hans14914

After having a non-sealed Spal fan fail on the 30102130 (dual 12" Spal fans as used in the SharkBlade) I wanted to go back and design a slim fan shroud that would:

A) fit the 928 radiator exactly
B) allow the installation of two of the sealed 12" Fans - 30102029
C) be slim enough to easily get at the crank pulley
D) be narrow enough to allow easy removal without having to undo the PS fluid reservoir or get tangled in the cooler lines
E) have a provision for good passive cooling at highway speeds

I finally got around to ordering the fans and got them measured and the footprints of both the fans and the radiator into CAD. It was a little tricky getting all the sheetmetal geometry right, but it was worth it, as I am able to get the shown shroud cut from a single sheet of aluminum with just standard brake bends.

Previous aftermarket 928 fan shrouds have required either trimming the original plastic shroud, or installation of a secondary part to provide the upper air-dam. This shroud included that part as well. It is easily removable by removing the two upper screw, and is held in place at the bottom by the three tabs, as this original shroud was.

In order to make this design work the way I wanted required intake snouts like those used on the early 32v cars. The 928Specialists and 928Motorsports air-dams use the factory part. I chose not to go with this design, as supply is limited. I have instead designed a new snout that is ambidextrous, so is the same on both sides, just flipped 180degrees. After looking around, I was unable to find a similar part, so think it will be a good fabrication aid for other radiator/shrouds, and is designed to be as slim as possible and use common 3" ducting.

Here is the link to the Spal fan intended to mount to the shroud:

https://webstore.spalusa.com/en-us/p...-12-c-12v.aspx

I am attaching basic renderings and 3D PDF's for your review. The files are going out for bid in the morning.

When looking at the shroud, the two large opening are those for the fans, the smaller openings are for rubber flaps to increase the amount of open area when there is high pressure in front of the radiator (at speed) for enhanced cooling. The flaps passively close at low speeds increasing the fans efficiency in traffic. Also, on the drawings the pink areas denote bends in the the shroud. The software automatically sees these areas, and can add elongation to the part and deconstruct it into a flat model for the laser cutting operation.

Thanks
Hans

kaelix

I know you said the files are going out for bid in the morning, but do you have an estimate as to how much this would end up costing?

Optimator

This looks great! It addresses all of the various shortcomings (in my opinion) of every other aftermarket electric fan setup I've seen for the 928.

fraggle

Gimmie gimme one of my unsealed fans is also on its way out.

MGW-Fla

Great work Hans! Keep us posted.

AirtekHVAC

OB?

ROG100

I will buy!!!

Tony

I guess I would need to know how these new Spal fans compare to the stock units as far as output (cfm..amps..etc)

what is the CFM of our stock fans? I would guess less than 1292 cfm?

anyone.

I need more cooling on my car in the summer and under extended load.

Ducman82

Will the vents fit my "s4" Kuhn snouts? That's the question

Glen McCartney

Nice work Hans. How is the piece you are working on for me coming?

69gaugeman

1151 CFM and 14.2 amps

Not sure what the stock numbers are, but the stock one in the GT works fine for me. I do need a new fan. Thankfully the cooler weather make this not a priority. Not to mention they are $200.00 each. Plus the sheet metal.

Looks good, though, Hans. I think you just like fooling around with the 3d drafting software... lol

69gaugeman

Now that I added a wetherpak connector for the fans at the top by the jump post, I can remove the fans in less than 3 minutes. Best mod I ever did.

hans14914

They can be found here for $109 retail, discounts for wholesale/volume purchasing. I also have a contact at Spal:

http://www.a1electric.com/Merchant2/..._Code=30102029

I am attaching the spec sheet for the fan, but pull a bit over 1300CFM under a no static pressure situation (traffic) at around 12.5amp.

They are much quieter and more efficient than the factory fans. I am not sure though if they have more output, I dont believe there is data available for the stock units. I do know that they did use a pair of these fans on the early 2000's Maserati's without any issue, and they are also essentially the same fan that is on the 928Specialists twin screw cars.

There is a higher output puller fan available if it is necessary.

Thanks
Hans

fraggle

The critical bit here is that both fans are sealed, unlike the original sharkblade units.

Keep us posted, Hans, I'm definately in on the buy. I have a C&R radiator in my car, though I wouldn't expect any fitment issues with your setup.

fraggle

I'd like the option of the higher output puller fan, will what impact the shroud design?