I was looking at a few threads about upgrading the 997.1 intercoolers to the 997.2 spec ones, but I didn't see any threads about putting puller fans on the intercooler to help lower the intake temperatures.

On my Exige, putting two 330 CFM puller fans on the intercooler lowered the intake temps over 40-50 degrees and the car went from heatsoaking after two laps to rock solid horsepower lap after lap.

Have there been anyone who's done some back-to-back tests of putting puller fans on the 997.1 intercoolers vs. upgrading to 997.2 vs. 997.2 intercoolers with puller fans?

It seems like the car would benefit greatly from adding puller fans especially at lower speeds due to the small side ducting, but before I slap some fans on, I wanted to see if anyone has already gathered empirical data on the charge temps.

Investing $200 on a good Spal fan setup seems like a good first step vs. springing $900 on the 997.2 intercoolers.

 

I seldom see IATs of more than 15 degrees above ambient at cruise. On the freeway it's more like 8 degrees. Even on the track IAts are almost never more than 30 degrees above ambient..

 

Interesting. Top Gear US's assessment of the GT2 was that the car really suffers from high intake temps, which was why I started thinking about this.

From what you're saying, I guess the location of the ducting gets a decent amount of air flow unlike the mail slot duct that the Exige has on the top of the roof.

At what ambient temps were you getting 30 degrees above ambient at the track?

 

Another possible solution would be to run water sprayers onto the intercoolers, or better yet direct water injection for decreased intake temps. I don't have a 911TT (05 C2S) but I do have significant amounts of experience with water injection on other turbocharged cars.

Anyone here running water/meth injection or an intercooler sprayer?

 

With the fans, you'll increase your charged air temp due to blocked air flow THROUGH the ICs at speed. Unlike your radiator, you're only increasing charged air temps while boosting and you should be boosting at speed, not idling around.

Spraying water onto the ICs is about 1/100th as effective as spraying within the air path itself. It's also dangerous as the water would drip down onto your tires.

If you spray enough meth and/or run enough ethanol (E85+), you don't even need ICs as your charged air temps will be lower than ambient.

John H

 

I have seen only one setup here on the forum using a spray system for the air chargers.



Judging by the fin count between the channels, I would argue that a more efficient IC would eliminate the need and potential problems with this complex setup. In addition, I recall Chad, cjv, mentioning it's effectiveness only when ambient temps are high.

 

It certainly is not the case on the Exige, where the IATs were much lower across the board with the puller fans. I guess it depends on how much CFM airflow the intercoolers receive through the ducts at speed on the TT. Has anyone taken any air flow readings for comparison's sake?

Also, the puller fans prevent the intercoolers from heat soaking at idle and low speeds, so in real life situations, you get more power on tap as a result of the fans. But again, this may be a moot point on the TT because of the location of the intercoolers and the ducts (which I'm still trying to find out).

 

am useing CO2 intercooler spray system .. its very nice to lower the IC temp only and reduce the heat soak !!!

Yousef

 

Top gear drove the car at surface temperatures of 165 degrees

 

Keep in mind that air is a much better insulator than water. The best cooling for any heat exchanger would be under conditions of cool moist air, like they have in the Bay area which is probably why Sharky set up shop there.