Just cleaned up the intake tract on my '97 318ti. Recent dyno results at HMS Motorsports by some folks on the 318ti digest showed real improvement through simple upgrades. I've done mine slightly differently since the dyno'ed car was a '95, but the end result is the same. BTW, the 318ti digest had it's plug pulled by the server owner. Should be back up soon (we hope)!

For you 96 and up M44 owners, you've no doubt noticed that the intake now winds it's way over the radiator to the passenger side of the car. It used to take a more direct path to the headlight area on the driver's side. Well, I couldn't see what good all that tubing was doing (other than blocking easy access to the front of the engine), so I've done away with it. There are no sensors that need to be relocated.

First, go out and buy a few feet of aluminum coated dryer hose, two clamps and a 12oz can of coffee (not decaf - the real stuff). Next, remove the cover over the intake tube above the radiator - two bolts on the top. You'll now see the intake tube exposed. The intake enters the airbox via a small curved pipe. Remove this; it snaps out of place by pressing the plastic locking tab on the top. You will not reuse this piece. There is a collar that connects the pipe you just removed to the rubber coated flexible tube that runs over the radiator. Separate it from the flex tube and save this piece. It snaps (barely, a real PITA) in the now empty hole in the air box. This makes a perfect attachment for the dryer tubing. Remove the air horn from behind the passenger side headlight area and the flexible tube. It's all just pressed into place with plastic tabs and stuff, a good yank gets it out of the way. Remove the support for the tube from the radiator shroud (2 more bolts on top). You can also pull it's metal bolt hole tab thingies. You now have a much nicer view of your M44.

Now, attach the dryer hose to the attachment collar on the air box with a clamp. Run the hose down between the power steering reservoir and the radiator overflow tank. Leave enough hose to easily reach the ground and then cut it. Open the coffee and start brewing 'till empty. Cut out both ends of the can. Get under the grill and find a way to fit the can into the area behind the front lower grill next to the radiator. You'll probably have to cut away some of the lower plastic shroud. Careful, it's not attached very firmly to begin with, don't pull it out of it's mounts. Once you've figured out a place for the can (this is the hardest part), mark it and drill two holes on either side of the can in the lower shroud. Pull the can back out and attach the dryer hose to it with a clamp. Put the can back into place. Run plastic tie-wrap through the holes and around the can to keep it in place.

You can also choose to gut the baffle from inside the stock airbox (I did). You're done. You now have a very cheap cool/ram air setup for your M44. I also noticed that my rubber coated hose had a big hole in it meaning I was sucking hot air from over the radiator (there's a Hooter's girl joke there somewhere). Now, only cool clean air. Careful going through deep puddles; you don't want to submerge the can and suck water (nah...).

What's this worth in HP? About 4 from computing the results of before-and-after timed single gear accelerations as well as 1/4 mile runs with a G-Tech pro (no butt-dyno for me). Saw an increase in the 1/4 mile trap speed from 84.9 to 85.8 mph. Not much, but not bad either for under $10 when most K&N cone setups and $$ exhausts fail to get more than that on OBD-II cars. Have fun!

• -- Ron Katona mailto:ron3b_at_cris.com 97 318ti Active