I re-calibrated my IAT table from the post that was given here and on H-T to compensate for AEM's lazyness..lol.

I still find my IAT's are HIGH, or @ least I feel they are.

On 6lbs of boost on my 30r my gauge says 125 degrees....

I'm thinking it's b/c the sensor is on the intake manifold, and it's getting heat soaked and not showing the true air temps, but I'm curious where everyone else falls.

 

this is a funny thing. heres my take.

your intake air has to pass thru the intake mani , and the intake mani gets hot as hell. so lets call the intake mani the oven. if you move the iat to a charge pipe, you dont know the true temp of the air going into the engine. the sensor reacts pretty quick. mine rises and falls just engine braking, or flooring it.

i always felt the intake mani was worth near 20 degrees temp increase. its an interwarmer if you will.

i woudlnt move the sensor. i feel thats the true temp of the air right before it enters your motor. mine would be about 100on the dyno and climb to 135 on a 4th gear pull. with the water setup, this is gonna be much lower!

125 is at the end of the pull right?

a quick laugher, now when i floor it, temps drop first rOFL. on a third gear long pull, temps overall rose 3 degrees hahahaa. i never thought i would see that.

 

I have my coolant completely blocked from the intake and IAT. Is this going to negatively effect my IAT?

 

Well, my IAT temps change a lot due to outside air, but on WOT, my temps are around 30-40 degrees above outside temp on average. Of course they sky rocket sitting in traffic.

 

I agree with that, but how much heat can the air take with it as it moves through the manifold and into the motor.

Yes it will increase it, but I don't beleive it's increasing to the actual temp of the intake manifold as it rushes past it so quickly.

Just my .02 cents of course.

 

I have been datalogging my IAT's for about a year and a half now. From my logs and modifications i have been able to lower my IAT's greatly by doing a few simple modifications.

- I removed the coolant lines that run through the IACV valve. I was able to drop temps about 15-20 degrees in different situations because of this.
- I built an intake from the turbo into the fender. I dropped IAT's an additional 20 degrees. In stop and go the IAT's still rise, but they drop very quickly. On cold days, the entire intake track is cold. This is including the intake plenum as well!
- Run the right sized intercooler. I made 475whp with a smaller intercooler. On multiple gear pulls i was getting heat soak due to the smaller sized core. Now my IAT logs don't budge through 3-4 gears of WOT on high boost!

 

Did removing the coolant lines not cause any cold start issues?

 

whats funny about that is i had no problems for like 6 months. This was during the winter, but then i thought i could get it to run better, so i cleaned it out. Cleaning it out completely messed up my IACV. I need to either reclean it, put the coolant through it, or buy a new one! I'll do some testing when im not lazy

 

Hondata IMG FTW. My intake manifold is decently cool to the touch... Definitely cooler than the valve cover...

John

 

the problem with moving the intake air temp before the throttle body is that now the IAT sensor doesn't see any of the effects of engine braking and isn't showing you the temps that are really going into the motor. until the motor and intake manifold heat soak the temps in the manifold will be very similar to the temps pre-throttle body. but drive a little, especially in stop and go traffic, and the manifold will heat up and start to heat the air going into the motor. yeah with the IAT sensor pre-throttle body you can see how well your intercooling is working, but you still don't know exactly what's going into the cylinders.

some people say the IAT sensor is getting heat soaked by the manifold, I don't think that's the case. once the manifold gets heat soaked it's over 140 degrees, usually over 150 degrees on a hot day or sitting in traffic. with proper intercooling you'll see temps way below that. like camuman said, now that he's got the water injection his intake temps drop in boost even all motor when you get onto the gas and get enough fresh air flowing into the motor the temps will drop.

as far as the IAT acting slow, that's not true either. when we had the temp sensor out of the car to correct the AEM IAT calibration we found the sensor reacted very quickly. just holding the sensor and blowing on it and it would react virtually instantly. it was fast enough that you couldn't see any delay at all from when you blew on it to the laptop displaying changes.

looking at an all motor run on camuman's car the stock IAT showed a temp drop within 0.5 seconds of starting the dyno pull. that's pretty quick considering some of that delay is the time is takes the fresh cold air to physically move through the motor. after the pull the temps started to rise (engine braking) within 0.4 seconds of letting off the throttle. not sure how much faster it's 'supposed' to be than that the other thing to keep in mind is that the IAT sensor only works in 1.8 degree increments. so the air has to change almost 2 degrees before it'll display a change, that's some extra time right there.

looking at a boosted run from my supercharged and intercooled CRX shows a different story and could be part of the reason people think there's a delay with the sensor. my CRX had an air to water intercooler setup in the manifold itself and the IAT sensor was in the manifold like the S2000. on a dyno run in the CRX the temps wouldn't start to rise until 2 seconds into the run, that's not a delay in the sensor, that's the intercooling keeping up at first. after the run when I let off the temps would continue to rise for another two seconds, level off for a few seconds, then start to lower again. again that's not a sensor delay, that's the intercooling system getting a little heat soaked in combination with engine braking. then as the intercooling system catches back up the temps would drop again.

if you only look at boosted setups it's easy to conclude that the stock IAT is 'wrong' because the results don't seem right with the temps holding high for a little after you let off the gas. but when you see how quickly the sensor acts out of the car, and how quickly it reacts all motor when sucking in ambient air instead of heated boosted air, you see that it's fine. bottom line if you've put in the correct IAT sensor calibration that we put together and you're seeing really high temps in the manifold, that's what's actually going into the motor. if you feel the temps are too high then you need to upgrade your intercooling setup or add water injection, etc.

sorry for the small novel, tried to cover a few points in one post