Safe limit for Intake Air Temps..
 

Hello all, I did a little searching on the upper limit for intake air temps and couldnt find much.

This summer, I plan on throwing the hottest air I can into my Echo's engine, while running premium to avoid predetonation (10.5:1 CR). Is there any problems to be encountered running 150degF+ air into an engine?

Ive seen mine max out the sensor at 200. Normal in the summer is about 150. 9.1:1 with 87. Though I do mix with e85 to reduce knock under hard acceleration.

Good grief! 200 is pretty impressive. Did you notice any extra gain at that heat level? Or did the gains stop at a certain temp?

Until detonation actually occurs, the rule-of-thumb is 'higher-the-better' for economy...and, the SAFE *way* to know if you're approaching detonation is to monitor the IGNITION AVANCE / RETARD signal from your engine...via SGII or UG. When you notice the IGNITION advance numbers going DOWN (ie: engine sensor has detected 'ping') it means you're getting close to detonation conditions.

Typicial progression is: PINGING comes first, then DETONATION.

Most modern ignition systems will just retard the hell out of the timing to match the temperature to keep the engine safe.

The gen 2 honda has a 10.8 to 1 cr and it starts to retard the hell out of the timing when the coolant rises above 190 and the intake goes above 130.

At highway speeds it will maintain 40° advance at 200. Mind you the motor is also under very light load and running around 2200rpm.

Benefits start to drop off after 150-160. But again, warmer is better.

in the summer my intake temp is about 130F but it represent the temp under my hood because I mostly sealed it and I removed the small pipe that goes from my air box to my headlight. but my battery do not like to be at 140-150f. if I see that temp I will remove some grill block. but I think there is no problem to go higher in intake temp as long as your under hood temp do not rise as well

Okay, cool. I'll try to watch the timing advance and see what happens. I've noticed how temperature is important for mpg since it is cold here now. 0-30 degree F intake air really sucks. Needless to say, I'm stoked for summer!

EchoFrancis-
I also took that tube off of the airbox, and was thinking..it would probably be better to pull in air from the other side of the airbox (back of the engine). I might do this by cutting a hole on the back side of the airbox and plugging the stock hole. That would raise IAT a bit more without raising under hood temps anymore

Mustang seems to be peaking at 220, best range is 200-220. Insight goes as high as 213, best range seems 200-213. Neither shows any type of error or issues at these temperatures.

I am not familiar with the pinging or otherwise.

Edit: Whoops, these are coolant temps- I don't measure Air Temps, my mistake.

I was having a temp rise of only 20 to 30 deg F over outside air temp. So my first try at modifying the air intake system resulted in temps around 120 with an OAT of 40 deg F.
I was thinking I had overdone it but sounds like its in the ball park
http://i203.photobucket.com/albums/a...ps47f833b9.jpg

I removed the intake scoop and made a cover out of al flashing . the red is the upper radiator hose. its on a Honda crz