Pic of inside a 911-6 shroud

[Massive Type IV]

Nice observation Sandeep.. Its not just a clue, but one main thing i have been preaching about for two years.

Its too bad that NONE of the 911 systems for TI and TIV engines are deep enough to use the 911 factory air diverter! The -6 engine is deeper and allows the space for the cone on the back of the alternator!

also note how low the shroud sits to the cylinders compared to your shroud. This decreases volume above the cylinders and bosts pressures to the cylinders. You can also see that all cylinders on the -6 engine are behind the fan, instead of on the -4 where the #2 and #4 cylinders sit directly underneath the fan and the airflow must travel 90 degrees to get to them easily.

A 911 shroud could be made to really work on the TI or TIV but the development would take a tremendous amout of time, design and trial- error and testing on the dyno and in the car.... I simply lack the desire to do it since there are cheaper alternatives that already work with no further development. After my last cooling bout with the TI DTM my *** is whipped and I don't want to do any cooling R&D for a long time!

The temperature differences that you see are EXACTLY what I saw with ALL 911 shrouds as a trait. Very uneven temps, even on your stock engine....If you change drive ratios to a higher ratio you will cool better but lose approximately 4 more HP from a system thats already sucking off atleast 15 now. I found a 1.3:1 drive ratio to work best for cooler overall temps, but the uneven splits still existed.

NOW, Zen has Dual CHT gauges and 180 Dyno HP with almost 10:1 CR..... His heads run 275 and dead even from bank to bank ALL THE TIME.....

Now, if you could make me one of those data loggers for the bug so i can toss my miles of wiring and crap for testing we could do some swappin.....