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Go back to Opel Speedster 2.2 16v

Intake temperature

When converting to the Rotrex supercharger, the intake air temperature sensor remained in the factory location, just after the airfilter. This isn't a huge problem, as the Rotrex setup has quite good cooling. But in order to be safe it would be better to measure the temperature just before it enters the throttlebody.

Measuring the temperature at this point also gives the oppertunity to use the extra features in ObdTuner to change ignition and fueling depeding on the temperature. This is an extra failsafe option.

A sensor that is very use ful for this job is the GM25036751.

This sensor has the benefit that it has the same connector as the stock sensor. Also, it is an open type sensor, which makes it react very quickly to changes in temperature. Which is important so the ECU can respond to it quickly.

There isn't much choice to mount the sensor. Best would be in the silicone tube that connects to the throttlebody. I found and adapter from QSP that was advertised as a 3/8 NPT, which is the correct thread for this sensor.

When it arrived, the sticker didn't seem to be correct. As it turns out, QSP don't make an adapter for 3/8 NPT :(. However, using some threadseal I should be able to get away with mounting the sensor in the BSP tread.

The kit is quite complete.

In order to allow the sensor to come out far enough of the adapter, I removed some of the inside thread on the lathe.

Now the sensor sticks out enough to get airflow.

On the car I located the spot where I want the sensor to go.

Next, I used the tool to make the hole in the silicone hose.

The adapter slides through nicely.

I put the locking ring in place with some threadlock.

And all is looking good now.

On the inside it looks quite good.

Again with some locktite I put the sensor in the adapter.

And again the inside, looks fine.

I put the silicone hose back on the car. The location seems to work fine with the sensor mounted.

I extended the factor wire a bit, so it would reach the location of the new sensor. It is still easy to go back to the original sensor if there might be any problem. And with everything wired in, it looks like this.

Afterwards I did a testrun with ObdTuner logging. As you can see in the screenshot below the sensor seems to respond fine when making the Rotrex do work :)