Venting under hood air..

[v6spider]

I've noticed since I no longer have a hole in the hood for a hood scoop that the air doesn't vent very well from under the hood.. So I'm curious about how people have done that. I'm thinking of venting it into the cowl.
Any suggestions other than cutting a hole in the hood?

Rob

[toplessexpat]

Shorten the weatherstrip on the top of the cowl? So there's a larger volume of air pulled from under the top of the hood?

[v6spider]

Shorten the weatherstrip on the top of the cowl? So there's a larger volume of air pulled from under the top of the hood?

There is no weather stripping on the hood .. I'm thinking of venting into the cowl with a series of 1" holes along the top of the firewall. I have a 1" chassis punch. It makes a clean perfect hole. Once I have all the holes I can put screen behind it.

Cheers!
Rob

[toplessexpat]

That'd certainly have some impact - although could well make the dash / cabin heat up somewhat!(?)

How about forcing venting with an intake at the front driver side, and an exist channel with nice aluminum radius around the exhaust exit on the passenger side? Or a fender vent?

[DieselSpider]

When moving the venturi effect should suck it out from the bottom and the cooling fan should force it through when standing still. Are you having a problem with overheating and such?

[azruss]

The cowl vents are a positive pressure area. That's why the put the vents there. That positive pressure will fight your effort to move air. A good chin spoiler should create a negative pressure under the motor and can pull heat out that way.

[4uall]

+10 on chin spoilers I rarely reach 195F anymore

[v6spider]

The cowl vents are a positive pressure area. That's why they put the vents there. That positive pressure will fight your effort to move air. A good chin spoiler should create a negative pressure under the motor and can pull heat out that way.

That is right! Hence why cowl induction is so effective. Boy I am glad I didn't cut in those holes I 'd probably be creating more of a problem. The spoiler is definitely something I want cause at the moment you can see the bottom of my radiator. So not only would the spoiler hide it it would also help to cool the engine better. so the only other option would be a set of hood vents like on the abarth spider..



When I was doing some testing after I installed the new clutch arm, I drove the car with the hood off and wow what a difference in cooling it stayed really cool around 175 degrees. With hood it creeps up to 200 degrees eventually after the engine is fully warmed up. The fan switch is set to come in at 190 degrees and ends up running almost constantly after that.

Cheers!
Rob

[azruss]

a chin spoiler does several things. It eliminates nose lift at speed. It turns a positive pressure area under the motor to a negative pressure area effectively adding downforce to the nose. It also forces more air through the grill. The downside is it adds to your aerodynamic cross-section creating more air drag at top end.
My airdam is very aggressive. My guess is I lose 5 mph at the top end, my fuel economy drops 5 mpg driving over 80, but the car never lifts and stays tight to the road, even at high speeds.

[v6spider]

a chin spoiler does several things. It eliminates nose lift at speed. It turns a positive pressure area under the motor to a negative pressure area effectively adding downforce to the nose. It also forces more air through the grill. The downside is it adds to your aerodynamic cross-section creating more air drag at top end.
My airdam is very aggressive. My guess is I lose 5 mph at the top end, my fuel economy drops 5 mpg driving over 80, but the car never lifts and stays tight to the road, even at high speeds.

I don't think that drag will be a problem with my spider!

Cheers!
Rob

[70spider]

My guess is I lose 5 mph at the top end, my fuel economy drops 5 mpg driving over 80

I'll never have that problem since I never travel on roads that have a speed limit over 65mph, and go out of my way to travel on roads with 55mph limits. "Captian Slow" has nothing on me.
Good luck on the venting I am thinking of putting the PO's chin spoiler back on once I get the suspension back together.

[toplessexpat]

On my 2000, with no spoiler - runs slightly above half, with spoiler - slightly below.

Spoiler seems a good idea in Texas heat!

[RRoller123]

Yes! I had the same experience in New England last Summer. Went without the spoiler for a few days (can't remember just why?) but the car ran consistently about 10 deg-F hotter. The handling was also not as stable, starting at about 50 mph. It was quite noticeable, and quite surprising.

[Ptoneill]

How about doing the trailing edge of your hood like I did the leading edge of my vent intake, yours would face the windshield. This would allow the heat to escape thru the highest point of the engine compartment....you could make a long continuous lift or have it match the lines made by the hood bumps...pulse would definitely keep the ice off the windshield!!





Another added bonus ...it would double as a hand hold to lift the hood!

[DieselSpider]

Yes! I had the same experience in New England last Summer. Went without the spoiler for a few days (can't remember just why?) but the car ran consistently about 10 deg-F hotter. The handling was also not as stable, starting at about 50 mph. It was quite noticeable, and quite surprising.

Over 65 mph in the Florida Heat I do get about the same with the Diesel. Car did not have the air dam when I purchased it and its on the list of considerations. I recently did a few 3 hour runs at 70/75 with temps around 90 on the roadway and saw this for the first time since I got the car in November.