911 Cooling Shrouds - Improving Internal Air Distribution

[Massive Type IV]

Excellent work Sandeep. I would like to see how those mods held up in a higher load arrangement, what is your gearing??? Tire size"?

#1 is generally, no matter what is done the coolest cylinder- This holds true on all shrouds except the stock TI doghouse which robs its air for the oil cooler from just above #1 and heats it up 20 degrees in my testing.

#1 and #2 are on the same tangent as the fan so you have increased pressure and volume there, but normally the FAT shroud bakes #2 and freezes #1, but the smallest engine I have used for the testing was a 2270. I would be interested in seiing the plenum pressures associated with the shroud with these mods compared to what I saw here. Do you have an old Boost gauge laying around that will go to 15 PSI??

Your temps are pretty close together now and definately acceptable, as far as the deltas between the cylinders, but your stock engine is still running 25 degrees hotter than Zens 2316.... BUT it's DTM cooled.. LOL

I really like your work on the shroud, it makes me want to speed up my development and get to the 911 shroud faster, but it won't happen till 2007 at this rate.

Like I have said all along, the 911 shroud is not horrible, but off the shelf none of them have touched a DTM, and Sandeep is proving that as well as the fact that they can be made to work if you have the instrumentation and time to make the mods.

[Bad bug]

I love the fact that he is doing this work. If all goes well we will have a 911 system that's a bolt on. I don't mind cutting the back of my deck lid.

[Massive Type IV]

The system that I already have the molds for does not require any cutting of the decklid. Since the outside physical parts of the shroud have already been completed (Joe did this before he died as he was working on a 911 system that actually worked with even air distribution) I only need to take the time to test it the way that Sandeep has and right now I have other priorities that are more important like a heater box exhaust system and my Billet heads.

I don't know if we can ever get a 911 system that will beat a DTM, it is my goal to make them exactly the same but I do believe the DTM will win the challenge in the HP loss from the fan category due to the radial fan primarily. I have an idea for this that would release pressure within the upper plenums of the shroud at high RPM when pressure with the axial fan skyrockets and reduce the HP loss- You'll like it.

Sandeep is having an easier time doing his work than I had imagined. Sandeep you should send me that shroud for a heavy load test when you are all done toi see how the mods impact the cooling on a bigger engine on the dyno. I now have my logger in place and can measure the temps much faster and easier. That would be a fun comparison.

[Sandeep]

Originally Posted by Massive Type IV

Sandeep is having an easier time doing his work than I had imagined. Sandeep you should send me that shroud for a heavy load test when you are all done toi see how the mods impact the cooling on a bigger engine on the dyno. I now have my logger in place and can measure the temps much faster and easier. That would be a fun comparison.

I think the reason I am having an easier time is that I'm only working with 3 diverters .. 2 stock with modifications and 1 that I added, and not trying to engineer a whole system like you did. I can also visually see the results of air distribution by using yarn tufts and looking through the fan while it is running to see where they end up pointing.

I'll send it to you during the winter for testing when I am freshening up my motor.

Sandeep