And this:

And this view on the driver's side, from the front looking toward the rear:

Thanks.

Looks like it will work. I am just hesitant to cut into the car like you did.

thesaint

Yep - I would not do any cutting until I have had a chance to measure the temps to see if it works as good as I think. I'm keeping the plugs that I cut out since they could easily be welded back in if need be. I gave that a lot of thought because you can often get into structural issues without even knowing it. It does not APPEAR to have any impact since it is just stamped sheet metal but you never know....

An additional caution on this mod: You may need to shop around to find the "super flexible" dryer heat duct which is a METAL FOIL. Regular metal dryer duct will not make the tight radius bends required in order to easily fit inside the space between the engine compartment and interior of the fender. DO NOT USE PLASTIC as it will melt and/or degrade rapidly. Do not use regular duct tape to seal everything - use METAL only. I would still recommend everyone to wait until I have posted temperature readings to see how well this works before cutting. It could be just a huge waste of your time.
(Although my test drive the other day WAS impressive, it offers no proof that it will be effective beyond all doubt)

SO WHAT HAPPPENED???

DID YOU DO THE TEST?????

DID THE VENTS MAKE A DIFF IN TEMPS??

First your ghetto intake and now this? Where will it end! ;)

I can't wait till you post that you took a saw to your hood to "vent" it. It'll be hilarious!

I love ghetto mods...cheap and effective. Hope this works. If so I'm buying a circular saw.

Ron, what are the other ghetto mods?

HD Racing (AKA:Homedepot): Manual Boost Controller
HD Racing: Cold RAM Air intakes
HD Racing: tourque brace[My favorite] two big ass(10" & 12") eye bolts...

Well, there are probably a few others out there, but my #1 cardinal rule is that a ghetto mod can't easily be seen or show on the outside of the car, cause I'm pretty much a diehard fan of the stock look. So, I never did get around to actually measuring the temperatures because I did not need to. The "hot air out" mod works extremely well....after a drive you can feel how hot the naca scoops are vs. the temperature of the fender right next to them. One of the biggest problems that all auto manufacturers are up against is having enough airflow through the engine compartment, with all the stuff they cram in there. While larger radiators like the Fluidyne and the Koyo are a help, they really are only more efficient than the stock at higher speeds and with highly modded engines. Intercoolers other than the stock (which is a total joke) are excellent as well, but they are damned expensive. I don't think you can find better fans other than the stockers, and the fan mod is worthwhile as long as they don't run all the time. A dp is an absolute must. All these items add up to decreased underhood and engine temps. I don't think I've ever seen ANY engine as inherently hot as the rotary - it's just the nature of the beast.

The reason the "hot air out" mod works so well is that you are actually helping to improve the efficiency of the radiator and intercooler by providing more airflow volume. A vented hood does the same thing. I think it would be ludicrous to make any quantitative statement about increasing power, but there is no question that this will help under hood components (and hopefully the engine) last longer.

I still plan on measuring how well it works - I just need to get motivated enough to spend the better part of a day doing this in a scientific method.

Damn, I get my FD next week and there are so many things I want to do to it since it's been in the shop. Keep us updated on new ideas.

Not important, but i was the 1000th view

Did you ever measure the temps. :D

This is a pretty interesting idea. The idea of cutting the FD makes me nervous, but I might get over it if this works really well. Do you think this would be too ambitious for a novice to try? Have you measured the temps or are you still satisfied that it is working well from your observations?
Sorry if that's too many questions.

Doesn't hot air rise? So a vented hood, in theory, should allow more hot air out whereas a 2" hole that has piping going downward would upset this flow. :confused:

Wow, talk about resurrecting a thread from the past.........:D

Anyway, yes of course - hot air rises - to the bottom of the hood, which is then literally sucked out the upper rear corners of the engine room by the low pressure area created by the NACA ducts at speed. And we are talking about TWO, 21/2" holes - one on each side. That's a pretty decent amount of air flow. The faster you go, the more it "sucks", until cavitation sets in and you have reached a maximum flow. What speed that happens at is anyone's guess.

It won't do a thing sitting at a stoplight - nor will a vented hood. That is why the Miata thermosensor mod is such a great idea also to help kick the fans on high at 205 instead of 217 while idling.*

(*I think that's the right temp differrence.)

water thermoswitch listed as switching on at 226F in manual. Yikes!

Wanna play with ducting, but gotta get new engine first, then brakes, then suspension then.... well you know :)

I STILL think it's cool you did this! My idol...

Nah, too lazy to go to the trouble. All I know is that it works VERY well, and what I was after from the very beginning was to improve the airflow through the engine compartment. (which hopefull improves airflow the radiator, intercooler, yadda yadda)

Like I said before, this was Mr. Chin's idea from the beginning, I just found kind of a funky and inexpensive way to implement it.

If he doesn't, I will... one of these days. I'd like to do a *good* job, it'd probably have to be split vents to go around the hood reinforcemens, but for a SMIC it should help, along with saving me a fucking thousand dollars. Hey, my car's already been totalled and put back together once, where's the harm =)

I did that (sig) I know it works cause I see the heatwave rising sitting @ the light.

ok i am kinda lost as of whre evrything is. where i marked it in green that is the engine bay and that i have it over the 4"square. and the blue is the bottome that wodl go to the vent. am i rigth if not i need this explainde d a bit more and pics form more of a distance.
joel

How hard is it remove the fenders?

jupiter....do you have any better pics of what you did? It looks pretty nice and clean from your pic

I hate to be a member of the ghetto club, but the last time I had my fender off I did this to my car too. There are some pics (a little higher-res and less cropped) HERE . They may not be the quickest to load, so be patient.

Can't say that I've driven it enough yet to notice anything significant, but I respected the theory behind it. Maybe I'll play with the digital kitchen thermometer if I get bored this weekend.

..dave

Yep, the green area is where you make the foil lined duct. You need to cut the hole in the interior side of the frame by putting your hole saw inside the exterior square to cut. BE VERY CAREFULL not to let the saw blade nick anything on the inside or you'll be paying big bucks to fix it......... The red area is where you cut the oval in the plastic duct to attach your 4" dryer hose.

Somewhere in this thread you mentioned that your passenger side vent did nothing originally, but I think now you're using them both for engine compartment airflow, right? I think you mentioned briefly that you changed the ducting for the oil cooler on the driver's side? But I'm not clear about that, given that I think it is supposed to use the driver's side fender vent.

I wonder if doing this mod only to the passenger side would cause any anomalies in airflow?

jds