I just had an experience tonight that I think has convinced me to relocate the intake air temp sensor.

I got stuck in a traffic jam for over an hour this evening in 85F+ heat. The car didn't overheat, which is good (lots of other cars pulled off to the side though, including a fairly clean GSL-SE).

However, my intake air temps climbed to 95C !!!!!!
Even at the low revs and load I was at, the PFC was already retarding the timing quite a bit.....

Just curious to see if anyone else has ever experienced intake temps that high. It took 15 minutes of nice low load cruising after I got out of the traffic jam just to lower the IA temps to the 60s C.

My normal cruising IA temps are in the upper 30s-mid 40s C, depending on ambient temp. Lots of hard boosting at 13 psi raises this to 45-47 C. Not to bad considering the size of the PFS intercooler....

 

wow, never seen it pass 70 C on my PFC, but then again I'm never in traffic for more than 10, 15 minutes at most.

 

wow man that's no bueno. I would imagine your fans were on too? Not helping i guess?

 

I was stuck in stop and go for 3 hours and traveled 2 miles and it was 100degrees outside and I have a big ***** FMIC with stock radiator, and my intake temps didn't go over 70, I had the heater on high and my fans blasting though... Man im glad thats over.

 

i got stuck in an nyc traffic jam...nothing like it in the world!!! I hit 86C intake temps. I thought that was by far the highest i have seen on my car or read about here.

 

Here in Miami with weather in the high 90's I try to plan my routes and time so I dont get in traffic. I dont know my intake temps Im currently saving for my PFC. Yet I know it got to a point the a/c didnt want to work and the car's idle was really bad . Yet at least I have an aftermarket radiator that helped keep things cool.
My suggestions is like I stated above plan your day around the traffic not in traffic.

 

my idle was never effected. That would have me worried!

 

Ya I forgot to mention I have a street port LoL forgot to mention that.

 

Sounds like that sensor got some heat stroke. Where do you have the sensor, and where are you going to move it?

Next time, turn off the AC...........hahaha

 

why would you want to relocate the air temp sensor. it is in the best place for it now since it is closest to the engine so the computer can retard the timing with the best most sensitive feedback. that's its job...the whole system was designed with the sensor in that location so why mess with the design? if your intake temps are high that's traffic's fault, not a reason to relocate the sensor. speaking of traffic though i got stuck for 30 minutes on the bay bridge at midnight last night...that's as bad as in the morning

 

95C intake? Sounds like the sensor probably got heat soaked. After driving around here in the 115 degree summer I have seen my air and temps do all sorts of things. I just put on a Pettit cold air induction system and that helped quite alot, but before I would often see intake temps over 90C. Over 80C sometimes even when I was on the highway. With the Pettit I havent done much siting in traffic, but when I do the temps are constantly climbing. Above 90C after sitting in traffic wouldnt really shock me too much. Of course you said you were in only 85+ temps, I would love to see that kind of cold day again!

 

Tyler,

I was stuck in traffic for more than an hour in 103 degree temps on 580 heading toward the race track last month. My intake temps hit 84C. That was the highest ever. But I know what its like, I was scared to even hit the gas, this was prior to my water injection setup. Every time I let off the gas it would backfire about 10 times.

I got a new intercooler duct last night, I'm sealing the edges with refrigerator type rubber seal, and I am sealing the top of it where that opening is. Also, the part that goes to the AC/Battery line will be sealed off too. I know you dont have the stock duct, but does it fit exact to the IC? my current duct has an inch all the way around, so this will fix it nice.


I realize in stop and go traffic that duct sealing will not help, but my intake temps have not hit that high yet. I would be weary of moving your intake sensor, I read that a few members blew the engine. Also consider my water injection setup, its cheap, reliable and very effective. Consider this, you drive the car in stop and go, your temps will still hit say 94C, but when you hit boost the air will be cooled by the alcohol/water before it gets in your engine. Check out this link below:

"One very impressive aspect of this project is the water injection. It virtually eliminated heat soak. On the dyno, three back-to-back runs yielded practically no loss in horsepower at 14 psi. On the dragstrip, a heavily loaded fourth gear produced 100-to-120-mph times that ranged from 3.13 to 3.15--only a 0.02-sec. variation from four back-to-back quarter-mile runs with no cool down in between. Stay tuned; Project M3 will return to the road course next."

http://www.europeancarweb.com/projec...4ec_projm3_02/

 

Do a search on it. It is a potential motor popper in the stock location. It is slow reacting and will heat soak, and pull fuel in doing so. Then when you go to romp on it and get nice cool air through there, it's still heatsoaked and pulling fuel = kaboom.

