engine compartment heat

[monteness]

The discussion of the K&N filter got me wondering,,has anyone done anything to add extra cooling to the engine compartment, mainly airflow from a hood vent/intake; if so did you make any vents in the bottom panel to allow airflow to exit the compartment, and did it produce any wind noise or buffeting? Anyone wrapped exhaust manifold, heat shield on your turbo if applicable? I saw a picture of a 951 with a hood intake, looked flush mount, over the exhaust area in DuPont Registry, not bad. Again, just curious...

Bret

[monteness]

To the area for the original air inlet or did you connect the two?

Originally posted by mideastmafia:
i routed some PVC piping to go from under my front bumper up to the hole in the fender for air flow..

SHAUN

[Lawrence Coppari]

What do you want cooled?

[monteness]

Well, I've been out of Porsches for while and recently purchased a 951. I didn't remember my 2 944NAs generating as much heat as the 951. I realize the turbo generates more heat, etc, etc,..I was just wondering if anyone had done anything to reduce the temp in the engine compartment, especially if someone had gotten rid of the factory airbox and was just running a K&N cone, turned in the direction of the original air inlet. There is thermal wrap on the market for exhaust manifolds and headers, wraps for your turbo(Calloway wrapped the exhaust side of their turbos, as most big diesels wrap their exhaust side for peak performance as much as safety,,,not comparing a porsche to a diesel). This was strictly a posting for thought and info if there was any. We once ran an air intake hose for an inboard boat to a PVC pipe, ran that through a built in cooler(with ice) in the boat, hosed it up to the K&N on the LT1; the boat was consitently a few tenths quicker 0-36mph with the hose hooked up,,,the intake on my boat(aluminum) has been Jet Hot coated and it's almost like a port and polish job, it runs so smooth and makes more power(both engines are Indmar)and cools down much quicker. I was just trying to get any ideas before I started experimenting..I will probably pull my intake and have it Jet Hot coated and reinstall. I'll let you know if any improvements. Jet Hot has offices in New Jersey, Mississippi, and California that I know of. My intake was about $169, don't know what the porsche will be but probably around the same price. If you call them, they will send you a box for shipping. You will probably need to tap a few bolt holes after they finish but all gasket surfaces were smooth and the coating was thinner there.

Bret




[This message has been edited by monteness (edited 12-13-2000).]

[Gary Peters]

Turbocharged engines heat the intake air when it is compressed. That is why they are much more efficient with an aftercooler on them. That is why it won't make much difference cooling the air before the aftercooler. Covering the pipe from the aftercooler to the intake manifold may make a bit of difference though. A larger aftercooler will make a difference on most turbo engines as well by getting the compressed air closer to ambient temp. N/A engines will definately benefit from a cold air intake but will not matter on a turbo engine.

The coating of the exhaust system helps the gases flow more smoothly through the pipes. I'm not sure why it does this but it is supposed to help on almost any car, esp the turbos. On a turbo it helps to reduce turbo lag. It helps keeping the temps down as well as.

------------------
'76 911S

'80 924 M471

[johnnybegood]

test

[johnnybegood]

If you wrap your turbo, make sure to NOT wrap the inlet half. If this is wrapped, then
all of the heat transfers to the intake housing, raising the temp in the intake as high as
70 -80 degrees. Using wrap on the turbo and the down pipe and exhaust side of the
headers, will drop the engine compartment several degrees. My 951 ran at 485 at the
top of the turbo and 375 to 400 two inches from the top of the turbo. With the wrap, I
have seen a drop of, 150 to 175 degrees in the engine compartment. Also, using water
wetter will drop the engine temp in the engine as well. Air that is heated expands, the hotter it gets, the more it will flow. With the wrap, the heat stays in the exhaust and keeps the air at a higher temp, allowing it to flow faster.(Ex: heating oil makes it flow out of a tube faster that cold oil). Same with air, air is a solid even though you cant see it, its there.
The colder it is, the denser it becomes (or thicker it is), and if it is thick, it will not travel as fast as hotter air, that's why the exhaust wrap works. If you are having engine heating probs, then there are more things that you can do to cool it down. I live in Texas, on a 100+ day and driving at speeds of 85 and over(hope your not the law
hehe) my car has not come close to the halfway mark. street temp is 145 and a 55
minute run, 85 mph (to and from), the temp was 297 at the two inch mark above the turbo and 225 at the outside of the intake. also if you use a aftermarket intake, (Im using huntley racing stage 3 intake system with 2.5 in. intake pipes, and k&n filter, and blow off valve), you don't have to worry about the hot engine air being used instead
of fresh air, (cold). The only time there is a big difference is when you are sitting at idle. When the car is in motion, the air crossing the intercooler is about 25 to 50 degrees above the stock air intake, but the amount of air that is available (Using an K&N filter system, or aftermarket air system) for the intake is well worth the trade. At the track, Ive seen 13.8 with the outside temp 65, 49 lbs of fuel, clean track and street tires. With slicks, I will expect lower numbers. If you have more questions about a cooler engine, then email me and I have more things that Ive done to my car that works. Hope this works for you
I am not a salesman, just a driver.

Good Luck

[monteness]

Good post. No overheating problems and yes, water wetter installed. That is probably one of the best ideas is to wrap the exhaust side of the turbo,,I may wrap the stock exhaust manifold and then check the temps. There is actually some wrap here where I work, that is in sheets of 8" x 24", for industrial turbos; I'll borrow a few sheets...I thought about sending the exhaust manifold to be Jet Hot coated(flow of exhaust) but if it ever develops a crack, $$$ wasted; just the intake will be done. And yes the K&N makes a difference,,I was just trying to give it a few degrees cooler to breathe on, every little bit helps in density.
regards
Bret




[This message has been edited by monteness (edited 12-13-2000).]

[BRose]

If your into wrapping things for heat protection then I suggest you start with wrapping the exhaust line before the muffler so it provides heat protection to your drivers side cv/axle. You will prolong the life of your cv's two fold if you do this. Remember, that pipe gives off a hell of alot of heat so use the right stuff.

BR