jakermc

Not surprisingly, my car arrived without the undertray in place and I am going to replace it with the aluminum one from 928 Intl. Unfortunately, they did not have any old NACA ducts from the stock tray to go with it. I also struck out with Oklahoma Foreign.

Does anyone have any spare ducts around or an old factory tray I could salvage them from? Willing to pay a reasonable price of course. I know I can run without them but in the TX heat you can never have enough cooling.

Alan

Try calling 20th street auto (dismantlers) in Phoenix, they just may have a car with an undertray - they have quite a few 928's in various stages of dissassembly. You can call or email with requests and they will tell you if they have it. In general the smaller the parts the better it is to just call....

http://20car.com/

Alan

Donald

Jake-
If you mean the ducting itself, not the NACA style inlet, clothes dryer exhaust hose works fine.

Mark

Also check with Rixter.

Alan

I didn't think there was any ducting - don't they just direct air upward from the tray...? Am I missing some ducting & if so where to...?

Alan

jakermc

I have never seen one in person since mine was missing, but I believe there was a NACA style inlet that was riveted to the undertray. I don't think there was any kind of duct on the other side, it just scooped up the air to vent the business side of the undertray. The new undertray is pre-cut and pre-drilled to accept the factory NACA inlet.

I now have struck out with 20th Street Auto and Parts Heaven. I called the dealer and the scoop is sold as an integral part of the factory undertray. Looks like I may under up scoop less unless I fabricate something.

jakermc

EDIT:

I am looking at the PET diagram now and it looks like the scoops attach to the engine side of the undertray. In other words, the shape of the ducts on the roadside of the tray is enough to scoop the air and the the attachments exist to direct the air straight up.

perrys4

can you post the PET picture?

Ed Scherer

I just remembered an old thread that seems appropriate...

Another undertray-related thread

(and note post #4 )

jakermc

Ed, thanks for the link! That's even better than posting the PET. Those vertical things are exactly what I am talking about. They seem to be unobtainable. In hindsight I probably would have purchased the OEM part to ensure I have them.

Maybe I can get a better look at one from one of the local DFW guys. It looks like it would be pretty easy to make something out of some aluminum sheeting that would serve the same purpose. It might look ugly, but if its just bending some metal and applying a few rivets I can at least get the functionality of the stock piece.

Ed Scherer

OK...

Really helpful, isn't it? (Well, I guess you can see that the ducts aren't a separately-available part.)

RyanPerrella

Ed,

Where is that diagram in the PET

Ive cycled through the 40 or so pages for the 928 and have never seen that diagram. What main group is that under?

Ed Scherer

I was using the PET PDF stuff, 928_USA_87_91_KATALOG.PDF to be specific (since I've got a '90, that's the one I usually consult first).

Main Group 8: Body / 801: body-in-white, frame, fender etc.

then skip one page forward.

RyanPerrella

AHHH!

yes i do see it, kinda obvious now when you mentioned its page after the body in white.

As for the ducts, those look like a pretty easy item to fabricate, Anyone have any dimensions on them. My cars missing both belly pans and i would want to add the ducts, may as well if your going to buy a new one and they are missing.

maybe someone thats got one down can take measurements, although i am sure it wouldnt be hard to make one just based on the picture posted of that one on ebay.

jakermc

There is a group of us meeting in the DFW area this weekend to work on a car that has its original belly pan in place. Maybe I can convince him to pull the pan so I can measure. Check back this weekend ...