TOYOTA 1NZ-FE
I’ve been intrigued by Toyota’s line of small displacement engines of recent. The NZ-series particularly as it was installed in almost all compacts sedans and hatches including Vios Cabs with the 2NZFE. Much to my surprise, these engines are good platforms for decent power if tuned well. The availability of parts adds the icing on the cake, as adding horsepower will keep the builder at ease.
There are two variants of the NZ line.
The 2NZ and 1NZ. Both share the same bore (75mm), but they differ in stroke: 73.5mm for the 2NZ and 84.7mm for the 1NZ.
A completely stock 1NZ-FE can produce a respectable 85whp on our Dynocom FX5000 dyno at Dynobox/Staging Lines. I’m quite familiar with this number, as I use a stock Yaris NCP90 1NZ-FE to calibrate and check our Dynocom whenever it acts up.
Room for Improvement
When I first dynoed a stock Yaris, I could only make a few extra horses. I can’t remember exactly how much, but it was close to 92-95whp. One thing I noticed throughout the dyno session was the sound of restriction. Where was it coming from? It turned out to be from the stock exhaust system. The owner took my advice and had the car’s exhaust system modified by Staging Lines to my specifications.
Modified Exhaust and Baseline Dyno Run
I then reverted the tune back to stock and did another baseline run on the dyno with the modified exhaust. Sure enough, it resulted in a 104whp baseline run. That’s a 14whp gain from simply modifying the exhaust system.
Tuning
Tuning the stock ECU is always a pain with the need for reflashing. You have to wait a few minutes for changes to write, ensure the engine temperature stays consistent, and so on. My life would be much easier with a standalone, tunable ECU, but I work with what I have.
As with all internal combustion engines, fuel and timing play a critical role in making power. Looking at the original binary file map for this engine, Toyota ensured reliability across various conditions and regions. I started playing with the fuel map and began seeing power gains across the rev range. Adjusting ignition and cam timing yielded even more significant gains.
116whp was the safest number I could run with this engine, but since I could always monitor the car, I decided to push it a bit further. This resulted in a final output of 121whp. Most people would slap a turbo on these cars and call it a day, but a 35whp gain from stock is a huge improvement—especially in an all-motor setup, which also eliminates the inherent dip before top-end.
Vehicle Info:
• Model: Toyota Yaris NCP91
• Engine: 1NZ-FE
• Power Gains:
• 85whp (Stock Exhaust)
• 104whp (Modified Exhaust)
• 121whp (Tuned)
• Fuel Used: 95 RON / 91 Octane
Considering a Project or Race Car?
You can’t go wrong with an NZ engine.
Photos by: James Morales Jr. / JM media
Words / Article by: @Cris Yap of Cris Yap Tuning Services
Special Thank you to the ff:
Rex Abrenilla proud owner of this Toyota Yaris
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