Something to consider re the Mantovanti...

Today I drove the heck out of the 328 and when I got back to the marina I was taking some groceries out of the "trunk." (note to self: "Do not put ice cream in the trunk again")

For some reason I put my hand on the AL intake tube and it was extremely hot - as in "WAY to hot to put your hand on it". Now, that's really no surprise given that it resides right there with the engine but it got me to thinking about the possible contribution to heating the intake air. The oem rubber hose never got that hot so I suspect that the air temp being delivered to the throttle body may be somewhat higher than it is with the oem hose.

I don't know this for sure, of course, nor do I have any handy way of checking the actual intake air temp. But it does bring up an interesting point...the oem tube from the right-side scoop on my 328 is heavily insulated with foam. The only reason for Ferrari to do that is to insulate the tube from engine heat and reduce the amount of heat transferred to the air from the engine. SO...I'm thinking that placing an AL, or any non-insulated tube in the intake may counteract whatever attempt Ferrari made to keep the air cool in the first place. The rubber oem hose does not absorb heat like AL does and I BELIEVE - again, no way to tell - that it will keep the air cooler than an AL or Carbon Fibre tube. Maybe tomorrow I'll do some checks with an IR temp gun to see the external surface temp difference between the AL and the oem after a decent run.

How much air temp difference exists and, if it does, how much power might be lost is between you and your dyno! But there is no doubt that the Mantovanti certainly looks good! I'm thinking that a double wall polished AL tube with some sort of foam-type insulation between the inner/outer tubes would be THE way to go!

So how hard would THAT be to make?

 

"Since the rest of the intake system is Al does it matter?"

Good question! The manifold air box is AL as is the rest of the system, as you noted. So even IF the Mantovanti absorbs more heat than the oem rubber, the question is, does the actual air temp in the manifold itself change? Since there is no way to easily measure the actual temp of the AIR, not the external surface temp of the tube/hose, I can't say for sure. but after further fooling around in the last hour or so, I'm now pretty comfortable that it makes no difference in actual air temp to the combustion chamber.

I am very pleased with the Mantovanti and certainly recommend it to all for "improving" the look of the system.

The only way to reduce the air temp is to do the old drag racing trick and pack ice around the intake manifold. That works fine for drag racing but it would be a bit "wet" for normal driving!