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19,589 Posts
Discussion Starter #1 (Edited)
Well, time for another Mother thread, this time regarding intakes for the 8th Gen Si. There is also a sticky about this, but it has not been updated.

Here is a thread by ErichPryde about how an intake works: http://www.8thcivic.com/forums/bolt-ons-all-motor/103077-where-does-stock-intake-pull-air.html

Discussion about intake ideas: http://www.8thcivic.com/forums/bolt-ons-all-motor/85353-custom-intake-need-feedback-inside.html

Review by JEA86 on all the intakes he has owned: http://www.8thcivic.com/forums/bolt...ve-review-intakes-i-have-owned-look-here.html

Interesting thread on intake temps on SRI. Enough that should dissuade people from getting one: http://www.8thcivic.com/forums/bolt...hot-w-fujita-intake-medium-outside-temps.html


Short Ram Intake


Price: $199

From Corsport: CorSport Online Store: AEM - 22516

Outperform every comparable intake system on the market
Every system is C.A.R.B. exempt, or pending C.A.R.B. exemption (50-state legal)
Utilize a complete hardware kit with soft mounts for a guaranteed perfect fit
Available powdercoated in Blue and Red, and in a mirror-polished finish*
One-piece, four-layer, cotton-gauze AEM air filter eases installation and features an exclusive air horn design that improves performance
Comprehensive installation instructions, AEM decals and license plate frame included
Manufactured and assembled in the USA
Limited lifetime warranty


CT Engineering: Air Intake Kit (06-08 Civic Si)

Price: $265

Gains were 8 HP on S/Ced and NA applications.



Injen -Price about $229 Uses a cotton filter that should be oiled


FujitaOnline.com F5 Fujita Air - Fujita Cold Air Intake and Fujita Short Ram Intake Systems- RideTuner LLC - Buy Fujita Online
Buy Fujita F5 Intake System - 2006 Honda Civic Si Short Ram


4. K&N V2-$269 Uses an oiled filter and a heat shield
K&N Typhoon Cold Air Intake Systems - World's Best Cold Air Intakes

Skyline4life review of K&N-good stuff: http://www.8thcivic.com/forums/bolt-ons-all-motor/89572-k-n-v-2-short-ram-intake-review.html


Weapon R Secret Weapon Intake Price: $239
Weapon*R Racing Development

The Secret Weapon Intake was designed, to increase air intake volume to the engine. The concept is to create two different air velocity profiles, one traveling at higher speeds than the other. This technology increases air volume and speed to the engine, which naturally feeds the engine 3x more air than the conventional air intake system. The intake pipe is bent out of high quality 6061 Aluminum on our Automated CNC mandrel bender. Polished to a high show quality finish. The SW1 Air filter features a tuned velocity stack to increase velocity and decrease turbulence. Only Comes In Polished. 1 Million Mile Limited Warranty Open pore high density re-usable foam Over 250 applications for Car’s / Trucks / SUV’s


Top Fuel SRI with cf power chamber that is supposed to compress the air to increase hp.


Good write up of Top Fuel Intake: http://www.8thcivic.com/forums/bolt...eview-top-fuel-power-chamber.html#post3427681


PRM Welcome to PRM Racing - Jet Stream Intake System

Info from danndan1: 09 civic on dyno video by prm_04 - Photobucket


Takeda Takeda Intake 2006-2009 Honda Civic 2.0L 4cyl Short Ram Retain

Filter type: Dry

Cost: $209


T1R A&J Racing*::*Engine*::*Air Intakes*::*T1R Carbon Intake System - Honda Civic Si 06+ (FG2)

Price: $567.81

We realized that the new model Acura CSX/Honda Civic K20 engines with DBW (Drive By Wire system) has poor throttle response. From our tuning experiences, in order to improve the throttle response, we have developed a bigger air box which increases intake volume by 20-25%. In that way, more air restoration inside the air box to provide a better throttle response and acceleration. At the same time, our big opening air duct to draw as much cold fresh air as much as possible to lower the intake tempurature so the performance will become more consisitant Under hot tempuratures.The T1R intake system comes with a big volume CFRP air box cover, T1R Dry flow air filter, T1R FRP air duct and nessecity hardware for installation.

