The inspiration for the StealthBox Intake came from our internal talks about what an ideal intake system for the 2015+ WRX should be. At GrimmSpeed, performance is key, but we also focus on other aspects. We aimed for an intake that runs quietly during normal driving but roars at wide - open throttle. It should fit seamlessly in the 2015+ WRX engine bay, not look like a shoebox in the fender area. That's how the StealthBox was born. We further took inspiration from the F - 117 Nighthawk for the stealthy look of the GrimmSpeed heat shield, and its performance is equally remarkable.
Part #: 060067
**Quick Specs**
- **+32wtq (14.3%) and +21whp (9.6%)**: Enjoy significant power gains.
- **CAD - Designed**: Perfectly mates with the factory turbo and ram - air scoop.
- **Low Bend Angle Aluminum Tube**: Minimizes restriction and maximizes performance.
- **Shielded MAF Sensor Placement**: Protects the MAF from heat, ensuring accurate readings.
- **Made in the USA**: Manufactured in Minnesota.
**Design**
During the design, variables like MAF diameter, placement, total bend angle, filter location, and heat shield design were crucial. The MAF sensor must be within the heat shield for accurate readings. Keeping the bend angle low in the intake tube reduces restriction, and raising the filter protects it from the elements. The factory ram - air scoop is used to feed fresh air. Our engineers optimized these variables with a 3D model, resulting in a 74 - degree bend angle and a well - placed filter. The heat shield shape follows the factory air scoop, feeding fresh air evenly and preventing still air.
We decided not to sell the intake without the heat shield as it's vital for performance. Other products might sacrifice performance for a lower price.
**Materials and Fabrication**
Each intake starts with a CNC - bent and laser - cut 6061 Aluminum tube. The thicker 1/8” wall thickness provides a 'thermal flywheel effect', reducing the impact of engine bay temperature changes. Custom MAF flanges are machined from the same alloy, and mounting brackets are made from 3/16” thick aluminum plate. Heat shields are laser - cut, CNC - bent, hand - assembled, and powder - coated for a durable finish.
**Performance**
Dyno and long - term road testing confirmed the intake's performance. We used the same baseline as our J - Pipe/Downpipe test for the 2015 WRX. After installation and retuning at the same boost levels and AFRs, the intake produced an additional 32ftlb at 3000rpm and 21whp at 5500rpm, with gains across the curves. Tuning is required after installation for safety and maximum gains.
**GrimmSpeed Stealthbox Intake Kit Includes**
- 1x CNC bent intake tube w/ MAF flange
- 1x GrimmSpeed high - flow air filter
- 1x Aluminum heat shield
- 1x 12' MAF harness extension
- 1x Silicon hump coupler
- 3x Stainless steel worm gear clamp
- 3x Rubber gasket material cut - to - length
- 2x MAF sensor machine screws
**Options**
Although only a small part of the intake is visible after installation, you can choose between a matching black or a wrinkle red for the intake tube. The heat shield will always be in our stealthy black wrinkle.
**INSTALLATION NOTE**: Install the air filter on the intake tube correctly. Push the filter onto the tube no more than 1' before tightening the clamp to ensure the filter's velocity stack works properly.
Using the GrimmSpeed StealthBox Cold Air Intake is easy. First, follow the provided written or video installation guide for the 2015+ WRX. Make sure to install the air filter onto the intake tube properly. Push the filter onto the tube no more than 1 foot before tightening the clamp to let the velocity stack in the filter work well. After installation, you need to tune your car to maximize the gains and ensure safety.
When it comes to maintenance, regularly check the air filter. If it gets dirty, you can clean it according to the manufacturer's instructions. Also, keep an eye on the mounting brackets and clamps to make sure they are tight and in good condition. The heat shield helps protect the intake from heat, so don't remove it. If you notice any strange noises or a decrease in performance, it might be a sign that something needs to be checked. Just give it a quick inspection and if you're not sure, you can always reach out to a professional.
