2004 Nissan 350Z - Power Pages

Baseline

Pros

The Nissan 350Z, with its potent VQ35DE 3.5L V-6 powerplant, is a longtime favorite among performance junkies, ranging from drifting to road racing across the world due the rigid chassis design, rear-wheel-drive layout, and reasonably affordable used car resale. Factory rated to deliver 287 hp, the Z is a great bang for the buck if you’re looking to achieve style, power, and impressive handling.

Cons

If you’re the type of individual who’s hell-bent on fuel economy, may we suggest you stay away from the 350Z. Although the 3.5L V-6 engine is quite the performance engine, it loves to devour fuel with an estimated rating of 18 city/24 highway, and that’s considering you’re not mashing on the accelerator from signal to signal.

NOTES

Prior to our baseline run, the 350Z was given an oil change and spark plug check/replacement before strapping onto the dyno. In stock trim, the 350Z delivered 247.9 hp and 244.3 lb-ft of torque.

Stillen Hi-Flow Intake Kit

Parts

K&N filter, Hi-Flow ring (velocity stack), brackets, mounting hardware, clamps, and instructions

Tools

8, 10, and 12mm socket; 10mm open-end wrench; ratchet; extension; screwdriver; and pliers

Installation time

45 minutes

Pros

The Stillen Hi-Flow Intake kit replaces the restrictive stock airbox to deliver additional airflow for an increase in power output. The intake kit uses a K&N cone filter that is both washable and reusable, incorporating an integrated velocity stack designed to eliminate turbulence while smoothing air as it passes over the mass airflow sensor for accurate readings. We like the fact that the Stillen intake kit is CARB approved and 50-state legal.

Cons

Due to the cramped engine bay, we found it easier to install the filter onto the Hi-Flow ring (velocity stack) before inserting into the Stillen urethane airbox. Both plenum intake tube and filter required proper alignment before installing the airbox and before finally securing them down with the provided clamps.

Notes

The Stillen Hi-Flow Intake kit recorded the largest gains in the top end from 6,000 rpm to redline with a gain of 8 hp and 7 lb-ft of torque. Consistent gains of 5 hp and 5 lb-ft of torque were seen from 5,500 to 6,500 rpm over our baseline run. We noticed a slight loss in power from 2,700 to 4,400 rpm due to the restrictive factory exhaust system choking the 350Z’s power—an issue we easily addressed using Stillen’s Race pipe and dual exhaust system.

Stillen Race Pipes

Parts

Race pipe (pair), mounting hardware, and instructions

Tools

10, 12, 14, and 17mm socket; 10, 12, 14, and 17mm open-end wrench; ratchet; extension; crescent wrench; and WD-40

Installation time

60 minutes

Pros

The Race Pipes are constructed out of stainless steel and feature a straight-through free-flowing design with a built-in expansion chamber that promotes more efficient exhaust scavenging, delivering horsepower throughout the rpm range with an emphasis on low to midrange rpm power.

Cons

The Stillen Race Pipes replace the stock catalytic converters for unrestricted maximum exhaust flow and therefore should never be used on your local streets or highway.

Notes

Dyno testing the race pipe netted some impressive gains with an increase in power and torque throughout the powerband—peak gains of 8.1 hp and 9.9 lb-ft of torque. The Stillen Race Pipes made 10 hp and 15 lb-ft of torque at 3,800 rpm over our previous run with plenty of gains in the midrange to top end from 4,000 rpm to redline.

Stillen Dual Exhaust System

Parts

Stillen cat-back exhaust system, exhaust gaskets, clamps, flange bolts, nuts, mounting hardware, and instructions

Tools

12, 14, 16, and 17mm socket; swivel; ratchet; open-end wrenches; extensions; breaker bar; antiseize; and WD-40

Installation time

120 minutes

Pros

Stillen’s exhaust canisters are constructed out of polished stainless steel and produce a deep tone while generating an increase in horsepower and torque. The exhaust is finished with dual 4.5-inch polished 304 stainless tips and comes with a lifetime warranty.

Cons

Due to the Stillen exhaust’s five-piece design, we suggest asking for assistance to help speed up the installation process.

Notes

Upon installation, the exhaust gave our 350Z a healthy bump in horsepower and torque, along with a slightly more aggressive exhaust tone. The dual exhaust system increased both horsepower and torque throughout the powerband. Our Z gained 9 hp and 10 lb-ft of torque at 4,500 rpm, while consistent gains of 8 hp and 7 lb-ft of torque were seen from 4,800 to 6,300 rpm.

Conclusion

Our final testing saw peak output improve to 270.1 hp and 260.8 lb-ft of torque—an increase of 22.2 and 16.5 lb-ft of torque—with the largest gains of 20 hp and 17 lb-ft of torque occurring at 6,000 rpm. With 270 hp to the wheels, the 350Z responded well to our modifications; acceleration was noticeably improved on the street. Our modifications simply paved the way for mods like aftermarket engine management, aggressive cams, and headers, as our future plans target the 3.5L mill into the 300-whp range.