ok i just took another look at that intake setup i posted and thought why didnt they make a heat shield out of ABS plastic and run the factory intake pipes thru there??? BMW's and VWs have cold air intakes with heat shields. It can't be too hard to do it

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Hey gang, I installed some duct work today. Don't know if it will work. I need to figure out how to post a picture. I have a digital Camera and know how to download etc., but how do I post it to site... <img src="graemlins/crying.gif" border="0" alt="[crying]" />

 

BTDAT... Temps sensors at the inlet..above the MAF..insluated tubes..insulated airbox above the radiator Yadda Yadda.

On average as you drive stady state you will find the temps above the MAF will only be a few degreees above ambient 7-10 if i recall. The time that the air spends inside the ductwork isnt really enough to get significant heat transfer. When you come to a STOP however, it is a different story. It DOESNOT take long for the itnake temps to skyrocket whn you are stopped, idling and there is no airflow. This is where the real advantage of insulating your tubes and airbox come into play.
Our cars are dawgs off the line and this HOT air doesnt help im sure.

Even with the 3 big slots cut on top of my airbox, when i drive steady state at lets say 60mph, even 20mph, the air temp above the MAF/in the box is only a few degrees warmer than outside. Again 10 at the most if i recall.

The killer comes in all this when you come to a stop. The hot air under the hood immediatly ivades the openings in the airbox (the holes i made)and the temp sky rockets. OVER 155 on a vegas 90' day. Thats the intial airtemp that the engine will suck in when you STOMP on it at the light. NOT GOOD! Once you start moving, it doesnt take much, the air temps drop quickly.
The key would be to get cool air to the opnings in the airbox top. To do that you have to start hacking some sheet metal away under the hood, near the blower tunnel and venting to the base of the windshield. MArk Kibort has done this on his car..in a crude way but im sure it helps. I saw a REALLY trick setup at DEVEK day on a yellow 928 racer. Long slot on the airbox top, vented to the base of the winshield, hood closes all they way. VERY CLEAN and i bet it works! Ive got it on video and will try to digitize a pic.
Big draw back in all this is WATER!!! very easy to suck water in from the base of the windshield. Best solution to that would be some type of inertial seperator. The air makes the turn but the water doesnt.

BLAH BLAH BLAH..

Inshort. 3" PVC pipe, insulated. Insulate the airbox and the top of the radiator shroud in front of the intake. Perhaps add a small metal deflector there as well to help more direct cool air in with out mixing with that infront of the radiator.

BTW..TARGET sells a nice little indoor/out door thermometer. DUO TEMP or something, silver in color. I ripped it all apart and added a long wire to the "indoor temp sensor" so i could place it at the MAF, while the other sat at the intake opening..and the display could be in the car.
Makes it easy to see the difference in temps as you drive.
HTH

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Regarding the RAM AIR INTAKES on the TRANS AMS. its BS. The only thing it will do is get cool air to the motor, which does help (what are we trying to do). NO RAM INDUCTION. MArk K has the exact stats ..but even the top fuel dragsters dont see much of a gain from the hood scoops at the speed THEY travel.

There a lot of improvement to be had on the intake system of the 928 not only on the upstream side of the MAF...as seen in the last issue of 928 forum (shameless plug for Adam) <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

OK, so last night I ripped out the duct work I fab'ed. I had it in front of the radiator, 2- 1.5 inch PVC pipes pointed toward the intake openings. 1st problem, restricted cooling, engine temp climbing on a cool day?! 2nd problem no apperarent HP gain.

Rethinking the radiator heat issue. Doing a feel for heat with bare hands; kids don't try this at home; the finned surface temp is not very hot,as expected. The structure of the radiators is the hottest, so I'm insultating all surfaces that the intake air is exposed to. This is almost a dead issue now. I don't want to butcher the car/resale.

Any other ideas? <img src="graemlins/crying.gif" border="0" alt="[crying]" />

 

I'm still ruling the vented hood and that air intake on top; but, a heat shield needs to be fabricated for the British idea. Mark Anderson's hood is also good but its just more cold air than ram air. Perhaps, there is no ram air because of the surface area of the air box, seeing that its real big and the fact that ram air must go STRAIGHT into the intake manifold, I believe the 928 one horseshoes to some effect. Maybe we should give up since Porsche already built this car to it's max.

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<a href="http://www.procooling.com/reviews/html/raytek_-_mini_temp_gun.shtml" target="_blank">http://www.procooling.com/reviews/html/raytek_-_mini_temp_gun.shtml</a>


get your self one of those! very handy for checking temps around the engine, tires...and of the chilled Coronas in the fridge. (34.5.F) LOL

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