bryan767

iTrader: (6)

Hey guys, so iv thought about this for awhile and i think im going to try the "jdm hood prop" thing out. bash me if you want to think its ricer, i dont really care. If it actually does create a negative pressure zone by the firewall that "wicks away" heat from the engine bay, then ill try it. 1jz's in general run hot.. add a big snail and only use electric fans and you'd be searching for more answers then get a vented hood and HAVE to park indoors every time it rained.

so whether you think its a good idea or not, does anyone have any pictures of a sc doing it, because i havnt seen any.

If i dont notice a change in my Intake air temps ill probably undo the mod, but ill be monitoring it with my ecu.

cmh

i was gunna do this to my car. it runs really hot. u will notice a huge change. and who cares what ppl think about ricer or not!? its functional... its annoying sometimes though cuz on colder days ur windows will fog often. like at traffic lights. i had it done on a few of my cars. gl

t4l

iTrader: (1)

With the right heat shielding/wrap/etc.. under the hood, there is really no need to make your hood fit wrong. Even with a turbo, if it is done right, it wont get too hot.

Propped hoods are for hondas where the engine sticks up to high to shut otherwise.

Biggu

iTrader: (12)

dont do it, with the way our hoods are it will look like crap.

scoobySC3

iTrader: (1)

I say try it and see how it looks, you can always remove it if you don't like it. Also are you worried about the underhood temps, or coolant temps? You can always make ducting for your radiator, which makes it much more efficient, as it creates a high pressure zone right in front of the radiator. That should help greatly with coolant temps, and perhaps have a side effect of slightly lowering underhood temps as you are forcing more air through the radiator and into the engine bay. You could also drill small holes between the fender and the engine bay, allowing the cool high pressure air in the wheel arches to vent into the engine bay. Not sure how much of an effect that would have on underhood temps, but I assume it would run a bit cooler.

I was also looking at the firewall the other day, you might try removing the seal on the back of the hood, on top of the firewall, and or, drilling small holes at the top of the firewall between the engine bay and the wiper arm assembly. That might act as a natural cowl and help wick air out of the engine bay.

Another option to try would be a front splitter, this will help create a low pressure zone under the car, which may help suck air out from the engine bay. It also will help with front end downforce, and should help create a bit more pressure above the splitter, which might aid in air going to the radiator.

I'm sure someone who has experience in fluid dynamics, or has built proper aero into a car could explain all the ways to get air out of the engine bay, and unfortunately my experience in this field is limited at best.


Edit - Also what T4l said, any coatings, heat wrap etc.. on the hot bits in the engine bay will help greatly with underhood temps. What sized turbo do you have on there? I think I have a nice fitted GT30/35 sized heat shield around here somewhere.

Hope this helps.
Thanks,
Rick

Kohinoor

iTrader: (22)

you could make some speed holes

kez

iTrader: (4)

^^^^^^^haaahhhaaaaa^^^^

addisonblc

iTrader: (4)

Did this to my first two 240sx's. It does actually work. They did a test of it in modified mag proven degree drop on numerous makes and models. But enough of said talk have you done it yet? My car runs a bit hot for my taste as well (1jz). Do what you do man

INTIMAZY

iTrader: (5)

Just a tip that I found quite counterintuitive at one time...

If you are running without your engine shroud underneath, put it back on.

I took it off after doing the swap and was just too lazy to put it back on while dealing with the small dumb leaks and issues that pop up after a major swap. Engine oil regularly ran above 220 degrees with shroud off (rarely ever above 230). After finishing my single swap, I put the shroud back on and noticed my temps came down a bit. My oil temps with shroud regularly stay in the 200-220 range and I have not seen 230 since. Despite a big single snail underhood and a crappy OEM oil cooler/warmer, temps did not increase at all and actually decreased slightly with the shroud back on.

Not a drastic change but just something I found by accident that seems to help... If anyone can more empirically test the theory by taking the shroud off and running a few days without it and logging oil temps, that would be pretty awesome.

t4l

iTrader: (1)

^ Yes, factory shrouds are about as good as it gets for cooling, I've seen several cars without them run several degrees hotter.

JDMb16bEG6

How do you figure that runnin with the under engine cover you run cooler? Wouldn't the heat stay inside, and with it removed wouldn't the air passing by would cool the air in the bay? I would just like to know how that works?

addisonblc

iTrader: (4)

No man. The factory shroud is pretty much a must. It funnels the air through your rad. It def does help. I ran mine a few days without it then put it right back on.

xxtoobsxx

iTrader: (4)

Cameron aka sw2uz did this and he runs cooler now. I believe he would run hot in traffic.

The factory lower engine cover has s few vents up front. As ther air passes over it it will create a convection cell scavenging hot air and pulling it through. Think of it like a tree line eddy. You take it off and the convection is lost, and the heat wont dissipate. Then the gods of, physics and thermo dynamics shall strike down and make you run hot!

In a nut shell, could get more technical but only. A few of us engineers, physicist and bio-chem nerds would understand.

INTIMAZY

iTrader: (5)

Unless it folds a protein in some way, this bio-chem nerd wouldn't get it either

That's why I said it was counter intuitive for me. I figured the shroud was there mostly for bumper bracing and cleanliness purposes. Apparently it make the car cooler. The technology of these cars is quite amazing. Even the little brake duct "flaps" are there for a purpose.

RINTHAL

iTrader: (1)

You talking about the kia sophia rolla mod? HAHA, im gonna go to the junk yards and cop some rear kia sophia back seat spacers and do this to the sc and report back! It will look amazing terrible though!