PDA

View Full Version : How to cool down an engine bay



4thgenceli
06-29-2012, 05:08 AM
I need help...

I need to cool off the engine bay by venting it somehow. I don't want to loose the heat shield on the hood, it'll fuck up the rest of the paint. I have a section that's fucked up already I'm planning to cut away and put something in there to vent, just not sure which style of vent/scoop is best to help evacuate the hot air.

Suggestions?

celica9303
06-29-2012, 05:14 AM
Shim the hinges? So the rear of the hood is up a tad bit?

kurt95gt
06-29-2012, 05:15 AM
Wrap the header an downpipe

90celicaGTX
06-29-2012, 05:16 AM
try a combination of hearder wrap or try the "jdm" hood riser lol
u know how they just space in up in the rear idk if its proven to cool stuff.

plus living n driving in phx traffic doesnt help i feel ur pain on it dude

celica9303
06-29-2012, 05:21 AM
Remove hood entirely? And only drive when no rain is expected......

kurt95gt
06-29-2012, 05:27 AM
Bigger fans will help too
Maybe make a duct that pulls colder air from the outside to under the hood
Then if im thinking right a vent that the opening is faceing the windshield would let hot air to escape from under the hood
where as with a scoop that has an opening facing the front of the car would force cooler air into the bay an hot air out the bottom

T-spoon
06-29-2012, 06:28 AM
Bigger fans will help too
Maybe make a duct that pulls colder air from the outside to under the hood
Then if im thinking right a vent that the opening is faceing the windshield would let hot air to escape from under the hood
where as with a scoop that has an opening facing the front of the car would force cooler air into the bay an hot air out the bottom

There's plenty of air coming into the engine bay. The problem is evacuating the hot air. Vents are definitely the way to go, and the layout of the CS hoods make sense. Large vent over the stupidly hot turbo/manifold and smaller vents on the back corners to give somewhere for the hot air to go. The factory plastics can actually help with that, but are a pita to take off and on for maintenance. I don't know what you can really do effectively otherwise without modifying the hood.

l0ch0w
06-29-2012, 07:03 AM
^yeah
Do it like an RC hood :)

4thgenceli
06-29-2012, 01:17 PM
That's what I'm thinking. Two small ones at the back and the big one over the manifold. Time to learn bodywork now....

Sent from my DROID BIONIC using Tapatalk 2

Mafix
06-29-2012, 03:14 PM
drive to maryland. you can have the hood you saw on my car at the dragon. i have a new one now.

CollapsedNut
06-29-2012, 03:59 PM
Get rid of the turbo.

4thgenceli
06-29-2012, 04:09 PM
drive to maryland. you can have the hood you saw on my car at the dragon. i have a new one now.

I saw that. Interesting thought, but I don't have the vacation time to make that drive. Researching options now....

celica9303
06-29-2012, 08:05 PM
Shipping?

4thgenceli
06-29-2012, 08:06 PM
Thats one of them.

Funkycheeze
06-29-2012, 08:44 PM
Make sure your undertray is good, you can even run a thicker end on it to keep air from going underneath the car and pressurizing the engine bay. Airflow thru the rad and engine bay is more a function of the pressure difference between the front of the car and the engine compartment, so anything you can do to prevent air from entering the engine bay not thru the rad, and evacuating air from the bay itself is good.

+1 to venting at the back of the hood - make sure also that the rubber weatherstripping at the back end of the hood has been removed.

4thgenceli
06-29-2012, 09:11 PM
I don't have an undertray on mine. That's one thing I need. I'll have to do some serious mods to it though allow access for the oil filter and intercooler pipes). I'll start by raising the rear of the hood & removing the weather strip for now until I can track down the rest of what I need (either buy new scoops or get Willy's hood).

Funkycheeze
06-29-2012, 10:20 PM
No undertray is a big problem - air will go right under the car and pressurize the engine bay, reducing flow through the radiator.

Mafix
06-30-2012, 08:06 PM
i can honestly say i've never had an issue. nor can i think of a single 4th gen guy that has. just my 2 cents though.

ChrisD
07-01-2012, 04:29 PM
I've always been a fan of the drop vent styles for the 16x - see my project thread for what I'm talking about.

Yeah, it gets hot in there!



Sent from my Transformer Prime TF201 using Tapatalk 2

4thgenceli
07-01-2012, 05:02 PM
I'm thinking about this one..
http://www.ebay.co.uk/itm/IMPREZA-GC8-96-01-REVERSE-STYLE-BONNET-SCOOP-VENT-W-NET-/270618013242?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3f02172e3a

That seller has other ones for sale including the CS style I like.

joe's gt
07-02-2012, 01:10 AM
No undertray is a big problem - air will go right under the car and pressurize the engine bay, reducing flow through the radiator.

