AEM CAI temp measurements.
08-10-2002, 01:29 PM
#31
INSTALLMENT #4 - STOCK AEM CAI - NO INSULATION.
Run #6:
Ambient temp - 25*C
Brief stops at red lights - IT rises to 6* over ambient within 30 secs. Once under way, IT comes back down much slower than when pipe was insulated. Even with non-stop driving, IT never dropped any more than 3-4* above ambient.
Once parked, IT rise far more rapidly than when insulated, peaks out at 61.5* after 35 minutes and begins to cool slowly.
Once under way, IT drops to 3-4* above ambient within about 2 minutes of steady driving.
Run #7:
Ambient temp - 20*C
Made several stops for errands.
First leg of drive before stopping, IT within 1-2* of ambient. Once stopped, IT rose rapidly. Once under way, similar observations as run #6. With each successive stop (5-10 minutes each), it took driving longer and longer to bring the IT down. Where it only took a couple of minutes with insulation, it now takes 4 minutes or more to shed the heat and IT would not get closer than about 3-4* above ambient.
Preliminary observations would indicate that an insulated pipe works better for inner city driving and faster heat removal once moving. From what I've seen of a bit of freeway driving, the insulation here seems less important.
Run #6:
Ambient temp - 25*C
Brief stops at red lights - IT rises to 6* over ambient within 30 secs. Once under way, IT comes back down much slower than when pipe was insulated. Even with non-stop driving, IT never dropped any more than 3-4* above ambient.
Once parked, IT rise far more rapidly than when insulated, peaks out at 61.5* after 35 minutes and begins to cool slowly.
Once under way, IT drops to 3-4* above ambient within about 2 minutes of steady driving.
Run #7:
Ambient temp - 20*C
Made several stops for errands.
First leg of drive before stopping, IT within 1-2* of ambient. Once stopped, IT rose rapidly. Once under way, similar observations as run #6. With each successive stop (5-10 minutes each), it took driving longer and longer to bring the IT down. Where it only took a couple of minutes with insulation, it now takes 4 minutes or more to shed the heat and IT would not get closer than about 3-4* above ambient.
Preliminary observations would indicate that an insulated pipe works better for inner city driving and faster heat removal once moving. From what I've seen of a bit of freeway driving, the insulation here seems less important.
08-10-2002, 02:26 PM
#32
Based on this, would you say that IT is going to be about 5 degrees lower with the insulation? Doesn't a 5 degree change in IAT equate to 1% change in HP? If so, I guess that would be about 2 additional RWHP with the insulation?
08-10-2002, 03:29 PM
#34
To be honest, I am not particularly concerned about every day driving, but am really interested in the benefits for autocrossing. I would bet that IT would rise upwards of 40 degrees while waiting in grid, especially after the 1st run. If IT takes a couple minutes to fall during the run, the run will be over before you get there. If there was some way to bring IT back down to ambient at the very beginning of the run, that could easily mean the difference between 1st and 2nd place.
08-10-2002, 05:40 PM
#36
This is a little off topic, but my "procedure" for keeping the engine cool at grid involves keeping the engine shut off, while running the A/C on its lowest setting. If I have enough time, I prop the hood open. With the A/C on low, both of the cooling fans come on. When it gets close to my turn to go, I close the hood, and start the engine, but I don't turn the A/C off until right before I "launch". This probably just heats the AEM up even more than it would idling, so I don't really know what would be best.
08-10-2002, 06:34 PM
#37
[QUOTE]Originally posted by gernby
[B]This is a little off topic, but my "procedure" for keeping the engine cool at grid involves keeping the engine shut off, while running the A/C on its lowest setting.
[B]This is a little off topic, but my "procedure" for keeping the engine cool at grid involves keeping the engine shut off, while running the A/C on its lowest setting.
08-11-2002, 07:26 AM
#38
I really wish I had an OBD-II scan tool to do some datalogging at an autocross. I really have no idea what temps I'm experiencing out there. I have considered using one of those pressurized pesticide bottles to mist the radiator with water in between runs, but haven't been motivated enough to actually try it.
08-11-2002, 03:16 PM
#39
INSTALLMENT #5 - NO INSULATION cont'd.
