Anyone running a ram air intake?

The Gas and Diesel Engines - VQ40De, VK56DE, YD25DDTi, V9X, Transmission, Transfer Case, Oil, Differentials, Axles, Exhaust...

Moderator: volvite

PYROtheNomadR51
Posts: 6
Joined: Sun Jan 29, 2023 6:54 pm

Anyone running a ram air intake?

Postby PYROtheNomadR51 » Mon Jan 30, 2023 9:11 pm

269CA7B4-DC87-482B-89F4-70A99121A4AC.jpeg
This is my pathy. I built an intake out of pvc and routed it through the grille. Haven’t had time to test it out to it’s full potential yet because my timing chain gave out right before I built it and my car is still in the shop. When I drove it to the shop though it felt very responsive to the throttle. Besides the volant intake ram air, I’ve only seen 1 other 4.0 with a similar setup and that was a frontier. Some people run a vacuum hose up to the air box from the place where the fog lights would be but I have fog lights so I opted for a through grille intake. I don’t think this setup adds horsepower on the dyno because air isn’t being forced into the air box but it definitely makes a difference in every day driving. I have yet to compare gas mileage but I wouldn’t have accurate numbers anyway because my evap purge valve had a fault code which I think was draining my gas faster than normal. My main reason for this post is to see if anyone else is running anything similar that isn’t a volant box, or if anyone has any suggestions to improve the gains I can get with this, thanks.


User avatar
AS_The_Crow_Flys
Posts: 116
Joined: Wed Jun 15, 2022 1:28 pm

Re: Anyone running a ram air intake?

Postby AS_The_Crow_Flys » Tue Jan 31, 2023 4:15 pm

Maybe this is a dumb question, what happens when its raining. Wouldn't that force water into your airbox?

User avatar
VStar650CL
Posts: 501
Joined: Wed Dec 09, 2020 6:19 pm

Re: Anyone running a ram air intake?

Postby VStar650CL » Tue Jan 31, 2023 6:33 pm

AS_The_Crow_Flys wrote:
Tue Jan 31, 2023 4:15 pm
Maybe this is a dumb question, what happens when its raining. Wouldn't that force water into your airbox?
Ram setups usually have a hump or incline to prevent direct water intrusion, but it will still make the incoming air extremely humid in a rainstorm. You get spatter caught in the airstream, and in the long term it's likely to cause some corrosion in places like the back side of the butterfly.

PYROtheNomadR51
Posts: 6
Joined: Sun Jan 29, 2023 6:54 pm

Re: Anyone running a ram air intake?

Postby PYROtheNomadR51 » Tue Jan 31, 2023 8:34 pm

VStar650CL wrote:
Tue Jan 31, 2023 6:33 pm
AS_The_Crow_Flys wrote:
Tue Jan 31, 2023 4:15 pm
Maybe this is a dumb question, what happens when its raining. Wouldn't that force water into your airbox?
Ram setups usually have a hump or incline to prevent direct water intrusion, but it will still make the incoming air extremely humid in a rainstorm. You get spatter caught in the airstream, and in the long term it's likely to cause some corrosion in places like the back side of the butterfly.
Yes I have thought of the water but I did add some things to hopefully stop water from getting in and I angled the pipe right at the dust traps in the bottom of the air box just in case anything does get through and I’m hoping a drop in k&n filter will help with the corrosion. But thats just my thinking, I could totally be wrong

User avatar
AS_The_Crow_Flys
Posts: 116
Joined: Wed Jun 15, 2022 1:28 pm

Re: Anyone running a ram air intake?

Postby AS_The_Crow_Flys » Wed Feb 01, 2023 10:50 am

How would a k&n filter help with the corrosion, at least the cellulose ones will absorb some moisture, but an oiled filter will just .... well not absorb the water.

PYROtheNomadR51
Posts: 6
Joined: Sun Jan 29, 2023 6:54 pm

Re: Anyone running a ram air intake?

Postby PYROtheNomadR51 » Wed Feb 01, 2023 1:18 pm

Maybe this is dumb but I figured since the filter is soaked in oil, less water would get through. I haven’t even put a k&n filter yet though and the only weather the intake has experienced has been rain and more rain and no sign of water passing through the filter. Some dodge challengers come with this stock with no bends to catch water so I assumed the water wouldn’t be an issue. And like I said I’ve even seen people over on clubfrontier running something similar

User avatar
ShipFixer
Posts: 769
Joined: Sun May 24, 2009 9:52 am
Location: San Diego, CA

Re: Anyone running a ram air intake?

Postby ShipFixer » Thu Feb 02, 2023 3:07 am

This article remains a good discussion of ram air:

https://www.cycleworld.com/story/blogs/ ... explained/

TLDR version - true ram air only works at high speed, and must be engineered correctly to work. It sort of works on very fast production super sport motorcycles at track speeds because they have a very short distance from the stagnation point at the front of the moving motorcycle to the intake runners. There's pretty much no point on passenger vehicles, or as one of my engine designer friends says you would see every vehicle maker out there killing for that 0.1 mpg improvement in CAFE score for whatever it is.

What you might be observing is the same improvement you get out of most cold air intakes. A shorter intake tract with an increase in "hydraulic diameter" and therefore less drag. On the other hand, maybe not. Only a metered test would show.

There is some logic to getting rid of the resonator box and labyrinthine piping for air; that's partly for water intrusion and very much so for sound, where high to medium frequency noises don't make tight turns very well (refraction) and don't escape to the outside world. I did that on my motorcycle, but a.) I know it doesn't actually matter for intake drag loss and b.) I just like the induction sound over the boring Honda "sewing machine" sound.

I would worry about not just water, but also increased clogging of the air filter or worse. The other good thing about a labyrinthine path to the intake tract is it makes it harder for everything from dust to leaves to get to the air filter. I'm surprised enough at what makes it up to the air filter in this thing sometimes, not sure I would make it easier beyond what a cold air intake does.


Return to “R51 Engine, Driveline and Powertrain”