ACUITY CURL CONTROL Cold Air Intake System for the 9th Gen Civic Si (OEM Intake Manifold)

$ 419.00

- $ 441.00

Availability: In stock

Brand: ACUITY Instruments

An Exceptional Intake System, Built on the OEM 2.0 mindset: Nearly 1.5 years in the making, the ACUITY CURL CONTROL Cold Air Intake system was designed and painstakingly refined to be the best...

An Exceptional Intake System, Built on the OEM 2.0 mindset:

Nearly 1.5 years in the making, the ACUITY CURL CONTROL Cold Air Intake system was designed and painstakingly refined to be the best performing cold air intake for the 9th Generation Civic Si. Perhaps just as important, it was designed with careful attention to how it integrates with the OEM chassis mounting points and electrical connections. It is built from superior materials and requires no cutting or extending of OEM wiring and no clutch system bleeding during installation. The kit is designed to be incredibly complete, meaning a very simple installation.


Air Handling:

With its hand-laid carbon fiber and bonded billet 6061 aluminum appointments, this intake's carbon tube is the centerpiece in both performance and appearance. Air enters through a large, 6" dry filter, mounted to a spun aluminum velocity stack that reduces to 3.5". The silicone couplers located on either end of the carbon tube are designed with reliefs to provide a smoother transition as air enters and exits the intake. The throttle body coupler features an integral aluminum hose barb. Silicone hoses are also provided for the valve cover breather and coolant bypass. The carbon tube features a bonded billet 6061 aluminum MAF mount and mounting boss, both anodized in ACUITY's signature purple. Also supplied with the kit are German-style hose clamps. While more difficult to tighten compared to traditional clamps, German-style clamps provide more even clamping and have formed threads and rolled edges to prevent damage to the silicone couplers. 


Battery and Wire Management

The supplied battery tray is both attractive and durable. This is thanks in part to the careful combination of stainless steel and aluminum, allowing it to be strong where it must and light where it can, all while providing a rust-resistant design that will age gracefully. With laser-etched wire routing callouts and integral mount points for the battery ground and all wiring extensions, the battery tray ties the CURL CONTROL kit together to make it the most well-integrated 9th Gen Civic Cold Air Intake kit available. No wire cutting or splicing is needed. Instead, wire extensions are supplied to allow plug and play installation.


Tuning and Performance

The CURL CONTROL intake is designed to reduce pumping losses and reduce negative Helmholtz resonance effects to provide improved power and more desirable torque and power curves. In both internal and independent testing, ACUITY found the CURL CONTROL intake to produce 5-10 peak horsepower over the leading 3.5" aluminum cold air intake systems and up to 5% more area under both the power and torque curves, meaning more usable power, especially when compared to the stock airbox. Additionally, the CURL CONTROL intake helps to improve low-end torque and reduce the torque dip seen in almost all other intakes in mid-range RPMs. The result is an intake that not only provides impressive results over the stock airbox, but also impressive improvements over competing 3.5" intakes.

Because the CURL CONTROL's intake has a full 3.5" inside diameter, the air velocity is reduced compared to stock, and the factory MAF calibration will cause the vehicle to run lean. For that reason, it's absolutely essential to use a tuning solution like Hondata, K-Tuner etc. to account for the increased airflow to the engine. If temporarily running the car on a base calibration, make sure that the calibration is at least proven to work well with a full 3.5" intake.

Upgrades Made Easy

With the variety of intake manifolds and throttle bodies available to 9th Gen Civic Si owners, we know that there are good odds you'll want to change one or both of those components down the line. We're here to make those mods easier. ACUITY sells the throttle body couplers for each kit separately so that if you ever change your manifold or throttle body, you can simply buy a coupler and upgrade your original CURL CONTROL kit.


Kit Contents:

(1) Bonded Carbon Fiber Tube
(1) 5-ply, Fiberglass-Reinforced Silicone Throttle Body Coupler with Integral Aluminum Hose Barb
(1) 5-ply, Fiberglass-Reinforced Silicone Elbow
(1) 6"-3.5" Aluminum Velocity Stack
(1) 6" Cone Filter
(4) German Style, Stainless Steel Hose Clamps for Intake Piping
(2) German Style, Stainless Steel Hose Clamps for Valve Cover Breather
(1) Silicone Valve Cover Breather Tube
(1) Coolant Bypass Tube
(1) Stainless Steel and Aluminum Battery Tray
(1) Intake Mounting Bracket with rubber isolation mount and hardware
(1) MAF Harness Extension
(1) Battery Sensor Harness Extension 



  • 2012-2015 Honda Civic Si (with original intake manifold)


Important Note About Aftermarket Motor Mounts (PLEASE READ)

The CURL CONTROL battery tray has been confirmed to fit when used with OEM and Innovative motor mounts. The kit is not plug and play with Hasport mounts. A small amount of grinding on the Hasport chassis-side transmission mount will allow the battery tray to be mounted, but it is ultimately the end-user's decision whether or not to do this. 


