Intake Air Temperature

[cjhutch]

What's a safe range for the intake air temperature relative to outside temperature? The under hood temperature on my car is pretty hot, but the car never overheats (Saab 9-3 2.0T). Lately I have been paying close attention to my IAT and it seems to be around 15-20 degrees F higher than the outside temperature. This afternoon I was stuck in slow moving traffic for a while and it got to around +30. I'd just like to hear what other people are getting for temps and if there is a safe range for FI cars.

[Drummerboy]

I dont have any kind of intake temperature regulator, so im not sure. But i'd like to know too.

what ems are you using?

[batlbrandon]

What is the number exactly? relative to outside will move around but there is def. a ceiling to that. I am generally around 100 degrees intake air temp. I have seen as low as 87 during a full boost rip, and as high as 120. Imo anything above that (120) is a bit too hot. I have seen a shitty intercooler set up and it was at like 140!!!! No bueno. Also where is the sensor located? that can make a huge difference.

[Kason23]

My IAT's seem to rise on rare occasions. But usually are in the high 80's at night and low 100's in this heat during the day. But w/m injection has since took a good 7-8 degrees off that once it hits the sensor

[cjhutch]

I dont have any kind of intake temperature regulator, so im not sure. But i'd like to know too.

what ems are you using?

I'm using the stock engine management system. The numbers are being read by my Scangauge II via the OBD port so it's getting all the information from the stock sensor. I do not have a FMIC and the stock intercooler sits behind the air conditioning condenser. Horrible setup and looking to go front mount pretty soon. I have never seen the temps go above 112 degrees and that was sitting in traffic on a 90 degree day. The reason I ask is out of curiosity and I'm also getting ready to do some custom tuning. No one here messes with Saabs so I'll probably be driving up to North Carolina to see a tuner there. I really want to get some baseline numbers in order to compare once the tuning is done.

I like my SG II because I've even logged IAT relative to TPS and also fuel trims relative to temperature and humidity. I've been geeking out on this stuff lately. In the morning when it's cool and the car warms up my fuel trim hovers right around -2 meaning it's running just a tad rich and the car moves like crazy. That's also before the intercooler can experience any heat soak.

[crashtke]

If I had to guess the intake air sensor is built into the MAF sensor. You are probably not getting the actual intake temperature from the manifold, but rather from the location of the sensor. I can't remember exactly where the intake temp sensor is on those cars, but if it is anything like the Subaru, it is built into the MAF. On my car I actually saw temperatures as high as 160 degrees while sitting in traffic with the STOCK intake. I know the Sabaruus (the one with the 2.0 subaru motor in them) had the exact same engine.

To really get a better perspective, try getting an intake air temperature gauge and locate the senor right before the throttle body. I have seen temps in excess of 190* when in full boost on a top mount.

[cjhutch]

Actually the engine in my car is nowhere close to the engine used in the Saab 9-2X. That's a Subaru boxster engine while the engine in my car is based off the GM Ecotec series. In particular it's the LK9 series that is only used by Saab as far as cars sold in the U.S. On my car the sensor is a combo pressure and temperature sensor. Just to give an idea of what you are looking at in the picture that's the charge air tube just before it enters the throttle body.You can see the sensor sitting just below where the hose clamp is.

http://i31.tinypic.com/r8f6dg.jpg

[crashtke]

Ah gotcha. I have not played much with the saabs other than the Saabarus with the boxster motors.