Why the plastic cover over the bottom of engine?
 

Here's a reader review of the 370Z off of cars.com. Funny, because I have a Mustang GT too and I'm thinking of doing the same thing: giving up the 'Stang for the Z!

I'm curious if anyone can answer his question about why Nissan put a plastic cover over the bottom of the engine? Is it as simple as "low car, protect the engine from pavement scraping"?

I had a 04 mach1, gave to my brother and got a z, i dont regret it at all, but i do miss the mach...

airflow restriction.

its there to create less drag, less drag=less air restriction=more stick to the road ...

Duhhh ... isn't fer those back woods trails ... and them four by fours? Ta keep da mud an' guck out?

(just kidding)

Ummm...No. less than 1/16" of plastic isn't gonna protect anything. It is for aerodynamics. Reduces turbulance and lift. Many modern cars emply a similar cover (I wouldn't put Mustang in that "modern" category)....;)

I'm not sure which piece you're talking about because I've never actually looked underneath my car, but I think that piece is there to create a "flat-bottom" type effect? It's a somewhat functional aerodynamic piece I believe.

Edit: Just read Modshack's explanation haha.

Like kdo2milger said it's an aerodynamic piece most other manufacturers do it also like Mercedes and Bmw, it is there to keep airflow from goint up into engine compartment to a minimum this is part of the less drag test they do at high speed, is there someone who can chime in and correct me if I'm wrong?

It'll also keep dirt and junk out of the engine bay...

Might be a PITA to get off and have to deal with for oil changes, but from what I've seen, at least they put the filter and drain in the right spot...unlike my Honda Civic - reach up passed the exhaust, between the steering components to the back of the engine...way up there where your arm is basically a straight shot to your arm pit...where hot oil will cause the MOST pain...with that, I've taken to removing the front driver's side tire/wheel, and going in through the side to get around that hurdle...

You can just take off the back four bolts and fold the plastic along the designated crease (it was made to do this) if you are lazy. I take off all 16 bolts and remove it during an oil change.

http://i576.photobucket.com/albums/s...stic-cover.jpg

http://i576.photobucket.com/albums/s...01721bolts.jpg

Haha! Yeah, I can see why people would think that, especially with the solid rear axle. :icon14:

I can't really complain though. The 'Stang has been a good car for me. I'd always wanted a Mustang (growing up, that was THE car) and when they redesigned it, Ford had me hooked. I just put some FRP axle-backs on it too. Nice sound. Not too loud and no drone. And no "fart" sound either! :tup:

I owned a Z back in the day. An '86 300. I loved the car, but it was kind of a POS. Soooo many problems with it. But with the 370 model... well, Nissan's got their hooks back in me! I've got new car fever again! :)

But I'm trying to be good and wait until it makes financial sense. With the economy the way it is, big purchases of any kind seems like the wrong idea. So I'm waiting for a bit. We'll see how long I can hold out. :excited:

If it were me...with a Mustang - the last thing I would do to that exhaust is anything but make it sound like a AAA Dragster...or a classic muscle car with glass packs...

I heard a buzz-box exhaust on a Mustang the other day...

I just laughed. What a waste of a good sounding engine. Save the buzz boxes for the FWD 4-bangers with the huge wing.

Ive got a 04 gt convertable, damm good car. If ford would have put a 6 speed in this year instead of a two decade old 5 speed there would have been one in my garage instead of the Z,kinda glad that didnt happen.

My 02 Audi TT had one and it was a pain to change the oil/filter. But you live with it due to the added performance.

:iagree: The Aud part was a little more substantial (had one too). The Z piece is really a thin piece of plastic...
Pretty cheezy..

Modern cars makers try to keep the bottom of their cars as flat as possible to minimize drag and maximize downforce. In the case of the drag, obviously a smooth surface will create less drag than an irregular one (such as the bottom of your car). For downforce, its used like an upside down airplane wing. Airplane wings create lift through their shape because the shape of the wing causes air to move faster above it than below it. That creates low pressure and essentially sucks the plane's wing upwards. Same thing applies to undercar surfaces and rear diffussers, except instead of creating lift ABOVE the car, you create the low pressure underneath the car, so that it sucks the car towards the ground.

A rear diffuser creates the same effect underneath the rear of the car. It creates negative lift and cleans up the air underneath the rear, effectively adding stability and downforce.

Here's s pic of modern day supercars to give you a better idea...

Enzo:
http://www.tamiya.com/english/produc...enzo/enzo6.jpg

GT-R
http://men.style.com/slideshows/mens...gtr/00004f.jpg

In the 70's they tried installing big fans that would suck the air out from underneath the car, effectively vacuuming it to the track. That got outlawed quick... heres a quote:

"Lotus, in 1978, developed a fully shaped underbody to its Formula 1 car that, along with sliding side skirts, created a low pressure area under the car allowing cornering speeds to soar. The side skirts would wear and often break and the sudden loss of vacuum would result in catastrophic accidents. This technique of ground effects was also banned."

http://jimsgarage.files.wordpress.co...8/lotus79b.jpg"




Makes for a fun read.

http://jimsgarage.wordpress.com/2007...round-effects/

I'm waiting for a used Enzo in the 20K price range. What a beautiful car.

And just adding a ditto on the aero effect to prevent lift.

You have no idea what a hard oil change is until you check out the new Civic Si (2006+). Well, I wouldn't say "hard" I guess. It was just more troublesome than it should have been.

I'm a die hard Z car fan but the 1984-1987 300ZX was... well it was like the Mustang II - fugly.... the '88-89 at least they put the European bumpers on so the car didn't look like a TR-7 wedge....

I had a plastic cover under mine... removed it. I haven't noticed a difference. At least the one on an Evo has separate pieces so you can get to various places (like there's a removable piece under the oil filter for that purpose).

Ditto on the aero effect, but what some people fail to remember is that the cover is commonly called a "splash guard." Not only will it improve the aerodynamics of the car, it will also prevent unwanted debri or pests from entering the engine bay (if conceived correctly).

I do have to agree, however, that Nissan went into overkill mode with the 16 bolts and 3 clips (which will probably be broken by most after the first oil change). It's a pain.

Yeah, What the heck. Those engineers probably didn't know what they were doing anyway. Pull off the spoiler and the aero flaps in front of the wheels too..

He'll notice a difference when that flimsy-looking oil pan is shot or a piece of debri blows a hole through the filter, or knocks it off entirely.

At least the Z uses bolts. Evos got a shitload of those crappy plastic screw clips that either don't unscrew or break.

Aero flaps?

The spoiler makes a HUGE difference. I've driven Evos with and without, and it's VERY noticeable.

Anyways, on an Evo, it's called a splash guard. Doesn't do too much IMO since it never gets dirty under there.

it started out as drip pan, so you would not get oil drips on your driveway. (older cars)

then it evolved into a shield to direct more air through the radiator, past the engine and through the transmission tunnel to cool the transmission. the trays got longer and longer.

then it turned into an aerodynamic aid.

is this a fact?