CAI/Ram or just a high-flow filter?

hunterk1 · 08-06-2006, 02:33 PM

All the CAI/Ram intakes I've seen feature a high-flow (presumably oiled) foam filter element. I would expect that the reduction in flow resistance going from the stock paper element to the foam element contributes substatially to the overall power gain obtained from such a mod - that is, some gain is from the element, some is from the fresh air, some from a smoother air channel. But how much for each?

The question is - how much of an improvement could one expect by just moving to a high-flow "OEM-airbox" foam element (K&N is one that springs to mind, this is what I put in my CBR 600 F2 airbox) rather than going all the way to a CAI? I recall the old "Filter Charger" ads of old claiming a modest 5hp gain by moving to such a high-flow element.

Also, (although the answer lies just outside my door by opening the hood) does the OEM airbox really take up air from within the engine compartment? It seems like the designers should have given it access to fresh air to begin with.

Zeeshan · 08-06-2006, 04:53 PM

yes, it does take air from the engine compartmebt...for the most part most cars do.

you will see a very small gain when keeping the oem intake and just dropping in the k&n.

when you switch to a cai, its not just the fresh air, but the fact that you bypass resonators, and all the other little bs compartments the air goes through, mostly to keep it quiet.

if you want a noticeable gain, you'll want a cai. the drop in filter will only give you minimal gains...the only advantage is that you'll never need to buy another filter....or at least not for a million miles...lol.

hunterk1 · 08-06-2006, 06:57 PM

Zeeshan, thanks for the info. I searched these forums and noticed that some people discussed removing the resonator for improved airflow. I'll probably just get a K&N filter for now, cheaper and easier to install.

Noel · 08-06-2006, 10:19 PM

Actually, the attributed gains is indeed the bypassing of the resonators and flow restrictions in prevention of other concerns like hydrolocking and also the ability to have this car driven in just about any road situation with reasonable common sense not to drive this into the mud or sand. Hence aftermarket intakes significantly benefit from "freeing" what is available, not producing more.

On bikes, it's a different ballgame altogether. Bikes are well tuned, well balanced and highly refined from factory. There is little need for tweaking to aid gains as more of the power delivery would be almost subjected entirely to how the rider can harness and extract what is available. So bike modifications vs car modifications are almost entirely different in nature and what direction they extract.

afici0nad0 · 08-06-2006, 10:21 PM

^

yes, try removing the resonator and installing the high-flow filter. see how that works first...

keep us posted...

Zeeshan · 08-07-2006, 03:41 AM

my hypothesis....probably 1/3 of the gains of cai. let us know how it works out!

hunterk1 · 08-07-2006, 12:02 PM

I'll definitely post results when I can make the mods. I am interested to see if the foam element + resonator removal yields anything noticeable.

I just got a new car, a new baby, and a new job (title), so my finances need a while to stablize

I'll be looking to do this mod come early fall.

Thanks again for the comments.

Type R Positive · 08-07-2006, 04:19 PM

Go straight to the CAI.
I got high flow filter before the CAI. Big difference between the two.

hunterk1 · 08-08-2006, 12:03 PM

Quote:

Originally Posted by Type R Positive

Go straight to the CAI.
I got high flow filter before the CAI. Big difference between the two.

Really? Thanks for the input. What were you looking for, high-end HP or low end torque? I expect that the CAI yields the best high-end. I'm looking for more torque... maybe I should just get the motor stroked

Heh, like that would be as cheap (or as easy)...

AcidLotus · 08-08-2006, 02:22 PM

I've got just the K&N panel filter in the stock box with resonator delete. Works well. Torque is still good and it flows. I could feel the difference over stock. While it's probably not as optimal as the Injen CAI and I know the intake manifold gets too hot to touch even while cruising down the highway, the loss of torque on the low end and stock look keeps me at the panel filter for now.

Zeeshan · 08-08-2006, 03:40 PM

Quote:

Originally Posted by exciv2000

I've got just the K&N panel filter in the stock box with resonator delete. Works well. Torque is still good and it flows. I could feel the difference over stock. While it's probably not as optimal as the Injen CAI and I know the intake manifold gets too hot to touch even while cruising down the highway, the loss of torque on the low end and stock look keeps me at the panel filter for now.

Hmmm....too much heat is not a good thing either. The gains you get from the new filter and no resonator, could be cut by just the heat alone.

AcidLotus · 08-08-2006, 04:19 PM

Quote:

Originally Posted by Zeeshan

Hmmm....too much heat is not a good thing either. The gains you get from the new filter and no resonator, could be cut by just the heat alone.

not necessarily true. The heat issue would be greater with the resonator on, but besides that point, the Injen CAI makes most gains above 3500 RPM. If I rarely go above 3500 RPM, the modest gains from an Injen and the cooler air are essentially worthless to me. Not to mention I would never have to worry about hydrolocking with stock airbox.
Dyno: http://www.injen.com/SP1431/chart_2_bg.jpg
Note, that's a stock dyno, not one with a resonator delete and K&N filter, which would surely close the gap.

afici0nad0 · 08-08-2006, 05:42 PM

Quote:

Originally Posted by hunterk1

I'll definitely post results when I can make the mods. I am interested to see if the foam element + resonator removal yields anything noticeable.

http://www.vtec.net/articles/view-ar...&page_number=4

Quote:

After doing our baseline runs, both cars were also subjected to our traditional intake mod test, whereby we tweak the stock airboxes (or remove them) to see if there is any power lurking in the intake. The answer? A resounding yes. The TSX gained about 5 hp...Imagine what a proper cold air intake will do!

fyi - they removed the stock airbox. so, they were running it filterless?

hunterk1 · 08-09-2006, 04:28 PM

Quote:

Originally Posted by exciv2000

I've got just the K&N panel filter in the stock box with resonator delete. Works well.

Good to know, some discussion was leading me to just go for the CAI (not that there's anything wrong with that

). My main motivation is to keep the stock look; not sure if that's important or not, but I'm thinking about resale value. I'm also trying to keep my revs down, both for mileage and for longevity. I contacted the local Denver tuner that you suggested and will be down there sometime this fall for a reflash and these mods. I mentioned that you referred me, hope that helps in the long run.

afici0nad0, thanks, that looks like a great link!

Zeeshan · 08-09-2006, 05:10 PM

Stock look doesnt really matter for a small bolt on mod like an Intake. You can always just put the stock intake back on and sell the CAI on these forums or ebay. someone would buy it. so i wouldnt worry about the resale value.