so i'm looking at ways to keep the under the hood temps down... and there's all these threads on low pressure high pressure? stuff that 19 year olds like myself just don't understand the concept of..... So i was wondering...i have some small washers on my hood as of now to raise it so the temps stay lower...in theory....

i was just wondering what kindof spacers people are running to raise their hood... since i read somewhere that this can decrease your under the hood temp by like 10%...

anyone have turn signal intakes they might wanna sell? that are still black?

 

Take a fluid dynamics course and you'll understand better.

<----19 year old engineering major :gay:

 

raising the back of the hood actually makes it a high pressure zone in the back. I'm sure you have heard the term cowl induction. Those actually pull air in at the windshield. This is useful on old v8s because the carb airfilter is right there. not useful on our cars (unless you have a v8 swap). Its just a "look" that people like. It will only decrease your cooling efficiency.

 

There's actually a thread up, the most efficient way to cool under there is to make sure your radiator is pulling air through it well, make sure you have your underpan on and if any sort of venting is done it's out the top of the hood.

 

If you're having trouble understanding the other thread, you basically just need to know that air flows from high pressure to low pressure areas, constantly trying to equalize since nature abhors vacuums.

 

hey now don't bust my ***** ...i'm a business major...Smeal is just calling my name right now!!!! yeah so I have a D in economics and I need a 100% to get a Mid C... i should be studying right now!!!! procrastination is a disease.

 

No kidding, and no offense was intended. I should be doing homework right now, but my brain has pretty much checked out for the school year.

 

damn I don't miss school

 

lol... yes you doo M2cupcar...yes you do...

so basically what is the most effiecient way to run the best pressure in a miata engine bay? make sure that my radiator lets air through? ....how does the heat dispurse from the exhaust manifold and what not? does it get sucked below the car?

 

no, the best way to move air through the radiator is to create low pressure behind it. You might have success if you work on the undertray, but its going to take alot of work to see if you actually make progress. Maybe you should look at the hell rad scooper:

I'm going to work on making an undertray to fit with it.

 

Man the "scoopers" are sexy, I want one. So simple to make though I might just have to do that in the fall.

 

heres the short version

hood risers work at low speed, great for cooling off in the paddock,
they do jackshit and ruin your air flow in the engine bay at higher speeds (+30mph), track events for example are the worse place for these.

I have them and they reduced my idle cool down time significantly. but it makes the fresh air vents on the cowl into more heater... so suck it up.

the ideal way (also more expensive) is really great shrouding and belly pan, the cheapest way is to use what mazda gave you and heat shield the sensitive stuff.

 

$10 works great:







and i still keep the bellytray:

 

The skin on your finger looks whack in that pic

 

:gay: Gloves.

 

vinyl glove. I'm acually going to install studs in the IC ports and move the scooper down a bit to scavenge in a bit more....I really need a pressure gauge, I'm probably going to redo the underbelly tray with aluminum as well.

 

The concept that air moves from high to low pressure is pretty simple. That forward movement causes high pressure areas at the front of the car is pretty simple. The hard part is figuring out where the low pressure areas in the engine bay are and how adding openings changes the position of low pressure areas relative to high pressure areas.

 

I really like your DIY scooper. Looks good and would get the job done. I've been wanting to do an aluminum undertray as well because mine is all beat to hell (thanks PO). I found this article about venting in aircraft.

http://cafefoundation.org/v2/pdf_caf...localflow2.pdf

Talks alittle about creating the low pressure needed to get the air out of the engine compartment. Basically involves creating an airfoil to create the area of low pressure. This could be incorporated with the undertray.

 

this thread is drifting here: https://www.miataturbo.net/forums/showthread.php?t=9485

 

link no work jsisco, interested in the read.