Yesterday, I decided to hook my OBD-II Bluetooth dongle up to my E46 and read a handful of parameters through the Torque app, one of which was intake air temperature (IAT). The ambient air temperature at that time was approximately 85ºF.
While sitting still at idle, the temperature read just shy of 100ºF... about 97ºF. I should note that my car was not entirely warmed up yet, but very close.
Once I got up to 60 MPH, the temperature was reading at...
Wait just a minute. Let me add a few other things here before I go telling you what it said.
1) Yes, my car is supercharged. That means it can pull more air in than a non-boosted E46.
2) Yes, my car is supercharged. That means more heat in the engine bay, which can heat up hoses, tubes, etc. much more quickly.
3) My car does not make boost until I really press the throttle down.
4) I am using the stock airbox.
Let me repeat that last one:
I have a supercharged ZHP and am using the stock airbox.
Now... onto the results...
At 60 MPH with steady throttle, the engine is pulling a vacuum and making zero boost, which means the engine is pulling however much air it needs to pull, just like a stock E46. With that said, my IATs read out at 89ºF. That was just 4ºF above ambient temperature!
On my first E46, I had an ECIS intake. With it, IATs at highway speeds were about the same. Except with the ECIS intake, I had to deal with an oiled filter, which always ran the risk of ruining the MAF because of just a little too much oil. Alternately, if I didn't oil the filter enough, it would allow for contaminants to enter the engine, causing even bigger problems than a bad MAF.
So what am I trying to say through all of this?
KEEP YOUR STOCK AIRBOX AND FILTER AND SAVE YOURSELF THE MONEY!
While sitting still at idle, the temperature read just shy of 100ºF... about 97ºF. I should note that my car was not entirely warmed up yet, but very close.
Once I got up to 60 MPH, the temperature was reading at...
Wait just a minute. Let me add a few other things here before I go telling you what it said.
1) Yes, my car is supercharged. That means it can pull more air in than a non-boosted E46.
2) Yes, my car is supercharged. That means more heat in the engine bay, which can heat up hoses, tubes, etc. much more quickly.
3) My car does not make boost until I really press the throttle down.
4) I am using the stock airbox.
Let me repeat that last one:
I have a supercharged ZHP and am using the stock airbox.
Now... onto the results...
At 60 MPH with steady throttle, the engine is pulling a vacuum and making zero boost, which means the engine is pulling however much air it needs to pull, just like a stock E46. With that said, my IATs read out at 89ºF. That was just 4ºF above ambient temperature!
On my first E46, I had an ECIS intake. With it, IATs at highway speeds were about the same. Except with the ECIS intake, I had to deal with an oiled filter, which always ran the risk of ruining the MAF because of just a little too much oil. Alternately, if I didn't oil the filter enough, it would allow for contaminants to enter the engine, causing even bigger problems than a bad MAF.
So what am I trying to say through all of this?
KEEP YOUR STOCK AIRBOX AND FILTER AND SAVE YOURSELF THE MONEY!