Heat on IATs shoot up!
10-09-2009, 09:14 PM
#1
PLATINUM SPONSOR
Thread Starter
Heat on IATs shoot up!
Took a road trip today in 58-61 deg. Ambient. Getting close to race weather and wanted to see how my modified I/C system reacts to mid temperature ranges.
With the PTE T stat, AC ON and cruising in the 70mph range,, IAT`s stayed 8-10 deg. over ambient and engine would be in the 168-170 deg. range. Pretty nice.
I then decided to try the old racer trick,,, turn AC off and hit the defrost/heater to Max. Well , engine temp dropped 5-7 deg. instantly, as expected. The suprise wa that IAT`s shot up 12-16 deg.!!! They also showed no sign of dropping either. All my test were done at 70mph cruise and about 8-10 minutes per test. I then tried turning off heat and AC, and within a few minutes, IAT`s were back at 8-10 over ambient. Turning the AC on, also created a short surge in IAT`s but they would recover pretty soon to 12 over ambient..
Conclusion: Do not run heater at track to cool engine, as engine temps are fine but IAT`s will leap.. This goes for street racers and other times when max power is needed..
These test were done in the 58-61 deg range, so hotter temps were T stat is open, may change results. My concern is to maximize race weather!!!
PS, it has taken 4500 miles for this new nickasil coated bore and rings to break in on mobil one 0-40.. Burned one quart evey 1K or so , changed oil and no oil burn for last 1K..
With the PTE T stat, AC ON and cruising in the 70mph range,, IAT`s stayed 8-10 deg. over ambient and engine would be in the 168-170 deg. range. Pretty nice.
I then decided to try the old racer trick,,, turn AC off and hit the defrost/heater to Max. Well , engine temp dropped 5-7 deg. instantly, as expected. The suprise wa that IAT`s shot up 12-16 deg.!!! They also showed no sign of dropping either. All my test were done at 70mph cruise and about 8-10 minutes per test. I then tried turning off heat and AC, and within a few minutes, IAT`s were back at 8-10 over ambient. Turning the AC on, also created a short surge in IAT`s but they would recover pretty soon to 12 over ambient..
Conclusion: Do not run heater at track to cool engine, as engine temps are fine but IAT`s will leap.. This goes for street racers and other times when max power is needed..
These test were done in the 58-61 deg range, so hotter temps were T stat is open, may change results. My concern is to maximize race weather!!!
PS, it has taken 4500 miles for this new nickasil coated bore and rings to break in on mobil one 0-40.. Burned one quart evey 1K or so , changed oil and no oil burn for last 1K..
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E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
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E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
10-09-2009, 11:44 PM
#2
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Join Date: Aug 2005
Location: Southern Cali (Ontario)
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is your IC system completely split?
I used to run the heater when my system was tied to the engine coolant, and it would lover my engine coolant and keep my IAT's flat.
I used to run the heater when my system was tied to the engine coolant, and it would lover my engine coolant and keep my IAT's flat.
10-10-2009, 12:19 AM
#3
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2005 E55 AMG
You can't use your defrost to bring down temps as it does turn the A/C compressor on to dry the air even with the heat blowing,You must turn the heat on floor or vent,this will keep the a/c compressor off aanf the condensor will not heat up
10-10-2009, 01:05 AM
#4
I've used my heater at the track plenty of times without IAT's shooting up. Running the heater really takes the heat out quick and I would recommend everyone doing this at the track...JMO.
10-10-2009, 08:50 AM
#6
PLATINUM SPONSOR
Thread Starter
Just know that high defrost /heat mode will shoot the IAT`s up a lot. More than with the A/C running..
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10-10-2009, 09:00 PM
#12
i did it last night as well, though in between runs when parked and not in the staging lanes and the hood open. it helps out for sure
