Varis Cooling Bonnet - does it really cool?
 

I tried searching and only came up with pictures, but no technical information. I'm trying to find out if there has been any functionality testing on the Varis Cooling Bonnet Ver 2 as far as it actually venting heat from the engine bay? Or is it just for looks? I'm hoping it is actually functional and draws heat out...especially the center vent for the radiator. Anyone have any info?

Here it is on Bulletproof's page: Cooling Bonnet Ver 2, Carbon for the Nissan Z34 370z

And the pic:
http://i159.photobucket.com/albums/t...psxlcammty.jpg

Yes. If you have seen infrared pictures of the hood they have hit the exact locations where heat is most prominent.

Interesting - i have never heard that about the Varis hood. I know they're legit, but just no one's spoken about that aspect of their hood before. Everyone seems to love the Fujimara hood's effectiveness , but i dont like the way it looks

Bullit - have you seen the Overtake GTR hood? Would vents located in a similar configuration on the Z34 engine bay be effective? It's two rear mounted smaller finned vents, then a larger center one mounted forward

The vents up front do really work, that's location where heat can exit out of the radiator most effectively, vent's near the middle or back of the hood really do nothing or actually hamper airflow.

I'm sure the location is optimal; but, what i'm trying to find out: are the vents designed in such a way that they allow airflow to escape the engine bay, or are they designed poorly and actually draw airflow in?

It looks like it would do a pretty good job of extracting hot air at speed, but without someone with this hood being willing to tape yarn all over it and go for a drive, we may never know.

I have an line on one of the V1 Varis hoods stateside. If I can get my hands on one I'd gladly do the yarn test. Based on the data I've seen they use the right locations so it is plausible it's pulling air out of the bay.

I think someone did the yarn test with the Seibon TS hood and the first 2 vents were good but the last one (which is waaaaay up by the windshield) was basically useless. I would imagine this one is just as effective with the vents on the left/right and the added center vent will be a bonus.

$2650 !!!!!!!!!!!!!!!!!!

Dry carbon hoods are not cheap, they weight next to nothing, plus the added cost of the currency exchange does not help.

The dry carbon V2 bonnet from them is around $3500 as well. Definitely pay to play if you want actual weight reduction while swapping hoods.

VSII-style is the only one I have seen that seems any good.

VSII-style carbon fiber hood for 2009-2010 Nissan 370Z

In general this is the airflow for all cars. The front of the hood is low pressure, as you get to the rear the pressure increases because of the windshield. A vent far enough towards the back of the hood would slow airflow in the engine bay, it's also where most cars have their air intake for the cabin because air is being pushed down and into the vent system.
http://www.buildyourownracecar.com/w...erBodyFlow.png

http://www.enterprisetech.com/wp-con...go_stream2.jpg

This is exactly why most hood scoops for combustion air toward the front of the hood don't any good and can actually reduce performance. A good hood scoop is either tall enough to get into higher-pressure air (which causes a lot of drag and hinders vision) or located near the base of the windshield (and facing rearward). Front vents work better for pulling hot air out of the engine compartment.

A picture (or two) is worth a thousand words. :tup:

This. The stock hood is aluminum. The run of the mill "carbon fiber" hoods sold by Seibon, ViS, etc don't save you any weight. I believe you need these pricey DRY carbon hoods to actually come out ahead.

would seem the Varis hood has vent in same position
http://i159.photobucket.com/albums/t...psu76a7fye.jpg
http://i159.photobucket.com/albums/t...ps35t67eaa.jpg