kind of like they do in the rally cars?

I searched, but couldnt find threads besides the ones that talk about the stock plastic piece that comes from the factory. But those are just for the front.

I'm talking about something that will cover the transmission and exhuast too.

My idea for this is actually for gas milage improvement. I bet most of us would probably pick up 2-3 mpg. also might make for high speed stability( or lift.. )

incorporate louvers to let out trapped air.

Just wondering if anyone has done this? TitaniumTT? Juiceh? Viking War Hammer?(maybe something like this could be put into a fab tech sub forum. ;D )


-Steve

 

it doesnt work if your hood isnt on...hahahaha, i would try a local custom guy (alum) and see if he could fab something up

 

Good idea.

 

Im planin to do mine, dunno about the whole thing, but at least hte front and rear.

I think it makes better sense to do it if you have a body kit as there is area to mount it up.

http://autospeed.com/cms/A_108676/article.html
http://autospeed.com/cms/A_2456/article.html

 

to do the whole underneath would be just like you said they do on the rally cars.
.take in consideration how much weight you will add to achive better mpgs..check for possible returns like the rear bumper cover that pulls air block stuff like that,,
i would reccomend a very good tune up and and 4 wheel alingment..free up some of the emmision..tipically emmisions hold back efficiency..and performance with in turn gets you better mpgs...and last like im doing now leave your foot out of the pedal only when you need it.. short shift a little it will help ,,,

 

Good post.

Well, i was thinking of using it in conjuntion with a rear diffuser and a front plastic skid plate. And i was thinking of using a very thin, light stamped sheet metal. I dont think it would add more than 20-30lbs.

And if anthing, just to cover the transmission/drive shaft area.

I honestly havent gotten under the car to really look at it yet. just an idea that popped in my head.

 

if there are any local off road fab places they work with alum skids all the time ive had a set done for my subaru

 

Do you do lots of highway driving?
Anything less than extended high speed cruising and there will be no MPG gains to be seen.

 

I've thought a lot about this for quite a while, and I think that it's going to be more work than it's worth, usually. Think about how much fab work it's going to take, because it's not just like one flat sheet of steel/aluminum under there (which I'm sure you understand).

With that said, I do wish you luck, because I always thought a full-body covering underneath would help, but for different reasons: I was thinking that it would help to keep things clean in case you ever needed to do any work underneath (I say this, having just pulled my motor and will be disconnecting the diff/supporting parts soon to clean and make sure they're alright).

Now, you might want to add this to your ideas...instead of one piece, make it a multi-piece set, and have them sort of overlap, starting from the back and working forward, sort of like roofing. I think one giant piece would be a hassle to deal with, and if pieces were ever damaged, you'd only need to replace said area, and not the entire sheet.

 

I plan on making a aluminum undertray from the front bumper to the firewall with ducting for my future V mount set up. Hoping to start on it within the next couple months once I get my engine in.

 

One giant piece would definitely be annoying to work with.

There are also some things to consider while designing a full underbody skid:

-You'd have to design it around the exhaust system
-Materials, you can get away with some 14-16 gauge steel sheets, or maybe thicker aluminum, but I've seen success in Jeeps using Lexan as transmission skids. Might be something for you to consider, and it might be easier to manipulate.
-It's never as easy as it sounds or looks.

I really do believe it can be done, all it takes is a crafty individual with time to tinker, as well as hair to pull out. I'd use thin lexan or plexiglass if abuse is of no concern to you. I doubt it would have rocks pushing up on it anyways.

I'd like to be the guinea pig and do this, but I've got another Jeep as a money pit, so the FC is on the back burners for the time being.

 

Lexan and some other plastics can be formed with a heat gun.

 

i think the exhaust would melt it underneath

 

Where is the heat going to go? You will toast the entire underside of the car!

Also, all the air coming in the front will need to go somewhere! Where is it going to go? I think it will try to escape through all sorts of little holes and gaps. If this is the case and you do not have a place for the air to go after entering the engine compartment, it will get really hot, cause drag, and once going fast enough, the air will actually STOP entering the front of the car (VERY BAD!).

In general, it is a bad idea all around! Before you say that you are going to louver it, how much drag do you think all of those louvers are going to create? I would guess the same if not more than the current underbody situation.

If you want to get air away from the bottom of the car, put on a front splitter and airdam. This will cause the air to seperate closer to the bottom of the car and will allow less air to take "the low road".

 

/disagree, partially

I believe most exotics have full-body skid plates installed, particularly to help with aerodynamics. Are you telling them that what they're doing is a bad idea?

I think complete enclosure is a bad idea because, like you say, our cars aren't really designed for underbody skid pads (whereas I'm sure the exotics use other methods for heat exhaustion).

On the other hand, it's just a measure of pressure. Take the amount of pressure coming in, and create enough exits for the pressure to escape. You could still enclose much of the underbody by the engine, and then you could completely enclose from the transmission back. (again, I would do this in a few pieces still, just for convenience sake).

 

oh, wvumtnbkr, just a side though, for some reason i just looked at your avatar and it looks like a circle k logo turned sideways hehe, don't know why i saw it like that

 

I don't think that's what he's saying,

But keep also keep in mind, companies like Lambo, Ferrari, Audi (like on the R8), and Bentley employ all kinds of aerodynamic engineers, and have access to wind tunnels. And they're made from very tough but lite polymers

The under body covering or skids that it sounds like you're describing sounds like it would be appropriate for a rally car out of the WRC. And those type of skids are designed to take a serious amount of abuse.

but i'm not really sure what you're trying to accomplish? are you going to try and rally race your RX or is it merely for looks?

But if you want to do it, screw the naysayers and go for it, build the car you want! and if you decide to go through with it let us know the results.