Cheapo (relatively speaking) 318is Cold Air Intake

[TIATO]

Cheap performance is good. In one of my previous cars (1.9LZ3) I had a full Dinan CAI system complete with software and bored out throttle boy. It did very well but also cost an arm and a leg $900+.

Was it worth it, heck yes. Cool sound, much better throttle response, increase in upper rpm power.

When I got the 318 I was immediately looking to upgrade the air intake system. However little if any prebuilt systems were out there. After enough reserach I saw that some owners made their own CAI. Inspiration struck.

Heres the parts list:
Ebay K&N Cone filter with e30 adapter plate - $50
Vibrant* #2173 3" dia. 90 deg. aluminum elbow - $25
Vibrant* #2182 Blue 3"x3" Silicone Adapter Sleeve - $9
2 extra 3" hoseclamps - $2

* Vibrant parts are available through any Keystone supplied car parts stores

Heres what it looks like:


I decided on the 90deg. elbow to get the filter as far away as possible from the engine and fan wash. I also removed the plastic cover from behind the headlight to improve airflow.

How does it run, great. Under WOT it growls loudly. When crusing around, its barely noticeable. Throttle response is GREATLY improved and while I did notice a little bit of a low end power drop, its much faster in the upper rpm ranges.

Next on the DIY list is a heatshield.

Mario[/img]

[MR 325]

Nice job! Thanks for the quick write-up.

[Werksmini]

Hmm im pretty sure that that spot on most cars is taken up by ABS and the radiator overflow res. Also a couple of other things on CAI's. Make sure to get the adaptor with the rectange adapter and not the circle one. Also, build a heat shield, that will be a huge factor in throttle response ect ect. Good writeup none the less.

[TIATO]

Werks,

ABS pump - right below the cone filter
Coolant reservoir - attached to the radiator
Rectangle Adaptor - came with Ebay cone kit

One day I will get around to building that heatshield, just have got to find time.

Lastly, Thank you.

[65Matt]

TIATO - Consider yourself lucky! I got slammed for posting a write up on my CAI!

"Ya know, with that trap-door AFM it doesn't do any good."

"A 3" hose ramming cold air in straight from the headlight to the airbox? That's more restrictive than a stock intake! It will choke your engine!"

:roll: Mmm-kay... :roll:

Anyway, good job, TIATO! It should improve even more when shielded from the hot engine bay.

[UNHCLL]

Technically speaking, neither of you built a Cold Air Intake.

65Matt - Your CAI setup has been tried by many people, and after mathematical calculations i was deemed that the ONLY time that setup would help is when you were traveling something like 200+mph to get an actual "Ram Air Effect"

It might truly collect cooler air, but the restriction by forcing it all to flow through that hole is a killer. No offence, but it also looked very..... ummmmm Back Yard Spare housing material. If you are happy with it thats awesome, and all that matters.

TIATO-
Most deffinitely make it a point to build that heat shield. While it may feel like you have achieved a gain, chances are you are losing overall power.
Looks very good, throw a different more professional holder in there and you could sell them. 8)

[Jordan]

Looks decent TIATO, consider making a nice looking bracket, and you deffinately need a heatshield!

[NCm42]

You need a heatshield or it will not help you power wise at all.

[TIATO]

You guys are going to make me design a heatshield a lot sooner than I had planned to. :D

Hmm, what to next saturday morning - replace the clutch master and slave cylinder, brake master cylinder and install the M3 steering rack or design and build a heatshield.

Decisions, decisions......

[Stu]

You guys are going to make me design a heatshield a lot sooner than I had planned to. :D

Hmm, what to next saturday morning - replace the clutch master and slave cylinder, brake master cylinder and install the M3 steering rack or design and build a heatshield.

Decisions, decisions......

Put the steering rack as priority, and the master cylinder and tranny parts.

A heatshield isn't that important. You're maybe losing a fraction of a horsepower without one, because you're cone filter is placed in a nice spot.

[808BMW]

So that fits perfectly on top of your ABS computer?

I'm going to have to try that.

[Werksmini]

I have the radiator hose in the way for a normal one, and that spot it taken up by stuff. Hmm, how is my car so different from othere m20's. (i know his isnt)

[rs4pro3]

No your not confused here is my 88 325is engine bay. My cone filter is some knock off autozone filter. And I know I NEED A HEATSHIELD.

The cruise control servo takes up a good amount of space

[808BMW]

Oh yeah, the cruise control blocks it...

What did you do with your cruise control stuff to make the filter fit?

[rayz]

Oh yeah, the cruise control blocks it...

What did you do with your cruise control stuff to make the filter fit?

nothing. if youre not running piping, it fits fine. the filter im using has a bigger diameter than that one above, and it fits snugly next to all the CC components.