Lowering engine compartment temps
 

I have been thinking of ways to keep the engine compartment cooler, which in turn will help keep the engine cooler. Big temps are once again on the way here in Vegas. Was wondering if anybody had some suggestions. I have no issues, but am always trying to improve if I can. I have removed the lower cover, I know this helps keep the compartment free of dirt and may provide a little more under aero dynamics, but I also know how much heat it traps in and that bugs me. I have also removed the rear rubber seal by the windshield to let heat escape. I was thinking of lifting the rear portion of the hood by placing washers in between the hood and the hindge plate, although the sides of the hood will then be higher than the fenders. I dont want to cut any holes in my hood!

Would this offer any significant gains in terms of cooling? Not sure how I feel about the hood being above the fenders.

I’m puttin’ speed holes in my car...

- H. Simpson

This

http://i1109.photobucket.com/albums/...akeover016.jpg

:yum::excited::tup::icon23::happydance::p:rofl2::i agree::D:werd::cool::rock::):happynewyear::xmastup ::xmasgrin::happyholidays::vuvuzela:

Where did you get that hood and what was the cost?

instead of completely removing the under shroud, i suggest getting one of these.

Z Speed Performance Aluminum Under Shroud (do a search for them under vendors)

http://www.z1motorsports.com/350_g35...600&page=popup

It's custom. Bought the hood vents from a vendor Carbon Signal (here on the forum) and had them molded in. All and all about $1k

Does this fit regular Z ,and Nismo?

frank, tehy make one for each model, regular and nismo.

they have a version for each

you beat me to it Dai. :D

The hood looks effen sweet.

That is Old School back in the 70s & 80s people did that. Don't know if the purpose was cooling the compartment or a trend.

Seibon sells a range of hoods with slots or vents in them. The one I like the most is:

SEIBON :: Hoods :: HD0910NS370-TS

Looks close to the one SPOHN has in that picture.

As for removing the undertray, I would imagine that would help somewhat, but heat does tend to rise. Removing the undertray might cause some nasty turbulence or something.

Just drive with no hood on. I see plenty of cars around the city with no hoods.

Start with replacing some of the internals first. Silicone , intake radiator and wiring hoses. This will protect the car from the heat that's exerted. Ceramic coated stillen header will help promote keeping things cooler. Then you might want to consider? (Depending on yyour drive style or if you are force feeding your car) a thermostat. An oil and power steering cooler will help keep things kool. Then finally, one of these slotted hoods.

Don't do the thermostat all it will do is throw CEL:shakes head:

why would a thermostat change cause a CEL?
it might not be too helpful in cooler months but i've been contemplating a thermostat swap for mine for a while. other than that, i would like to take control over the fans and crank them on at a lower coolant temp but that requires uprev.

my quest to find a coolant temp sensor that had different scaling was futile also.
even if i found a suitable one, the sensor is in a very awkward spot to reach. easier to wire up a switch to kick the relays on

Because it will take the car too long to warm up and the water temps will fall too quickly and you'll get a CEL

:iagree:
The car has certain presets built in, you can "overcool" the car and cause a CEL if it does not warm up fast enough.

On the venting side:
-Vented hood
-Vented fender liner (GTM sells a prefabbed one but you can DIY it)
-Undershroud
-Better heat management (Wrapping intake pipes, headers, etc)

Cooling:
-Tune with fan speed adjustment
-Radiator upgrade
-Radiator fan upgrade
-Oil cooler
-Radiator fluid swap (doing a blend of antifreeze & water)

Since the back of the hood and windshield is a high pressure area, wouldn't removing the seals there or raising the back of the hood cause air to be forced under the back of the hood at speed? Kind of like a cowl induction hood on a domestic? Airflow coming in that way would interfere with the air exiting the back of the radiator. I'm all for lowering underhood temps, but I'm not sure tha's going to work as planned. I would expect it to have some positive effect when stopped, just not at speed.

Right now the next items I've got to do for heat management is venting the fender liners, putting in a slightly lower temp thermostat, and going to a different mix of antifreeze and water. A vented hood may happen down the line, but I'm not sold on that on a daily driver.

The ECM takes a look at your ECT's and your IATs to determine if your thermostat is doing what it should. If this check fails it will trip a code.

Well you might get a good report here soon...if something happens for me. ;)
On the hood seals, it would depend on the air pressure under the hood. Like the GT500 this is true, that is why they vent from the front because air pressure is pushed forward to that point and is released from there. The Z might push air backwards possibly or down even while driving which means the best venting is the vented hoods and under the car.

Need someone to run some pressure tests on a stock hood and determine airflow during idle, slow driving, WOT, etc.

Or just tape a bunch of 1" pieces for yarn all over the area and see which way they move.

Go to a 25/75 mix of coolant/water instead of the typical 50/50. This can easily drop coolant temps 10-15 degrees.

If I did just a basic flush of the system, meaning there is still some in the system somewhere. How much water v coolant you think?

That's next on my list. Even with the CSF radiator, lowered fan temps and an oil cooler, it gets a little hot in traffic if I've been beating on the car earlier and it's over 100 degrees. I'll see the temp gauge move up 1-2 dots.

The back of the hood typically is a high pressure area and raising it is a double negative. Not only does it disturb proper flow through the radiator(s), it lets heat into the cabin.

The belly pan isn't just just for splash protection, it acts to aid flow through the radiators, especially helpful when there are two or three that air has to flow through.

That's exactly what I thought.

Saves weight too! A win-win for sure!

Heat wrap your exhaust from the Header to the H-Pipe. Wrapping the exhaust keeps the exhaust gases hot and flowing faster out of the engine. We do this on Trophy trucks and Rock Crawlers. Faster the gases leave the engine the cooler the engine will run. Its good for 2 to 3 degrees and simple to do.. :twocents: