot outside. I'd say 50 hp.

Big Poppa

Yep, you will take a performance hit on very hot days. Unless you are willing to strap a swamp cooler to the front of your car not a whole lot you can do about it.

kn7671

I really don't think the heat ambient temp accounts for the power loss we are experiencing. I think overly cautious programming for high temps is the cause. When I tested turning the AC off the other day for a few minutes when it was 103F outside, the power seemed more normal, closer to how it feels first thing in the morning when the temps are in the upper 70's/low 80's when the AC is on.

I've owned 24-cars since I started driving in 1987, including 9-Mustangs, and I can only recall 2-cars that had an extremely noticeable power loss when the ambient tempertures were over 90+ with the AC on, one being my current 2011 Mustang 5.0, the other my 2004 Pontiac GTO 5.7L 6M.

While the above does point out that the power loss were experiencing is greater than what we should be experiencing with high outside ambient temps, it doesn't prove that anything is necessarily wrong with our Mustang's, only that its happening. Hearing from other people on other similar posts across several forums is that this may be normal for our new Mustang's.

2010MustangGT

Clearly researched.

karman

Just going by the Dynojet calculation for SAE, the difference between 50deg. and 70deg. on my Blue 2006 was 16HP (and that is not on these fancy new 5.0 engines). An even higher temp. would be even more of a loss. At 103deg., it would be even higher (theoretically it might even get close to 50HP ).

Modshack

kn7671

Basically the chart points out that a 200 bhp motor at 20C (68F) should only experience at 3.5% power drop at 40C (104F), dropping that 200 bhp motor to 193 bhp.

Apply that formula to our 5.0's, and at 104F ambient, should still be capable of producing 398 hp.

Almost all A/C compressors will consume more power than the higher external temps. I still say that Ford over cautiously programmed some safeguards in the computer with high temps and AC enabled. The throttle response feel becomes soft and lazy in response with these variables, so the computer must be delaying throttle input and decreasing timing to save the A/C compressor.

Modshack

Not really...Any power fall-off is strictly related to Intake Air Temps (IAT's). That sensor in your intake not only measures air flow but also temps so it can send appropriate date to the ECU. Hotter IAT's result in timing being pulled back. The Engne bay temp has very little if anything to do with power output, unless it is causing the IAT's to rise (heat soak).
Water temp is pretty tightly controlled at 190-205 degrees by the Thermostat and fans. Cycling the AC compressor on and off has no impact here.
The 2011+ design is very efficient at pulling in cool air from outside the bay to keep those IAT's as low as possible. Even my Steeda open element runs at ambient when moving because this air feed is so efficient.

Ethanjbeau

Who uses Celsius these days? Its so overrated

karman

You bring up an interesting point to the chart presented.
I know of no one that runs cars at 100deg. C.
How is that chart accurate.
Where did it come from?

RONINV8

my car feels like a 300hp car today. So hot!

AlsCobra

^^^ good one.

MRGTX

Whatever you're losing, the guy in the Camaro in the next lane is losing the same so it doesn't matter that much unless you're comparing hard acceleration data.

Fat Boss

As long as it's physics and not PCM limiting then that is true.

houtex

Good lord. At 40C it's 104F! I don't know many who are running beyond that... What a silly chart.

/I'm sure it meant 'F'...

fdjizm

Yup heat soak kills my car as well, I've run 13.2's in the summer, 12.8's in the fall with no changes lol

HoosierDaddy

I assumed the chart was for FI. It is possible to get 100 degree C (212 f) with enough boost. Of course if it is getting into the engine, you need to fire whoever engineered your inter-cooler.

karman

Then the question begs:
Is the chart intake manifold temp. or air filter intake temp.?
The OP was talking about CAI air temp., not intake manifold temp..