Threads: http://www.8thcivic.com/forums/bolt-ons-all-motor/142261-t1r-intake-full-review.html


CAI or Cold Air Intake

AEM - Cold Air Intakes




AEM CAI #21-519C (Version with "Flow Straightener/Coupler to fix MAF issues)

Great thread by OrdnanceMarine: http://www.8thcivic.com/forums/bolt...flow-straightener-coupler-fix-maf-issues.html


AEM-Price about $260 Uses dry filter and seems to have tried to address the vanes in the MAF housing.
AEM - V2 Intakes


From Mattelis and his thread:


Future intakes possibly coming out:

KingMotorsports Type R- $790 or higher. Supposed to be working with Samco as well as address issue of MAF sensor. From KingMotorsports:1.3.2008 UPDATE: Mugen Air Box for 2006+ Civic Si
We have completed initial test fitting of the Mugen airbox on the 06+ Civic Si. We have found while the airbox physically fits the USDM Si perfectly, the ID of the USDM intake hoses are slightly too small to fit the Mugen airbox. We are working with Samco to produce a correctly sized intake tube that will also have a provision for the USDM mass air flow sensor. More updates to follow.


Password JDM-Probably $500-$600 Will require a battery relocation [Zeuceone says that it is not coming out, although I haven't read that myself-status pending]



Carbon fiber/exotic intakes:


Gruppe M- cowl induction-$1200 -the ultimate in intakes. Carbon fiber, cowl induction, bling up the wazoo.



GruppeM Inc. - English version site - Top page


Mishimoto Carbon Fiber intake-

Price: $255

Mishimoto Carbon Fiber Air Intake System 06-UP Honda Civic Si- P/N: MMCFI-CIV-06SI


Jay's Racing Intake for FD2:

Yesterday I cam accross the JsRacing intake for FD2R... don't remeber seing it here.

It has the same "problem" as the GruppeM, there is no location for our MAF! But it is easy to fix (I think).

But What I like, is that it is similar to the OEM box but with a cone filter inside. It is getting fresh air from the front grill where the OEM resonator is sitting. So it is very similar to NitrousG35 and 200HP_EP setup! (and my future setup!!!:dance:)

PLUS: (from what I undersand), the top cover is design to capture drawing some fresh air from the top front grill...

Here some pics of the installed intake:

On Jsracing website:


Blitz cf intake:

Pricey at 100,000 yen--though still cheaper than the FD2 one.




Home grown/DIY

Nitrous G35 cowl induction


2. Mike_Si_29 cowl induction-similar to Nitrous G35. Mike was the first to actually construct a DIY cowl induction. He provided inspiration for me and I used some of his ideas. Kudos to him.

2B. ataraxiaone and his cowl induction: http://www.8thcivic.com/forums/bolt...nduction-done-finished-finis-woot-woot-7.html Go to post #122

3. Homemade Icebox-DIY Si airbox


4. Xenin-his ideas and thoughts:

4B. Xenin and his M&M scoop installed along with a CRV intake tube: http://www.8thcivic.com/forums/bolt...take-duct-installed-yes-pics.html#post3187043

5. Juss-cone filter in lower Si airbox case:

6. CanyonDriver-X style

Dyno test of CanyonDriver K intake: http://www.8thcivic.com/forums/bolt-ons-all-motor/81664-cavemans-k-intake-results.html

7. X-Factor -he was the first to really think outside the box with a CRV intake tube, sectioned MAF housing and Apexi filter with stand. Too bad things went the way they did.



8. GeezerSi DIY on Fog light opening to get colder air to intake on CAI or M&M:

9. Tredd and his X-factor type intake: http://www.8thcivic.com/forums/bolt-ons-all-motor/102471-installed-my-diy-xintake.html

10. B Lou and his intake using a CRV intake tube and 80mm Apexi filter with stock MAF housing:

11. blckbrrygod and his custom CAI:

12. Thread by redviking about innovative intake where battery is relocated and filter is placed near factory cold air inlet. http://www.8thcivic.com/forums/bolt-ons-all-motor/107055-new-sri-set-up-repost.html#post3285609

Original blog: My 2006 Honda Civic Si JDM FD2 Blog - On Demand | Jack's Honda Civic FD2

Remove OEM intake and battery:

Relocate the battery with a custom tray, were the OEM intake filter is.

Final product:

12. 200HP EP and his homemade T1R airbox with Amsoil cone filter and soon to be added M&M scoop"
So I decide to made it because of heat soak problem.
I used:
-original X intake
-CRV tube
-amsoil filter (same as NitrousG35)
-SI intake box with the cover rebuilt by me
-OEM gasket to perfectly seal cover and base together. I cut the little lip all around the OEM filter and used it with the gasket.