Can't necessarily say that flow isn't reduced, but if it is it must be negligible because with and without undertray, my coolant temps stayed the same. I have to disagree that its a big problem. I have been running without undertray for years and have yet to experience any issues on a 3s.

MrWOT
07-02-2012, 06:51 PM
Spacing the rear of the hood w/ washers a few mm. I used more than an inch of spacers on mine, looked ghetto as feck though :p Cowl hood ftw.

rizin
07-03-2012, 03:20 AM
This
Remove hood entirely? And only drive when no rain is expected......

I guess it is time to remove the engine also. Need to take it apart now and ceramic coat the valves, combustion chamber and top of pistons. Next the ex. manifold, turbine housing, and Dp. Then when you don't have money for fuel your heat problem is solved. :screwy:

I would try heat wraps the big problem that I don't like with them is they like to hold moisture.

T-spoon
07-03-2012, 03:27 PM
Can't necessarily say that flow isn't reduced, but if it is it must be negligible because with and without undertray, my coolant temps stayed the same. I have to disagree that its a big problem. I have been running without undertray for years and have yet to experience any issues on a 3s.

Yikes, anecdotal evidence FTL. That's real mythbusters science right there :hehe: Coolant temps under normal conditions shouldn't change. The thermostat/radiator/water pump/fans can handle it if working properly. Measure under-hood temps if you want real info. Heat issues are not limited to how the engine itself is effected, but also other things under the hood like wiring. Also have to compare apples to apples and a 5g and 4g are significantly different up front.

4thgenceli
07-03-2012, 04:24 PM
I can say this.

When I open the Mazda's hood after the same drive it's normally hot. You can see some heat wave shadows and can work with stuff using rags (oil cap, etc).

I opened the Celica's hood after the drive (3 miles, non- spirited maybe hitting 3lb boost) and it felt like I opened the oven door to check on dinner. Blast of heat and I couldn't mess with much in there it was just too damn hot.

Granted these drives were on the hottest days so far (112+ temps). I just checked this morning after the 3 mile drive to the bus stop and it was hot, but not blistering hot.

UtahSleeper
07-03-2012, 06:04 PM
I like the vent you found on ebay. Maybe you should get a spare hood and play around with it :)

I am considering something like the vent you listed, but going to go with more of a look from an older evo.

Here is one I have considered.
http://www.ebay.com/itm/04-05-Subaru-Impreza-CARBON-FIBER-BONNET-Hood-VENT-WRX-/261044424574?hash=item3cc775cf7e&item=261044424574&pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

4thgenceli
07-03-2012, 06:14 PM
I even like the style of that. It's large enough to open up over the whole turbo and exhaust manifold. It'll create the vacuum necessary to draw out the heat. I don't think it'll be too bad honestly, just cut the hole for the mesh, rivet it down and bondo it up.

Funkycheeze
07-03-2012, 08:17 PM
I didnt notice the lack of undertray until I got on the track and really started to stress the cooling system at high speed. Undertray makes a big difference - especially a custom one that deflects air away from the underside of the car.

underscore
07-03-2012, 08:17 PM
I like the older Evo style, it should match the 165 quite well.

As far as cooling first I'd find the plastics for under the engine, those can help a lot & keep your engine clean to boot. Then raise up the hood with some spacers for the time being, until you can get some vents in there to help with the heat flow.

Facime
07-03-2012, 09:01 PM
make your own custom cowl hood. Its not really that hard. You will need a cutting wheel and a welder and a little sheet metal but a couple days work can lead to some pretty nice custom work. I made these hoods for supras, the hood for a celica wouldnt be any different.


http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/278030_417598944946162_1829870595_o.jpg

http://sphotos.xx.fbcdn.net/hphotos-ash4/406169_417597218279668_180370194_n.jpg


http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc6/194853_417599041612819_2105856787_o.jpg

http://a4.sphotos.ak.fbcdn.net/hphotos-ak-ash4/474604_417599184946138_615522669_o.jpg

187flatliner
07-05-2012, 12:13 AM
and now im so coming to your place to drop off a hood.

UtahSleeper
07-05-2012, 07:44 PM
The hood looks cool. I would be curious on how muuch the design lowered temps under hood.

I always figured a vent(s) towards the back would benefit more since hit is going to rise to the highest spot, which is the back and this would give it a way to escape. Pluse, when driving isnt heat going to get pushed to the back as well?

Facime
07-08-2012, 04:24 AM
the front vent hood for the supra was for a buddies 1JZ swapped mk3. That vent was right behind the radiator so hot air through that could escape and not heat the bay further. It was closed at the back. The gray hood was actually never installed on a car as the guy that commissioned it went a different route. No actual underhood temp readings were ever taken, but you could definately see the heat coming off it just sitting still.