engine undertray on my04 STi
 

i know this is a topic thats been talked about before but, what do you lot think of them?.

is it really needed or is it something that can be taken off for good.

is there any advantage to having it fitted?

dan

My 04 STi has never had one , it's JDM so I don't know if it came out of the factory like that , but the threads for the undertray bolts don't seem to have been used .

ok matey. can i just ask, do you find your engine bay gets dirty easily ?

I'm interested in ths too - I have a JDM WRX with an undertray and I was thinking of ditching it when I do the oil change - my engine bay doesn't seem to have been kept all that clean.

the oil change was my main reason for this. i know its not hard to take off but the oil change would be so much easier without this.

dan

Took mine off 18 months ago (JDM '05 STi). Engine does not get any dirtier - although I clean it yearly anyway, and oil temp dropped by nearly 10C as well.

Some will say that it's needed to assist airflow through the engine bay but I've not had any problems.

Not entirely sure, as aerodynamics seems like complicated business, but I'm thinking not having one might affect things such as:

* fuel consumption (increased drag)
* high speed front end lift - worse handling, breaking etc.

I wouldn't remove it for the above reasons, a flat underside at the front will be better for airflow under the car than all the lumps and bumps you'll expose if you take it off, the flatter the underneath the better :)

hhhmmm some interesting coments

dan

It catches all the oil drips before they damage the drive.

:lol::lol::lol:

Without one, it means you spot any oil leaks before damage is done to the engine ;) :D

Well ive just taken mine off. the two main reasons not to (stated above), mean nothing to me, firstly aerodynamics :- my scoob poodles round at 30 mph so im not worryed about that, and fuel consumption :- doing a few hundred miles a year, i aint worryed. lol.

now its a little easier to do oil changes and it mite help with under bonnet temps too. we shall see.

dan

How many bolts/nuts involved there Mate - I'm gonna do mine too:thumb:

pm sent

4 bolts & 2 clips from memory, having just replaced the one that was missing off my friend's Type R :D Made a huge difference to my lap times at ScoobySprint at the weekend ;)

i thought you said earlier in this post, not to remove it ?

dan

It didn't come with one on, don't think any imports do for some strange reason!

Are you saying that the undertray did actually improve lap times when fitted then?

ok cool :thumb:

No idea!! :D Maybe if we got out of 2nd gear it might have!

I've read something, somewhere, on how Subaru reduced lift by adding underbody flat panels on the newage cars, not just the front tray but panels on the gearbox, down both sides of the prop and the diffuser at the rear. You'd need to be doing motorway speeds to notice any difference though.

:lol:

Mines JDM it has an undertray.

Forgot to mention i was referring to import classics! :o

;)

this is what mine looks like. (blobeye STi).

the white rings are the 12mm bolts x4

the red rings are the clips. you pop the centre of them out x4

the green rings are the clips at the back. i just pulled the tray and they came out

dan

http://i307.photobucket.com/albums/n...4/DSC00022.jpg

Very clear:cool: Great job there Mate:thumb:

And looking at that picture, I can't believe it's designed with aerodynamics in mind :rolleyes: :) :lol1:

i dont need aerodynamics at 30 mph matey. lol. thats all the car ever does. its only there to be polished, lol.

dan

no probs dude, :thumb: