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R18 Custom cold air RAM intake (Complete Guide)

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6.2K views 14 replies 6 participants last post by  oplix  
#1 · (Edited)
Total cost was around $50 with tax

$20 DNA motoring drop in filter (same as K&N) from Amazon

Following pieces from Home Depot:

$18 3' HVAC aluminum piping
$4 90 degree PVC elbow
$5 for two hose clamps

1. replace oem air filter with high performance
2. remove all factory intake piping and resonator after the filter box
3. connect HVAC piping to intake box (+hose clamp) and route it to where the factory intake resonator used to sit.
4. use existing drain hole in driver side fender liner (around where factory resonator sits) and make some incisions with scissors around it to make tabs that you can bend back. (You can also cut a custom hole out but I chose to just make tabs in case I want to go back to stock)
5. fit PVC elbow inside the hole using the plastic tab incisions to fit it through and hold it in place. Inlet should be facing forward towards front of car.
6. mold end of HVAC piping so that it sits snug on top of the PVC elbow. Secure it with second hose clamp.

Super responsive throttle and sounds amazing at 3k+ RPM. Fuel trim seems to be slightly better than stock for MPG.

I also used some gloss black vinyl wrap on the PVC elbow to make it look nice.

This is also considered a ram intake because the faster you are moving, the more air is pushed into the intake.

There is also an advantage to having a cold air intake with the filter at the factory intake box instead of at the front because you will never soak it in rain.

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#4 ·
I think my cell phone case cost more than all your parts lol.

Pretty sure there is no gains maybe make some extra sound which makes your butt dyno think you got some extra power lol.
 
#6 ·
Total cost was around $50 with tax

$20 DNA motoring drop in filter (same as K&N) from Amazon

Following pieces from Home Depot:

$18 3' HVAC aluminum piping
$4 90 degree PVC elbow
$5 for two hose clamps

1. replace oem air filter with high performance
2. remove all factory intake piping and resonator after the filter box
3. connect HVAC piping to intake box (+hose clamp) and route it to where the factory intake resonator used to sit.
4. use existing drain hole in driver side fender liner (around where factory resonator sits) and make some incisions with scissors around it to make tabs that you can bend back. (You can also cut a custom hole out but I chose to just make tabs in case I want to go back to stock)
5. fit PVC elbow inside the hole using the plastic tab incisions to fit it through and hold it in place. Inlet should be facing forward towards front of car.
6. mold end of HVAC piping so that it sits snug on top of the PVC elbow. Secure it with second hose clamp.

Super responsive throttle and sounds amazing at 3k+ RPM. Fuel trim seems to be slightly better than stock for MPG.

I also used some gloss black vinyl wrap on the PVC elbow to make it look nice.

This is also considered a ram intake because the faster you are moving, the more air is pushed into the intake.

There is also an advantage to having a cold air intake with the filter at the factory intake box instead of at the front because you will never soak it in rain.
I do recall FKX/Team 3D makes ram air for our cars. Just replaces the driver side fog light. Personally I wouldn’t use ram air on a R18 as I just noticed I used more gas and didn’t gain much power wise. It looks cool but it worth it imo. Maybe for a Si, yea.
 
#9 ·
Which brings us back to the often repeated truism that getting significant hp out an R18 is difficult without major (aka forced induction) mods.
 
#13 ·
I like home made things like this. They always work out surprisingly cheap if done right.

I really want to do a cold air intake on my 1.6 i-dtec. I've noticed a significant performance difference between hot days and cold days. The current intake is literally right at the top of the engine bay behind all the radiators!

I stripped loads of parts out the other day and can't find a single decent place to put one! :cautious:
 
#14 ·
Honda typically makes the inlet portion of the intake right at the gap between hood and the forward cross brace ahead of the heat exchangers (PSF cooler, A/C condenser, radiator).

That is the best place to put it for cool inlet flow while maximizing height to prevent hydrolock if one should foolishly drive through deep water.

These guys ain't no dummies. They know how to build a car, and the proof is in the sales and longevity of their products.

I seriously doubt Honda dropped the intake a half foot and dragged it back a foot to place it directly behind the radiator in your car. The piping leading to the TB? Of course that stuff is in that location, it has to go somewhere.

Heat soak is greatly exaggerated. I've instrumented intakes using K thermocouples and a 4-channel datalogger (I use a Monarch Instruments model 309). It may heat soak while stopped in bumper-to-bumper traffic on a hot day, but the moment you increase the smallest amount of throttle angle, you're back to ambient charge temps going to the TB.

OF
 
#15 ·
Well I went back to stock + resonator delete. I think it's probably the best option.

I do still like this ghetto mod a lot but I would recommend using a smaller inlet elbow. The one in the pics is like a 3" I think. I would recommend a 2". I noticed better torque with a smaller inlet.