Knowing where to put bonnet (hood) vents

To work effectively, bonnet vents need to be placed at the right locations. But how do you work out where that is? Note that my most recent aero book (replacing the one shown in this video) can be found here - www.amazon.com/Vehicle-Aerody... or Amazon in your country.

[@tonybailey89]

I've wondered this so much in shopping for a vented hood for my Stinger GT2! I was torn between the rearward placed vents and the designs with the large opening towards the front, thank you so much for explaining this I'll go with the most frontward placed vents for the best results pulling that hot air right off the back of the intercooler, oil coolers, and radiator under the hood!!

[@JulianEdgar]

Yes, that is *very* likely to be better than the rearwards placement. To be *certain*, you could do some very easy aero pressure measurements.

[@tiggernits1508]

So glad I found this channel. I'm very interested to see everything in the aerodynamics book. Definitely ordering it.

[@Miguelgarage]

Everyday we learn something different, thanks.

[@masterofpuppets2004]

for raceing applications it might be a bigger deal where you place them, but for everyday driving you will benefit no matter what. like sitting in traffic and allowing heat to extract. under hood temps get the hottest when you're sitting still.

[@JulianEdgar]

You can position them to do both.

[@camlobesvtec]

Excellent I'm learning

[@JulianEdgar]

Great!

[@Steve-b1o]

The old school holdens used vents/flutes in the guards behind the front wheels do these achieve venting from the engine bay or mostly a cosmetic thing.

[@JulianEdgar]

Cosmetic.

[@Pwnulolumad]

Where would you position the vents of a supercharger Audi a7? I initially considered copying the hellcat charger design, but realized the a7 grill has way more air coming in with the open hexagon design, while the hellcats and scat pack chargers all have a hard front fascia with the only way for air to enter being their headlight ram air tube system. The main goal I’m looking for here is to cool the supercharger and regular radiators. It’s not a huge v8 that has block cooling deficiencies, only heat soaked superchargers

[@JulianEdgar]

I don’t guess or copy other cars. I make some simple measurements on the road and then do it right. I suggest you do the same!

[@camlobesvtec]

I modified my rsx bumper openings on the front bumper to allow as much air in the engine bay as possible. I know I have allot of pressure under the bonnet. I will for sure be making an undertray. Based on this information, if you are familiar with the front end of an rsx, where would you place a hood vent or vents on the hood?! It makes so much sense now. My hood spacers are useless because in my opinion the air flow is hitting the fire wall and flowing downward through the largest opening in the engine bay. Plus I'm turbo charged, I'd like to evacuate the hot air too. Your expert opinion would greatly help.

[@JulianEdgar]

Happy to help as much as possible, but need to see some pics.

[@camlobesvtec]

Just using your imagination haha. I cut open the stock front grille. I cut the fog light area, opened it completely. Then I placed large honey comb mesh to cover the openings. If you know this language haha I put a b series radiator in my rsx to open up the throttle body area to make room for my same side intercooler. You guesstimate I'm cutting

[@JulianEdgar]

@@camlobesvtec What does an RSX look like? As I said, I need pics - that car was never sold here as that model.

[@camlobesvtec]

It's a 2004 Honda integra type R where you live . In America, the rsx 02- 04 .I'll have to find a way to send you some pics. I'm new to KZbin

[@JulianEdgar]

@@camlobesvtec Put them up on a photo hosting site and then put the links here. Pics of your car, preferably. I use postimages.org/

[@LuisMartinez-ks1uw]

Would this apply a car with only 106 horsepower? Would it see any cooling efficiency changes from a vent?

[@wrx450]

What an excellent series of videos. Book order incoming. I discovered your channel today and have watched many videos. A few questions if you don't mind. I have a heavily modified bugeye STi which is street car but will be used for Time Attack and track days as well. Cooling is a major priority as I live in Cyprus which is very hot. I have modified my front bumper so the opening to the front mount intercooler is only as big as the actual finned surface area to force air through rather than around the intercooler. I will be ducting between the intercooler and radiator so there is no spillage around the sides as I need air into the radiator. I have vented the bonnet just after the radiator and intercooler with a WRC type vent, but not ducted to the vent as just impossible. I tested with wool tufts and it is definitely dragging the hot air out. After watching a few of your videos, a mistake I believe I have made is a reverse scoop where the original bonnet scoop is and lifting of the bonnet at the rear with spacers as these are high pressure areas. * Should I remove bonnet spacers and also close off the original scoop? I see huge amount of heat escaping when stationary but have not tested with wool tufts but suspect it does not drag the air out when moving, but does help when stationary. * Should I instead add some vents to the sides of the bonnet closer to the front? * I added WRC front fenders and have removed the wheel arch liners as they were old and cracked. I believe I saw a comment in another video where you may have said add them back in. If added in is it still worth adding vents to the top of the arches? Would the arch liners not just block high pressure air escaping? * Re underbody. I am considering a full flat floor as much as possible although leaving exhaust uncovered. I may use marine plywood as this is what they use on my BAC Monos, despite it being a £150k car. Re the front undertray, given the Subaru exhaust manifolds hang down so low, I would have to use aluminium with some type of heat protection and also add in some venting after the radiator and possibly around the manifolds. I have a dry sump so don't have to worry about the sump intrusion. Thanks and sorry for the rambling on. I wont make any changes until I have your book in hand!

[@JulianEdgar]

1) Yes, 2) Yes 3) Measure pressure difference between wheel arch and fender top and see if the vents would do anything 4) Marine ply is fine - see kzbin.info/www/bejne/gmq6dImijLWWr9U My major aero book covers undertray shape for downforce.

[@wrx450]

@@JulianEdgar Thank you for your reply. Appreciate it.

[@sambo92]

My srt charger has a duct that splits and points to the sides of my heads, would that be better or worse than just having a regular hood scoop like the scatpack? Thank you

[@JulianEdgar]

Sort of thing easy to find out in 5 minute of testing. Don't guess, test. www.amazon.com/gp/product/B08Y49Z6DT

[@barshushan]

Could hood vents have any aerodynamic properties? ( downforce)

[@JulianEdgar]

They can have an influence on lift, yes.