Intake Routing Challenge

I'm going to plumb my Airflow Snorkel to my Gen I TRD Intake. I understand the possibility of limiting air and decreasing performance by doing so, and am going to leave myself the option to disconnect the snorkel inside the fender well during daily driving if I so choose.

The challenge is connecting the 4 inch round snorkel outlet to the 4.5x5.5 inch oval air box inlet.
Obviously - Must be Air/Water tight and preferably using worm gear type band clamps. I've asked a couple companies about a custom made transition pipe, but @ 500 dollar tooling charge and a 50 piece minimum run...Not gunna happen.

For reference:

 

How about a 4" stub pipe with a base inserted from the inside of the CAI, protruding outwards. Then you could use a standard rubber furnco pipe clamp to join the airflow snorkel pipe to the new pipe since they'd be the same outter diameter. The stub pipe with base would have to be epoxied to the CAI box so as to be water tight and to take any jostling that occurs while trying to connect the 2 pipes.

 

BRILLIANT!!! Now to find the perfect stub pipe...

 

Airaid make something called a UBI or U Build it intake tubing kit. Not sure if it is in 4"? As well, it could be likely to much material than you need....

You could also just purchase a piece of aluminum 4" tubing from a performance shop locally of or order a piece online. Usually sold in 1 foot lengths minimum.

Just need to measure the I.D. of the TRD inlet.

There are also reducer silicone couplings, but that would be an awkward fit due to the tapering oval inlet.

 

This might help?

http://www.hps-siliconehoses.com/hp...ler-silicone-hose-black-reinforced-4-ply.html

Not sure without doing some formulae, what a 5" circle would be when changed to an oval?