Vented hood thread

[DEpointfive0]

Originally Posted by DIGItonium

My car is still at the body shop, but hopefully it'll be done tomorrow. Here's the Aero Jacket one off OEM hood modification. The shop is going to look for an aluminum mesh grill, so the car will go back to get the grill cut and put on at a later date.

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Can we get pics from the underside of the hood?

[DIGItonium]

Originally Posted by DEpointfive0

Can we get pics from the underside of the hood?

I'll take some pics after getting the car back. The tech definitely cleaned it up nicely.

[Rusty]

The base of the windshield is a high pressure area. That's why the old cowl induction hoods, the L88 hoods, the Z28 hoods and the Trans Am hoods, just to name a few, all had their cold air intakes there. Using that high pressure area to push cold air into the carb. If you're thinking of using that area to vent a hood to release heat. It won't work.

[cooltoy]

Looks good.

[Chuck33079]

The problem is when you have high pressure air coming in from the back side of the hood, it can stall the air coming in through the grill, reducing airflow through the radiator.

That's at speed, though. At a stop, it'll still vent hot air. That's why we need to check which direction air is moving at speed.

[DIGItonium]

Thanks, all. I'm not sure I even need a thermal camera since it's easy to test with the cooling fans running. The front most vent doesn't flow much air at all, but the one in the middle vents lots of air. That should give you guys a ball park.

Overall, I'm liking these vents especially the middle one. If you guys have Aero Jacket cut them out for you, be prepared for lots of prep work to make it look clean. The tech at the body shop did an excellent job cleaning things up and adding additional reinforcements. It should be further improved once grills are added.

[GaleForce]

Originally Posted by DIGItonium

Thanks, all. I'm not sure I even need a thermal camera since it's easy to test with the cooling fans running. The front most vent doesn't flow much air at all, but the one in the middle vents lots of air. That should give you guys a ball park.

Overall, I'm liking these vents especially the middle one. If you guys have Aero Jacket cut them out for you, be prepared for lots of prep work to make it look clean. The tech at the body shop did an excellent job cleaning things up and adding additional reinforcements. It should be further improved once grills are added.

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I wouldn't get Aero Jacket to make the hood for me after seeing what they gave you to work with. Your tech did a great job cleaning up their work. Looks great!

[DIGItonium]

Originally Posted by GaleForce

I wouldn't get Aero Jacket to make the hood for me after seeing what they gave you to work with. Your tech did a great job cleaning up their work. Looks great!

It's a one off kind of thing. I ended up spend way too much on this hood after all is said and done. Issues keep piling up... now my DVD HU is dead after picking up the car. No guarantee the shop is going to cover it.

[GaleForce]

Originally Posted by DIGItonium

It's a one off kind of thing. I ended up spend way too much on this hood after all is said and done. Issues keep piling up... now my DVD HU is dead after picking up the car. No guarantee the shop is going to cover it.

I understand.

Hopefully you get your head unit sorted out ok. Have you checked the fuses?

[wstar]

Originally Posted by DIGItonium

I'm not sure I even need a thermal camera since it's easy to test with the cooling fans running. The front most vent doesn't flow much air at all, but the one in the middle vents lots of air. That should give you guys a ball park.

Yeah but I assume you mean you're looking at the coolant fan flow with the car sitting at a stop. Everything can change pretty dramatically once the aero effects come into play at speed (80mph wind hitting the front grill, flowing over the car in some unknown shape, bouncing off the windshield, etc).

Ideally we'd wind-tunnel this stuff, but that's pretty unlikely to happen given the costs. The yarn thing is really the way to go for at least understanding the airflow on the outside skin of the hood. Differential pressure gauges can tell us for sure where the pressure buildups happen both under and over the hood. Between those two we can probably make some pretty good approximate design choices.

To me, the real tragedy is that the community will have to eventually do this itself instead of some manufacturer doing it with their own resources and time. The ratio of vented hoods being sold by vendors to vendors actually doing research to make sure they're effective is sad.

[Chuck33079]

Originally Posted by wstar

The ratio of vented hoods being sold by vendors to vendors actually doing research to make sure they're effective is sad.

That ratio is directly in line with the ratio of people who want a vented hood because it looks cool to people who want a correctly designed vented hood. Digi's is one of the few I've seen where the vents look like they're in the right place and shaped right.

[wstar]

Originally Posted by Chuck33079

That ratio is directly in line with the ratio of people who want a vented hood because it looks cool to people who want a correctly designed vented hood. Digi's is one of the few I've seen where the vents look like they're in the right place and shaped right.

Well, sure, I could've restated my opinion as a statement about ratios of types of owners too, and I might've done it with sharper words than that, but then the whole forums would come down on top of my head There's nothing wrong with owning/driving a sportscar just for the look-and-feel, but it starts bugging when people throw so many hours and dollars into modding the hell out it with very functional-sounding parts any have no idea whether they're functional or counter-productive...

[wstar]

Yeah you can use Torque on android. My RaceKeeper datalogger tracks coolant temps throughout my track sessions, too (well, when I don't have a bad SD card or some other tech issue holding it up, as was the case the past time out). Even NA engines can use a little more airflow through the radiator if they can get it, when doing track events in the TX summer heat. Radiator airflow correlates with oil cooler airflow too, since it's all in the same air path.

[synolimit]

Originally Posted by wstar

Yeah you can use Torque on android. My RaceKeeper datalogger tracks coolant temps throughout my track sessions, too (well, when I don't have a bad SD card or some other tech issue holding it up, as was the case the past time out). Even NA engines can use a little more airflow through the radiator if they can get it, when doing track events in the TX summer heat. Radiator airflow correlates with oil cooler airflow too, since it's all in the same air path.

I wanna hook my iPad up. What's the best program and cable and easy plug and play?

[wstar]

Originally Posted by synolimit

I wanna hook my iPad up. What's the best program and cable and easy plug and play?

I don't know, I don't use iThings in general, usually. A google search might tell you. For Android I prefer the bluetooth OBD-II dongle from Kiwi. I think iThing people tend to use the Wifi version because of some Bluetooth software issue Apples has about generic data protocols. No idea what app they use with it.