DeWolf

I did this on my 86 as well. Not sure why people are bothered about drilling out the old brass threads and epoxying in the new sensor. That old sensor is probably as old as your car and once you put the new one in it will probably be there longer than you'll own the car anyway.

Ramp

This is why I love this forum.

I was going to try exactly what Dundertaker tried. I'm still thinking there must be another location that will work - but, perhaps not. DeWolf is correct, that it's probably never going to be an issue drilling out the OEM mount but I like the thought of reversibility.

I'm going to wait to do this mod until I finish the intake refresh (next couple of weeks). Once I have a smooth running car, I'll do the mod and report back.

PC-85-928S

is this mod only for S3's?
does it work on S4's?

The Forgotten On

S4's don't have a temp sensor. They have knock sensors instead which are much faster and more accurate.

hacker-pschorr

Monitoring intake air temp with a computer mapped to adjust accordingly can help prevent detonation. A knock sensor can only react after the detonation has occurred and will keep trying to restore full timing until it starts to knock again. If something is really wrong (like horrible gas or extreme intake air temps) the engine will continue to knock, pull back timing, advance timing, knock again...rinse repeat. This cycle is not ideal.

With an intake air temp sensor, in the event high intake air temps are enough to warrant the computer to make adjustments, those setting will remain until the temp starts to drop.

In a perfect world a car would have both, which many modern cars do, especially the boosted ones.

As for speed, these new intake air temps sensors are incredibly fast, which is why people are switching them in 85/86 cars. Years ago Mike Schmidt (Z) and I did some extensive testing of every air temp sensors we could find. The VW unit was the best by far and even lightly breathing on one during a hot day would react instantly.

If you can only have one or the other, yes knock sensors are preferred. But there are other advantages to the air temp sensor.

TM___

So, to round up, there really isn't another location in the airbox housing to fit this sensor, other than drilling out the existing hole? Is it an option to place it in the neck just above the MAF?

Ramp

IFRC. yes the existing location is fine but I was able to drill a new whole near it, cap the old whole with the body of the old sensor (cut off the internals) and install the newer bosch sensor/

BTW, I have a brand new one never installed if interested.

TM___

I have a sensor on order, but thanks. I'll see if I can get it in the neck.

928NOOBIE

If you put the sensor in the neck above the MAF you will impact the operation of both in unexpected ways and not positively either. Neither item was designed for the use case you propose. There are used airbox bottoms widely available. Make the investment.

This change makes the car much more responsive. A great upgrade.

85euro928

Curious why you say this? What were your results with installing the sensor just above the MAF? I ask bc I have this same sensor installed in that location, albeit with a different air filter system, and I've never had any trouble with it. Wondering about your symptoms?

Thanks.

928NOOBIE

I have mine where the stock sensor is. In my mind I am picturing the install of the temp sensor directly above the MAF, below the airbox...the upgraded air temp sensor is big...about 1.5 inch tall X half inch wide....so a significant presence where air comes together so lot more airspeed and pressure...sticking the big temp sensor directly above the wire will change how air presents to the hot wire...

On the air temp sensor side where it resides stock compared to directly above the MAF pushes a lot more air velocity and pressure than stock location.

MAF readings should fluctuate a lot more with the turbulence and the velocity and volume of air hitting the temp sensor...I think both would perform better if the upgraded sensor is installed either in the stock location or near it...but would suggest not to install it directly above the MAF, below the airbox.

I installed a photrographers' honeycomb above the MAF...to straighten out the air and it did...and the car ran hopelessly rich....until I removed it.

Definitely am interested to read results regardless of which direction chosen to move forward and wish for only the best.

JJ.Bert

It is recommended to leave it to a professional mechanic

85euro928

So your answer is conjecture, not based on empirical knowledge?
I say send it, it worked for me, it'll most likely work for you.

928NOOBIE

I have not done the mod discussed but I have put objects directly in the path of the MAF and they impacted it and had to be removed.

So to clarify, yes, specifically for the mod discussed my comments are conjecture. I don't have empirical evidence related to this specific mod. This is an opinion.

I have / am using the temp sensor being discussed but it is installed in the stock air box temperature sensor location. Wishing only the best.