Unfortunately, it would only be false to say that you know what you're talking about.

I didn't say that engine BAY temps would increase from it. I said ENGINE TEMPS would increase. Unless you are hiding illegal immigrants under your hood, why do you care what the engine BAY temp is? Our engines are NOT air cooled. They are water cooled. Don't get too hung up on the temperature of the air inside the engine compartment. Just let the radiator do its job.
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Gernby's right...as usual.

 

^What BAY temps will affect though is IATs and that IS something you want to keep cooler. A hot bay will definitely heat soak the airbox worse.

 

If you can reduce engine bay temps WITHOUT reducing air flow through the radiator, then I agree that reducing bay temps would reduce IAT by some amount at slow speeds. However, at high load / speeds, the engine bay temp has very little to do with the true temperature of the intake air. Keep in mind that the IAT sensor is not perfect. It reacts slowly, and is not perfectly insulated from the engine bay itself. Therefore, the temp of the intake air might be much, much cooler than the IAT sensor indicates.

 

I think Gernby's thought is solid but it's based on a lot of presumption. While you want as much flow through the radiator as possible, any air that would enter through those new vents has obviously already choosen a different path than through the mouth of the bumper. The air that flows through to the radiator is not sucked in it's purely chance and aerodynamics. I would assume that futzing with some extra vents here is not going to make air that would have normally gone through the radiator choose a different path. Carry on and cut up your bumper.

 

I can attest to this. I have recently modded my intake system to draw air from the headlight and as part of this I did some logging runs to understand the affect of the mod.

I did 3 runs. 1. Stock PRM intake, 2. PRM intake thermal wrap, 3. Thermal wrapped PRM and headlight intake.

The runs that seem most pertinant to this post are 1 and 2. Basically thermal wrapping the intake to insulate against the engine bay temps. What I found is that thermal wrapping had no affect on IAT temps for the intake. I can find a link to the thread if desired.

Sent from my AT100 using Tapatalk

 

Why would you assume that I was presuming? I have datalogs showing that "hood vents" increase coolant temperature significantly on a track.

 

That's great. But as you know every combination of parts (and the condition of them) equals a different result. Not to mention how the car was driven, air temp, coolant/water ratio... It seems you assume that your one result applies to every scenario. It's great you're trying to test and educate but science doesn't stop with one set of results, or two, three.... Seal the radiator airway and see if your previous tests hold true.

I'm not interested in a pissing match and I don't mean to offend you but all of your posts seem to come from some self given authoritative pulpit.

 

from the looks of the picture, if you had a cooling panel, any air that entered through those vents would flow over the radiator and directly into the engine bay; depending on your turbo set up, that air should also feed the turbo...

i cannot see how this could have any negative effect..

 

too high engine bay tem is a real issue with the turbo setup.
it just reminds my lively Turbo Miata days that so much engine bay components were slowly but surely getting fried....

 

It isn't self given ... it's just part of an engineer's DNA.