richardew

It always bugs me when people talk about how leaving the engine tray on cooks your engine. Well, I’ve had mine on since new and as far as I can tell it hasn’t affected anything in the engine. I’m adding a qt of oil every 5000 – 7500 miles. Gas consumption hasn’t changed any since new, ~23-23 mpg on the highway, 16-18 mpg in the city. The seat of my pants tells me that performance hasn’t changed much. I regularly hit triple digits in the car going up mountains (no speed traps going up the mountains ). In 1996 when I bought the car there was no talk on the internet about removing the engine tray. The 993’s were all still under warranty, and there wasn’t as much internet, at least not in my house (14.4 k dialup).

Now here’s my theory about the engine tray:

1.Hot air rises, cold air falls. You need the engine tray to keep the cold air from falling out of the car!

2.The hot air rises, and needs to escape. That’s why I drive a convertible. I keep the top down whenever possible. That’s whenever the temperature is >60-65oF, and if it’s raining, as long as I’m able to go >50 mph.

Just my $.02

HAPPY HOLLIDAYS TO ALL
GO EAGLES!
GO REDSKINS!

David in LA

Robin 993DX

It's one of those better be safe than to be sorry deals. I think what really set the tone right from start was this was this was a recommendation from Bruce Anderson in one of his books.... so... that's pretty much did it.

As far as the long term effects of leaving the tray on, I beleive it is dependent on what you use the car for. Under normal usage having the tray on or not will likely not make a difference. But for someone who heavily tracks their car or get stuck in traffic all the time it would be better to have as much air flow as possible. Having the tray off does expose the cooling fins on the cylinder to open air and allow engine cooling fan to push more air through the cylinders. It was the original flat 6 air cooled design, to allow fan blade to push the air down to the cylinders and draw heat away from the cylinder and pushes the heat under the car. IMHO, it is just not natural to have a plate underneath the engine that blocks the air flow.

jimbo3

Not much going on in Ambler, PA today?

Amfab

One issue with the heat rising due to the engine tray being installed is it can affect your rear speakers. The extra heat will cause the speaker cones and suspension to become more compliant—this in turn can cause mild distortion as transients hit the voice coil and the flexiblity of the cone changes. The foam suspension connecting the outer part of the cone to the basket will also become more compliant and lower the speakers resonant frequency. These factors coupled with the speaker dust issues (see: https://rennlist.com/forums/showthre...t=speaker+dust ) can cause substantial loss of performance and fidelity. Having the engine tray off allows the hot air to be blown rearward, most importantly, aft of the speaker mounting locations. This is not as big a concern for the Cabriolets as it is the Coupes and Targas as the Cab speakers are further forward. Now, remember they are lower, so they are in closer proximity to the drive train, but not directly over the engine compartment, and as Richard has mentioned, heat rises.

Mark in Baltimore

I'll give cabrio993 the honors of summoning Frahnkenshteen . . .

Robin 993DX

ROTFLMAO!!!!

Looks like I need to lighten up a little. Missed the whole point.

Mark in Baltimore

But. Wait. There's. More.

Mark in Baltimore

'Nuf said.

Mark in Baltimore

Dear God, please make it stop.

Mark in Baltimore

Well, it's nothing that Gay Spiderman won't cure.

Mark in Baltimore

Batman wants in on the action, too.

Cactus

Thread of the day.....Maybe even the week!!!!!

bluejam

Made my morning! Mark, you are good!

993USMC

Reasons why I recently removed my tray:

1. Excess heat was causing the wax to melt on the rear fenders and engine lid
2. Rear tires were wearing at a quicker rate due to the high temps
3. My son complained of burns on his back after riding in the back seat





OK,
Not really