Real IAT Mod Kia stinger gt 3.3t

[Tigershark]

Anyway if you want to alter the IAT to influence the tuning (like making it read cooler than actual to increase timing and lower boost) in my opinion you should just use the JB4 to actually adjust the IAT directly. Most JB4 systems are wired to do that. You can check by seeing if you have the green wire going to spot#1 on the DB25 connector. To enable the IAT spoof you need to invert the JB4's MAP connections so the red/yellow MAP connector is on the manifold, and the brown is on the charge pipe. Then just enter the desired IAT target under "IAT SPOOF" in the JB4 app. Easy.

It's useful here and there like if you're sitting in staging lanes for a long time with the engine on and the intercooler and turbos heat soak. But remember colder IAT means more timing but also LESS boost. And warmer IAT means less timing but MORE boost. So you're trading one for the other when you start altering the signal.

Interesting. I was unaware of this function on JB4 until now so good to know. Thanks for the insight!

 

[7thSonEngineering]

Not trying to crap on fellow engineer and entrepreneur but why would the charge air temp differ much before and after a throttle body with a plastic manifold?

And if it did wouldn't the manifold charge air temp would be more closely matching what is entering the cylinders?

Anyway if you want to alter the IAT to influence the tuning (like making it read cooler than actual to increase timing and lower boost) in my opinion you should just use the JB4 to actually adjust the IAT directly. Most JB4 systems are wired to do that. You can check by seeing if you have the green wire going to spot#1 on the DB25 connector. To enable the IAT spoof you need to invert the JB4's MAP connections so the red/yellow MAP connector is on the manifold, and the brown is on the charge pipe. Then just enter the desired IAT target under "IAT SPOOF" in the JB4 app. Easy.

It's useful here and there like if you're sitting in staging lanes for a long time with the engine on and the intercooler and turbos heat soak. But remember colder IAT means more timing but also LESS boost. And warmer IAT means less timing but MORE boost. So you're trading one for the other when you start altering the signal.

Why would the charge air temp change before and after the throttle body you ask?

It doesn’t. The issue is with the placement of the temperature sensing portion of the MAP sensor. The plastic intake manifold sits on top of an aluminum engine with 190-221f coolant running through it. The plastic intake manifold absorbs this heat and in turn the TMAP sensor begins to read elevated and artificial temperatures because the sensor body heat soaks as-well.

What do these elevated temperatures do? They effect timing which effects mpg and low end torque.

What does this mod do?
It changes the location of where the ECU collects intake air temperature readings. I call it the “Real IAT sensor relocation kit” because the readings obtained at the new location are nearly the “real” charge air temperatures coming out of the intercooler into the engine.


Concerning temperature spoofing. This method can work in specific scenarios like Terry mentioned.

Temperature spoofing or feeding the ECU artificial temperatures has it uses but also can have several negative consequences.

-Incorrect Fuel Mixture
The ECU relies on accurate IAT readings to adjust the air-fuel ratio. Spoofing the sensor can lead to a too rich or too lean mixture.

- Timing Problems
The ECU also uses IAT data to adjust ignition timing. Incorrect readings can lead to premature or delayed ignition, reducing engine efficiency and potentially causing knocking or detonation.

- Knocking and Detonation
Incorrect timing due to spoofed IAT readings can cause knocking, which over time can damage pistons, valves, and other engine components.

ECU Learning and Adaptation Issues
- Our ECUs are designed to learn and adapt to driving conditions. Spoofing the IAT sensor can confuse the ECU's adaptive learning algorithms, leading to long-term performance issues even after the spoofing is stopped.


Terry thank you for the info on how lower IATs effecting boost levels. I believe the JB4 has the ability to “recorrect” the drop in boost due to the near ambient IAT readings. I don’t own a JB4 so correct me if I’m wrong Terry.


Has anyone noticed drops in boost pressure after installing the mod?

If so even with the drop in boost pressure did your vehicle still pickup power?

 

[Tigershark]

Terry is welcome to read my latest data log from the JB4 on the previous page. Boost read off of boost1 and 2 shows near 18lbs initially around mid 3k rpm and starting to taper down closer to 17 by early 4k. This trend continues all the way to 6500ish rpm when I let off.

 

[BIG-D]

While you are here please Terry, any reason why the electronic thermostat cannot be programmed to open earlier?

I have seen 103*C/220F+ on my scan tool

It has been a long time standard practice for tuning on a BARRA engine to bring the fans in at 72C/160F and fitting a 72C/160F thermostat...

Every car with this adjustment made more power safely with more timing compared to a factory 220F stat.

Thoughts ?

