Ed Hughes

If the new factory plastic pans actually have ducts for $230, then this would be the way to go, and I'll probably not waste any time on this project. Coming from a background in metal fab, my guess would be that these wouldn't come in at less than $150/pair in a decent quantity. I thought they were no longer available.

ROG100

When I first bought my GTS I got a replacement pan from Porsche and its been fine ever since.
I have also seen many cars without the pan without ill effects.
I have fitted the aluminium one from 928Int - great and no ill effects without the ducts.
So the ducts direct air to somewhere? MM maybe.
I have seen no conclusive proof that any of the above combinations have a detrimental effect on the car in normal use.
As for protection I would go with the aluminium one.
For a reduction in drag coefficient I would think having one is better than not.
Other thoughts welcome.

Ed Hughes

Roger-all valid points, it would seem that the greatest asset of the belly pan is the protection aspect, and to your point alumiNIUM (!!) would work best.

The only thought I had here was the thread I referenced where it seems more than a few people were "ductless", and if they were **** like I am, they may want to rehab to original specs. I was having coffee with a friend yesterday and he mentioned the fabricator, and something in my head clicked on this...

JP Rodkey

My latest purchase has a newer non-metallic pan, without the ducts. I'm sure drag/coefficient is part of the reason for the pan. However, one thing I've noticed (and haven't seen mentioned on the forum) is that virtually EVERY 928 I've worked on has a lot of sand and grit distributed around the engine bay. I'm talking caked on sand/grit along the valley, on the flat between the heads and block, in the block divits under the coolant crossover, on the frame rails especially under the PS reservoir, etc. Don't know how much time, if any, those cars spent around the ocean or other sandy areas. I'm now of the opinion that the overall low posture and low road clearance pick up natural sand and grit from the roadway. Our side mirrors seem to be more prone to nicks and pits than other cars, IMO, and maybe for the same reason? It seems reasonable to me that pans would go a long way toward keeping rocks and grit from getting kicked up and sucked up into the engine bay.

Oh.....put me in for a couple of sets.

ROG100

Ed,
Sorry did not mean to HiJack the thread - coffee has not kicked in yet and my fingers ran away with me.
I would like to have the option of being able to get the ducts and I am sure 928 Int would like to sell their aluminium ones with the ducts.
If they can be had for a reasonable price and emulate the factory I am in for a dozen sets.
Roger

the flyin' scotsman

928 Int list both the original and the new aluminium version.........now the question is does the original have ducts..........Jim/Mark?

Ed Hughes

No need for apology-it's all valid discussion on the topic. I just wanted to clarify my intent on this.

ROG100

If only you Americans could spell correctly!

the flyin' scotsman

Now Roger you'll get all sorts of mail re. the colour of tyres on bright aluminium wheels.

Ed Hughes

Hey, I did...look at my second post, I even capitalized it!

SteveG

FWIW, aerodyn and sand go hand in hand; there is strong updrafting under there. My '85 has a pan and still had considerable sand in the lower regions; I believe it only spent a couple years near a beach, maybe the PO had the pan off, but he didn't do a lot maint, so I doubt it, but the grit was doing its thing on the crank pinch roller.

danglerb

Just a random thought on plastic vs aluminum pans, plastic might have been used to do very little damage if it got snagged on something, break away easily etc.

I am still curious about where the air goes from the factory ducts.

Bill51sdr

The airflow is directed at the engine mounts and I believe, the starter.

Rob Edwards

As 50 lightbulbs go off in the heads of 928'ers everywhere, I'll vocalize it: do the OEM hydraulic mounts fail prematurely due to chronic overheating in the absence of directed airflow? Is there any data (anecdotal or otherwise) to support the hypothesis?

Jim M.

As Bill stated the ducts are there to air cool the motor mounts and the starter. And yes I would suspect that a large number of hydraulic mounts fail due to the heat. If you have a later car (don't know what year it started) the hydraulic mounts have a heat shield, at least my 93 does.

Why couldn't these ducts be made from fiberglass or better yet carbon Fiber? I'll bet I could make one out of fiberglass in less than a day, just make a mold of the interior shape from a metal one, position the tabs for the mount and fiberglass goes on!

Jim Mayzurk
93 GTS 5-spd