Important Note About Aftermarket Batteries (PLEASE READ)

The CURL CONTROL battery tray was designed for use with an original equipment sized battery. Larger batteries may create fitment issues. 



Customer Reviews

Based on 5 reviews
I love it

Good Day 9th gen peeps,

After reading and talking to many forum members and facebook "friends". The hype was in the forefront of my mind for many weeks. As many of you know i decided to replace my Skunk2 Cai with the Acuity Cai. I also did not want to write a review without solid numbers. Unfortunately this written review is about 5 months late. Sorry Russ. Life & depression got the better of me.
But i digress, The intake is a very high quality piece. Every step on the installation was much easier then the Cai i replaced. Every part looks like it could have been handcrafted and as for the Carbon Fiber it probably was. There is no rattle, no breakage of any of the parts. None of the parts hit while i drive to and from my work, and just for clarification i live in the pothole capital of Massachusetts. Also i would like to point out the attention to detail with the battery relocation plate.
It is riveted, laser engraved & fit like a glove.
Now i would like to point out that the picture i have attached are of a befor and after dyno. I gained 3-4 whp from just the intake swap. Same dyno, same guy running it & with in 10 degrees of outside temp. Not bad, but not anything i can "feel" with my Butt Dyno. hahahaha
I would also like to say that if my Intake manifold was swapped out for an RBC i would see a larger gain, my OEM manifold just does not flow enough to completely use all of the flow that this Cai gives. I also have a catted downpipe, so that will also restrict the flow.
Would i do it again if i had the chance? Absolutely! No dough in my mind and no hesitation at all. This is by far the best Cai on the market for our cars.

Acuity cold air intake

Acuity makes very high quality 9th gen products and this intake is top notch , Best on the market . Customer service is also 5 stars !!! If you want the. Best for you’re Civic look no further , you will not find better ! Thank you Russ and everyone at acuity job well done .


To start this review off, I would like to give a BIG THANKS to Russ from Acuity!! I usually don't write reviews, especially ones like this. Anyhow, not only was my ordering experience completely easy, fast, and satisfying, but after receiving the Acuity intake for my 9th gen had me shocked! The quality of this product from them is top notch! Russ is here to make you 100% satisfied, and is here to help you in ANY way he can at ANYTIME! Installation wasn't too bad, just make sure you have the correct tools (swivel extension definitely). After installing the intake on my Civic, I couldn't believe the cleanliness of the install, sound, and power this bolt on produces. I am in the process of tuning it with VitViper Tuning as we speak. Only a few revisions in, and I can already tell that this intake is the BEST on the market in my opinion! Take my advice, and run with it! You will not be disappointed whatsoever! TO EVERYONE AT ACUITY INSTRUMENTS THANK YOU FOR THE AMAZING PRODUCT, AND KEEP PRODUCING FOR US RACE ENTHUSIASTS!

Cold Air Intake

Super pleased with it and the quality is amazing!!! Can’t wait for my tune to be finished with this beauty on!

Best intake on the market

For anyone interested in the Acuity intake, I bought it and tested it against my old Skunk2 intake. With the skunk2 I was making 191/171 tuned and after the Acuity cold air install my final numbers tuned were 198whp and 175wtq. A total peak gain of 7whp and 4wtq and also carried the power to a higher rpm. From 6100 and beyond Acuity takes over. This intake sounds freaking awesome and looks great. Easier to install over the skunk 2 as well. Very good price and fast shipping.

Please note that ALL orders ship out the next day, unless we are unable to fulfill your order, at which point we'll contact you immediately. Unfortunately, we cannot ship same-day at this time. So overnight shipping will arrive in 2 days, 2-day shipping arrives in 3 days, etc. If you require overnight shipping, please contact one of our vendors that carries inventory.