Now I'm waiting for the M&M scoop... and this is my temporary version :laughing:

13. Kenua6 and his ducting from the lower bumper to the base of the airbox, ushering in cooler air to the intake: http://www.8thcivic.com/forums/do-y...made-ice-box-led-plate-light.html#post2914719
Just did some little thing over the weekend, I already did the KN drop removed resonator and 6k HID few week ago, but I think the that intake sucking the hot air is not good so I go ahead and did custom piping for the intake, and also I moved the rear spoiler move rear cause I dont like the rear spoiler when I first got the Si but now I love the spoiler alot more.

finish all the typing please enjoy the picture guy!!:dance:

home made ice box

Some pepboy ram air kit and 135 degree silicone hose I sell size 2.75"


Civic93 and his beautifully constructed airbox cover, T1R type scoop, mock ups, prototype and molds. Definitely the most sophisticated system to date for the DIY'ers:

Here are some updates on my intake that I am making. Let me know what you think. As of now both molds are done. Going to sand and wax them and make some final products soon. http://www.8thcivic.com/forums/bolt...ates-my-t1r-mugen-style-intake-lots-pics.html


Company called, "Backyard Special". Made scoop similar to M&M:

Blog Archive FD2 Intake Air Ducts

Initial observation of the product was that it was of a lesser quality compared to the M&M, which had a nice FRP gel coated finish. In fact, the piece i had where the 2 separate fibreglass pieces butts were met, besides having the normal faint line, it had a crack! But I guess, functionality wise, it will work just as well (regardless of fibreglass finish).

This air duct gets the cool air from the large front air dam and gets routed towards the airbox in a more direct path. It also has a larger catchment surface area and should be more efficient.

Here are some pictures of the installed product:


DIY by Ray

I like the stock Si airbox well enough, but simply couldn't resist the opportunity to make something.

~3" air filter --------------- Apexi 80-025
OEM airbox lid ----------- 17210-RRB-A00
(2) 3" couplers ------------ Spectre 8771
(1) 3" 22 degree elbow ---- Spectre 9728
aluminum or steel strap ----------- scrap
aluminum block-------------------- scrap
mounting bolt -------------- 1/4-28 allen
1/4" rubber, flat, and lock washers

I chose to retain the stock intake tube rather than using a CR-V one, and removed the stock airbox. I cut out the MAF housing from a new OEM airbox lid ala the X-intake, and modified the vanes in standard X-intake fashion.

I made an aluminum insert for the boss on the side of the MAF tube that orignally mounted the clip for the MAF wire. This insert has a hole drilled into its side which is tapped for 1/4"-28. The side mount bolts to this.

To tune the intake a 3" tube is placed after the MAF housing, before the air filter. Considerable testing has shown a ~4" length to be optimal for my car, but this is very critical. 1/8" of an inch either way is a big change, and getting the tuning just right is what makes the intake worthwhile.

Note that the bellows construction of the OEM intake tube section allows it to be compressed or stretched some distance. Exactly how long you have the tube extended or compressed by your mounts will affect your tuning and influence the optimal extension length. For these reasons it is recommended you try different extensions lengths to experimentally arrive at the opiimal length and insure the best results. This is easily accomplished with tube spacers, which we will get to in minute.

The Spectre 8728 3" 22 degree elbow I used for my extension is an inexpensive chromed plastic part that works well enough.

Amazon.com: Spectre 8728 Chrome 22-Degree Elbow

It is easily shortened and is strong enough to clamp to with force. It is about 6" long as delivered, and needs be shortened for best results. You cut the ends off with a hacksaw or other device to where you achieve roughly 4" in length when measured down the centerline of the curve pipe. This entails cutting off nearly all the straight ends, leaving just a bit more than the curved center section alone. Save the pieces you cut off to be used as spacers to arrive at the optimal length.

Cut the tube a little longer than 4" and then progressively shorten the tube in small increments, noting the effect. You should be able to tell when you've gone too short, and then use a spacer to regain the desired length. The best spacers are the ones that were the very ends of the tube, as it they have lips on them at the end that increase the outside diameter. These will sit squarley against the end of the MAF tube end to allow consistant mounting.

Two of the familiar Spectre 8771 3" couplers are used to join the extension onto the end of the MAF tube.

Amazon.com: Spectre 8771 Coupler/Reducer-Black

The asssembly can then be mounted to the OEM instake tube just as the original airbox was, with the only complication remaining being mounts. I made two, one that screws into the aluminum block pictued above on the side and one that goes under the bottom most bolt on the Apexi filter and down to the bolt under the shifter cable, the same one used on the x-intake.

