Airbox fabrication

[papak]

I have been interested in improving the performance of my 2.3l Duratec with an eye toward cost effectiveness. Toward this end, I decided to fabricate a cold air induction system. It seems that the consensus is that you gain 1% for each 10 degree drop in inlet temperature. From a closer look at the physics, this relationship varies with the temperature range but for our purposes, that ratio is reasonably accurate.

I found a very nice airbox on the Jenvey website for $275 and another nice one on the SBD site for $592. The several others I found are in that price range. Ouch!

I had an old ITG “sausage” type filter sitting in the shop with worn out foam on it. This would normally cover the four 48mm ITBs with 50mm tall trumpets. I stripped off the foam and found that the underlying stainless steel screening is epoxied to the base. I opened up the front end of the screening to accommodate a 3” fiberglass tube. I then used an ultra fine fiberglass tape normally used for drywall seams to cover the outside of the shell. This stuff works great as it has a light adhesive on one side and is easily trimmed with scissors. I used some expoxy saturated mat on the inner surface. Once all of this set up, I hit it with some 80 grit. This was followed by a fair amount of lightweight filler in several thin layers interspersed by sanding.

Using a couple of manilla file folders, I determined the outline of the necessary blocking plate to fit the drover’s side of the nose fairing opening next to the radiator. This was transferred to aluminum sheet, cut and bent as necessary and mounted to the radiator mounting bracket. This was then trimmed to accommodate a 3” aluminum tube. The tube was mounted so that it extended in front of the radiator. I mounted a foam “sock” type air filter (Uni NU-2483ST) in the front of the tube (treated with K&N filter oil). This filter (or similar) can be found in many motorcycle or ATV shops.

Aside from the potential power gain, the impact on engine sound is noticeable. This cancels nearly all of the intake noise and consequently, makes the exhaust sound crisper. I considered fabricating a rubber baffle to surround the entire radiator (as in light aircraft installations) but the present cooling system works great as-is and the under-hood temps are not uncomfortable. There are 152 louver cut into the bonnet of the Birkin. This, in combination with the airflow around the radiator, eliminates the transmission tunnel heat issue entirely.

 

http://www.usa7s.net/vb/attachment.php?attachmentid=15275&stc=1http://www.usa7s.net/vb/attachment.php?attachmentid=15273&stc=1http://www.usa7s.net/vb/attachment.php?attachmentid=15274&stc=1

 

In the end, the total cost was under $100.

Edited April 22, 2019 by papak

[papak]

As you can see, I haven't fully mastered attachments.

[xcarguy]

As you can see, I haven't fully mastered attachments.

 

 

Your fab skills more than make up the difference.

[panamericano]

Great job. A nice, useful mod.

[John B]

That's really "Cool"! :driving: