Vented CF Hoods/Heat Dissipation

[dizzariot]

Hey guys. I didn't want to start a poll so I figured I'd post here. Contemplating buying a Seibon Carbon fiber hood for my SR'd hatch. A friend of mine has a shop locally and can get me one for dirt cheap. My stock hood came with no heat insulation so my (white) hood is yellowing in the center.

So as far as 'tech' is concerned, is a vented carbon fiber hood really going to cool my engine bay as much as the market wants me to believe? I've seen people post claims of 15 degrees cooler before on Mazda forums. Again only posting here to get personal accounts.

....oh and would it look :bow: :hey: in your opinion(s)?

EDIT - This is the one: http://seiboncarbon.com/store/products/dv-style-carbon-fiber-hood-for-1989-1994-nissan-240sx.html

[fliprayzin240sx]

I've had one, I liked it. Better than being a gay and spacing out your hood because people think that actually helps with cooling.

[Fuego]

While I can't give you any numbers, the amount of hot ass air coming out of my hood when the fans are on makes me think it's true.

[fliprayzin240sx]

Its not just not, when driving, the hood is aerodynamically designed to suck the hot air out of the engine bay. Basically, the air flows in thru the bumper, thru the radiator, then cavitation effect straight up to the vent.

[dawagarage]

lol @ 'a gay'

hey now, when i had over heating problems i went the inexpensive route of pbm hood spacers!
idk if they worked though... but they suited me because i would only overheat at stops, not at speed. so the hot air had an extra escape route.

overheating was caused by (the notorious) entrapped air, which i burped the fuck out of the system but it didnt escape til i finally installed that damn breather tank.


never did actually get to test if it worked at speed...
(by taping streamers near the rear of the hood to see if they would be sucked in or blown out.)

[dizzariot]

HAHAHAH no I would never be 'a gay' and do that...the fakies (rims) on my car look cholo enough and I fear that hood spacers will send me over the edge of cliff-o de cholo. I'm on the fence about spacers anyway, but what hotboiblaze says is consistent with what I hear: spacers only help at a stop.

I just want to eliminate the high temperatures and the yellowing hood in one blow, so it's either vent the stocker and repaint or carbon fiber.

...then I have to worry about people telling my I want to be fucking Takumi Fujiwara since my white S13 will be 'panda' ...

fliprayzin240sx - thanks for painting the picture for me, I forgot about the aerodynamic aspect of the hood.

[Croustibat]

it works ... only if your aero is sorted out.

Meaning you did not remove the undertray, nor did you add hood spacers, nor did you remove the "gasket" (is it that word ? ) going around the hood and popups to seal the engine bay. And it even gets better if you did NOT enlarge the bumper mouth, and made ducts like that : "bumper=<rad>=hood "

This would be the best, the front part of the duct creates more pressure, the seconde one create a vacuum, and air travels from high pressure to low pressure zones.

Hood spacers make air enter the engine bay by the rear, by allowing the pressurized air a path to a less pressurized place, completely blocking your cooling the faster you go. It does help when coming to a stop though ... Although if you get idle overheat, then you have another, real problem, that you should sort instead of masking it :picardfp:

Carbon vented hoods looks rice anyway. I dont know if it looks gay, but i do believe it is the best way to make your car look like a riced honda. This of course is only my opinion :keke:

[Mikester]

Its not just not, when driving, the hood is aerodynamically designed to suck the hot air out of the engine bay. Basically, the air flows in thru the bumper, thru the radiator, then cavitation effect straight up to the vent.

That makes perfect sense, Ray- But I had the opposite experience. Remember when I switched to the vented CF hood in my 180? My temps actually went UP by a few degrees. Now, to put it in perspective, we're talking about going from avg 64C to about 67-68C (not even remotely close to overheat), so I didn't care in the least; but I definitely took note of it. Then when I sold the CF hood & put the stocker back on before I beat feet, the temps went right back down to 64-65. Again, just throwing this out there. I plan to get an identical hood for the "new" build; but more for the aesthetics than the function. I wonder if this experience was due to the fact that I still use the clutch fan/shroud so maybe the air flows differently than it would with electrics? Dunno.

[180 drifter]

i think with proper ducting the vented hood would work great. if you just let the air blow around in the bay then it may not work like it is supposed to. like one of the people mentioned above, the undertray also helps with ducting air.

[Butcher240sx]

I just sold my seibon hood. Didn't notice any difference in temps. But I did notice some drag at highway speeds with the vented hood, that went away with the stock one back on.. Putting my mechanical fan and new fan clutch with the shroud back on made a difference in temps though.

[Floridaman]

HAHAHAH no I would never be 'a gay' and do that...the fakies (rims) on my car look cholo enough and I fear that hood spacers will send me over the edge of cliff-o de cholo.


...then I have to worry about people telling my I want to be fucking Takumi Fujiwara since my white S13 will be 'panda'


LMAO........ thats all i gotta say about that! funny shit bro!

[Croustibat]

LMAO........ thats all i gotta say about that! funny shit bro!

You just revived a 3 year old thread to post rubbish. Just like you did in 8 other posts; you used the last one to say you had something to sell :picardfp:

Can someone ban this guy ?

[ThanatosG]

i was actually searching this topic the other day so i'm glad he brought it back to life =) I already ordered a d-max hood because the oem carbon fiber i was looking at was out of stock. So hopefully the vents work out. I'm doing a 1jz so i figure that added vents can't hurt.

[angel mkiv]

LMAO........ thats all i gotta say about that! funny shit bro!

Florida...why am I not surprised?

[dizzariot]

You just revived a 3 year old thread to post rubbish. Just like you did in 8 other posts; you used the last one to say you had something to sell :picardfp:

Can someone ban this guy ?

He was banned once. He's a racist/bigot. He's bumping thing because somehow it proves something negative about me. I'm not sure what that is, however. I'm sure he'll fuck himself over again soon.

Florida...why am I not surprised?

Check out my quote. It also came from this asshole.

[Kingtal0n]

you can measure where air will be found to move, the increments are small but they are there. You would need several sensors/locations. One outside, where you measure the atmospheric pressure as a reference. then, install a sensor under the hood, by the bumper, anywhere you are curious where air is moving to or from, behind the radiator, in front of the intercooler, etc...

you find the area with the highest pressure, and lowest pressure, with reference to atmospheric. I suppose you would expect the highest pressure to be in front of the intercooler, and a low pressure at the hood vent, or behind the radiator, giving you an idea that air is moving to the area of low pressure of course. But if you found the reverse to be true, you would know you had to fix something.

measurements would need to be in sensitive increments, and done by computer to analyze on a log. The idea of comparing multiple gauges while driving for this sort of thing is cumbersome and unwieldly but could be done over time with the right resolution gauge. You are probably measuring less than a 50" span of H2O difference compared to atmospheric.

The same thing can be done with crankcase pressure to find out how good your PCV system is working, and how much vacuum is lost when adding length for a catch can for instance.

I was looking at picking up one such sensor but they are fairly expensive. So now I am looking to experiment with OEM sensors to see if any are sensitive enough for the job.

Florida is great, its miami that sucks if you like to drive. The traffic there is horrendous from sunrise to sunset. If you are rich and never have to leave your house its fine.

[jr_ss]

He's not talking about doing an experiment, he's talking about venting his hood. A couple inches behind the back of the radiator is a great spot for such vent. It's been proven to work just fine at relieving under hood temps.

[bmbweber]

I definitely feel a lot of heat coming thru the vents on my hood. I would imagine it has a suction effect pulling out the air at decent speeds.