「Turning an Old Man’s Slow Sedan Into an NA Fighter」A JZX90 with Modified Sports Injection!【OPTION Back Number】

2020/04/26 13:10

The car we introduce this time is a low-grade NA Toyota JZX90 Tourer S. The mechanical tuning brought a 60ps power up by upgrading the intake and exhaust systems. (OPTION May 2002 Issue)



The feeling of a direct 6NA in a JZX90 Chaser!


Simple intake/exhaust mods give a Tourer S 60ps of added power!


This was a JZX90 Chaser Tourer S that was bought second hand without much thought. The owner knew it was a lower and slower grade, but after realized it was even slower than expected, he decided to tune it.


”Is it possible to improve NA response and incease power?” asked the owner. He consulted with tuning shop Grand Slam (※) and sports injection using a Weber Alpha kit was proposed.



The throttle bodies and injection adapter are Weber Alpha, and other parts are one-off original. The exhaust manifold was carefully selected. Max output jumped from 160ps at normal to 220ps tuned, achieving a 60ps power up.



Inner diameter of the throttles are 45mm. The Weber Alpha kit is said to be extremely accurate, powerful and reliable. Intake manifold that connects the engine and throttle bodies is a complete one-off original. The length of the intake pipe is calculated and both the length and angle are set to take advantage of maximum power.



Although the funnel spec gives off an exciting exhuast note, a stable intake is achieved by equipping it with a surge tank and air cleaner. Of course, you can shut out dust and dirt too.


As injectors for Toyota are not suitable, Nissan RB20 injectors are used. Also, two GT-R solenoid valves are used to keep idling up when using the air conditioner.



The engine management the CP was rewritten and setting was refined in the DC system to control idling.



The suspension is based on Ohlins PCV coilover. Brakes have an Alcon caliper kit for increased stopping power.



Originally it was an automatic transmission but after powering up with sports injection, a manual swap became neccesary. A Tourer V 5-speed (R154) with an ORC single clutch was installed.



The total amount for parts, installation and setting seem to be around 900,000yen. It is easily possible to increase power from this state so this is a good as a tuning base or to drive as a spirited daily. (* tuning shop Grand Slam is currently closed.)