 

Why don't you guys put 1 or 2 fans on the intercooler? I know Permacool is pretty popular, and SPAL makes small ones for the smaller smic's like the blitz or greddy

 

IC fans won't help heat soak much and moving the IAT sensor doesn't change the fact that its getting darn hot under there when you're not moving.

IMO you heatsoak because air around your intake heats up and you draw in hotter air. Only the stock and box intakes are any good at keeping the intake air cool. Someone mentioned the pettit intake, i have it and it and its heat shield are a joke as far as getting only cold air.

Also, your engine is hot. The lower intake manifold and upper intake manifold suck up a lot of heat through contact and this inturn heats your intake air and temp sensor, which is why some think its a good idea to move the temp sensor. When you're moving, the belly pan is designed to use airflow to pull hot air out of the engine bay. when you're not it probably gets close to 200F under there. nearly 200F degree water is going through the rad so the air blowing by the fans is hot, i've only been able to measure it as high as 160, my temp sensor stopped there. a vented hood or some well placed fans to vent that hot air may help.

sorry, that was a lot of common sense that likely everyone already knew...anyway my temps topped 70C in traffic the other day, rad fans full blast (wtr temp never went over 89), IC fan full blast, pettit intake, pettit IC.

 

hmmm...well let's say we do want to move it for the sake of trying something different. there are only two options:

1. closer to the engine in the LIM: this is an even hotter location than the UIM and not going to help your cause since it isn't that much different than 8-9 inches away from the stock location.

2. farther from the engine: a place such as the exit of the intercooler will definitely give you slightly lower intake temps but also decrease the accuracy of your reading since you are farther away. you want a high reading that more accurate or or a nice low reading that's out of wack?

the bottom line is when we are sitting in traffic with the fans on blowing hot air into our IC's and intake the stuff gets way too hot and there's nothing you can do about it. the sensor is a thermocouple which reacts slow because that's the nature of a thermocouple...reacts slow but has a wide range of operation. i think the water injection might be a decent solution if you want to push your car in such situations...but why would you boost in bumper to bumper traffic?

 

I wonder if a small fan on the intake for occasions like that would help? Just something to pull air in from the nose when a certain air intake temp is reached.

 

I wasn't suggesting to boost in bumper to bumper traffic. The point is, you have 94C intake temps, when you get out of traffic and boost, the water injection will cool the charge before you detonate from the high intake temps.

while you are in bumper to bumper traffic your intake temps will be hot.

 

Rynberg:
check this thread...

https://www.rx7club.com/forum/showth...hreadid=202786

some forum members have tried it and soon i will too... I will relocate it on the intake elbow (OEM) and i think its the best location for me...

in addition i will need to install the water injection (from ZeroBanger's thread), to cool the engine down.

this will be great mods to increase the engine's life...

 

I have a 4" fan that I've contemplated putting on next to the passenger headlight. I would need to cut out an opening inside the engine bay to improve flow, but I think that would help offset some of the horrendous heat that comes out of the radiator. My intakes last night were too hot to the touch (Apexi). I need to get some sort of deflector to redirect the hot air...

Seems like the best thing would be that one hood with the air inlet. Too bad I don't like its looks...

 

Forget bumper to bumper, think of staging lanes at a drag strip. You heat soak in the lanes and then go make a pass. All of a sudden your intake temps drop a ton because air is moving through the intercooler, ect, yet the heatsoaked sensor still thinks its 80C and keeps the motor lean accordingly. You are not losing accuracy relocating away from the intake, you are increasing it. The air going in is MUCH cooler than the aluminum intake manifold to which the sensor is attached. Go to the PFC forum and do a search on it, this has been discussed and backed up with data.

 

How about some sort of intake shield that would work with the stock air box. Keep that hot air from entering. If only someone could come up with something like that. Maybe that could be used during the summer months, and switch back to an "open style intake" the rest of the year.

 

ok forget bumper to bumper. if you are talking about the drag strip that is a totally different story but rynberg started this thread on the premise that he was driving in bumper to bumper here in the bay area. i see the point about moving it closer to the ic for the dragstrip but that's an isolated case. if all around versatility is the case then i don't see any reason to relocate it.

 

Ok,

You are in a drag strip, you have 40 cars in your lane in front of you. You move step by step and your intake temps reach 84C. you floor it, just as marshall describes your engine pops.

Now...

You are in bumper to bumper there are 40 cars in front of you. You move step by step and your intake temps reach 84C. you floor it...

What happens? How is this any different from the drag strip?

 

so how do u keep the temps down...On a hot and muggy night stock radiator and feed bumper greddy FMIC and a scoot hood my average temps around night time driving around looking for a race my temps are around 38-40 on the pfc......What can u do to keep them lower....