IAT + Coolant Temps
06-08-2009, 04:32 PM
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IAT + Coolant Temps
Went off today for a spin in my car since I figured out that my OBD2 laptop software + cable works with my version of car. So I thought I would take it out to get some baseline temps etc and see what it's like during operation...
Coolant Temps
84 deg C - back road
97 deg C - town driving
Intake Air Temperature
31 deg C - back road
63 deg C - Town Driving
Now both of the max figures kinda shocked me a bit and both figures for the IAT too!! Now i know that town driving is obviously going to have increased temps but with the system at 1.1 bar leaving the boiling point to be somewhere around 102 deg C it kind of got me worried that there may not be too much play in the system... and this was just a cool night in Scotland... Does the additive to stop the water freezing allow for the boiling point to be increased further or not? If not then maybe increasing the pressure in the system to 1.3 bar will allow a possible 107 deg C to be reached in turn giving my system a bit more breathing room under hotter days...?
Now for the intake temps... the town value was crazy, even went out and touched the manifold myself just to see what it was like... mucho hotto!! 31 deg C though for spirited driving still seams pretty high IMO, is this mainly due to the bay holding a lot of heat or the fact that it's metal on metal contact to the block with coolant flowing through the TB? I was thinking of purchasing the Hondata IM gasket to reduce the temps and also stop coolant running through the TB to help improve the efficiency of the engine...?
Basically my goal atm is to modify the engine to make it as efficient as possible prior to further tuning so that I know I have a good base to work on... (this includes cleaning the IM itself too of all that oil!)
Just thought I would share the figures with you... prob a useless thread but I'm bored and I wanna make people bored like me...
Coolant Temps
84 deg C - back road
97 deg C - town driving
Intake Air Temperature
31 deg C - back road
63 deg C - Town Driving
Now both of the max figures kinda shocked me a bit and both figures for the IAT too!! Now i know that town driving is obviously going to have increased temps but with the system at 1.1 bar leaving the boiling point to be somewhere around 102 deg C it kind of got me worried that there may not be too much play in the system... and this was just a cool night in Scotland... Does the additive to stop the water freezing allow for the boiling point to be increased further or not? If not then maybe increasing the pressure in the system to 1.3 bar will allow a possible 107 deg C to be reached in turn giving my system a bit more breathing room under hotter days...?
Now for the intake temps... the town value was crazy, even went out and touched the manifold myself just to see what it was like... mucho hotto!! 31 deg C though for spirited driving still seams pretty high IMO, is this mainly due to the bay holding a lot of heat or the fact that it's metal on metal contact to the block with coolant flowing through the TB? I was thinking of purchasing the Hondata IM gasket to reduce the temps and also stop coolant running through the TB to help improve the efficiency of the engine...?
Basically my goal atm is to modify the engine to make it as efficient as possible prior to further tuning so that I know I have a good base to work on... (this includes cleaning the IM itself too of all that oil!)
Just thought I would share the figures with you... prob a useless thread but I'm bored and I wanna make people bored like me...
06-08-2009, 04:44 PM
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Engine heat = good for engine longevity as long as its not overheating. Most cars now are built to hit op-temp fast, and keep it there. It makes the most power when its hot (not intake side, the engine overall). The boil point of water+coolant is higher than jsut water, not sure if your 102 takes the coolant into account (damn people using C not F 
)
)
06-08-2009, 04:48 PM
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Special peeps use C (thought it would be a gd idea to put units in to save imperialist americans from confusion 
)
Yeah the 102 value was from a water vs pressure table I found which obviously doesn't take the coolant in to account. I had a feeling that it would increase the boiling temp but not by how much... So the engine coolant temps that I had would be an acceptable band then??
(thought it would be a gd idea to put units in to save imperialist americans from confusion )Yeah the 102 value was from a water vs pressure table I found which obviously doesn't take the coolant in to account. I had a feeling that it would increase the boiling temp but not by how much... So the engine coolant temps that I had would be an acceptable band then??
06-08-2009, 05:02 PM
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Pure Water || 50/50 || 70/30
Boiling Point 100 C/212 F || 106 C/223 F || 113 C/235 F
The temperature of the coolant can sometimes reach 250 to 275 F (121 to 135 C). Even with ethylene glycol added, these temperatures would boil the coolant, so something additional must be done to raise its boiling point.
The cooling system uses pressure to further raise the boiling point of the coolant. Just as the boiling temperature of water is higher in a pressure cooker, the boiling temperature of coolant is higher if you pressurize the system. Most cars have a pressure limit of 14 to 15 pounds per square inch (psi), which raises the boiling point another 45 F (25 C) so the coolant can withstand the high temperatures.
^quoted from howstuffworks. haha
Had to look it up ;P
Boiling Point 100 C/212 F || 106 C/223 F || 113 C/235 F
The temperature of the coolant can sometimes reach 250 to 275 F (121 to 135 C). Even with ethylene glycol added, these temperatures would boil the coolant, so something additional must be done to raise its boiling point.
The cooling system uses pressure to further raise the boiling point of the coolant. Just as the boiling temperature of water is higher in a pressure cooker, the boiling temperature of coolant is higher if you pressurize the system. Most cars have a pressure limit of 14 to 15 pounds per square inch (psi), which raises the boiling point another 45 F (25 C) so the coolant can withstand the high temperatures.
^quoted from howstuffworks. haha
Had to look it up ;P
06-09-2009, 02:48 PM
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Good info Nick. I've been doing some IAT monitoring also to improve my PRM intake performance.
My numbers here in the tropics are very similar to your's. I'm using however dual digital thermometers placed in various air intake locations.
During highway driving, when air in the traditional CAI filter location is at 31C the OEM air box intake location is at 37C. At a stop the difference quickly goes to 31C vs 60C.
Pulling intake air from behind the right headlight reduces the differential 31C vs 32.8C driving and 31C vs 40C at a stop. I'm hoping that's enough to reduce amount of ignition timing retardation caused by high IATs.
My numbers here in the tropics are very similar to your's. I'm using however dual digital thermometers placed in various air intake locations.
During highway driving, when air in the traditional CAI filter location is at 31C the OEM air box intake location is at 37C. At a stop the difference quickly goes to 31C vs 60C.
Pulling intake air from behind the right headlight reduces the differential 31C vs 32.8C driving and 31C vs 40C at a stop. I'm hoping that's enough to reduce amount of ignition timing retardation caused by high IATs.
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