Fitted a ACT guage from Harvey a few weeks ago and thought that I would post a my experience so far.

First, the sensor is installed in the connecting pipe between the intercooler and the throttle body and samples the temp a couple of times a second.

Second, the car - standard TMIC on a 2003 WRX. The car is running around 1.3 bar boost on a VF34 turbo (with supporting mods)

First impression was that on the road it's not possible to really tax the intercooler while still trying to keep my licence! I did a couple of nice runs along good country roads and it stayed less than 10C above ambient (average 5C) even on full boost. However, being on public roads means that being on boost doesn't last long so it wasn't that taxing a test!

The other thing I noticed on the road was that heat sink at traffic lights really wasn't a problem. To be fair I haven't been stuck in traffic for too long, but it only climbs a few degrees every minute and it takes less than a few seconds of driving for it to go down. Ambient temp in these cases was less than 7C.

Heat sink was noticable (as expected) after a long drive then leaving the car on the drive for a while. After an hour on the road and 30 mins on the drive the intake temp was around 30C (ambient 4C). Again, temp dropped very quickly as I started to drive.

Then on to Brands Hatch for a track day. Ambient temp didn't go above 3C. Two things to note for this test - first that it was the short version of the track (1.5 miles) and there is only one bit where you can accelerate for any length of time (through the pits straight). This means that after a full boost run the intercooler has time to cool down. The second thing to note was that the car had a boost problem (now solved with a 3 port boost solenoid) so wasn't at peak performance.

The results at brands were interesting - the intercooler seemed to cope well throughout the track day with average temp on boost of 20C and peak of about 25C. Due to the cold ambient temp (3C) the temps fell very quickly off boost.

Second track day (yesterday) at Bedford autodrome. Boost problems fixed and ambient temp now 11C. Also a couple of map tweaks to cope with potential high temps on long boost runs. For those that don't know Bedford, it's a long track (4.8 miles) with a couple of nice long straights and quite a few higher speed turns. My highest speed on the circuit (measured by my PSI3) was 129mph (stupid speedo was showing nearly 140 - so inaccurate at the higher speeds!).

Running the track day at Bedford showed the limitations of the WRX intercooler. Running along the longest straight (from around 3000rpm in 3rd to 6500rpm in 4th) temps climbed steadily to 43C (don't worry, the engine map was tweaked before to take account of this and I was using octane booster). The charge temps cooled well on certain parts of the track with slower speed corners, but they stayed above 20C the entire time (remember, ambient was 11C).

Conclusions then. I'm probably running the WRX TMIC at the limit of what it can provide. I'm not planning to up the power any more on the car so I'll probably not go to the expense of upgrading it for now, but I'll need to remember that as it gets warmer in the summer on tracks like Bedford I need to be careful of the air temps on long boost sections of track. If I didn't track the car then I probably won't give it a second thought!

 

Nice writeup!

 

very useful was toying with the idea of uprating the intercooler but think il wait now till i hit bigger power CHEERS!!!!!!!

 

It'll be interesting to see what happens in the summer when the ambient temps are much higher!