in response to Threads concerning Oil and Coolant Temps:
Coolant Temps
https://my350z.com/forum/autocross-road/194615-coolant-temps-on-the-track.html

Coolant/Oil Temps
https://my350z.com/forum/autocross-road/260563-post-your-track-day-oil-temps.html

I decided, oh what the hell i'll try this and see what happens.

i already have a vented hood that is near the front of the car, slightly behind the radiator. i know that the back of the engine bay where my turbo reside and above the plenum get extremely hot under hard driving conditions.

methodology: the air flow where the windshield meets the hood should allow for the air to come out and sweep up and around the edge. normally this area has slightly turbulent flow, allowing the air moving over to stay attached to the windshield longer..

theory:i can use this to my advantage: faster attached air means that there will be suction from under neath the edge of the hood. i might even think about put a little lip at the trailing edge of the hood to allow the air going over the hood to start building pressure sooner than typically before it hits the windshield..

execution:




Removed the black plastic coverings in front of the windshield. removed the battery and brake plastic coverings and all the rubber weatherstripping. i had to remove the windshield wipers first and a bunch of clips.. i think i saved like 5 pounds in plastic alone!!

i had some left over door weather strip molding that i used to line the bottom of my windshield as not to look that ghetto.. imho this would work even better w/o the wiper blades too.






NOTE: you can SEE the plenum ... silver thingie.



welp. i have been seeing consistant 200-205 degree water temps under hard driving (brief track stint two weeks ago) and consistently on the freeway at around 190F.

i will take data points this week as i drive around and see how both oil and water temps are affected and will post when i have enough data samples to give a decent report.

expected results: hood that will slightly flex due to the removal of the center bracing (hood typically rest on the black plastic piece & rubber weatherstrip.)

also need to make a little screen for my in-cabin filter. aka a/c inlet

 

^^ why dont you also make something to support the hood so it wont flex?

 

nice

 

hood spacers dude, hood spacers

 

to bad it doesnt look as clean and finished as it did w/all the stuff on there.

 

hardcore!

 

Make sure you don't have any exhaust leaks; I would hate to see you pass out from carbon monoxide poisoning.

 

I'm very curious to see your temp results.

Traditionnaly, there is a pressure build up at the base of the windshield. So air would just stay there and block any potential air flow. Same as with the covers.

It could be different with the slope of the Z windshield. Keep us posted.

 

well. hopefully i wont have the engine moving in the garage.

the car pulls air from the engine bay normally. just by removing the plastic...i dont think i altered much.. but i can see how it it was drawing air from 'outside' the engine bay with the vent in the plastic next to the wiper blade

 

No-Luck hood......

Edit:

 

^^
i know. but i gotta make due with what i gotz yo!

when the heck is that hood ever gonna show up?

 

I thought about that when I paid attention to the thread title....."My cheap cooling modification......" New hood isn't exactly cheap....doh!

hood - crossing my fingers for the end of this month.....I'll be in hog heaven if it comes and the wing comes the first of May.....

 

On most every car ever made, the hood/windshield junction (the cowl) is a high pressure area. That's where air is drawn in for th HVAC system and why cowl induction style hood scoops are so effective.

How will creating a duct from one high pressure area (the cowl) allow flow to another high pressure area (the engine compartment)?

 

i'm not ducting in, i'm trying to get air to suck out.

 

But, it won't, or at least not very much and maybe the wrong way. All fluids flow from high pressure to low pressure. The greater the pressure difference, the greater the flow.

By your description you're venting the engine compartment near the radiator. This will work because the front of the car is a high pressure area and the front part of the hood is a low pressure area. That's why lots of race cars run a radiator extraction opening in the hood (the GT40 is a classic example).



By extracting air out of the engine compartment, you're making the engine compartment a lower pressure area. If its lower then the air pressure at the base of the windshield, air will be drawn into the engine compartment through the duct that you've created. Now, this might help your problem by creating flow in the stagnant air near the firewall (which is caused by venting the engine compartment behind the radiator.)

 

just make sure it doesn't rain and get all over the battery or wiring

 

cool

 

To vent air you need to put a vent on the hood where the air is still attatched. The base of the windshield is a high pressure area. It will only vent when you are not moving.

 

nice!

 

i've been sick so no data.

i am gonna put a gurney flap at the trailing edge of the hood to make the air sweep up before the windsheild.