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I've noticed a few turbos with holes punched through the nose panel. I'm assuming this improves air flow to the intercooler. Does this really provide any benefit? Any recommendations for prefabbed panels?
As noted above, I've measured ~20* temp drops with a well vented nose panel (I'm talking under hood temps here, not intake air temps). It's a worthwhile mod I think, and how the factory should have done it (along with some better ducting) in my opinion. As far as keeping temps in control in the engine bay, nothing beats real heat extraction vents on the hood its self. I don't know why porsche didn't do this from the factory as well.
I have yet to see a correlated temp drop after the intercooler.
The problem that I've always seen with these lie in the wind tunnel testing. The bumper produces a low pressure spot just above it, directly where the "installed vent" is located. I often wondered if the high pressure air in the engine compartment didn't in fact push air back through the intercooler to the low pressure vent that people cut in.
This might very well explain why Porsche stopped venting the nose panel in the 924 turbo.
But it's just speculation until someone does some hard testing on an actual road at speed.
Will be following up with proper hood vents the next time she is in the Body shop, something like this these...
In that location but larger, like this...
After doing some aerodynamic modeling it seems like the nose panel will really be effective with the hood vents to provide an escape for the air coming in from it.
I have yet to see a correlated temp drop after the intercooler.
The problem that I've always seen with these lie in the wind tunnel testing. The bumper produces a low pressure spot just above it, directly where the "installed vent" is located. I often wondered if the high pressure air in the engine compartment didn't in fact push air back through the intercooler to the low pressure vent that people cut in.
This might very well explain why Porsche stopped venting the nose panel in the 924 turbo.
But it's just speculation until someone does some hard testing on an actual road at speed.
TonyG
I'd have to agree. There is enough theory to believe that a nose vent by itself may even be counter productive. I would say that if it's a road only car then don't do it from a functional point of view. If you just want the modified look then go ahead. On a track car I wouldn't do it without putting in hood ventilation to allow any increase of air pressure to escape from the engine bay. Without the hood vents I wouldn't be surprised if you don't create a stall zone that may even increase your i/c temps.
The other thing is that if you do manage to get more air under hood and don't vent the hood, it will want to escape somewhere else. This is likely to be underneath the car so you could see an increase in front end lift. This is more pertinent on a track car but just thought it worth mentioning. A road only car probably won't see enough effect (good or bad) so it's likely to be more of a cosmetic change.
Yeah I think it absolutely makes sense to have the hood vents in conjunction with this. I need some body and paint work so I'm just putting together all the pieces I'll need before hand.
I have yet to see a correlated temp drop after the intercooler.
The problem that I've always seen with these lie in the wind tunnel testing. The bumper produces a low pressure spot just above it, directly where the "installed vent" is located. I often wondered if the high pressure air in the engine compartment didn't in fact push air back through the intercooler to the low pressure vent that people cut in.
This might very well explain why Porsche stopped venting the nose panel in the 924 turbo.
But it's just speculation until someone does some hard testing on an actual road at speed.
TonyG
Originally Posted by 333pg333
I'd have to agree. There is enough theory to believe that a nose vent by itself may even be counter productive. I would say that if it's a road only car then don't do it from a functional point of view. If you just want the modified look then go ahead. On a track car I wouldn't do it without putting in hood ventilation to allow any increase of air pressure to escape from the engine bay. Without the hood vents I wouldn't be surprised if you don't create a stall zone that may even increase your i/c temps.
The other thing is that if you do manage to get more air under hood and don't vent the hood, it will want to escape somewhere else. This is likely to be underneath the car so you could see an increase in front end lift. This is more pertinent on a track car but just thought it worth mentioning. A road only car probably won't see enough effect (good or bad) so it's likely to be more of a cosmetic change.
For the same reasons, I did not modify or add this kind of header panel.
To clarify, the front bumper creates a high pressure, which decreases as the air passes over the nose. The hood sees low pressure. So the vent shown in the photos is still in a relatively high pressure area, and the hood (low pressure) is perfect for venting the air from the high pressure inlet.
Once the air hits the windshield, it creates another high pressure area. It's often used for an air inlet to the engine's induction - remember the '69 Z-28 cowl induction? NASCAR uses the base of the windshield for their induction too. Bringing the cooler air in for induction measurably increases power.
Unless you get one like the panel offered by LR, you are not doing yourself any good. As stated above if you modify the stock header the opening is in a low pressure area regardless of a vented hood. The panel LR offers juts out into the high pressure so air is being forced through the vent.
The primary purpose for this vent is to move more air across the intercooler. My hood is vented behind the intercooler which is also ducted.
11-26-2014, 05:07 PM
Replace nose panel?
