[doug_porsche]

Took off the undertray and diffuser panels to do some maintenance and upgrades and was just curious what everyone thought about driving without them? Will it damage anything? How much would it affect aero and downforce? Any negative affects from weather? Just curious everyone's take on this?

Will it damage anything?
no

How much would it affect aero and downforce?
Lots

Any negative affects from weather?
Water and dirt getting into engine compartment. Not a show stopper, but best to be avoided.

 

[LostPawn]

I’d guess it would affect aero some, not sure how much on public roads at lower speeds. My concern would be debris getting into the engine bay; I end up with pebbles and what not in there with it on.

 

[bri3d]

I've driven around without mine quite a few times while testing stuff out. Neither panel is structural, the car won't fall apart.

I wouldn't drive that way for too long because you'll get dirt and crap all over, and then when you put the panels back on the dirt and crap will all fall into the panels and rattle obnoxiously until you clean everything out (a pain).

Here's a good writeup on the Exige's aero: https://docs.google.com/file/d/0B5k...IwNS00N2NhLWE5YWEtYmE1NTdjMDA3MjU1/edit?pli=1

Airflow under the car is very important to the Elise and Exige, and while the stock diffuser with exhaust cutouts isn't particularly great it's certainly dramatically better than no underbody.

The rear of the car will look fairly broken/stupid without a diffuser also.

I'd be fine (and have) driven with no underbody to test or go to the alignment shop, but I wouldn't daily drive that way and I certainly wouldn't go anywhere near any performance driving.

 

[holmz]

the milage goes down.

 

[enderw88]

Took off the undertray and diffuser panels to do some maintenance and upgrades and was just curious what everyone thought about driving without them? Will it damage anything? How much would it affect aero and downforce? Any negative affects from weather? Just curious everyone's take on this?

Is it really that difficult to reinstall? Do things right, or leave them to people who will. It seems like compromising for expedience here doesn't get you much in terms of time saved and can only have negative effects.

 

[spiller]

^^^ settle down, you're over-reacting.

He just wants to know if there is any issue with driving the car short distances between maintenance. the simple answer is no.

 

[btotheje]

You can feel it's not there over about 75 kays. It won't do any harm.

 

[enderw88]

^^^ settle down, you're over-reacting.

He just wants to know if there is any issue with driving the car short distances between maintenance. the simple answer is no.

I am not really excited by it, I have been working on old German cars too long. You get lots of these sorts of questions on the M3 forums and they inevitably lead to people having lots of problems that they can't solve because they were taking shortcuts. But those cars are really complex relative to an Elise and there is a lot more temptation to do this. I should realize that because there are far fewer "help me troubleshoot XXXX" on this forum.

 

[spiller]

^^^ M3 forums, then I'm sure there'd be lots of questions like "there's a 1 inch wide crack in my trunk floor, did BMW build it that way from the factory???".

 

[Swic]

I got halfway through a maintenance job when I suddenly had to go out and get more tools. Wife had the other car, so I drove out in the Elise slowly and carefully with no undertray or diffuser. It was fine. Watch out for the rear panel flailing too much and make sure all the metal grommets are secure, they could get loose. I'm assuming you don't actually want to keep the panel off, right? Because as others mentioned, it would dirty up the engine and mess up the aero.

 

[aschen]

I drive mine without the diffuser and undertray if I need an alignment. That way they could put it on the rack with qballing

I see it as good practice not taking a short cut. Same thing for getting 4 new tires.

 

[enderw88]

I drive mine without the diffuser and undertray if I need an alignment. That way they could put it on the rack with qballing

I see it as good practice not taking a short cut. Same thing for getting 4 new tires.

What is "qballing"?

I have gotten so paranoid about tire shops that I pull the wheels and just have them mount the tires...alignments, unfortunately, are a bit out side my skill set other than simple toe settings.

 

[LostPawn]

What is "qballing"?

This

 

[enderw88]

This

ooooo...I've seen the pictures, never heard the term.

 

[David Craig]

This

There are 10,000 threads and 99,999 seem to have that picture.:clap:

 

[TachItUp]

There are 10,000 threads and 99,999 seem to have that picture.:clap:

I'm not sure if that math adds up rotfl

 

[jkk4567]

thanks for all the advice. and no I wasn't trying to take shortcuts, was just curious how things would go if I had to drive it to a shop without the panels.

 

[XoXoX]

One advantage to no under tray is if your car were stored all winter you can shake out the dead mice like a pepper shaker...




,

 

[doug_porsche]

thanks for all the advice. and no I wasn't trying to take shortcuts, was just curious how things would go if I had to drive it to a shop without the panels.

If the shop is close (same state?) and the weather is good and you go legal speeds, you will be fine.