What's up guys I wanted to share my latest mod I did on my Supercharged setup. I was noticing the performance was a bit sluggish lately and so I hooked up my Hondata to my laptop and cruised around data logging and I noticed on a 75* night my IAT was reading 134* on the darn freeway! so I was stumped! my Procharger Supercharger is designed to stay cool and give the coolest air charge so I wasn't sure why the temps started to read so high or I just never noticed the IAT reading so high but it didn't make sense. My Intercooler is new no clogs or dents. So I came to the conclusion the sensor was heat soaked from being mounted on the manifold. So I purchased a IAT bung to relocate the sensor to my charge pipe and used a Skunk2 block off plate for the manifold. The sensor read high still but when I used a new one the temps read correct at 80* on a similar 75* night. Also I noticed the performance felt much better.

 

That's a good place for it. Mine is in a similar location; about 6" in front of the throttle body in the charge pipe. There's **some** debate on this as the temps inside the intake manifold can be warmer but, I've found no fault in running my IAT sensor this way. Gives accurate reading to the air getting drawn in.

 

I agree!, I think there shouldn't be any debate.., I mean at OP temp I can barely touch the manifold but I can touch the charge pipe as its much cooler to the touch. And the fact that the sensor was new when I installed it a long time ago when I had a electrical gremlin I couldn't find I replaced the IAT for good measure with no luck only to have it get heat soaked down the road.. I like the idea its reading more accurate as the IAT temp plays a big role in performance.

 

Why not just change your fuel and ignition trim tables to reduce the compensation for elevated IAT's ??? Do you honestly think the air is any different inside your engine just because the IAT says the temp is lower ??? Reduce the fuel add/subtract and the ignition retard and you would create the same result... without any welding, painting or buying any parts.

 

That's where the debate comes in. It can be speculated highly in either direction here. What is known for sure is the sensor is going to be heat soaked in the manifold at minimum. Since the compensation is made based on sensor reading, that figure is already skewed.

 

Txdragon, I don't think "Debate" is the right word here. I cannot disagree with you that heat soak will make the IAT sensor read unusually high when mounted into the intake manifold. BUT, if the ignition retard is set to zero at higher IAT values, there would be no reduction in power. So in essence, one would alter the Ignition Compensation tables to move the "normal" operating range higher in the temperature spectrum. By keeping the IAT sensor in the intake manifold, you will get greater fuel/ignition adjustment at the cold end of the temperature range as well as the higher end if you choose. When one mounts the IAT into the intake tube/charge pipe, the values stay far more consistent and the adjustment range stays very narrow. This allows for what appears to be better performance only because the area of the IAT compensation tables being used is very small. IF you zero the tables say above 85' F, you would accomplish the same thing when leaving the IAT in the manifold because the heat soak would be essentially ignored electronically.

The thinking is why use a hammer when you can use the keyboard to accomplish the same thing... and ultimately have the same result.

 

I got it now. More than 1 way to skin a cat!

 

Absolutely my friend.

 

Moving the sensor is more a mechanical way to resolve the issue and the other way is simply tuning it out.. If I got that right?

 

Well I agree but I don't touch anything that has to do with tuning the engine im just not comfortable with that. IMO this modification will ensure a longer life and better performance from the sensor in the long run, As I stated the sensor started to read up to 140* on a chill 70* night. I don't see why anyone would rely on any compensation from the ECU using a heat soaked sensor that's reading around 70* hotter than what it should. I think it would be much more ideal to have it in this location so that it never gets damaged from heat soak and if it ever does im sure the tuner set some type of compensation to use at that point. My point is I think the longevity of the sensor is safer in this location or am I over thinking this?

 

You got it.

You are over thinking it. IAT sensor failure is really uncommon on it's own... the failures are typically customer induced. Since the plug style is common between the IAT, IACV and Purge Control solenoid, plugging a 12v+ plug from the IACV or Purge/Cut solenoid into the 5v+ IAT sensor damages the coil/resistor inside if you are lucky... or shorts it out and melts the end of the sensor off if you aren't. Either way, it must be replaced.

