Do I really need the engine undercover?
 

Do I really need this?

https://www.rx8club.com/rx-8-parts-sale-wanted-44/wtb-rx8-engine-undercover-195188/#post3519896

We have a little group of RX8 owners and 3 of them don't have it. They just took it off and said that they really don't need it. In your opinion, do I really need it? Do you have it on? I really do not want to spend 140 dollars on something I don't need.

The undertray is what directs the air to go through the rad instead of under it :)

How well do you think the rad is going to work with less air going through it?

Thought so ;)

It also keeps the rocks and larger stuff from taking out your condenser and radiator :)

I don't have one.

^ Dan is the man, listen. Not to mention you will have no AC or radiator if a big enough rock pebble (or something else) bounces up.

It really is a stupid question.

Yeah, people drive around without front bumpers too.

It does affect air flow without it the engine will try to over heat

I've driven 600 miles straight without it. I rebuilt my car and never got around to buying it after all the body repairs. Works fine though, never over heated.

Why remove it is my question, understand if you dont have one after a collision or something and cant afford it, but if you have one, why take it off?

It's funny how the "home expert" has these ideas of "useless parts". Why do you think Mazda would put something totally unnecessary on the car adding extra weight and cost?

Before you remove ANYTHING, find out what it's for and if it's something you can compromise the plus and minuses of removing.

Yes you need it.

Ha love these threads. It's a good question to ask so everyone knows, but he is right. Mazda wouldn't put that there if it didn't serve a purpose.

Cooling aside it also has some aerodynamic properties.
Slap 4 suspension potentiometers on your car and see what happens at 120mph with and without it.

I agree they put it on there for a purpose, but I just drove from TN to northern Indiana without one with no problems (I do have a dual core mishimoto radiator). Just saying, do you absolutely need it, no, but you have to understand you're taking some risks (stones doing damage, etc like others mentioned).

Get on the track or do multiple back to back autox runs and you will see just how necessary it is.

This argument is still going?

I'm gonna join the "You need it" camp.

Dude with the mishimoto, you should read up on the horor stories of not sealing off your radiator for proper air flow.

As others have cited the undercover is there for airflow (both aerodynamic and channeling to a/c condenser and radiator and also for some [albeit thin plastic] protection from road debris.

Manufacturers don't include useless parts. It's not good for business, either initial sales or in-warranty maintenance costs.

Can you go without? Of course you can. But why???

btw: I actually added aftermarket condenser/radiator and oil cooler screens as one of my first mod's.

I've actually got the undertray at my parents house, it's got a few breaks in the plastic though (I heard it can be plastic welded?), I'm planning on putting it back on but for a week or two I think I'll be alright without it.

3M Gorilla tape works wonders.

Gorilla tape? I've heard of Gorilla glue... which is like super glue on steroids. Gorilla tape must be like duct tape on steroids then, yes?

Yep, pretty much.

I am guilty of this:sad:

The undertray is not 'necessary' but is good to have.

I would choose to keep mine for 2 main reasons.

a) It forces air through radiator aiding in it's efficiency. You should see how well intercoolers perform when you have a sealed off duct going towards the intercooler (seen this on my friend's highpower FC RX7, cooling the intercooler with water during dynoing did very little for power).

b) It smooths out the air flowing underneath the car for better aerodynamics. Turbulence under the car causes lift.

Do you have gauges? If so, I am amazed (and speculative) that you stayed within safe levels. If not, you don't know anything except that you didn't suffer mass cooling system failure, which is all the stock gauge is going to tell you. it has four marks: cold, normal, one more notch (about the middle) and "oh shit".
Running the car without this tray seems insane; your radiator might as well be pointed at the ground, so unless your local roads get swept every day and are debris free, your playing russian roulette every time you drive.

Just put it and get this thread over with.

I never really thought about it being used to direct air. I just thought it was there to look cool lol. All these points, though, are very good and I am definitely keeping mine on. What the rest of you do is up to you lol.