My 7 is hardly a DD, but since I like to take it to work sometimes just to drive it, and because I live in an extremely congested area generally, I'm inevitably goinng to spend a good bit of time in traffic.

What I notice in these situations is that my coolant temps are stable (85-86c) but steadily rising IATs. They'll go from 45ish c in open driving to mid 50s to high 60s the longer the car is in traffic.

Assuming the car isnt driven hard while IATs are high, are these numbers cause for concern or just a fact of life?

The car has upgraded rad and smic, plus the R1 oil coolers, but what else could/should be done to lower IATs? I should do an enclosed, ducted airbox of some kind but I'm not sure what else.

 

Yeah, I've been there plenty of times. I just avoid boost, and once on the freeway, accelerate easy into speed until intake temps are good again. I've never had issues driving this way. As long as your coolant temps are good, you're fine.

How long are you stuck in traffic for?

 

Around an hour.

What would IATs get to on a factory stock car sitting in traffic? I imagine pretty high as well.

 

like 60c. really if you're not moving, IAT's aren't really important, although you'd probably want to let it un-heat soak before you romp on it. well in theory your map is tuned so 60c intake temps don't blow it up, but ymmv!

 

Heat soak is a reality in the summer. If you're concerned, consider relocating the IAT sensor from under the UIM.

 

What does moving the sensor do? Is it inaccurate in the stock location or am I just moving it somewhere cooler to lie to myself?

 

Presumably if the IAT is moved from an area prone to heat soak, as the UIM is IMO, then it will not read as high and add a bit more fuel. More fuel = safer AFRs. I said "consider". I not selling it necessarily. I moved mine some years ago and felt it helped. Initially it went to the stock plastic compression tube, later to a metal tube at the same location, both just upstream from the T-body. Both with far less mass than the UIM. I didn't bother to log IATs for comparison and I also moved to a PFC and a faster reacting IAT (probably at least as important and should have mentioned it earlier) about the same time. So YRMV. If you change to a faster reacting sensor it's really a no brainer (IMHO) to relocate it at the same time. Just reach under the UIM, unplug the stock sensor, leaving it in place and extend the two wires to the new sensor. Done.
https://www.rx7club.com/3rd-generati...ng-iat-459686/
https://www.rx7club.com/3rd-generati...sensor-897984/

 

I happen to have an extra fast IAT sensor for sale. Shameless plug I know.

 

That's no biggie. Just don't boost it. Your rad and oil coolers aren't doing much for low AIT's

Things that work wonders on AIT's are Vmounts and A.I.

 

A fast reacting IAT sensor will help but in order to make that work you will need a PFC. Then you're gonna want a tune. But since you have a fuel computer you might as well make the car flow better with hi flow exhaust and intake mods. The stock intercooler will not keep up with the amount of air flowing through it so you're going to want to upgrade to something larger... welcome to the game.

 

Almost forgot: one of my friends has a relatively stock car (just an intake) with a pfc and he sees AIT'S in the 60's.

In other words, its not out of this world

 

AFAIK the fast reacting sensor works with stock ECU, I ran mine with stock ECU for a few weeks before my tune. But that won't stop your car from heat soaking in traffic, mine still heat soak and I usually just avoid boost till temp is back in the 40s.

 

Yes, this is correct; it does work with stock ecus.


What he said^^^. Cannot be overstated.


Other things you can do include adding a fan & shroud to the IC that operates whenever the main rad fans are on (to prevent hot engine air recirculation through the intercooler--a common problem);

Moving or adding a BOV that is post IC. This will move some volume of air though the intercooler during cruise and light load, reducing stagnation and helping evacuate the heat quicker after a heatsoak situation; and,

AI has been mentioned, but I'll add that a small amount 60-->120cc/min (this is a M1 or M2 nozzle) injected pre-turbo into the airbox (or primary duct) starting at a few psi of boost will also help cool things down quickly during typical casual driving conditions. (AI is great for helping to get the heat out, preventing knock and keeping your engine clean; however, it will not super cool the IATs unless you're running meth [too] and a lot of it.)


I investigated this years ago, not because of the concern over the IAT but, rather, I wanted to regain that 'crisp' feeling that is lost when things get heatsoaked (and the throttle response turns to a mushy or soggy feeling). What I learned is that applying several of the mitigation measures mentioned above does help and makes for a more pleasing experience. I should also mention that my car sees daily use and I live in southern cali where it tends to be warmer and more of a concern.

 

I have simmilar proplem with my oil temps on traffic lights
Hiway driving or even normal driving in town i have 78-85c oils temps
In traffic 100c plus!!!!
IS this normal? Do all off u have the same temps?
I have 2 R1 oil coolers 2002 model big rad and fmic no hi temps on water on air some times as well on 60c air
Btw only in summer time i have this issues (35c+ the good days)

 

Vmount intercooler, fast-acting intake temperature sensor, and meth injection. Personally I won't boost a car if the intake temps are anywhere near the 50s. A stock mount intercooler is a terrible design as the radiator discharge blows directly on it. It only works when the car is constantly moving. To compound the problem, the stock intake temp sensor is so slow to respond that even though you are moving, it still thinks the car is hot and pulls fuel. This has cost many people motors. The cars I set up have no problems maintaining 20 degree C intake temps under boost in 80 degree F+ weather

 

When I had a stock IC in miami heat / traffic . i saw intake air temps as high as 80 C ...

Yeah not fun . I changed to a large stock mount with a pettit duct , and a fan to run and help when the car isnt moving . and I can honestly say it made a difference . now my intake temps usually stay in the 40's if I'm stopped for long it will climb to the 60's but goes back down asoon as I get moving.

ofcourse Vmount is the way to go . but since I wanted to keep things stock ish with AC I like the stock mount.

 

I just stay off the boost when I have outrageous intake temps due to hear soak.

 

Does any one have oil temp info on traffic lights ?

 

I've spent years combating this with my FD. Better IC and AI is simply a must. AI helped the most. I've learned how to trigger injection before boost and keep it there and when it's time to move, AI drops temps so quickly so you don't have to sit there not boosting for a while to enjoy the car again. Every FD should have AI. I've yet to encounter any better way to actively reduce intake temps. All these other mods that have been mentioned help the problem but AI squashes it.

I've also seen some install fans on their ICs to help combat this as well.

 

there is no fan on the oil cooler, so temps are inverse to speed.

 

I would add one more thing since I just did it today on my car. Clean your intercooler. Inside and out. I think most FDs produce some oil down the intake track and it settles in the intercooler. I usually clean mine every spring but procrastinated until today. Dish soap and hot water in the utility sink and you might be surprised on how much oily emmulsion comes out.

 

I have a daily driver FD with a stock ECU and I run a fast acting IAT- it works absolutely fine.

I have removed the AC system completely. So my traffic trick is to simply push the AC button- it activates the fans at full highest speed and does nothing else.

Can cool the water temp from 98C to 79C in a matter of a few minutes and keep the car running at 80C water temp while sitting in traffic for however long I want.

 

Stupid question: I see the benefit of AI but - if you shouldnt boost over 50c IATs - how does it help in traffic? Most of the systems only inject under boost, right? So if traffic clears but you're heat soaked with 60s IATs, and therefore shouldnt boost, what do you do? Or does AI plus a fast temp sensor mean you can just romp on it while heat soaked and everything will cool so fast it doesnt matter?

What's the most basic and keep-it-simple-stupid AI setup for a car that's solely looking to keep temps under control in traffic or at the track And not to crank the boost up or make more power?

 

Cool. Details?

 

Boost-activated, water-only. If you really want simple and stealth, use the WS washer bottle for the tank.