Mauri

As some mentioned before the forum seems to get a bit boring, so now i try to do my part

I did a little uprade to my IC some months ago, which i would like to share with you. "My" Porsche specialist told me that the air-flow to the IC is far away from perfect. The air gets lifted at the back window and hits the rear wing just about at the last 3-4 inlet stripes. So most of the IC gets no airflow. He tested it at the wind channel from Sauber (Swiss Formula 1 Team).

First i couldn't believe, because i had porsche as genius engineering in mind and why should they put inlet stripes on the wing when there is getting no air to them? they could easily put some outlet stripes on it, to get the hot air out from the engine bay? However i noticed that every time i washed the car and drive it back home, theres always some drops of water on the wing. Most of the car gets dry very quick but in these area there really seamed to be no air-flow.

So i decided to put some fans on it, as my porsche specialist suggested.

Here are the pics i got:







wow, this post seems like reading a book

what are you're thoughts about it? any of you heard similar things about the air-flow?

dholling13

I have always wanted to do this because my intercooler gets heat soaked at the track; intercooler temp numbers would dictate if this is a worthwhile change or not.

tjr

Interesting, but I'm not really sure what the advantage is, beyond the obvious of reducing the temp very slightly? I would have thought some ducting would have the same affect (like the 993 GT2 rear wing) and would certainly look a lot better!

BTW, although that intercooler looks like the standard one, I've never seen one with any marking on the outside like that, here's mine:



The part number should be 930 110 330 01 - yours looks like 930 110 914 01. Is it perhaps a factory upgrade?

dholling13

Maybe yours was refurbished for some reason? Here's a picture of mine.

stu.p

my car is stored away just now in its bubble so i cant have a proper look!!
I do see what you are trying to acheive here but personally i would prefer to try and redirect the air if possible rather than fit the fans,,the fans may help though maybe some of the main bodies of the fans may also be blocking the ic there a bit..you would have to check ic outlet temps to confirm at say a good average speed to check..Maybe at slow speeds though this may have better cooling

kleinbbc2

My 1991 intercooler is stock with no marking

Black_Hat

In School I has Otto Cycle theory , for extra credit we had to (try ) to improve the mechanical fan on an
air cooled motor 36-40 hp vw ..one experiment was to use electric fans .( I realize this is a pull not a push set up )
but long story short an electric fan will not come close to the volume or pressure ...and a big enough fan & motor will have too many drawbacks . best bet is to copy what Porsche did while racing .

stefan

Mauri

Since i did the job, there was always too cold outside to get a difference. Maybe i will get some results in the next 2-3 months.

I will try with a sensor on the ic body, if it makes any difference with the fans. I also want to do a dyno run in the next months, there i will a try to do a run with and without fans.

The solution with the gt2-wing is for sure the better one, but it "kills" the look. I doesn't look bad, but its just a bit too much (or just too racey) for a standard car which is manly not on race tracks.

For the markings on the ic, i don't know.. maybe the marked one's are left overs from the 930s and where built in the early 964 (mine is 08/1991). The ic on mine is the original one afaik.

screamingflat6

Hi,all

Very interesting subject,we have all seen on utube etc our 965's on the rollers with the operators searching for bhp.
I have noticed in the past on some of the footage the rear fin has been removed and there is large ducting straight onto the Ic creating mass cooling(ram air) straight into the Ic.
I was wondering has anyone on here tried a water sprayer system that sprays water across the Ic core which in theory should make denser air.
I was also wondering if anyone is running a rsr rear fin and lost performance as I have been told that the air being flowed around the Ic and not directly into it can have a negative on the performance.
I have the above spoiler and need your advice as making a special frame or putting a seal around the Ic frame will be time consuming.


Regards Gaz,,

TB993tt

Mauri
Can you ask your man who has seen a 911 in the Sauber wind tunnel for more information and what he thinks of the article below which seems to contradict what he says -I am interested in what is really happening back there....



The pic below seems to confirm what your man says although I understood that it was the combination of the cooling fan and the low pressure under the car which drew the cooling air through the engine lid ?

Mauri

I will ask him next time.

On the 993tt its another story, because of the little lip on top of the back window the air-flow doesnt lift so much. Maybe the hole construction works a bit better also.

He also mentioned that racing teams did lift the back window from the 964s so that they are even with the frame around and the air-flow want lift. Maybe we can prove that by checking some photos from 964 racecars.

TB993tt

Like this:

tjr

That spoiler is a easy addition to a 965 - 911addict has one.

Mauri

Hmm exactly like in that picture, is that 964 prepared for racing? Maybe there's really a point about that air-flow break on the back window.

I'm not sure how much that lip would bring, maybe 911adict can check this once with some drops of water or taped on stripes? Could be very interesting.

TB993tt

If you read the article above which I posted it claims the "lip" with the brake light in is an afterthought "which never saw the wind tunnel" and is actually a backwards step aerodynamically !