 

[BIG-D]

In a nutshell and just my thoughts, after a drive pop the bonnet and try to hold the sensor on the plastic manifold now go hold the charge pipe sensor ...chalk and cheese heat wise, so inside the manifold has to be the same ?

But I can confirm I am making all the boost I had before...
I even had to refit Terry's diff brace because off the mark wheelspin was becoming stupid without it.
Which proves this mod works because timing makes powaahh!!

I am still working on relieving heat from the engine bay with heat sheilding around my dump pipes and turbo beanies, as well as air redirection...

Peace Daz

 

[GT1JP]

Car: Kia Stinger Gt AWD 2019
Ambient temp: 33f
Weather: Snowing
Date: 12/21/2024
Time: 4:16am - 4:38am
Purpose: Testing potential mod
Mod Name: IAT sensor relocation kit (prototype)
For sale name: Kia stinger Gt Real IAT ( Jan 2025 release ebay)
Car Mods: BMS BEF, Takeda intakes, Megan secondary downpipes

The purpose of this post is to investigate whether relocating the Tmap (temperature + mass air pressure) sensor increases the Hp and torque on a kia stinger or any other vehicle with this motor ( 3.3t). Why would someone want to relocate the Tmap sensor you ask? Because the Tmap sensor is attached to the intake manifold which heat soaks and this effects the minimum IAT the the engine will see. This effects timing, HP, TQ and Mpg. Typically the IAT sits between 20-40f above ambient.

The relocated location of the tmap sensor is actually the stock location for the map sensor on this motor. The Tmap sensor is located behind the throttle body (figure 1) and the map sensor is located on the charge pipe before the throttle body (figure 2)

View attachment 89199
(figure 1)
View attachment 89200
(Figure 2)

So the Map sensor and Tmap sensors swap places. This makes this Mod completable in 5 minutes with my sensor relocation cable.

Lets get onto the prototype installation pictures.

View attachment 89201View attachment 89202View attachment 89203

View attachment 89204

View attachment 89205

Now beings the road test. Notice the Time in the top left hand corner of the screen shots.
View attachment 89206
Time: 4:16am - The temperature ambient temperature was 33f this screen shot is post pull (50mph -120mph). Notice that my lowest IAT (intake Air Temperature) temps were 39.2f. The peak IAT Temps were 48.2f. (Hp and torque numbers are estimated by the app)

View attachment 89207
Time 4:21am - I Pulled over on the side of the highway and removed the mod. Reset the app values and this is what the IAT temp shot to 60.8f. So now that I'm back to stock I will do another pull (next pic)


View attachment 89208
Time 4:22am- Notice the peak HP and Torque numbers (estimated) and compare them to the picture at 4:16am. (54-130mph pull). Also note that with the sensor relocation mod the boost levels are lower (idk why)

View attachment 89209
Time 4:31am - I pulled back over and reinstalled the mod got back on the highway and did a pull 111mph top speed (remember it was snowing).

View attachment 89210

Time 4:32am- Just cruising along and letting temps drop to see where they fall back down to.

View attachment 89211
Time 4:38am- Driving on the highway and checking to see if my mpg increases. Notice my min & max speed and also how low the IAT temps have dropped.

This finishes my testing for today and my thoughts on this mod are. More low end power in terms of just driving around, Better mpg (seemingly) and the car accelerates faster when I step on it.

The estimated HP and Torque numbers above:
Pull 1 (modded) : 421hp 470ftlb
Pull 2 (stock) : 414hp 429ftlb
Pull 3 (modded): 426hp 488ftlb

So estimated hp and torque gains of
7-12hp
41-59 ftlb

Not bad for a 5 minute mod.

I just seen this and was wondering if you have some available for purchase? I’m interested in the relocation kit

 

[Terry@BMS]

Why would the charge air temp change before and after the throttle body you ask?

It doesn’t. The issue is with the placement of the temperature sensing portion of the MAP sensor. The plastic intake manifold sits on top of an aluminum engine with 190-221f coolant running through it. The plastic intake manifold absorbs this heat and in turn the TMAP sensor begins to read elevated and artificial temperatures because the sensor body heat soaks as-well.

What do these elevated temperatures do? They effect timing which effects mpg and low end torque.

What does this mod do?
It changes the location of where the ECU collects intake air temperature readings. I call it the “Real IAT sensor relocation kit” because the readings obtained at the new location are nearly the “real” charge air temperatures coming out of the intercooler into the engine.

