M42 Intake Modification
by Bob Collins
I was wandering through Pep Boys one afternoon looking for a piece of flexible duct of large diameter tubing I could rig to the intake hole. Well, there it was, the Mr. Gasket 'Air Cleaner Adapter Ring' P/N 6404. It was $5 USD and worth the effort. The airbox has this cone that is about 1.75" Dia opening that flares to about 4.5" Dia.

The problem is that the little end, has the duct that runs forward to the driver's side kidney. The cone sits 90% inside the airbox and leaves about .5-.75" from the end of the cone to the back of the airbox. This configuration seems to leave the airbox a little choked for fresh cool air. The problem with removing the cone is then the duct from the kidney to the airbox has no location to attach, and the opening of the airbox is about 4" dia. I cut the adapter ring at the large end down from a 5-1/8" dia. to about a 4.75" dia. This fit perfectly against the airbox's large opening. The smaller end of the adapter ring fit perfectly to the round end of the duct piece that runs from the kidney to the airbox. I did have to remove the airbox from the car and the cone from the airbox. This is not bad, the nuts that hold the airbox are 11 MM. There are only 2 of these. They bolt at the driver's side wheel well, right next to the cruise control unit if you have that. Once you remove the airbox, you will see how the cone is held only by a couple of snap fittings cast right into the plastic. Pull the cone out and keep it in a closet for later use. For what, I don't know. :-) Anyhow, then you have to whittle down the large diameter of the ring to fit against the airbox. Be careful with that shop knife. Once this is done you can press fit the intake duct that goes to the kidney to the end of the adapter ring.

1.Blow up of how the intake, Mr. G. part, and the airbox match up

2.The kidney to airbox connection duct w/ the Mr. Gasket part press fit

3.The whole setup back in the car with the filter and cover still off of the airbox.

That is it. Feel free to do something else, but this worked nicely for me.

Bob Collins


http://www.318ti.org/notebook/M42_intake/
September 17, 1999