The idea here is to take advantage of the flexibility of the ECU when you can. The OBD-1 ECU offers a much greater compensation range for the IAT circuit over OBD-2 style systems. The factory settings may not be ideal for a forced induction application, but that is WHY you can adjust them. There are technical advantages to having the ability to protect the engine when IAT's are unusually high... say a pump failure on an air-to-water intercooler heat exchanger. The "feel" of less performance would be a warning sign for the operator to pull over and assess the cause. If you KNOW that you will experience elevated IAT's because of heat-soak, heavy bumper-to-bumper operation, etc... you can TUNE around the issue. If slow IAT response is a concern, you can use the S2K IAT sensor because it has an exposed probe tip and reacts much quicker than the plastic coated/insulated Civic/Integra sensors... although it will read 25-30 degrees F high. Knowing this, one would skew the correction values up say 30'F in the compensation tables to offset the temp values produced by the S2K sensor.

 

Ok im still very unfamiliar with how all the compensation values work but what happens when parameters go past the compensation set for the IAT temp? does the ECU keep adjusting? say for example If using the S2K sensor and i skew the correction values up 30'F in the compensation tables to offset the temp values produced by the S2K sensor and the sensor gets heat soaked and reads 40 to 50 * hotter does the ECU keep adjusting or does it only compensate for the extra 30*F that was set in the parameters ? Sorry if this sounds confusing cause its still a bit confusing to me on how it works but then again that's why im blind when it comes to actually tuning anything with the software and leave it alone for my Tuner.

 

https://www.hondata.com/help/smanage...mpensation.htm

^Read this. My tune has fuel compensation values set up for an IAT range from -40F up to 212F. The ECU will interpolate (linearly?) between the values in the tables. Hopefully you don't see IAT's below -40F or above 212F where you live. As long as you are within that range, you should be able to adjust the tune to compensate appropriately.

So, for example, if you were using the OEM Civic IAT and your "normal" IAT value was set at 110F (no adjustment to overall fuel compensation), then you install the S2K IAT knowing that it will read 30F higher, you would adjust your fuel compensation tables so that your "normal" IAT value is now set at 140F (30 degrees higher, and no adjustment to overall fuel compensation), then you would shift the rest of the tables up by 30F as well.

Make sense?

 

Just to add, if your intake manifold is too hot to touch I would run a phenolic heat shield intake manifold gasket on it they can make a pretty large difference by helping insulate the manifold from the engine plus they are reusable. I agree with jr that adjusting the iat corrections is the way easier and much more efficient way to do things.

 

Yea but for me its easier to do the mod, its not that hard really to have someone weld the bung than me going in Smanager and possibly screwing something up cause im not that good with the tuning aspect although I wish I where. I like the idea of the sensor located in a cool spot compared to the manifold, I heard this is why Honda located it in this area on the K series design.

I have the Hondata gasket on and it seems to keep temps down a bit as far as I can tell.

I appreciate every ones input!

 

I understand that getting into tuning can be scary but honestly man if I were you I would download your tune about 3 times and save all 3 copy’s as backups. That way if you mess anything up you can go and load a prior map in there. Hondata makes it very easy to learn how to tune or even just make a few small adjustments. I think people get scared of it more often then they should because of all the horror stories. I can say that I’m very happy I learned my way around a laptop, also there’s stuff you can get dialed in better then a “pro” tuner with time, like coolant temp corrections, ait corrections, cold idle speed etc. stuff that they can’t tune really because it takes different weathers, cold starting the car and seeing exactly how it behaves before operating temp. Most of my cars I’ll tune at operating temp then spend a couple of weeks making small tweaks here and there till everything is perfect.

 

Yea im learning allot lately and I mess around with certain things I know what im doing like Idle control, I set a new redline and things like setting up my AFR gauge but far from tuning, but im learning and its kind of fun and interesting.

 

One thing at a time is good. The more you use it the more familiar you’ll get with everything.

 

^^ I've been playing around with my Neptune for a couple years now and have learned so much. The basics are fairly straightforward and some of the more detailed aspects take a bit longer; compensations and such. I've found that navigating through the EMS has also given a more in-depth experience with troubleshooting overall. You learn how the engine responds to various components and sensors. It's really helpful. I couldn't recommend more to familiarize yourself as much as possible with your tuning platform.

 

Exactly man, the more you get into the software the more you realize what each sensor does and what effect it has on the engine and how it runs. It really makes diagnosing stuff way easier. Its fun to once you get a bit more in depth and start tuning more cars you really get a good grasp for what works and what doesn’t and you can see how far the torque curve is carried because the fuel curve is almost identical to the torque curve.

 

at the intake manifold, bottom side

 

What's the difference with it on the bottom or the top (OEM location)?. Manifold is still crazy hot..

 

Yes im getting more comfortable with things and I have been watching vids on how to tune!