[pedodoc25]

Got my new car today and popped hood. Didn't realize there was a hood release lock but it wasn't. Popped off very easily. Any idea what this is? I reattached it but want to make sure I didn't screw something up. Thanx in advance.

[Vic55]

Ill take a stab.... I think its a thermostat or something like that. But hell what do i know LOL.

[northtorque]

+1 on temp probe (likely resistance based given two electric leads). Likely for ambient air temp. Hey, how about spoofing the probe with an ice cube and see if the turbos will make more boost for the given ambient temp. If it works, I hereby patent the idea and shall call it "race-cube".... Addendum: alternate marketing name "ice-chip"...

[norbtx]

Maybe its to control the shutters.

[BDWonder]

Originally Posted by pedodoc25

Got my new car today and popped hood. Didn't realize there was a hood release lock but it wasn't. Popped off very easily. Any idea what this is? I reattached it but want to make sure I didn't screw something up. Thanx in advance.

+1....i saw.it.too the other day...just peeking out of behind the grill...very strange...kinda leaning out of the corner.

[Bönz]

Yes, it is 100% the ambient temperature probe.

[BDWonder]

Originally Posted by Bönz

Yes, it is 100% the ambient temperature probe.

What exactly is ambient temp?

[Lloyd_Christmas]

The sensor that provides you with the current outside temperature. It should have no impact on ECU/performance parameters

[northtorque]

Originally Posted by Lloyd_Christmas

The sensor that provides you with the current outside temperature. It should have no impact on ECU/performance parameters

I wouldn't just assume that (however, you may just be right)... since the F90 no longer has MAF sensors to assess airflow it would stand to reason that the ECU will adjust timing and alter boost based on a whole bunch of surrogate parameters (pressure, ambient temp, intercooler return temp?, knock sensors, etc). Regarding temp, it has to get that info from somewhere... maybe there is a dedicated sensor in the airbox / intake side but if not then a temp probe sticking out in the fresh air ahead of the rads is the cat's meow.

[fstezaws]

Originally Posted by northtorque

+1 on temp probe (likely resistance based given two electric leads). Likely for ambient air temp. Hey, how about spoofing the probe with an ice cube and see if the turbos will make more boost for the given ambient temp. If it works, I hereby patent the idea and shall call it "race-cube".... Addendum: alternate marketing name "ice-chip"...

Just because there is more boost doesn't mean there is more power. Turbos have an efficiency range where 2psi less could actually make the same amount of airflow.

Plus, if BMW isn't using a MAF and doing something more like dpeed density tuning, then "spoofing" outside air temp will just cause more knock and reduce safety. Just my $0.02.

[northtorque]

Originally Posted by pet3r

Just because there is more boost doesn't mean there is more power. Turbos have an efficiency range where 2psi less could actually make the same amount of airflow.

Plus, if BMW isn't using a MAF and doing something more like dpeed density tuning, then "spoofing" outside air temp will just cause more knock and reduce safety. Just my $0.02.

Totally agree with what your saying, all the parameters need to be taken in concert together in order to make any meaningful gains - I was joking around on the ice cube thing there! Sorry OP for the jacked thread - I'll go back to looking an ice cube tray!

[creedthings]

PSA comes off very easy don't mess with it lol