Mike Kojima posted on May 12, 2009 06:40
Although this is a pretty clean and straightforward installation, it is pretty involved and requires that the front bumper cover of the car be removed. This isn’t that hard but if you are mechanically inept, this is a more involved installation than your typical cold air intake system.
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| The air filters on Stillens 370Z long tube cold air intake are located in front of the radiator on top of the bumper beam and behind the bumper front fascia. This about the only place it would fit. Unfortunately this allows the intake to suck up hot air from the radiator even with airflow to the front of the car. Removing the bumper cover gives nearly 10 more whp across the board which shows the intakes tuning is right on. Stillen make us some bumper vents and a hot air heat shield to go with this intake and rule the world! |
Since the stock intake system is so efficient we were pretty sure that the Stillen intake was not going to make much difference and we were both right and seriously wrong. When running on the dyno, the Stillen intake produced on the average 3 more whp but less torque at 270 whp and 216 lb/ft with the power gains coming high in the powerband above 6700 rpm. Below 6700 rpm, the Stillen Intake lost a slight bit of power and torque. This isn’t the whole story though. For the sake of curiosity, we removed the front bumper fascia and ran the car with the airflow of the dyno’s cooling fan blowing straight on the filters. We were amazed to see that the Stillen intake belt out an additional 10 whp nearly completely across the board! Not believing our eyes, we ran the car with the bumper cover off for many pulls and the numbers repeated. We then replaced the bumper cover and the power numbers dropped to what they had been.
Stillen’s cold air intake is clearly a superior design with great power potential but the bumper traps hot air in the vicinity of the filters which nullifies most of the gains. We hope Stillen reads this and creates a bumper vent and heatshield kit so that the full potential of this great intake can be realized. Since people do not drive without a front bumper we are only going to show our with bumper cover power results.
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| Stillen's 370Z exhaust system gave decent gains across the board and produced a pleasant exhaust note |
Next we installed Stillen’s Exhaust System. As we have always stated, we feel that the 370Z is cursed with a corked up exhaust and a good exhaust system should free up power. The Stillen system is a high quality part made of stainless steel. It appears to be mig welded using an easily formable grade of stainless like 409 for the tubes with high temp coated mild steel flanges. Higher grade 304 stainless appears to be used in the muffler bodies and the exhaust tips. The Stillen system uses twin rear mufflers that are transversely mounted. For the most part the Stillen exhaust is a high quality piece but the tubing necks up and down from 2.5 to 2.25" in several places and in our opinion a system should be at least 2.5" all the way through. The Stillen exhaust uses slip joints and clamps in a couple of places which we don’t really like but on the other hand, the Stillen exhaust is reasonably priced.
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| Stillen's 370Z exhaust system features all stainless construction. We didn't like the slip joints but the cost is right |
Powerwise the Stillen 370Z exhaust did not disappoint It cranked out 6 more wheel hp at 276 whp and 219 lb ft of torque with gains coming across the board with the greatest.
gains at the higher rpm range with no power loss anywhere in the useable power band. The Stillen exhaust had a nice sound as well and was not in our opinion excessively loud or boomy. Stillen if you are listening, we think you might find more power if you experimented with larger tubing and kept the diameter constant over the length of the exhaust.