RolexNJ

I am considering having this done to my car, and would like some help from those who have done it, or, have done research on it. I already did a search on this, but wanted some current input. From what I can gather, its seems that the hood mod is more for cosmetics than functionality. If you guys can, please provide me with some photos of some hood mods, not the scoop type though. I think at the same time I'd like to add the 968 mirrors. Attached are some pics that I found too. Please post away some photos, comments, suggestions, cost, and which side of the car to install too. And I do have a Dynatech strut brace, so I'm not sure if that would intefere with the hood mod.

Techno Duck

The underside of the vent in the normal location will interfere with the strut brace mount. You can cut out a portion of the underside of the vent which hangs down, basically a notch to fit around the strut brace mount. I did this on my friends car. Its nothing structural.

The other thing is there are no mounts for the hood shocks on the 931 hood. You can source the parts from the 924 or 931 and use the hood prop. What i did was make some very simple brackets and weld them to the underside of the hood. Just need to be careful, the metal skin of the hood is deceptively thin.. i accidentally burned a hole in the skin (arc weld) when i was welding it, had to fill the gap on that very carefully. .

Personally on a turbo i would not put the hood vent in the stock location, i would do what HorsePowerFarm did and use it to feed a MAF setup or put vents in for heat extraction.

ehall

Winslow's car, the lower black car, has the vent in that area to bring cold air into the area of the turbo, to help keep under hood temps down. I don't know how well that works. If you go find a pic of the 924 Carrera GTS, you'll see that they ran a hood scoop over the turbo in that car as well. They raced in that configuration. The turbo was on the exhaust manifold side of the car. Brumos won the GT class, at LeMans, with one of those cars, on B.F. Goodrich street tires.

BTW, the white car is a photoshop that drifta944 did. I'm of the opinion that there are only couple of good hood mods, below.

ehall

notice that most of these cars have both inlet and outlet venting. The Carrera, at top, was a street car. For racing, on the Boss car, there is also outlet venting. Personally, I like the 968TRS solution best, but a good compromise would be Beni's car, bottom right.

V2Rocket

would mounting a NACA duct backwards work well? so that the narrow end is facing the windshield (to pull heat out)?

ehall

It depends on it's location. The shape, itself, isn't the best solution for air extraction. Look at the shape of the 968 IC outlet vent. Of the vents on beni's car. Those will extract more air as the the outside air will pull air from under the hood. This is old race technology.

V2Rocket

after looking at the shape of the naca duct some more youre right...its too small in the back...

general rule of thumb is something like outlet should be twice the inlet size, right?

Lorax

Part of creating an effective outlet is having a design where the air moving quickly over a lip or angled edge will actually start to pull air out from under the hood

This is what I'm using towards the front of the hood, I will also probably add some louvres towards the rear.


Just though I would add that.

V2Rocket

dude, cannot wait to see your car.

Lorax

Yeah... me either... lol.

Been in the garage for 6 months.

Lorax

Anyway back on topic: Rolex, You could easily have one of the guys at D9 mold you a FRP hood that fits like factory with a naca duct anywhere you want. Could use it to cool the turbo or anything really.

fbgh2o

Rob:

PM me if you want to talk about 968 mirrors. Just finished my install.

https://rennlist.com/forums/944-turb...8-mirrors.html

David Floyd

Would you really want to cool your turbo ?????????

ehall

no, but you would want it to pull hot air out, that would otherwise stay trapped, as you know. I think your car has the best solution, without doing tons of crazy 968 mods.

reno808

i have a 931hood lool and its white