Anyone felt how hot their airbox gets?

[PeteE30Tourer]

After the recent threads by Sal about under-bonnet temperatures, i flipped my bonnet when i got home after a 12 mile drive home and was pretty amazed how hot the airbox was - certainly hot to the touch! There was a stream of very hot air being blown up by the alternator fan right onto the airbox.

Strikes me that must warm up the air going into the engine a fair bit, therefore sapping power.

How hot is yours?

Might get some temperature probes from work and do some experiments like Sal did.

[Simon]

Pretty normal really, apart from the obvious induction noise silencing job of the airbox, it also does a good job of keeping the air entering the engine cooler than what a non fed induction kit would, especially if the original feed pipe is still fitted to the airbox, taking colder air from behind the headlights.

When giving it some, I don't think the air entering the engine through the airbox would hang around long enough to be significantly effected by the high temp of the airbox.

I did some tests on air intake temps years ago on my 316i, I used a halfords in car computer, with an external temp probe (not exaclty scientific I know!) but it gave the answers I wanted, I tried placing the probe in a variety of places, inside the airbox, inside the feed pipe between the airbox and throttle body, and found that air temps where siginificanlty lower using the original airbox than an induction kit.

[Demlotcrew]

What about infra red heat? that can penetrate the box and heta the air?

Im going to lign the bottom of my airbox to counter act this.

Andrew

[Brianmoooore]

2500cc engine pumps (approx.) a litre of air for every rev at WOT. That's about 67 litres a second at 4000RPM.
Air isn't going to hang around long enough in the airbox to be heated much!

[Simon13]

WOT?

[6potWil6pot]

Wide Open Throttle!

[PeteE30Tourer]

Thanks for the replies guys. I'll worry no longer!

Isn't this place great??!!