Quadcammer

I'm looking to do a little project with an engine undertray but my car did not have one.

Does anyone have one they aren't using and would like to donate to the cause?

Thanks!

see below for the idea

badabing

I've been looking for one too. Quad and I are neighbors.

Joe@Fabspeed

its a shame.............i threw out literally hundreds of those rear engine bottom covers from NA 993 and 993TT cars since 1994. Many shops threw away those cumbersome bulky undercovers. I dont even see them at SWap Meets anymore because enthusiasts often dont want them except for concours originality.

You maybe able to find one. Typically, 993/993TT owners remove them so the engine runs cooler, saves 8# or so off the rear end......... and you can see the beautiful flat 6 engine case and twin Turbos.

The cover was designed to slightly quiet the 993 to comply with SWISS drive by noise regulations. It serves no other purpose and retains so much heat that you greatly shorten exhaust valve guide life and ultimately an expensive top end rebuild is required when she starts to burn oil and smoke.

This is why the 1st thing a new 993 owner often does is remove the cover and often throws it away as its bulky and not getting reinstalled.

jo-hans

I just detailed my engine tray - now I can store it with the other clean one......

EMBPilot

You must be joking.

Mines in the attic. It'll cost u shock top.

Quadcammer

You've had one of these the whole time?????

I talked to you about my plan wenis!!!!!

anyway, if you don't want it, I'm fine with a trade for shock top.

2qwik4u

I have one. I'm in staten island, come and get it.

Quadcammer

Ok, so here is my plan.

I worry, probably for no reason, of a stone or road debris hitting the engine case and putting a hole into that sucker. Expensive whoopsie there. In addition, with no mufflers and no undertray, my turbos are basically right behind my tires with no barrier. All that road debris, pebble, dirt, snow, rain, etc are just flung right onto the turbo. Its messy and probably not doing anything back there any favors. My wastegate actuators are already a bit banged up.

The whole undertray is useless to me, but I think there are useful parts. My plan is to cut it in such a way that I can:

1. Protect the engine case without impeding airflow to the cylinders/heads.
2. provide even the least bit of protection for the turbos while leaving good airflow to them.
3. allow me to still lift the car with a floor jack without removing this thing.

here is my drawing of the plan:



thoughts?

nine9six

Quad,
I like your thinking, but have come up with an alternate design to eliminate the sharp angles and increase the ridigity of the undertray, while still allowing your turbos cooling air and your cases more substantial protection.

I know this is not symetrical (See modified STOCK)...It can be done symetrically on a CAD drawing and easily water-jetted into this configuration.

Is the hole in your modified drawng, for oil drain access?

Your thoughts?

EMBPilot

I think quads got too much time on his hands...

Quadcammer

appreciate the idea. I'm not an engineer so strength is something I don't know about. I figure its not heavy and adequate supported, but who knows.

The hole is so that i can get a jack on the engine case seam without removing the tray.


oh and airplane driver, zip it fella.

Kika

I'm not a mechanical engineer, but I do know that the curved cut outs will be better

phoneyman

From an engineering standpoint, nine9six is correct. If I were to do this project I would retain some more materials like his picture suggests for some sheer strength. Its kind of a toss up because if you hit something right on or very close to the edge you could damage the tray, but still protect the engine bits better.

Another idea is to do triangular cutouts from the bottom edge of the top beam to ~ the middle of your center beam, and same thing from center beam to bottom beam. Kind of a compromise between saving weight and the difficultly of cutting the tray. Just my 2 cents.

I think this is a pretty cool homebrew idea. Good luck.

NYC993

That's the last thing I would worry about.

My worry would be something flying into the engine bay (leaves, paper, plastic bag etc) getting stuck and catching on fire. I know...chances are slim.

I would keep most of the tray intact and cut out long but slim openings for the heat to escape if that's the goal (almost like a grill). Or maybe have them across the tray to get more air resistance.

Pags993

I removed mine with no plans of ever putting it back but how about modifying it similar to the motor sound air box covers. Create a template or just pattern out a grouping of 1 inch holes or whatever size you think would work to allow air flow without compromising structural rigidity? Plus I think it would look pretty cool if laid out in a grid format.