Weatherstripping removal..might not be a good idea

[flashbk2]

Ok Craig O. you do what you want ...I do the same ! But if you think DC does everything right why would you want instructions for manual boost control....doesn't DC know best ? Seems to me you lack a little consistancy in your thinking ! I removed a piece of weatherstripping not the whole thing ,I installed MB control ,and oil catch setup,none of which DC decided to equip the car with. It's a great little car and it's the 3rd one my family has owned . Just because a mod wasn't installed by the factory ,doesn't mean it can't improve performance or engine operation . I realize you are an engineer and have more expertise but maybe just maybe logic and formulas don't always answer every question.

[TripleJackInGA]

......does not compute............[:0]

[don668]

I read an artical (car&driver, Road&track or something like this) that mentioned how the PT was designed so air was passed through the grill, over top of the motor, and down the firewall to aid in cooling the turbo. The air would then be vented out under the car.

This makes sense to me.

Don

[Cal Cruzer]

Hmmm, whereas I read an article chatted online with and engineer that said the lip under the front of the car was designed to create a small low pressure area directly behind and below the rad to draw the hot air that has passed through the rad down and out of the engine compartment.

IMHO hot air is bad, getting rid of it is good. Nature abhors a vacuum. Removing hot air air from under the hood has to be drawing more air from somewhere. I have not studied the dynamics of the way air flows under the hood of the PT but I doubt that anyone else here has either. We will have to just agree to disagree. Bottom line, IMHO, it ain't gonna make that much difference anyhow when you are dealing with temps of 1200+ degrees or more coming out of the combustion chamber that turbo has to be able to withstand the stresses of high temps. I mean just step back from the trees here for a second and take a look at the forest. Whether you have 80 degree air or 100 degree air back there it just isn't that much difference in the big picture.

Just my $0.02

[CraigO]

Don sez:

"I read an artical (car&driver, Road&track or something like this) that mentioned how the PT was designed so air was passed through the grill, over top of the motor, and down the firewall to aid in cooling the turbo. The air would then be vented out under the car."



This is EXACTLY what happens. Dats the facts, Jack!
Do what some of ya'll like, but having the 'stripping on is the correct way to treat your Cruiser!

Craig

[bigdogdad]

Just want to add what I just saw on a TV show, but it involved airplane engines. Again, I just telling what I saw, I am not a car machanic in any such way and do not pretend to be. I usually don't answer these types of forums but thought this might be of interest.

This was a single engine aircraft that the machanics totally enclosed the sides and top of the engine to force the air to flow over the top of the engine and down and then out. They did this to cool the engine. I thought this was interesting enough to add to this thread.

[Gary04GT]

quote:...the PT was designed so air was passed through the grill, over top of the motor, and down the firewall to aid in cooling the turbo. The air would then be vented out under the car."

quote:...the machanics totally enclosed the sides and top of the engine to force the air to flow over the top of the engine and down and then out. They did this to cool the engine...

It appears as though the above quotes are supported by the picture below showing the air-flow pattern directed by the insulation under the hood of the GT Turbo. The blue lines show how the insulation is contoured to help direct the intake/front grill air over the motor to the rear and down. The green lines show the direction of the air-flow--front to rear. I'm certainly no car expert but this seems logical to me--just maybe those DC engineers designed something correctly and intended the insulation to remain in place. As for my turbo car--the insulation stays!

[Ant]

The hood insulation is not what is being referred to, it is the rubber weatherstriping that runs along the rear edge of the engine compartment.
Yes air will flow over and down, but that is when the car is moving.
What happens when you are in traffic idling or moving at a slow pace. Where does the hot air go? Removing the rear weatherstriping will allow some of that hot air to escape through that little gap.
When the car is moving the air flow should still move over and down, the small gap should not inhibit that pattern or flow.
There has only been 1 person to actually test the temps with both scenarios. The latter has been shown keep the underhood temps cooler. If someone else has access to test equip. and a little free time, then do some testing. Up until then I have to go with what has been proved. This test was not done by a shadetree mechanic. It was performed by an engineer as well, with a HEAVY background in engine building, racing, fabricating, and machine work. A professional!
Don't go out and remove you "strip" if you are not comfortable doing so. I am not trying to get anyone to do it. Just responding to the orginal post and having fun building my car

[Gary04GT]

quote:The hood insulation is not what is being referred to, it is the rubber weatherstriping that runs along the rear edge of the engine compartment...

Good point, well taken. However, my car's weather stripping also stays. [|)]

[Sci-Fi]

Think there is a bit of confusion about all the points being made on this thread. Removing a portion of the weatherstripping does allow heat to escape when the car is turned off, at a stop, or at idle. At speed there is a suction effect, similar to a cowl induction, where the air is actually drawn into the engine compartment at speed through the cutout. The original air flow design was to force the air over the engine and out at where the exhaust header/cat/turbo/etc. is to provide some cooling and/or force heated air out. There has been a safety concern about cutting the weatherstripping because of a possible, if unlikely, exhaust leak/gases migrating to the external or cabin outside air vent and possibly creating local heat pockets, especially around the pcm and wiring. On the other hand, allowing the trapped heat an escape route may prevent discoloration of the hood from heat damage and provide better cool down. IMHO, there isn't a right or wrong, anything one does is a compromise and carries some risk and benefits.