vented carbon hoods
 

I see a lot of vented carbon fiber hoods for sale from various manufacturers and of various styles, but how do people keep it from raining on your engines? are there some type of gutters installed, or do you just let the engine get wet?

they typically come with them installed however you will be just fine with them removed

I have had my hood for about 3 years with no issues. Just make sure your PCM and fuse box covers are on!!

or at least dont go into a freaking car wash with them off.

I've had the rain gutters off my car since I got my vented hood, no issues. If you look into your engine bay you'll see you're going to get more water in there from below then what will fall in from the vents.

What kind of idiomatic moron would do that? :SHOCKED:

excellent info guys, just what I wanted to know. I prefer the looks of the vented hoods as well as the idea of a cooler engine bay, just wanted to make sure. thanks again.

Yeah im still worried about my hood without the covers underneath... I know with them removed it helps alot but still :/ Im not going to put them back on but it makes me a little uneasy when its pouring rain...

my factory hood has a dent, but I've always liked the look of carbon fiber. perhaps I'm a poser, but I'd like the CF hood just because I like it, even with no other reason. I'm still shopping brands though.

^^^ Seibon... :)

I was looking at seibon, thanks for the info.

so what problems will i encounter if water does get in there? like for example what can go wrong if i run without the gutters and water does get in there?

I'd say run the gutters in the rainy season and take them off in the summer.

good point, but lately we have had at least 1 day where it would rain here in cali every 1 to 2 weeks.

Ehh I have no idea what rain would touch but there's obviously connections down there that would get wet. I found some of them and wrapped them up my best with electrical tape... But I think the benefit of how much heat escapes is worth it, especially on hot summer days with 100 degre heat...

I've driven my car in downpours without the gutters and have had zero issues. When you're driving at speed most of the water doesn't even fall into the engine, if you look at how the vents are cut there isnt a straight line for rain to get in there. At highway speed the air basically pushes the water away from the vents.

biggest problem is if you don't dry off your pcm/fuse covers and let the water sit on there you will get big nasty white water marks

easy fix for that is to use turtle wax ice on the covers. It's one of those synthetic wax meant for paint (dont use it on your paint). It does work great on the black plastic of the car. I put a coat on every 6 months and it stays shiny and easy to clean off the whole time. it also keeps the water spots from forming.

so watch the weather channel.... lol

I've gone through two nor cal rainy seasons without issue. It is fun to see the heat pouring out of the vents knowing that they're working

Exactly why I still keep mine off...

How much heat do you think is released through these vents? Anyone have any engine temps or data on this?

I didn't have a temp gauge till after the hood. Expo has a thread where he simply raised the back of the hood up a half inch and saw declines in temp. I would have to assume 6 large vents would do even more.

Having owned a Seibon KS, I'm not really a big fan.

A few reasons:

1. Heavier than stock hood.
2. Hood flexes and bends over bumps.
3. Doesn't reduce engine bay temps while the car is moving.
4. It can reduce engine bay temps while idling in traffic, but it's minimal. Your engine has no load at idle, so it's useless.


While rain gets into the engine bay - it really doesn't hurt anything.

My conclusion is that the only reason you should want one is for bling. It's useless otherwise.

Or if you have a top-mounted intercooler.

While I'm not disagreeing with you I'd like to see some proof or data on these points.

1) your hood may weigh more than stock but others may not. Mine seems to weigh about the same. Different hoods from different batches can
weigh more or less.

2) as in #1 your hood may of been made poorly, mine doesn't flex over bumps at all... I've had no problems

3) I'd like to see data on this.

4) I'd also like to see data on this, I don't see how it would be minimal... I see tons of heat escaping. Data or evidence please.

I'm not disagreeing like I said, I would just like to see proof or some type of data behind this. For all we know you could just be making this up...

Where's my camera?

Edit: Damn it! It's at Ray's house.

http://sphotos.ak.fbcdn.net/hphotos-..._6422360_n.jpg

http://sphotos.ak.fbcdn.net/hphotos-..._3660524_n.jpg

wow that interesting, one way not to block airflow to the radiator

There is no way wet carbon over fiberglass that must be reinforced is going to weigh less that the aluminium hood that comes stock on the car.