Run #8:
Ambient: 20*C
Mixed sun and cloud, winds moderate.
No new observations to make. Same old, same old.
I did, however, at the end of my trip, sit on my driveway and let the car idle at 2700 rpm for about 4 minutes. While just sitting there, the heat built up around the underside of the car and the ambient temp rose from 19* to 28*. The IT rose from 23* to 35*.
As it's not likely that we'll be getting any real hot weather in the coming days, this was my last run with the thermometer in place. I think I've proven what I set out to prove and came out with some consistent observations.
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In urban city type driving environments, insulating the AEM pipe will only gain you about 2 degrees on average. Where the non-insulated pipe will "generally" give you an IT 1-2*C above ambient, the non-insulated will give you an IT 3-4*C above ambient.
The AEM does deserve its name, "cold air intake". But it should be noted that the stock system can be made to achieve the same IT by simply using the "radmat" and insulating the rubber intake tube. One is ugly and costs a few dollars. The other is more visually pleasing and costs a couple of hundred (USD). The AEM though, can shed its heat more quickly once it sits a bit and soaks it up. The other mod has much difficulty once heat soaked.
END OF TEST.
Run #8:
Ambient: 20*C
Mixed sun and cloud, winds moderate.
No new observations to make. Same old, same old.
I did, however, at the end of my trip, sit on my driveway and let the car idle at 2700 rpm for about 4 minutes. While just sitting there, the heat built up around the underside of the car and the ambient temp rose from 19* to 28*. The IT rose from 23* to 35*.
As it's not likely that we'll be getting any real hot weather in the coming days, this was my last run with the thermometer in place. I think I've proven what I set out to prove and came out with some consistent observations.
------------------------------------
In urban city type driving environments, insulating the AEM pipe will only gain you about 2 degrees on average. Where the non-insulated pipe will "generally" give you an IT 1-2*C above ambient, the non-insulated will give you an IT 3-4*C above ambient.
The AEM does deserve its name, "cold air intake". But it should be noted that the stock system can be made to achieve the same IT by simply using the "radmat" and insulating the rubber intake tube. One is ugly and costs a few dollars. The other is more visually pleasing and costs a couple of hundred (USD). The AEM though, can shed its heat more quickly once it sits a bit and soaks it up. The other mod has much difficulty once heat soaked.
END OF TEST.
08-11-2002, 03:52 PM
#40
Registered User
The A/C on while the car is not running is a great cooling trick. Here's what I usually do at the strip, and also on the dyno to bring coolant temps back down to a consistent starting point.
1. Engine off
2. A/C switch on
3. Temp to full hot
4. Fan on high speed
These first four steps ensure you're removing as much heat from the system as possible. However, you have to do one more thing:
5. Every 60-90 seconds, turn on engine for a few seconds.
This last one is an old drag racer's trick and circulates coolant throughout the engine and helps to move more hot coolant to the radiator. On the dyno with the OBDII scanner, doing the first four steps will slowly bring observed coolant temp down. But when you do step 5, the measured coolant temp drops immediately on engine startup, usually about 5-8 degrees. Do it a couple times and you quickly reduce the temperature of the whole system.
Also, don't run the A/C with the engine on. The heat being dumped by the A/C condensor is substantial and will only serve to heat up the engine/coolant. Even with the A/C on low.
UL
1. Engine off
2. A/C switch on
3. Temp to full hot
4. Fan on high speed
These first four steps ensure you're removing as much heat from the system as possible. However, you have to do one more thing:
5. Every 60-90 seconds, turn on engine for a few seconds.
This last one is an old drag racer's trick and circulates coolant throughout the engine and helps to move more hot coolant to the radiator. On the dyno with the OBDII scanner, doing the first four steps will slowly bring observed coolant temp down. But when you do step 5, the measured coolant temp drops immediately on engine startup, usually about 5-8 degrees. Do it a couple times and you quickly reduce the temperature of the whole system.
Also, don't run the A/C with the engine on. The heat being dumped by the A/C condensor is substantial and will only serve to heat up the engine/coolant. Even with the A/C on low.
UL