FSZE Protege5 Track Build

2015 Mazda 6

With the JDM engine installed last year, I had always been curious on what it actually makes in comparison to the US engine...

Above, I have the dyno comparison of the US FSDE engine with bolt-ons that makes 113 hp and 102 tq . And with the JDM FSZE my car put down 132hp and 137tq on the dyno using the US engine harness and Mazda MP3 ECU.

The real reason for going to the dyno was because I was able to source a proper JDM harness and ECU to properly run the FSZE engine in my car. The harness and ECU was from a guy in Canada that had purchased from someone else, that extended it to fit in a LHD vehicle. So I removed the US harness to get ready to install the JDM harness...

Here is the US harness shown up top, and the japanese harness below. The car that the harness came from was a ABS car, and mine was not, so it is excessively long with things I did not need.

In order to use the FSZE ECU I will need to remove my lightweight pulley and swap the crank sprocket to the matching JDM sprocket on the left...

The harness was in, and I just needed to plug in everything and crank it up..

So being that the JDM harness was a ABS car, it used the ABS unit to monitor speed with the speed sensors on each wheel. In order to get around that I needed to run a signal to the speed sensor in the trans.

I had a spare harness to pull the proper connector from and make a harness for the speed sensor.

I was lucky enough to be able to get in touch with a guy from Australia, that had access to the JDM wiring diagram, and combined the information with another local friend that was able to identify the proper pin to remove and install to plug the speed sensor in..

I ran the speed sensor plug to the speed sensor on the trans...

And magic... we have a working speedo!

The JDM cars only run off a single o2 Sensor, so I plugged the secondary O2 sensor bung..

I was able to get back on the dyno and compare the two numbers. So with the US MP3 Ecu the car made 132hp and 137tq, but with a dying power band, that peaks at 3500-4000 rpm and falls down to 90hp at redline...which explains how and why the car drags on the straights.

And with the proper JDM ECU , the car makes 130hp and 135tq... but the powerband is much more useful and ideal . From 3500 rpm to 5500- rpm I am making power and holding it in a decent range to redline...

Here is a video of both sessions..

There was a final piece to the JDM puzzle that I needed to experiment with on the dyno. And that is the intake manifold, which features a resonance chamber to match the performance of the FSZE engine, which may make up for the loss of power in the higher rpms.

The intake manifold is a oem part, so it fits like a stock manifold would. But the fuel rail is different, which will require some re routing. But its a pretty straight forward install.

It was time to address the clutter of ABS mess stuffed in corner above. The idea was to remove the covering of the harness, and completely remove the ABS portion, since I had no use for it.

Harness out again...

Harness wrap removed, and the exact point of regret set in. As you can see the harness was extended previously by someone else and while they did do a good job. The cluster of red wires just makes this much more tedious.

ABS plug , and speed sensors portion removed from the harness.

Everything wrapped back up, and ready to go back in the car...

I would be lying if I said everything went as planned. It absolutely did not, first of all when I attempted to install the harness back in the car. I had the lengths off on several sensors, so I had to then go back and extend a few connectors to make it sit properly. Once that was settled the engine bay was much cleaner. And the mess of wires were gone. I am wanting to get back to the dyno and see if the intake manifold changes anything power wise or makes the powerband even better. But I realized I have spent weeks on this hunt for power, and I needed to get back on track with the long list of repairs for the 2021 track season.....
2015 Mazda 6
- Update with more in depth on the dyno session and everything. I have a lot to catch up on!
2x 2001 SP20 323's
Uuugh that red spaghetti monster is nasty! Good work getting everything up and running though.
Can confirm, a JDM sport20 pulls harder for longer than a FS-DE car, 100+ kph in second gear!


2011 MX5 GT
Sa-WEET! I wish there was more knowledge floating around like this when I had my Protege. It was all rumors and speculation about the FS-ZE engine. Glad to see you're tackling the project with success. My guess is you'll see positive gains up top with the FS-ZE manifold. I believe the 626 manifold is choking the top end with it's long skinny runners. Still, 135 hp/ft-lbs at the wheels with an MP3 ECU is strong. They were only rated for 140hp at the engine when new.