Why This Intake Makes Sense for the RX-8
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The stock intake on the RX-8’s 1.3L RENESIS engine does its job, but it is a restrictive design — this kit replaces the factory air box with mandrel-bent aluminum tubing, red powder-coated, and an oversized Dryflow synthetic filter. AEM Intakes+1
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Dyno-tested gains: approx +8.4 HP at 7300 RPM. AEM Intakes+1
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Filter location designed in the passenger side wheel well region to reduce intake air temperature for denser air charge. AEM Intakes
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Oil-free washable filter media rated up to ~100,000 miles between cleanings (depending on use) — long term cost savings
AEM Air Intake Systems are designed to produce massive horsepower and torque gains as well as better engine sound when used as a replacement for the factory airbox and air filter.
Performance Benefits
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Sharper throttle response due to reduced intake resistance.
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Improved airflow at high RPMs which suits the RX-8’s high-revving nature.
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More engaging induction sound under load.
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Quality appearance — red finish adds visual impact in the engine bay.
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Reusable filter saves money over time compared with paper-element replacements.
AEM intake systems are designed, tuned, and dyno-tested to fit specific cars and trucks. These air intakes usually include an oversized AEM Dryflow synthetic washable air filter for outstanding air flow, filtration, and performance while allowing easy oil-free cleaning. Most AEM intake systems use mandrel-bent aluminum intake tubes, powder coated heat shields, and high quality hardware designed to reduce restriction and reduce intake temperature.
Installation Notes & Considerations
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It’s a bolt-on system using existing mounting points and sensor fitments.
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Expect install time of ~1-2 hours depending on familiarity.
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After installation check for clearance around wheel well and ensure filter isn’t rubbing splash guard or debris.
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Since this is 50-state legal for qualified vehicles (CARB EO D-670-21) it’s safe for street use in most jurisdictions. Confirm your vehicle meets the qualification.
The design and components of each intake system vary so consult the installation instructions for more information on the contents of each part number. AEM manufactures a variety of intake kit styles including short ram intakes, cold air intakes, dual-chamber intakes, Brute Force intakes for trucks and SUV’s, and Brute Force HD intakes for diesel applications.
Final Verdict
If you own a Mazda RX-8 with the 1.3L RENESIS engine and are looking for a performance intake upgrade built to quality standards, the AEM 21-485R is a solid choice. It offers measurable gains (+8.4 HP on one test), better airflow, improved induction sound, and looks good under the hood.
For enthusiasts who demand more than stock without diving into full race-spec modifications, this intake delivers good performance, good build quality, and good value.
Joseph Riggs –
An amazing piece to buy if you have troubles with your rx8 idling really low this can be a huge difference to the car it has a really mean sound to it that’ll definitively put a smile on your face and is quite easy to install the red is brighter than expected but it does work out well for the car (some pieces do not go the way it was packaged it could give you some head scratching if you think it is that way)
keaton manshaem –
Was hessitant to buy for awhile considering the price. But i have to say it was worth the purchase. Product is very well made and easy to install. The hardest part was taking the front bumper and metal bumper off to fit the piping. Install took me about 2 1/2 hours but could be done quicker. Sounds pretty good throughout the RPM’s but really impressive 7-9. Also comes with dry wrap for the filter which is a nice add. The only Con I can think of is the price/time it takes to install. But as you probably already know, anything with this car is a little more money. Overall I give it a 5 star because its very well made and a nice add without to much trouble.
Jon –
Great product. Sounds amazing. Gives my rx8 an aggressive growl. Looks fantastic in the engine bay. Easy to install though the instructions are not good. It’s pretty straight forward to install.
Kaben Hanson –
My original intake had become brittle and parts were cracking off, purchased this one and it works well. Note, you will need to cap off a vacuum port on the upper plastic intake manifold on the driver-under side just past the throttle body, it’s the secondary air injection port. Car ‘might’ run a little funny for a short time after install, but the computer gets it figured out fairly quickly. Car runs great, would recommend
Joshua Terpstra –
Had to hammer crash bar to make it fit.Otherwise very easy to install.
Ayayou –
This is a great looking setup once installed. The largest part of the job is to remove the front bumper. The install took about 4 hours.The intake sound is deep and throaty at high revs (6000 rpm +). Not too loud. It feels like it should be complemented with an after market cat back.
chris –
Well worth it for the price. I’d gone back and forth for a while on whether or not to get it. Finally I did order it (Amazon had it the cheapest with free shipping). Install was a little sketchy. The instructions arent the clearest and I was guessing on some parts. In fact when it comes to the clamps and hoses (rubber connectors) it doesn’t really tell you which to use, so I put it together wrong. Lol. Luckily I was able to change it without pulling everything back apart.Performance wise,throttle response is better. As far as sound, I run a straight pipe from the cat, so I can’t hear if it sounds differently or not in the cab, but in the engine bay at idle is has a cleaner sound.Had to argue with myself whether or not to give it 4 stars for the instructions, but it’s too great of a product to knock it down that far over paperwork. AEM claims ~8HP gains at about 7800 rpms, I saw about 6.5-7 on average, which is still not bad for this car.
Amazon Customer –
Fits the rx8 nicely.