911 Cooling Shrouds - Improving Internal Air Distribution

[Bad bug]

I feel left out. I don't have any data to share but i do think if done right the 11 blade will work. Samcat had a 11 blade setup that di work well on a stock 2.0l type4.

[Sandeep]

I have finally received my 11 blade fan factory diverter in the mail ... time to start playing and logging the data

Its a good thing the 911 fan/alternator setup can be removed from the shroud and unwired in about 3 minutes :agree:

Sandeep

[Wally]

Cool!
Curieus what your accurate measuring device spits out

[Sandeep]

That datalogger of mine is using I/C's accurate to 1.0C, converting to F, accurate to 1.8F.

My VDO oil temp gauge/sender is off by about 12F at 180F oil temp measured in the DS tank. My logger reads 180.8F, and an infrared thermometer measures in at 179.8F

Sandeep

[Sandeep]

Wierd .... I just installed the factory 911 alternator cap with 2 diverters into the FAT shroud .... it fits with NO modifications and the back and top of the diverters hug the back of the shroud .... almost like the shroud was made to fit this like a glove.

Now for a road test/logging session to see if it amounts to anything positive.

Sandeep

[Sandeep]

Looks like that diverter does make a difference after all ... 30degF cooler on average for 3&4 and 15degF cooler for 1, but 2 stays the same on average :shrug:

I think that 3&4 are getting more air now and 1 is getting less (but might have been getting too much in the beginning and the shroud may not have been able to get rid of the air around #1

Out for some more testing and more diverters !

Sandeep

[Wally]

Originally Posted by Sandeep

Wierd .... I just installed the factory 911 alternator cap with 2 diverters into the FAT shroud .... it fits with NO modifications and the back and top of the diverters hug the back of the shroud .... almost like the shroud was made to fit this like a glove.

Now for a road test/logging session to see if it amounts to anything positive.

Sandeep

Yes, the same with the BAS shroud: I thought about it as well and I think they probably made/modelled the shrouds of an original 911 shroud for the part thats directly behind the fan housing.

Interesting data!

Greets,
Walter

[Sandeep]

Wally,

I've made quite a few changes to the diverters on the alternator cap but I can't seem to get the temps on 3-4 to drop anymore, 3-4 are still about 40 degF higher than 1, and 2 is about 25 degF higher than 1.

I am going to try the T1 under cylinder tins now, but still wonder why #1 runs so cool with the T4 tins ... can't get it above 325 degF no matter how hard I try.

#1 has a nice airflow path from the alternator ring ... almost a direct shot of air to the head. Perhaps the diverters are directing the air to the cylinders and not the head on the 3-4 side

I will try the T1 tins first and then try your method of the horizontal plate over the cylinder bank as the airflow may be having a hard time getting past the first fin on the head towards the case. It is much taller than the last cylinder fin towoards the head and perhaps this is an airflow barrier.

More testing !

Sandeep

[jim martin]

Originally Posted by Sandeep

Wierd .... I just installed the factory 911 alternator cap with 2 diverters into the FAT shroud .... it fits with NO modifications and the back and top of the diverters hug the back of the shroud .... almost like the shroud was made to fit this like a glove.

Now for a road test/logging session to see if it amounts to anything positive.

Sandeep

have to bump up this thread again,new to this site and must admit its excellent reading.i would love to see the picture of this 911 2 divider cap if some one has one handy.

[Sandeep]

Here are some pics of the mods ...







The shroud looks pretty rough after all of the mods, so I'll fix the holes with fibreglass and then get it repainted.

Sandeep

[Massive Type IV]

I have a Race- Technology DL-1 logger with digital SPA instruments for quick reference.

The logger is set up for in car use and Dyno use by simply disconnecting the wire harnasses that are hard wired into the Bug, 914 and the dyno.

The logger even utilizes a GPS to track map the position of the car at the time the data was recorded, so I can literally watch the temps rise going up hills and etc all while measuring TQ and HP and even G forces...

I am having a real learning curve with this logger- It has so many features that its very confusing to get used to, but DAMN is it awesome (and expensive)

[SuperRSi]

Sandeep,

Where did you order your 911 fan diverter from?

Thanks,

Randy

[Sandeep]

Lucky find on EBay

Sandeep

[piledriver]

I have considered making a small plenum and using perforated metal plates for the same purpose on each side of a cali setup.

This reduces the velocity, increases the turbulence, forces more air to the heads, and makes the pressure more uniform. (all very good things)

(Think "cool tins" on TOP of the jugs, with lotsa holes)

Cali setup has pretty good side to side, but on each side one jug runs hotter ~30-40 F, Probably the same across the head. (using IR setup)

[Schmuck69]

Any chance we can get some pictures of the third deflector that you added to the 911 divertor? I am running the same set-up.

-Britain