rotorocks

This mod is the result of a collaborative thinking of a group of very talented individuals (which is what this site is all about). If you want more info on the original idea behind this, please read this: https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/hood-ventilation-ideas-123434/
But I posted the results here, as I thought that this is a more appropriate place for it.


After a day elaborating on the topic, I settled on an inexpensive, or rather completely expense FREE solution based on the hint from MazdaManiac:

To do this you'll need:

1. 2 blocks of plastic hard rubber or some other hard material sized approximately 1/2"X1/2"X3/4" (Hight may vary slightly depending on how your hood cover is aligned)

2. PVC cement or other glue or adhesive.

Now roll your sleeves and get to work

1. Remove the rubber seal in from the cowl (the back of the engine compartment above the firewall).

2. Install the plastic blocks (I just glued them into the two off center holes on the panel where the rubber seal used to be mounted)

3. Close the hood.

There will be a very slight resistance as you are locking the hood. That is because the rear portion of your hood cover is pushed up to enlarge the opening. If you look at the hood from inside the car you'll see now that there is about a half inch tall opening all across the width of the hood. If you look at it from the outside, you'll see no difference, and no misalignment.

http://picasaweb.google.com/vdarevsk...05087982547106

http://picasaweb.google.com/vdarevsk...05075097645202

http://picasaweb.google.com/vdarevsk...05066507710594

This hefty little mod helps to keep your under-hood temps and running and idling coolant temps lower by an average of 6-10C while driving in a 95-100 F outside temperature, and costs nothing.


Happy modding everyone.

DrewMan

wont this cause the hood to bend?

rotorocks

No, it just pries it up a little, without deforming anything.

mac11

iTrader: (1)

Just wait until a few thousand miles of heat cause that little stretch to stay permenantly. You do know aluminum is pretty malleable, right? especially when warm? and that its a good conductor? So the engine bay heat will wam it up much more than a steel hood.

Red Devil

Any plans to post pics?

rotorocks

ohhh.
sometimes a pick is worth a 1000 words as they say, but this mod is so simple it just feels like posting pics is not worth the effort.

But ok
I didn't have the time to take pics of it, but maybe today I will.

rotorocks

Updated the original post with pics

shaunv74

Nice. Very nice and simple. Any coolant temp or oil temp differences to speak of?

lepichichi

iTrader: (10)

pics please

rotorocks

Mine runs around 6-10C cooler.

StealthTL

iTrader: (1)

Gonna hafta call bullshit on that one.

Coolant runs 10*C cooler?....just not possible.
Oil?....even less likely, sorry.

S

rotorocks

I have a very large Intercooler sitting in front of the radiator, and it blocks quite a bit of the airflow. Causes the car run hotter. As i posted in the other tread. It run in the figures of a 98-100C degrees. After this, the cooling temps are holing up in the area of 90-94C on a highway going around 80-85 mph.
Same thing when idling.

Call it what you will.
I have no interest in this to bullshit.

P.S
I bet if it was Racing Beat or some other company offering these things for like a $50 and claiming the same numbers, people would be all over it like flies around the droppings...

shaunv74

Actually I would believe it at highway speeds. According to Racing Beat's observations the biggest problem with the cooling system is airflow evacuation from the engine compartment.

rotorocks

Over a 100F here today, i just got back from lunch, and had to go like 7 miles in city traffic to get the visual inspection for the insurance company, and back. Drove nice and cool, never even got over 94C. You can actually see the waves of hot air pouring out through the opening as the car sat at a traffic light.

mac11

iTrader: (1)

The air does not evacuate the engine bay through this opening when traveling. only when moving very slowly or not at all.

XDEEDUBBX

not sure if it was mentioned in the previous thread but why not just buy some metal washers and bolt them under the hood to where the arma attach to it. The honda guys do it all the time. That way the hood wont "bend". Probably as cheap if not cheaper than those pvc blocks you mention.

mac11

iTrader: (1)

It was mentioned. No one cared. The hyundai guys do the same.

Trekk

Dude... I mean really. Have you proven it doesn't work on a RX-8? Or are you guessing and stating it as a fact?

We have a few people here that have done the mod and claim it works for them. Then we have a few that haven't done it and KNOW (some how) it doesn't work. I will try it soon and see what happens, before I go as far as just saying it will or will not work (N/A set up).

MazdaManiac

iTrader: (3)

Why do you continue to repeat this? This is your theory only. The facts, despite running contrary to the supposed science, indicate that air does leave this gap in a reasonable volume at all vehicle speeds.
Don't bother trying to save face on this one or beat your chest. You just got it wrong, so let it go.

As for pics, I think rotorocks went a little overboard with the plastic chocks - I just used adhesive, medium density insulating foam from Home Depot.
Just pull the strip off and put 4 or so 1" long strips of foam along the cowl at a regular interval.

I got another good, real-world test that this works yesterday:
Normally, if the ambient air temp is over 107°F or so, I cannot maintain a highway speed over whatever 4kRPM is (I don't look at my speedometer much, so I don't remember what that RPM correlates to speed in 6th, so you do the math) for more than a minute or two with the A/C on before the car starts to overheat. By overheat, I mean add 2° or 3° past 220°F every 5 seconds until I take a countermeasure. I've easily seen 240° a few times, but I've always caught it and arrested it by letting off a bit and turning off the A/C compressor for a minute or two until it stabilizes under 215°F and then I start the cycle all over again.
On Thursday, I traveled the 130 miles or so across the desert from Blythe, CA to Phoenix in 110°F ambient with an average engine RPM of 5100 RPM (again, you do the math) and never saw the coolant temp go over 217°F!. I never turned the A/C off even once and these temps stayed stable for the 2 hours of the trip in the middle of the afternoon in moderate traffic.
YMMV.

mac11

iTrader: (1)

I didn't say it doesn't work. go back and read the posts i have had on exactly what i did and what is going on.

Yes, heat rises, therefore at a stop or slow speed hot air will pour out.

when you are moving there is a low pressure zone in the engine bay and a high pressure zone at the cowl that actually draws ambient air in from the base of the windshield down into the engine bay. What it does after that is anyones guess as I haven't mounted a camera in my engine bay to date.

rotorocks

Because by doing that you misalign the hood cover and the fender.
Just stop to think how ugly it is going to look if the corners of your hood stuck out 1/2"? It was one of the things i listed when starting the other tread.

You are like an old record player.

mac11

iTrader: (1)

I forgot, what you post is fact regardless, what someone else posts are just theory. How silly of me.

mac11

iTrader: (1)

WTF are you talking about, its been done on thousands of cars w/o misaligning anything.

rotorocks

Then perhaps you would like to implement this on your car and post the pictures?


Dude, take a look at the second portion of his signature, and after that just ignore him.

MazdaManiac

iTrader: (3)

Actually, that is true. I test what I say. You just flap your gums (fingers).

Nope. The air continues to leave through the gap at the cowl I have the laser thermometer measurements to prove it.
Go get some fresh air.