I have spares of all the body parts for the front end of my car, so I'm thinking about making use of them. I'm considering venting this part of the front:






Something like so?


Then vent the hood like steve84GS TII:






Now, my car is relatively stock for now so I'm not making excessive amounts of heat under the hood, so would this be beneficial, or would I be pretty much wasting effort at this point?

 

You wouldn't want a reverse vent there. The reverse vent is meant to be after the radiator, to funnel the air which the rad has heated out of the engine bay.

You want something more scoop-like there, to funnel cold air to your rad.

There's a pic of a silver japanese SA that has a vented front panel, I'll see if I can find the pic

If you have the spare parts, no reason not to cut some vents in it, but I don't see it doing a big difference for a stock car.

Jon

Edit: OH I see what you're talking about now, I missed pic #2

No you don't want to do that. There's a reason why all the air coming in the front of the car is funneled through the rad. If there's another path for the air to go with less resistance it'll go that way, instead of going through your rad and cooling your coolant! So when you're on the highway, that would actually raise temps rather than lower them

Just do the vented hood. That will get the hot air out of the engine bay, or just do the front cuts on the header panel, that will get more cool air to the front of the rad.

Don't do the cuts on the *back* of the header panel.

 

cutting vents in it will make more pressure behind the radiator which will make your radiator less efficient.

 

the under hood vents you put infront of the radiator would let air that was going to the radiator go somewhere else in turnraising under hood temps. Your radiator needs all the air it can get. If you want to use a reverse vent it goes after the radiator to vent out the hot air AFTER it has passed through the radiator. and you can put holes in the front valance in front of the radiator in a way to get more airto the radiatorallowing it to cool better.

 

This is a GOOD idea:



This is a BAD idea:



This is a GOOD idea:




The reason the second one is a bad idea, has basically been explained though

Jon

 

Alright, thanks for the info!

Is there any other ideas for venting/other stuff for the front body parts? Would venting the pass. side headlight lid be a good idea?

 

Venting the headlight cover may have benefits if you have a sealed air intake drawing thru it. Kinda hard to do with pop-up lights, but not immpossible.
Venting the front fenders, behind the wheelwell, could help, but only if you also vent the inner fenders. This will also weaken the sub-frame assembly.
Venting the hood, as the pics show, is probably the only way to reduce under hood temps, without creating other issues. Of course, placing the hood vents too far back, can also have a detrimental effect, due to the high pressure area in front of the windshield.......

 

Actually this particular hood vent raises another potential problem, yes it definately cools the radiator, but in so doing, reduces the air flow through the rest of the engine bay.

The problem i see, and I'm open to reasons why this isn't a problem, is now less air can move through the engine bay and the exhaust heat has less airflow which in turn is going to retain the exhaust heat within this area.

I'm considering a heat shield to direct this exhaust heat under the car or out via a fender vent, as previously noted in the case of a fender vent, this has to go through the inner and outer fender. This would be fed via a hood scoop and flows the air across the exhaust and out of the engine bay thereby lowering the engine bay temps overall.

 

Yes, venting the hood will reduce the air flow across the exhaust. Will this have any adverse effects?

 

The most heat created under any rotary hood is from the exhaust so I think it would raise the underhood temps.

I feel the need to test......lol

 

LOL. I understand that.
I can state that I dramaticly reduced underhood temp on my car, by replacing the beehive with a 2nd gen FMOC. I tested this by raising the hood after running at the local road course before and after the swap. It felt much less like a blast furnace after the swap, even though the outside air temp was warmer. Totally scientific method..... LOL

 

Yep, that sounds like one of my tests......lol

I'd probably run a thermometer underhood if I can find one in the correct range.

 

Hey, sorry to hijack the thread, but is that a Jacobs FC1000 amp in the first pic? I am new to this, just bought a 1985 Gs. My questions is would this be a good/efficient amp to get considering my car has a 1/2 bridge port, RB intake, 650 Holley carb, full RB exhaust, etc? ( have stock ignition)

Thanks!!



Buy the way, interesting idea!

Ryan

 

After looking at my car for about an hour, I don't think I'll be able to do anything to the hood, that would be of any benefit without major modification to the placement of the radiator and such. So that idea will have to wait until I get some $$$.

Won't stop me from trying it, though.


BridgePorted12A - Yeah, that's an FC1000. Though, I can't help you with any info when it comes to a modded car. All I know is that for an un-modded engine, can't beat it.

 

I want to see something done with reverse cowl induction (have I got that right?). I've seen this on some aftermarket Z car hoods. The center of the hood is raised, and the back of it is cut out.

Found one. Kind of like this, but maybe not so dramatic... Ignore the side vents, its just the center that I'm referring to.

 

The reverse cowl is a pretty cool idea. It uses the low pressure of the air going over top of the cowl to create a "suction" type effect inside the cowl. The high pressure under the hood is drawn through the cowl and over the car. Lowers underhood temps pretty well.

Another thing to consider: Look at a 79 Trans am between the front tires and the doors. There's an air duct there, which works the same way. I suppose if you want to, you could use the fins from a Z3 there, but most ricers do that for looks. If you cut holes in the fender and have some ducting to the engine bay, it would be pretty functional.

 

Get hood pins. Stack washers ~.5" high, lower hood, place pin. Hot air will get sucked straight out of the engine bay.

Heh.

 

Its not that simple, the base of the windshield has the highest build-up of pressure for air flowing over the body, so you could easily get a reverse effect, and find your cowl sucking air into the engine bay.

 

One thing they do in avaiation is create a low presure area AFTER the area producing the heat. This literally sucks the cold air through the engine and exhaust the hot air. I don't see any reason when it would be possible to put ducts under the engine bay, with ah wxit at the back. The key for the suction effect is the outlet must be larger than the inlet for two reasons - the hot air under the hood expands, and youu want more air TRYING to get out than what can come in. That's what creates the suction. Some cars like old firebirds had vents in the side of the fenders to exhaust hot air from under the hood. Its a similar idea, but has been done mostly for looks in the past.

 

If I was going to do that, I'd just run no hood haha.
That's what started this whole thing, I took the hood off my car to fix a few alignment problems with the body panels, and took it for a short drive with the hood still off. On the butt dyno it felt like it liked the open, cool air ALOT more, and the temp gauge was visibly lower the entire time. There for I've realised I need to get more, cooler air into the engine bay.

 

I run my drift sessions with my hood latch moved up(meaning you unbolt the 4 10mm bolts, move the mechanism up and reinstall just 2 bolts) the hood stays secured and my temps dropped like a rock. Take a close look at my avatar.
Not sure about the high pressure, I'm not running speeds over 55mph when I start my drifts.