2010-2014 Mustang Information on The S197 {GenII}

do hot days hurt your car's power alot?

Thread Tools
 
Search this Thread
 
Old 7/2/11 | 09:14 PM
  #1  
2012GT's Avatar
Thread Starter
Cobra Member
 
Joined: February 18, 2011
Posts: 1,019
Likes: 0
From: South Carolina
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).
Old 7/2/11 | 10:10 PM
  #2  
karman's Avatar
Tasca Super Boss 429 Member
 
Joined: January 4, 2006
Posts: 3,907
Likes: 31
Cool

High ambient temps will hurt you no matter what.
You could try a hood like my white car has:
do hot days hurt your car's power alot?-chinpixs001largee-mailview.jpg
There is a direct flow to the CAI from the hood scoops.
http://www.stage3motorsports.com/pro...enom-Hood.html

Last edited by karman; 7/2/11 at 10:15 PM.
Old 7/3/11 | 12:31 AM
  #3  
Fat Boss's Avatar
Mach 1 Member
 
Joined: April 8, 2011
Posts: 621
Likes: 0
From: An hour from Laguna Seca
Massive loss of power on mine when it is hot outside. I'd say 50 hp.
Old 7/3/11 | 05:34 AM
  #4  
Big Poppa's Avatar
Team Mustang Source
 
Joined: May 25, 2005
Posts: 1,267
Likes: 0
From: Skopje, Macedonia
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.
Old 7/3/11 | 06:00 AM
  #5  
kn7671's Avatar
Mach 1 Member
 
Joined: July 26, 2004
Posts: 724
Likes: 0
From: Arlington, TX
Originally Posted by 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).
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.
Old 7/3/11 | 09:17 AM
  #6  
2010MustangGT's Avatar
Cobra R Member
 
Joined: September 12, 2009
Posts: 1,774
Likes: 0
Originally Posted by Fat Boss
Massive loss of power on mine when it is hot outside. I'd say 50 hp.
Clearly researched.
Old 7/3/11 | 09:42 AM
  #7  
karman's Avatar
Tasca Super Boss 429 Member
 
Joined: January 4, 2006
Posts: 3,907
Likes: 31
Post

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 ).
Old 7/3/11 | 02:21 PM
  #8  
Modshack's Avatar
Mach 1 Member
 
Joined: July 15, 2010
Posts: 532
Likes: 0
From: Greenville NC
Old 7/3/11 | 06:41 PM
  #9  
kn7671's Avatar
Mach 1 Member
 
Joined: July 26, 2004
Posts: 724
Likes: 0
From: Arlington, TX
Originally Posted by Modshack
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.

Last edited by kn7671; 7/3/11 at 06:42 PM.
Old 7/3/11 | 06:54 PM
  #10  
Modshack's Avatar
Mach 1 Member
 
Joined: July 15, 2010
Posts: 532
Likes: 0
From: Greenville NC
Originally Posted by kn7671

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.
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.
Old 7/4/11 | 09:42 AM
  #11  
Ethanjbeau's Avatar
Cobra Member
 
Joined: February 12, 2010
Posts: 1,411
Likes: 0
From: MA (north shore)
Originally Posted by Modshack
Who uses Celsius these days? Its so overrated
Old 7/4/11 | 02:18 PM
  #12  
karman's Avatar
Tasca Super Boss 429 Member
 
Joined: January 4, 2006
Posts: 3,907
Likes: 31
Where did the chart come from?

Originally Posted by Ethanjbeau
Who uses Celsius these days? Its so overrated
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?
Old 7/4/11 | 03:15 PM
  #13  
RONINV8's Avatar
Member
 
Joined: May 30, 2011
Posts: 7
Likes: 0
my car feels like a 300hp car today. So hot!
Old 7/4/11 | 03:58 PM
  #14  
AlsCobra's Avatar
A Man Just Needs Some....
 
Joined: April 9, 2011
Posts: 16,852
Likes: 34
From: Louisiana
Originally Posted by RONINV8
my car feels like a 300hp car today. So hot!
^^^ good one.
Old 7/4/11 | 04:29 PM
  #15  
MRGTX's Avatar
Shelby GT350 Member
 
Joined: May 18, 2010
Posts: 2,310
Likes: 14
From: CT
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.
Old 7/4/11 | 05:01 PM
  #16  
Fat Boss's Avatar
Mach 1 Member
 
Joined: April 8, 2011
Posts: 621
Likes: 0
From: An hour from Laguna Seca
As long as it's physics and not PCM limiting then that is true.
Old 7/4/11 | 07:42 PM
  #17  
houtex's Avatar
Legacy TMS Member
 
Joined: February 2, 2004
Posts: 7,582
Likes: 670
From: Insane
Originally Posted by Modshack
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'...
Old 7/4/11 | 07:48 PM
  #18  
fdjizm's Avatar
Cobra R Member
 
Joined: June 6, 2008
Posts: 1,666
Likes: 2
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
Old 7/4/11 | 10:39 PM
  #19  
HoosierDaddy's Avatar
Legacy TMS Member Moderator
 
Joined: January 8, 2011
Posts: 648
Likes: 531
Originally Posted by karman
I know of no one that runs cars at 100deg. C.
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.
Old 7/5/11 | 10:26 AM
  #20  
karman's Avatar
Tasca Super Boss 429 Member
 
Joined: January 4, 2006
Posts: 3,907
Likes: 31
Originally Posted by 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.
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..



All times are GMT -6. The time now is 03:45 PM.