I just spent half an hour rubbing my face on the bottom of my zed screwing the plastic tray that goes under the engine or should i say gearbox.

 

Anyway my question is wouldnt a zed be better off without this as surely it would help the heat escape easier, or is there some weird and wonderful function that its performing?

 

(and no its not a MASS reducing mod!)

I presume its just for protection. Stop things flicking up from the road and into the engine???? that is a complete guess.;)

You definately need this on i would say.

I had mine off drove it round the block when the road was a little wet (not raining and the road wasn't soaked), no more than say, 600m a week later there was white blobs al over the engine even on top of the plenum!

Start of rust underneath too which wasn't there before.

So i had to spend the next saturday cleaning it all off. :mad:

Yep,

I'd say it was there for a reason,most probably to stop all the water,salt,mud,stones and other sh*t from going in the engine bay.

Also looking at it from the front,then it could help in getting all that luverly cold air in through the front bumper and helping in keeping the engine cool....That's my guess anyway!

Cheers,

F.T.

Well i was thinking that if it came undone again i'd pull it off, but all things considered i think i'll keep it.

My bugger blew off 2 years ago, came out of the back of the car like a square of bog roll :eek:

After which i could have put said sheet to good use !

Never replaced it, no probs & no wet in engine bay ever.

 

harve

Is this the big undertray that fits to the front bumper?

 

If so mine has never had one fitted to it in the 3 months i've owned it. It broke off on the way home from buyng it and have never got around it re-fitting it.

 

Ivan

It's likely to help cooling rather than hinder it. by having it there, there will be an area of low pressure built up under the car which will improve flow of air from the front through to the bottom of the car.

 

Someone with a Techtom and way too much time on their hands could check this but rules of aerodynamics would support it !

Hmmm can't see what you mean Dave????? The cover is there so that Nissan can stiick an extra hours labour on your bill every time they remove it :D Can't see any problems with not having it there tbh. As far as cooling is concerned, I can't see it making that much difference either - for proper engine thermal control ALL cooling should be done by the radiator anyway. The waterways are designed to keep the temperature even throughout the block - if extra cooling is provided in other areas then this in theory could cause warping and cracking. However, like I say, the added cooling will be MINIMAL. There will be a slight bit of extra turbulence under the car but again MINIMAL

 

CheerZ,

 

Andy

The theory is that if you have an area of lower pressure beneath the car then this will increase the flow of air through the rad. The air normally flows because it's at higher pressure in front of the rad than behind it (caused by the air immediately in front of the car being compressed).

 

I know Iain Mac noticed a huge benefit in cooling when he put small ducts in his bonnet and that's the same principle. There's an area of low pressure above the surface of the bonnet and this means that the cooling effect of small ducts is far greater than people might imagine. But if you put the ducts in the wrong place (where there's an area of high pressure or turbulence) then ducts can make cooling worse.

 

But I'd agree completely that the effect is likely to be minimal and I'm very much quoting theory rather than something I've seen work on a 300. But if someone was bored it would be good to get it measured by a Techtom or by Eric's system to see how big an effect it really gives.

 

Dave

 

P.S. Haven't sent Le Mans info out yet as I'm moving house. Probably will be early next week now - apologies.

Right ok gotcha - wasn't saying you were wrong, more that I didn't understand wtf you were on about :D One point is though that if you look at how flimsy the cover is, there's no way it could hold any kind of pressure that would be of any use... IMO

 

CheerZ,

 

Andy

 

PS Excuses Excuses :D:D:D

Just because I see that Techtoms have been mentioned twice in this thread I thought I say that my one seems to have broken and I'm deeply unhappy about it because it is extremely useful and informative ! :(

The tray helps air flow under the and into the engine bay and shod be left on. If you look under an F1 car it is completely flat as are most supper cars this helps the car to be sucked to the ground.

P.S thanks AndyP for help on superchip but after some research and talking to powerchips it sound as if it is moor like the JWT chip.

All the best Sid.

Originally posted by sid

If you look under an F1 car it is completely flat as are most supper cars this helps the car to be sucked to the ground.

True. But if anything was sucked downwards, the undertray would be the first bit to kiss the road! As my namesake says, there's not a chance it could hold any pressure or contribute to downforce without coming to pieces.

I agree on a few points, yes the undertray is important and so is the Techtom.

 

Which is the most important????

 

LMFAO :D

The undertray on mine was crap ,held up with tie backs,looked crap and was falling off due to disstortion being top quality jap plastic,so took it off,after much deliberation and examination of the bottom of engine bay etc,all it does is stop/hide oil and crap falling onto drive ,and if you have got an oil leak with it on,you sure aint gonna know about it till its to late,at least with it of you can see if theres anything happening,its just a cosmetic thing,all or most cars last few years have em on,even me old granada,and i cant see that helping aerodynamicly on one of them!Also took off all be sound proofing on underbonnet,made no difference to the sound,but engine definatly does not get so damn hot,all it ever did was act like a quilt to keep the heat in!.

ps,sold the zed today ,i know,i know said i would,nt,but need a breather finance wise,but,soon be drivin again,watch this space,:D :D :D :D :D ;)

My advice and it is far from being technical and I would've thought that this was more common sense, is that it's critical to the protection of the engine and electronics.

 

Not rocket science guys! ;)

Not rocket science guys! ;) [/b]

Stick, gunpowder, tube to put gunpowder in, match...

Had no under trays on mine for well over a year now, no draw backs or improvemants, just the same, no probs either when all roads were flooded over here a few months back, in fact me zed managed to go where many cars didn't :D

cheers

smithy :cool: