The Plastic On The Underside Of Your Engine.

[Douse]

Hey all, I am curious of peoples opinions relating to the plastic on the underside of the engine.

I had to take it off to do some work and I am unsure about whether to put it back on.

There are pros on cons both ways.

If i leave it on it:

a) Protects against grime build up

b) Can reduce air flow around the angine

c) Is a pain in the ass everytime i need to do some work under my car

Is there that much to gain by putting it back on? It should keep the engine cooler although I dont like the idea of crap building up on the bottom of my engine, especially near all the belts.

So what do you think?

[Habler]

I have a metal one under mine.... But thats to protect the sump from the evil ripple strips

[Yawn]

I say keep it on. But if you have a 32gtr then take it off and sell it to me

The evil ripple strips ripped mine off

[siksII]

Put it on, if you dont have the engine bay will get dirty very quickly, and you will get water on the belts.

[Douse]

Hahaha nah sorry man just a GTS-T

I say keep it on. But if you have a 32gtr then take it off and sell it to me

The evil ripple strips ripped mine off

[dmr]

i don't beleive it will keep the engine cooler. maybe just the sump.

i had mine off while doing some work underneath the car for about a week or so, and it got filthy under there.

keep it on imo, it's there for a reason.

[Liz]

keep it

it will actually increase air FLOW rather than reduce it. It'll stop air from coming up underneath the car which would inhibit the flow of air coming through the car!

you've gotta give the air that you catch with your intercooler and radiator somewhere to go or it won't flow freely!

[QWK32]

the thing is a pain in the ass when you drop tools or bolts/nuts when your working on your car.

[Fujiwara]

anyone know where you can get replacements?

Or metal ones for that matter?

The one on my GTT has a slash on it

[bryyy]

GKTECH sell metal ones, not sure if he does them for r34 though, im sure he could make something up.

leave it on though, it definitely increases air flow, and in some cars without it they can overheat (my old FC for instance.)

[adam-__-]

I don't think taking them off will cool the engine in anyway. Heat rises and the cover is at the bottom.

[Thunderbolt]

There was a decent article on Autospeed regarding undertrays on cars. See here: http://autospeed.com/A_2160/cms/article.html

If you can't be bothered reading, then it basically says that having no undertray is detrimental to radiator and intercooler performance (on the test car anyhow). However a nice custom undertray that has been tested, can make and even better outcome than the factory one.

[TTT]

keep it

it will actually increase air FLOW rather than reduce it. It'll stop air from coming up underneath the car which would inhibit the flow of air coming through the car!

you've gotta give the air that you catch with your intercooler and radiator somewhere to go or it won't flow freely!

this is true.

same reason people get radiator deflectors/air guides, intercooler air dam guides etc.

it forces the air to go through where it should rather than the path of least resistance.

[Douse]

Cheers guys, I think I will put it back on

[Habler]

A mate of mine got an aftermarket metal one. It was costly for what it is (a metal sheet with one bend and some bolt holes)

Easy solution was to get a metal fabricator to copy the design and make one up for us. This ended up costing $20 per piece with no bolt holes. You then put bearing blue on on the bolts while they are in the holes and push your metal sheet up on to it and WELLAH! Drill out the spots where the bearing blue has touched.

Our metal sheets ended up fitting both skylines and s13's with the bolt holes just being in different places. I have seen places charging $150 for these, well worth just working one out yourself maybe using your plastic one as an indicator.

But got to agree with bolts and tools falling on it = ANNOYING