I used some scrap aluminum plate for the straps, some 1/4" thick diamond-plate that was left over from another project. It was in 1/2" wide strips perfect for the job. You can buy similar materials at the home despots of the world. For the side mount I used two piced, forming a triangle for strenth. I cut the bracket a bit too short, and extended it with a short lenght of steel strap, bolting the aluminum L-bracket to the steel extension. The whole affair is bolted to the boss that the stock airbox mount bolts too.

The extension worked out well, as it allows articulation of the bracket and you can get it positioned in just the right place to avoid compressing or stretching the bellows, aiding in getting the tuning right. The bottom mount can easily be bent forwards or back to arrive wherever the filter ends up.

When you get the length just right, the part-throttle power compares very well to the OEM airbox, and there is less bucking in the lower gears. Mid-range power is excellent, and the top-end hit very satisfying. Here is a 1-2-3 blast recorded in-car with my rather lame mp3-player's voice recorder function:


And a little off-vtec stuff:


Sound is great in person, with a very nice purr/growl in normal driving and a significant war-cry WFO. Driveability is very nice, too. Mileage seems unchanged vs. the stock setup. I put the stock back on, and it sounded waaay too quiet... heh.


x fg x Custom ram air intake v3.0[/B]

So I got some bumper damage to to the front of my car so naturally, I decided to have some fun and modify my car while it was getting fixed. So I guess the short hand version of what i did was, I ran a tube from my factory intake box, to my fog area, cut a hole out of the fog light cover, and connected the tube to the hole to get a direct flow of air from outside of my car, to the intake box.

The idea here is, is the air that hits the front of my car, will enter the intake piping directly, and then cause a "Ram Air" effect in the intake. Does it work? I will never know untill I dyno it with a powerful fan placed right in front of the intake to simulate me driving at speed.

So heres how I did it. I purchased a brake duct and some silicone brake ducting tubing. I cut the hole out of the fog light cover, and I also cut the fixtures on the back of it to allow for the brake duct to be placed directly behind the fog light cover. I cut the brake duct to size and I cut it so it fit fairly close to the bumper. And I 40/40 glue'd it on, making sure it had a complete seal. So now what I got is a hole in my front bumper, with a duct behind it that reduces down to a 3" hose fixture. This is where I clamped the silcone brake duct tubing. The tubing is nice and smooth on the inside, its non kinking, and its heat resistant up to 550 degrees. I ran the tubing to my airbox and I attatched it there. As for the air box itself. I took it out, and I smoothed out the inside and I put in a K&N air filter to allow the air to flow more free inside the box.

So with that, I now have a conceptual Ram Air Intake. Like I said before, I do not know if this really works, But its just a theory and an idea I had. But I posted it because I had a fun time making it and quite frankly, I think it looks pretty clean. I still have 1 more thing to do to it, and that is installing a mexh like filter in the ducting to prevent things like cigarette butts and what not from flying into the intake.

Here are the parts that I ordered from Pegasus Auto:

And here are pics of it installed:


Intake from unknown source:


Bignewegg http://www.8thcivic.com/forums/bolt-ons-all-motor/162643-custom-ram-air-6-intake.html

Hey this is not my final product but I just couldn't wait to try it out. I went out to the car and test fitted all my parts and so far so good. Here are a couple pics. Also if anyone has any input or ways to improve the design it would be appreciated. I got some help from NitrousG35 from where to get the MAF housing. I ended up using the stock box and cutting it out. it was exactly what I needed.

I will need to remove the battery and relocate it for my setup to work. I've seen some other people do this with a CAI but i don't think I've seen anybody go my route with a ram air from the fog with a scoop my size.

there is so much room there without the bracket i could probably run larger tubing!

I used my Injen SRI as a test tube at first and it almost worked out but the end of the tube is some weird size and I couldnt find tubing to connect it.

Thats where the custom tubing comes into play with the MAF housing sitting in between.

Here is my complete setup. Yes that is a 10" scoop leading to a 6" tube that tapers down to a 4" then a 3" !!

I test fitted it all and started the car up. Sounded fairly similar to the SRI I have in there but I'm sure at speed it would be even better and at WOT.

I will have a video of the part where I have the car on in a couple hours.

I will gladly take any criticism and comments. I would like to know what ya'll think and how if anyway i could make it better. O the scoop will sit right behind the driver side fog light and yes I will remove the foglight and run a screen and filter in that spot.


