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The Plastic On The Underside Of Your Engine.

Douse

By Douse,
in General Automotive Discussion

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Douse Collaborator

Douse

Posted
Posted

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?

Liz Grand Master

Liz

Posted
Posted

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!

bryyy Proficient

bryyy

Posted
Posted

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.)

Thunderbolt Rising Star

Thunderbolt

Posted
Posted

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 Grand Master

TTT

Posted
Posted
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.

Habler Rising Star

Habler

Posted
Posted

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

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