The notion that sensors "heat soak" (in a plastic manifold no less) doesn't seem accurate at all so me. The element of the sensor is exposed to the incoming air and isolated from the body of the sensor by design. Air is moving through the manifold at the same rate its moving through the charge pipe. The manufacturer could have selected either location and determined the manifold worked for them. I don't believe the temperature readings in the charge pipe or manifold are very different, but its easy enough to datalog both at the same time in one log to compare. Maybe I'll do that one day when time permits.

That said even if the sensor could heat soak, in most cases, you'll make more power with a relative WARMER reading on the sensor, due to how the car maps out load based on charge air temperature. There are of course exceptions especially when tuned and on higher octane. But this isn't a JB4 thread so I don't need to go in to the various scenarios here.

Anyway just my $0.02 on it. I don't think this wiring change is doing what you think its doing.

 

[Terry@BMS]

While you are here please Terry, any reason why the electronic thermostat cannot be programmed to open earlier?

I have seen 103*C/220F+ on my scan tool

It has been a long time standard practice for tuning on a BARRA engine to bring the fans in at 72C/160F and fitting a 72C/160F thermostat...

Every car with this adjustment made more power safely with more timing compared to a factory 220F stat.

Thoughts ?

It's not something I've looked at. In theory we could change the tables on the flash side but I haven't seen enough cars overheating to justify spending time on it.

 

[7thSonEngineering]

I just seen this and was wondering if you have some available for purchase? I’m interested in the relocation kit

Currently out of stock but will build more harnesses later this week. I will send you a DM

 

[GT1JP]

Currently out of stock but will build more harnesses later this week. I will send you a DM

Yes please! After reading all the posts about it I’m really interested in it.

 

[BIG-D]

Edit: Not worth it never mind...

 

[StingerMG]

Why would the charge air temp change before and after the throttle body you ask?

It doesn’t. The issue is with the placement of the temperature sensing portion of the MAP sensor. The plastic intake manifold sits on top of an aluminum engine with 190-221f coolant running through it. The plastic intake manifold absorbs this heat and in turn the TMAP sensor begins to read elevated and artificial temperatures because the sensor body heat soaks as-well.

What do these elevated temperatures do? They effect timing which effects mpg and low end torque.

What does this mod do?
It changes the location of where the ECU collects intake air temperature readings. I call it the “Real IAT sensor relocation kit” because the readings obtained at the new location are nearly the “real” charge air temperatures coming out of the intercooler into the engine.


Concerning temperature spoofing. This method can work in specific scenarios like Terry mentioned.

Temperature spoofing or feeding the ECU artificial temperatures has it uses but also can have several negative consequences.

-Incorrect Fuel Mixture
The ECU relies on accurate IAT readings to adjust the air-fuel ratio. Spoofing the sensor can lead to a too rich or too lean mixture.

- Timing Problems
The ECU also uses IAT data to adjust ignition timing. Incorrect readings can lead to premature or delayed ignition, reducing engine efficiency and potentially causing knocking or detonation.

- Knocking and Detonation
Incorrect timing due to spoofed IAT readings can cause knocking, which over time can damage pistons, valves, and other engine components.

ECU Learning and Adaptation Issues
- Our ECUs are designed to learn and adapt to driving conditions. Spoofing the IAT sensor can confuse the ECU's adaptive learning algorithms, leading to long-term performance issues even after the spoofing is stopped.


Terry thank you for the info on how lower IATs effecting boost levels. I believe the JB4 has the ability to “recorrect” the drop in boost due to the near ambient IAT readings. I don’t own a JB4 so correct me if I’m wrong Terry.


Has anyone noticed drops in boost pressure after installing the mod?

If so even with the drop in boost pressure did your vehicle still pickup power?

I definitely agree with moving the IAT sensor from the back of the manifold to the charge pipe because like you said. The heat from the engine leads artificially high temperature readings.

While my car can still boost to 21-22psi of boost during short spikes, I noticed my boost is a little lower on avg but my butt Dyno still says I've picked up more power. I cannot definitely say so because I've installed the 1 inch manifold spacer and the Harness within a week of each other. I'm thinking the combination of the lower IATs due to the harness and the longer intake runners/more plenum volume has lead to my low and mid range power band feeling wider and smoother.

My air/fuel, fuel trims, and cylinder retard (timing corrections) are perfectly fine. I cannot speak to how the harness works with the JB4 but I can confirm that it works perfectly fine with a Lap3 ECU tune.

 

[StingerMG]

Currently out of stock but will build more harnesses later this week. I will send you a DM

I think the big 3.3t Tuners should give the real IAT harness a shot and test it out.

 

[StingerMG]

Not very scientific but these screenshots show my intake, ambient, and coolant temperatures while taking a ~50min drive around town and sitting in traffic. I do have a mesh lower grille so there is more airflow hitting the rad and other coolers, affecting coolant, oil, and trans temperatures.

