yes/no/maybe?

 

You can alway's switch to the oem 350Z engine cover which does not cover the oem pleneum. I have no opinion about the heat issue however.

 

I've wondered that too! Anyone know about the heat?

 

I don't have my engine cover on after installing the Crawford plenum and the temp. gauge reads the same. However, when you pop the hood the heat is more noticable.

 

If you are concerned about this type of heat, Hydrazine has designed hood spacers that go between the hood and the hinges to put a gap between the firewall at the rear of the engine compartment and the rear edge of the hood. Hydrazine's testing indicates that this gap allows the engine compartment temps to drop by drawing cooler air in through the gap. Here's the thread on My350z.com with pics.....Hydrazine's Hood & Plenum Spacers

 

I vote yes.

 

Can't quite tell from your pic and response if you are saying "yes, removing the cover is better for heat"

 

I would think so. I have the 1/2 Motordyne spacer and I cannot believe how hot it gets underneath the hood. No less, bolting a big piece of plastic on top to boot! It would be nice to see some type of tasteful "cowl-type" hood opening. Something very discreet and simple. Nothign like those on the Camaro or Mustang.

 

i have just took mine off for the spacer this weekend...yea i think without cover the engine can release heat better but without a vented hood i dun think there is a noticable difference.
IMHO i dun know why there are engine cover to make it look nice and neat, i like how the engine itself look. and coz u already have a hood to cover it ...haha

 

I'm a skeptic about underhood temps. Things like insulating your intake tube? The air that rushes through the tube does not have time to affected by the engine compartment temps. It goes through so fast that it won't make any difference (this is of course while you're moving).

As for taking of the engine cover, I dont see what this will do for you either. For any improvement in performance you'd have to change the underhood temp by more than a few degrees. And again, while you're moving enough air is circulating through there that whether or not the cover is on should be irrelevant...

 

I think that the issue is heatsoak (build up of heat while you're not moving). Lets say you're waiting to stage for a drag race and you've been pretty much idle, or moving very slowly, for around 5 minutes for example. That initial "gulp" of air that your engine takes is likely to be pretty warm. Same applies for stop and go city driving.

 

Heatsoak is real. But I don't think taking off your engine cover is going to fight heatsoak. I'm not trying to be an ***, I'm just sharring my thoughts. If you were really worried about it, I think you'd be better off cutting vents into your hood and add in a manual switch to your radiator fan. Bottom line is that your hood is keeping all that heat in your engine bay.

As for the drag strip, the best thing that I know to do is to keep your engine off and push it up to the line while keeping your hood up as long as you can to let the heat dissipate.

One crazy idea I've had was to use active cooling. The name escapes me (although I thihnk it's called the Pelitier effect) at the moment, but there are device you can use on computer chips that cool them dramatically. It is capable of reaching VERY cold temperatures (below freezing i think). If you could somehow line part of your intake with something like this you might get some bennefit from the cold air... The downside of course is that while it makes one end of the heatsink very cold, the other gets very hot. There may be no way of doing this, but I just thought it could be a fun experiment...

 

You beat me to the punch! That is exactly what my response was going to be. I would tend to agree that if we were flying down the expressway at 90, heat might not be relevant between the cover and a bare plenum. However, sitting in traffic or possible stop-and-go traffic may make a difference in temperatures. On second thought, it may be possible that the intention of Nissan was to simply protect the owner from possible burns with an exposed plenum. Therefore, Nissan implemented the cover as a shield from the scolding heat of the plenum. Perhaps it was not so much aesthetic than a safety measure. Overall, I do agree that the omission of the cover is not going to make or break the car.

Regardless, we would be better off gutting the innards of our cars to save on weight. It would be easier to shave off a hundred pounds in order to gain 15hp than to redesign airflow under the hood.

 

There are measurable gains to be had (granted, they are generally only visible at he strip) by cooling down the intake manifold (upper collector).

My experience at the strip indicated the equivalent of 10-15 hp difference between a heatsoaked motor and a fully cooled one.

The real trick is to keep the car just cool enough to not have it pull timing--giving you max power. A/C running, hot temps and other factors all contribute to what I call "power fade"