Team-BHP - About bonnet scoops

Quote:

Originally Posted by iceman91

if water gets in......it does not matter...the intercooler is similar to the radiator..in fact the cooling will be much better!!!
water in the engine bay is bad only when we put in performance filters which are open...else you can pop the hood spray water inside and not to worry!!!

So what you're sayin is if i had a free flow intake just under a hood scoop im in for big trouble in the monsoons.....not that i have one but it was in the book.

Well here is my two bits... Bonnet scoops are primarily for increasing airflow to the air intake components in the car however it can also be used to cool other parts under the bonnet.

Rear facing scoops are designed for letting the air pressure out from under the bonnet.

As for the rains yes water getting into the intakes of naturally aspirated cars can induce knocking however small amounts of water into a turbo actually enhances performace of the vehicle because of the retarted timings(You can read more on this by searching on water alcohol injection for turbo vehicles).

As for the intercooler it is a completely sealed unit as it requires to maintain the turbo's pressure water will only enhance performace by reducing the charge temparature and will not affect the engine in any way.

After Seeing so many Fake Hood scoops on cars, I've been wondering , with so many intercooled turbodiesels out on indian roads(including my lowly indica) , will adding a Hood scoop really help? I've seen them on scorpios, but do they actually work?

More than that , are they practical, I mean, during heavy monsoons , wont there be water entering .
Also, are there any less obvious ways to deliver cool air to the intercooler ?

Quote:

Originally Posted by greenhorn (Post 895738)

it depends where the intercooler is. on the scorpio mhawk the intercooler is right under the hood scoop so it works well. on cars like your indica if the intercooler is on the front on the engine then a hood scoop wont help. also water entering isnt a problem for the intercooler. its a problem for the air filter.

A forward facing hood scoop(usually external) is very good at cooling the engine bay as air can be directed to any part of the bay which might either require cooling like intercoolers or air-flow like air-filters.
For example i have seen an Ikon with a very small hood-scoop at the left corner of the hood above the head-light so that the high-flow filter gets cool-air directly. He protected the scoop opening with a mesh to prevent debris from entering and a sliding cover inside the hood so that if it rains he could close the scoop.
But an external hood scoop, will also produce aerodynamic drag as it is a hindrance to the air-flow.

Downward or Rear facing Inverted scoops help heat to exit the bay due to the low pressure created(effectively a small vaccum due to the air turbulence at the top-end of the scoop) and the heat vents out travelling from the windshield and back.
But due to the gaping hole(depending upon the design), water will enter from there and enter the engine bay. Usually these inverted scoops are placed near the center of the hood due to its asthetic appeal aswell, but the water entering from there might also find its way into the distributor, electricals and spark plugs which might hinder the engine functioning as well. So the inverted ones do have fuctionality but limited due to the above factor.
Forward facing inverted scoop(Well! I hav'nt seen one personally) would not be a good idea in the first place because it will generate a hell lot of drag air from the front will directly enter the engine bay and thus the -ve push.

Just my 2cents.!!

Quote:

Originally Posted by Rahulkool (Post 895943)

^^ in indica actally there is tube kind of arrangement to suck air from front to the intercooler at the back :) chk the arrangement below the bonnet ......

yea, i know there is, but I'm not sure if there is any airflow within the engine bay at all. and whether the air will be cold.

how do the scoops in the scorpio/landcruiser protect the engine in the rains ? I'm sure SUV's will encounter a lot more rain than your average sportscar.