 

[Terry@BMS]

Not very scientific but these screenshots show my intake, ambient, and coolant temperatures while taking a ~50min drive around town and sitting in traffic. I do have a mesh lower grille so there is more airflow hitting the rad and other coolers, affecting coolant, oil, and trans temperatures.

I think the big 3.3t Tuners should give the real IAT harness a shot and test it out.

If we wanted to change the IAT signal location we'd just switch the wires in the JB4 harness. But IMHO the first step here should have been quality data showing the variance between the sensor reading under different conditions. Like sitting at idle, during cruise, and during full throttle.

To do this you'd tap in to the IAT position on each sensor, and ideally plot their voltages over time. The JB4 could be setup to accommodate that. But a "ghetto" method to get a similar result would be to connect the meter so the + is one sensor signal and the - is the other sensor signal, so you're only monitoring the voltage difference, and then see how that changes.

I expect you'll see some difference sitting at idle, and then once the vehicle is in motion very little difference. And that voltage variance would provide some context for how much of a signal change you're getting.

 

[7thSonEngineering]

Here are updated installation instructions for the "Real IAT sensor relocation Kit"

I will be creating a second installation guide for those with piggyback tuners ( JB4, Racechip etc etc)

 

[oddball]

While you are here please Terry, any reason why the electronic thermostat cannot be programmed to open earlier?

I have seen 103*C/220F+ on my scan tool

It has been a long time standard practice for tuning on a BARRA engine to bring the fans in at 72C/160F and fitting a 72C/160F thermostat...

Every car with this adjustment made more power safely with more timing compared to a factory 220F stat.

Thoughts ?

Using a 160 degree thermostat has been a hot rod trick for decades. Cooler engine temps, in general, can support higher power. However, higher engine temps result in better emissions - specifically lower NOx IIRC. OEMs have been raising the running engine temp slowly over the past few decades and now 210-220 is not uncommon.
ECU tuning can change the thermostat control, but you're dependent on one of the tuners having an interest in finding that specific section of the ECU and figuring it out. I doubt there's enough to gain to make it worthwhile. And this directly impacts emissions, so with the major increase in pressure from EPA on the aftermarket over the past couple of years, I doubt anyone is going to stick their neck out.

BUT, the "electronic thermostat" is just a resistor in the wax . Tap the wires, figure out how it's controlled, and build your own control box! Also need to drive the radiator fan to actually get lower temps. I doubt you're looking at much change at the end of that. "Back in the day" it was a technique for drag cars to get an edge because they tuned their carbs for the cooler temp. Now with modern controls that's less of a problem, but a hotter engine will still tend to detonate more than a cooler engine.

The notion that sensors "heat soak" (in a plastic manifold no less) doesn't seem accurate at all so me. The element of the sensor is exposed to the incoming air and isolated from the body of the sensor by design. Air is moving through the manifold at the same rate its moving through the charge pipe. The manufacturer could have selected either location and determined the manifold worked for them. I don't believe the temperature readings in the charge pipe or manifold are very different, but its easy enough to datalog both at the same time in one log to compare. Maybe I'll do that one day when time permits.

That said even if the sensor could heat soak, in most cases, you'll make more power with a relative WARMER reading on the sensor, due to how the car maps out load based on charge air temperature. There are of course exceptions especially when tuned and on higher octane. But this isn't a JB4 thread so I don't need to go in to the various scenarios here.

Anyway just my $0.02 on it. I don't think this wiring change is doing what you think its doing.

I think it's less about heat soak and more about exposure. I haven't pulled the sensors myself, but I thought there was a comment in here somewhere that the temp sensor in the manifold is buried away from the air stream, while the charge pipe sensor is better exposed to the air stream.
Yeah, plastic heat soak is nothing like aluminum heat soak, but it still happens.

 

[BIG-D]

I guess the companies that sell catless downpipes might look into it then...

*Facepalm*

 

[7thSonEngineering]

Supplies arrived early. I was able to build a few more harnesses today.

 

[Terry@BMS]

We did some dyno work last week on our latest Stinger project. While it was on the dyno Payam decided to give this mod a test by redirecting the the manifold IAT signal to the chargepipe sensor. Those with a JB4 can do it rather easily by cutting a wire on the JB4 harness and extending it another part of the JB4 harness.

Anyway the results were we did see an intake temp reduction of around 10-15 degrees on average. The bad news was it resulted in zero power gains or differences. Just not enough of a change to do anything. Your mileage may vary.

Details will be the video we're posting later today on our youtube channel.