1st Dyno Drama

At long last, the guessing game has finally come to an end. With the turbo, i often ask, how many horses is my Charmant making? Today, i get to put a number to that question.

The Dog has gotten its long overdue dyno-tuning finally today. I had been using rough fuel map and safe ignition timing so far and never dared enough to push the 4A-GTE to the maximum from being too afraid of having to rebuild the engine for the third time. With the dyno tuning she just had today, i can feel safer in hitting full throttle on The Dog.

The tune was done in Khatulistiwa Surya Nusa workshop in Jakarta. As far as i know, KS Nusa has the only steady state dyno in Jakarta. A steady state dyno is best when you want to tune each important cells of your fuel and ignition map as it allows you to set a defined load to the engine. For example, if you want to tune cruise speed cells, you can set a load of 50kPa and just play with the gas pedal to get you the desired RPM and tune away.

This being my first time seeing a dyno tuning process directly, i was really unprepared for what i'm about to face. Well, i know that's what they do on the process but, still, hearing the engine being revved to 7,000 RPM made me cringe. I was afraid something might just break and had to do another rebuild. Luckily, everything went smooth and the engine was safe..

Or is it?

At the finalizing phase of the tuning, the engine died a few times after just being revved to 6000+ RPM. At first, it was only the connector to the VR sensor that came unplugged suddenly. The same happened on the second time. On the third time it happened, i decided to tie the connector tight to the VR sensor. Sadly, the engine refused to turn back on. After a short panic, i finally found that now the VR sensor has gone to auto parts heaven. My guess is that the sensor's bracket still not sturdy enough and vibrated too much at high RPMs, causing the sensor to hit the trigger wheel.

Luckily, the tuner managed to get a power run before the engine died. So, here's the result..

See anything weird? Other than a note saying that my VR sensor was damaged, there was an unusual slope on both the torque and hp curves. Here's what happened.

Notice how the boost pressure slope matches the previous curves? So what we have here is an unstable boost pressure. That's the bad thing about using manual boost controller. They tend to be unpredictable. I guess i better look at getting the electronic boost controller feature on MS to work now. I was also a bit discomforted seeing the AFR on boost region. The tuner aimed to just around 12. I always thought that boost regions should get at least 11.5 but the tuner explained that with such small boost, AFR of 12 is still safe.

Obviously, i couldn't get the engine running with a damaged VR sensor and getting a replacement sensor will take a while from Ebay. Thus, i had to call a towing service to get The Dog home.. Sadly, this also meant i was unable to attend a gathering held by my fellow Charmant lovers from Daihatsu Charmant today. Oh well, there's always next time, i guess..

Getting the engine running again is top priority now. I need to get a replacement sensor ASAP.