328 folks - check that air intake hose!

This morning I discovered that a couple of months ago, when I had the ac (badly) serviced, the tech, in removing the airfilter assy to better access the ports on the compressor, had broken the large intake hose loose from the filter housing. (another piece of evidence to support the old saying, "If you want anything done right, do it yourself.")

When I opened up the filter housing the filter was about 1/3 obstructed by foam and black paint or plastic flecks. So I pulled the hose completely out and found it is in as bad a shape as most 328 hoses. I took pics of the cr@p on the filter and the hose but, unfortunately, I just discovered that i had forgotten to bring the cable to download pics from the camera so I can't post it.

So over the next few days, if I have time - I'm pulling/cleaning the boat's heat exchangers - I will try to fabricate something to do the job. Hardware stores have some sheets of foam that might be workable though I'm sure folks here have tried that; I'm not sure if the foam in question will withstand engine heat, etc. OTOH, it can't be any worse than the foam on the hose right now!

At the moment there is no hose at all and the filter is getting its air directly from the hot engine compartment. I'll certainly report if I can tell any difference in power!

 

I made up a new hose using the original core and 3/4" foam and the entire setup wrapped with overlapping strips of duct tape. I know it may sound bad but really, it looks good. If I had black duct tape (do they make that?) it would look pretty much like the original. At the moment the 3M adhesive, which holds the end caps to the foam/hose is setting. Tomorrow I'll install it on the car. From an operational view, it is identical to the original - same core with the same foam surround. Appearance-wise, not so good - grey duct tape color instead of black but what the heck, it will work fine for now. I could spray paint the hose flat black but the paint would flake off as the hose bends so that's not workable. If there was some sort of "rubbery" black spray paint you couldn't tell it from oem...

Again - I have pics but can't post them. Maybe I'll break down and buy another camera-to-computer USB cable...

 

I don't even know what that Ebay thing fits - it's got nothing to do with any part of the 328 intake as far as I can tell.

The other post is it...the hose from the intake scoop to the air filter housing.


Hmmm...re gorilla tape; it may be just the thing. I could un-duct it and Gorilla it instead...

 

I looked at the Ricambi parts diagram and I see that ebay hose shown as the hose for the 328 - both the earlier and the ABS 328. But since it is not the hose used on my 89 328, I guess the foam-covered hose was the last version of that intake hose.

 

This woke me up in the middle of the night - a sudden flash of "knowledge!" (or maybe not!)

Anyway, I suddenly realized (OK, "Believe" is a better word) that the purpose of the foam on the 89 328 air filter hose from scoop to airbox has nothing to do with reducing engine heat in the incoming air; it has to do with noise! Yep, the foam reduces airbox noise. The earlier, non-foamed "hose," being thin plastic, will not reduce the noise nearly as much.

I realized this yesterday when running down US 50 at about 70MPH, after removing the airhose. There was a decided drone in the car that was not there before I removed the hose. I am firmly convinced that is why Ferrari used that hose - to reduce noise in the passenger compartment, and that it has no effect at all on anything else.

The short length of hose involved, coupled with the fact that most of the intake system (airbox to manifold) is metal and heat-soaked from the engine, means that the miniscule amount of heat, if any) that could be picked up from the engine compartment with that short piece of hose is meaningless.

So, I have totally changed my view re this hose. Other than for "concours" stuff, there is no reason whatsoever to worry about whether this hose is insulated or not. As far as I am concerned, the only thing that I would consider as far as replacing it would simply be the color.

I am going to use the foam hose I made, after re-doing it with the black gorilla tape in lieu of the duct tape (thanks Maestro!) since I already made it up and I like the reduced noise anyway.

Again, the above is just my opinion based on my observation/deduction but I'd bet 100 bucks on it!

 

Black undercoat might work pretty well - I didn't think of that. It has some flexibility which paint does not.

I bought the Gorilla tape a little while ago so I'll go ahead and try that since I bought it and go from there. I guess I'll break down and buy another USB cable so I can post some pics later today.