Mike_Si_29 CT intake with custom airbox: http://www.8thcivic.com/forums/bolt...t-intake-custom-heatshield-small-battery.html

Hi guys,
I decided to build heatshield for my CT intake. I got small battery, relocator kit, 3" HPS silicon tube, sheet of aluminum, mold insulation (good up to 1300F), and some screws. I also have NACA scoop in front of radiator like many of you do. Air is guided underneath the filter. Still didnt get a chance to compare intake temp. to the outside air. Also, I will probably data log my AFR later on to make sure its in a right range.
I thought about making cowl induction, as i did earlier, but i think it will restrict some of the air for CTSC 2. I would have to make a pretty big hole in a cowl. Plus i already made one, so i decided to try something different. I dont know if i gained any hp or not; my main goal was decrease intake air temperature. I will give you more updates later on after I drive for a while. RPMs at idle are stable, but we will see. Anyway, here is what it looks like. It still needs a few minor touch-ups here and there which I an gonna do later on. Comments/suggestions are always welcome. Thanks for viewing...:wavey:


HPS Silicone Intake tube

From Samer327: http://www.8thcivic.com/forums/intake-spacer-discussion/148623-hps-silicon-intake-hose.html

HPS is now making silicon intake hoses to replace the existing OEM intake tube. The tube is made from high temp, multi-ply silicon intake hosing, which should improve airflow and keep air inlet temperatures cooler. We will be dyno testing later and measuring air intake temps as well.

Differences I noticed

Throttle response seems better

RPM down low doesn't bog as much

Smoother powerband from idle to redline

Looking to get on the dyno after Long Beach Grand Prix.

Here it is

Here it is installed

This is my Stock 08 Si vs DCRH without CAT

Here is the stock intake, DCRH vs the HPS Sil tube, DCRH


Stock 08 Si Stock intake, header vs HPS intake tube, DCRH

So there was a significant increase from the removal of the stock header and cat which is to be expected. However after that, the intake becomes the choke point. We didn't expect to see that great of an increase of with just the HPS sil intake, but apparently it was able to free the airflow up. With the diameter of the intake being larger on the MAF side and restricting down to the tb, we are not only able to increase the air volume, but also increase the air velocity running into the intake manifold. Another factor is probably the intake itself able to keep the intake temperature pretty steady, we tried to do pulls as consistently as possible monitoring intake temps and engine temps. I think the combination of these factors makes for the significant increase in performance.

However if you are just running a stock header, cat and adding the HPS sil intake, please do not expect to have such significant gains. This gain is only due to the fact that both the HPS sil intake and a DCRH was added. As you can see the power curves of the OEM and HPS sil intake are almost identical, but the HPS sil intake will provide more power output mid range and high range rpm.


Thanks for the help from the 09 Civic Si Coupe Owner Jonathan, HPS was able to complete a baseline dyno on a stock 09 civic si coupe (with no performance mod) against the HPS silicone air intake tube being installed.

The result is pretty consistent with what they expected before the baseline dyno. Basically the overall gain is not as dramatic as the other aftermarket air intakes, but the HPS silicone air intake tube does shift the whole power band upwards yet still maintaining a safe air/fuel ratio. You would see the gains from everywhere throughout the horsepower and torque curve.

2009 Honda Civic Si dyno in the HPS in-house Dynapack 4000

Dyno Chart - Baseline vs HPS Silicone

Air/Fuel Ratio

Torque shown - Baseline vs HPS Silicone Air Intake

Dyno Movie Clips Coming Soon!

If you guys have any questions please feel free to ask. I will answer as best I can.

I asked HPS for group buy pricing on this and they told me they will get back to me

Premium Member
19,589 Posts
Discussion Starter #5
^ Done. Thanks. :thumb:

Premium Member
30,957 Posts
great info like always :thumb:

2,243 Posts
I have a question about the GruppeM Intake. How would you drive the car in the rain? Wouldn't water get in through the cowl? I also think that if you paired up this intake with: Headers, Bigger Throttle body, CR-V tube, spacer and a Reflash then gains will be 15+. Adding an intake alone to a car will not make mad power, but working with other parts, it can become a nice combo.

2,885 Posts
i feel so special having my name mentioned in the intake list :giggle: I took it off though and went back to a stock air box because i was worried about my AFR's. When I have some money i'll do a before and after AFR dyno sesh just to put the info up on here.

14,929 Posts
Bill, and his "Mother" threads FTW!!!:thumb:

Premium Member
19,589 Posts
Discussion Starter #18
the power chamber design was scrapped. so thats not going to come out.
Zeuce, is that official official, or is that like the on/off K-Pro? Could you link me up so that I could check that out?

7,214 Posts
anyone have more info about mishimoto? I am in the market for an intake...Still can't decide sri or cai and I like in PA. I am looking for the most power...If I can't find anything about mishimoto im getting an injen cai
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