Hey guys just wondering if anyone had any idea how effective our ducts in the quarter panel are(next to door)? I've been looking around and couldn't find anything compelling. I know some of you gurus have tons of knowledge on this platform. Would appreciate any help. Thank you!

 

I just read a book that said that Porsche had some trouble getting the needed airflow into these ducts. The solution was the air exiting in the low pressure area behind the rear tires.

Basically, the exit vents pull air into the intake vents. This change made the duct very functional and effective.

I definitely don't want to see a "scoop" trying to pick up more air, while potentially adding more drag and noise. My assumption is that a functional scoop can't add more air without being in the airflow. If it's in the airflow, it's adding drag and creating more noise. If it's not, than it's more than like not functional.

Later, Steve

 

I was thinking about this as well. I wonder if putting a gurney lip on the leading edge of the exit vent (behind the wheel) would help pull more air through the intercoolers.


It may not be that effective, since it is sort of out of the airstream anyway with the inward curve of the body and the tire in front of it.

 

Keep in mind that air is being drawn through the ducting, not pushed through.

Later, Steve

 

Has anyone ever used Spal fans in conjunction with the intercoolers, push or pull fashion?

 

While I seem to recall coming across info that gave the temperature drop of the incoming air charge due to the intercooler and thinking it was pretty darn good I do not have this info at hand.

Indirectly I think we can infer they are pretty effective in that there are aftermarket intercooler makers and they offer bigger -- thicker anyway -- intercoolers and claim an improvement (drop) in intake air temperature, from around 20 to 30F better than stock. This suggests the air flow supplied the air ducts is pretty substantial if just larger intercoolers can deliver this improvement in just being a big thicker/bigger.

They are a very intelligent design. They do not jut out into the air flow so they do not affect the car's aerodynamic drag, nor do they collect rock chips or the intercoolers much if any trash. They work based on air pressure differences with I suspect a high air pressure area created at their opening with the air pressure after the intercoolers in a low pressure area. Thus no moving parts, well, if you don't include the car.

 

There is really no need. If the turbos are not making boost there is no incoming charge to cool. The fans add electrical load to the alternator and this affects the engine all the time.

Besides I think the stock layout with no fans works pretty darn good and I touched upon this in another post.

 

Fans only function at idle or low speeds. At speed, the airflow speed and volume greatly exceeds what the fans are capable of.

I won't say the the airflow is only pushed or drawn through the ducting. It's a combination of both that makes it effective.

I love seeing modded cars where they slam a huge ebay FMIC with no ducting and expect reasonable airflow through an the I/C, condensor, and radiator.

 

Fans wouldn't be used to keep the intake charge cool at idle but to keep the Intercoolers from heatsoaking after hard runs.

 

i used to run MR2 turbos. They suffer from the lack of good intercooling, even though the intercooler was placed inside the air duct they always heatsoaked when running hard. it was normal practice to upgrade to a larger but still size limited intercooler, (which still would heat soak on high hp applications), and add spal high flow fans. They were triggered by a temp sensor in the engine bay but I often unplugged the sensor so it could run all the time when I tracked the car. it was a noticeable difference and was documented to lower the overall intake temps.

I know the 911T is a different design, but anything can be improved, right...

 

Well, that is the key. Improved.

The heat the intake/intercoolers have acquired goes away PDQ once the car is moving. While ridding the intercoolers of the heat could help I guess if tracking involved a race start from stop there is still the heat of the rest of the intake system and the heads. In a longer race a few milliseconds advantage at the start can't make any real difference.

Does your car have the engine compartment fan fused to run all the time the engine is running? If so this can help remove the heat soak even though the car is not moving fast enough to move any air through the intercooler ducts.

In the case of the MR2 it reads like it was just a lousy intercooler setup. You did say the car suffered from lack of good intercooling. It is a bit easier to improve something that has plenty of room for improvement, quite another to improve something that someone has gotten much closer to perfect.

 

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worry more about getting some good ICs and not the ducks... they do a good job....

I trap in the 150s and ran a 9.66 sec 1/4 on my 6" thick ICs.... and that's with the air filter on top of it...

markski

 

Holy Cow how does that even fit , are the ducts even functional at that level?
I plan to get some upgraded Intercoolers when I eventually
upgrade the turbos. Your package is looking enticing but not sure I'm ready just yet.

 

Lol that's how we do it.
Your not going to get that price I offer and what comes with anywhere on the market.
Markski