I monitored coolant temps, but I'm not going to be giving you proof of anything since I've sold my rx8. :)

Easy_E1's Turbo II must have played some weird tricks over MazdaManiac's mind... :)

Indeed.:bowdown:

I love it!!!

nice thread... thing is... none of the hoods that i've looked come with rain ducts

Having owned a SEIBON hood for about 3 years now I can confirm much of what Mysql has posted with the exception of the flexing over bumps. At speeds in excess of 90mph I can see some slight flex and had had the hood flex above 110mph enough that it caught my attention.

I've not noticed any dramatic improvements in cooling at speed. The venting is not designed to channel air into the engine but more to channel air out. As such, I don't see how the velocity of airflow is going to be enough to carry away heat.

In regards to the weight, with the exception perhaps of a dry carbon hood there isn't going to be any fiberglass hoods with a wet overlay (as Jason pointed out) that are going to be lighter than the stock hood. If they are lighter it will be 1 or 2 pounds max.

You can get the same effect by skipping lunch and saving yourself $600+ in the process.

I think a vented hood helps but it by no means is a silver bullet. You'd be better served investing in a better radiator.

I've also driven without vent guards since I bought the hood including driving through various heavy rainstorms with zero problems of water getting under the hood. Everything is well protected.

MM, have a fan below that pulling down air?

That's a pretty sweet setup. Reminds me of the TMIC's (in this case trunk) that the 2nd Gen MR2's do. Anyways, a lot of them mount them to the bottom of the trunk lid and cut out the opening and set fans to pull air. Or is it push..I forget.

Just because it looks cool and is kind of not really relevant..but still sweet. EMBED!

Not carbon hood but I currently have the autoexe hood, its very effective for heat loss through the top and has a gap at the windshield area too and the best part is no inconvenience during raining at all coz the hood comes with proper drainage system, rain water gets drained on radiator cap

The autoexe hood is one of the few that would give you the best venting benefits as the vents are over the business area of the engine bay.

The version of the seibon hood I have has the larger vents towards the front which doesn't help much.

Leg Motor Sport CF vented hood with scoop

http://www.leg-sport.com/shop/img/000066.jpg

http://blog-imgs-27-origin.fc2.com/l...t/P1000941.jpg

http://blog-imgs-27-origin.fc2.com/l...t/P1000932.jpg

Painted

http://blog-imgs-27-origin.fc2.com/l...t/P1010143.jpg

Were can I get that Mazda air duct?? I check the site but i can't find it..?
Also while driving with a vented hood does get alot cooler in the engine bay but on the light it's gets not as cool but the vents help...

Interesting MM have you taken it out driving yet and logged g/s the first thing that came to mind is rxsti lol, what did you do with that giant fan you had under the hood previously? I was trying to think of a cheap way to vent my hood as well and mocked up a few vent styles. There is a local S2k guy who cuts hoods and does a really good job for a great price.

what are some vendors of vented carbon hoods you would trust? ebay has many, I questioned 3 of them so far and none of them have the item in stock. I can't see paying a seller and then having to wait for them to obtain the item elsewhere, I'd rather just get it from the source if possible.

Varis
Most people run away when they see the price though.

The S2K is really easy to make vented hoods out of the OEM due to the way the hood is designed. they usually just trace around the support brackets. The RX-8's is ... unique. Take off the fire cloth off the bottom and see for yourself.

my factory hood is dented, and although I could repair and vent it, I just like the vented carbon hoods. I've ordered a carbon rear lip spoiler and would like the carbon hood as well, but I don't want to spend a fortune and don't want to deal with a shady vendor where I'll be wondering where my hood is a month from now.

I'm sure we all want inexpensive quality mods :)

don't get me wrong, I'm not a cheap skate, I just want to make sure when I buy an item it's at a good value with equally good service.

Yeah i know I have two hoods and spoke with the guy who has done over 200+ hoods very well known on the s2ki forum. Hes dealth with one other rx8 with the cone structure under the hood for i guess crash absorber purposes he said its a pain in the butt but it can be done. Thanks though that was my first question to him and he sent me an email with a picture of an 8 he has done and the underside. I mean MM has done it although his shape wasnt complex i guess it can be done if you take your time.

Ebay and quality doesnt belong in the same sentence.

You would be surprised at the good stuff you can get via E-Bay.
But you absolutely must know what you are looking at.
There are even a lot of copy-cat products that aren't half bad.

I often get cheap e-bay stuff and then modify/improve them, saving a bunch of money over "name-brand" stuff.
There are many basic things that are just that - basic.
The Chinese are perfectly good welders. lol

Hey MM, any pics of what your hood looks like underneath it where you made the cuts? Any issues cutting through?