luckett

https://rennlist.com/forums/showpost...4&postcount=21

FRporscheman

I was wondering about the passenger side NACA duct all this time. Seems like it would be cooling the exhaust, if anything, and isn't that no bueno?

RajDatta

It terminates right at the distributor cap. Not sure exactly what kind of colling is needed there .
Raj

PorscheDude1

I am surprised the "resident authority" does not know the answer to this one.

It is indeed fuctional. It was used to direct cool air to the exhaust manifold. There is a plate bolted to the manifold and the duct directs cool air underneath to force hot "Turbo exhaust " from under hood.

FRporscheman

But on a turbo, you want the exhaust to stay as hot as possible, to have the best turbine response.

I guess the passenger duct can keep the engine bay temps down... but if the exhaust is shielded or wrapped properly this shouldn't be a problem, I think.

RajDatta

If anything you are the one talking like an authority so why don't you point all of us to the part you are taking about.
Here are 2 pictures a factory 968 turbo S.




A better angle for you



Raj

boost feen

Heres a few pics of my setup before it was finished in March '07, these are fiberglass copies of the factory units! The 2 piece intercooler RS setup which I just cut a hole in my hood and installed some special fastners to fasten it down! The inside duct I used a seal to mate up to the hood duct for very nice flow through the front enlarged opening in which I used 2 951 intercooler vents cut and 3m bonded up together to provide lots of cool air to the Lindsey stage II intercooler which stays very cold! I dont think you want much air under the car so I would say the passenger side NACA vent is just for looks! The 951 turbo S and cup cars did just fine without fresh air into the engine compartment!

Heres my 968 CS recaros I just painted along with my 3 piece turbo S wing!

boost feen

I really believe that NO ONE should make any assumtions about the 968 turbo S and RS cars since none of us worked at the werks department in the early 90's! HAH!

RajDatta

Amen to that!!!

Raj

RajDatta

Shawn, car looks amazing. You did an amazing job.
Kudos.
Raj

boost feen

Thanks RAJ
For those of you interested in actually obtaining the factory repro of the 2 piece intercooler vent I know fitzegerald racing has them but getting ahold of them takes a few weeks it is possible though! I made molds of all my parts before I installed them as I got them kind of on accident and they are very high quality TUV reproduction pieces made in an autoclave! The NACA vents are a little more time consuming, I could post some pics of the 2 days of prep and install it took me to fuse them to my hood! Then the 2 more days after I painted my body parts of the factory dual hood latch setup as this was the hardest part of the whole 8 month process of building my car! I custom made a replica of the air duct that attaches to the factory 951 airbox and feeds cold air from the drivers side NACA vent on the hood into the engine! This car is amazing and the best part is I kept everything very simple just as the factory motorsports team did! you see they had already developed the 931 into the 937 then the 951 into the cup cars! SO why try and spend a zillion dollars on aftermarket custom made mumbo jumbo that your always fussing with everytime you drive the car??? I have 400 RWHP at 16 PSI but I run 12psi as I feel its too much for the chasis anyway! I did some minor engine upgrades like B&B 951 headers, super 61 turbo, dual port wastegate, 3" downpipe to 4" exhaust, but tried to keep it simple and easy! I didnt spend that much dough and every part is a simple factory bolt up piece no custom special one off parts! The body work is the only exception!

FRporscheman

Shawn, that's exactly what I had in mind, a frankenstein of factory parts. Except you went all the way and made one of the nicest replicas I've seen. I'm just going to make a turbo 968 that will follow the spirit of the turbo S, using the 951 parts and such.

Why was the dual latch setup the hardest part of the job?

PorscheDude1

I was referring to the RS. This was most likely installed on the endurance cars. For instance a car going down the Mulsanne Straight wide open full boost for 35 secs. 350+ times for 24 hours.

May have been installed on factory S cars for looks.

RajDatta

Nice try.
So, you are talking about the one and only that actually has it. All the other ones, turbo S or RS including the one from Hershey did not have it. This does not even look like a factory part.
I guess all that wiring that is sitting by the cage is also on all the cars now? These are race cars and they have lots of mods on them that weren't on turbo S.
Also, Arash asked about the NACA duct and not a NACA duct on the one turbo RS in Houston.
Raj

Jason Judd

Shawn,

I think you might be missing a part on your intercooler exhaust duct. On my car, there is also a piece that sits inside the engine bay, that helps deflect the air from the outlet side of the intercooler up into the exhaust vent. It mounts on the intercooler exhaust side; and looks like a scoop somewhat.

I also got my parts from AU fitzgerald racing; and can attest to the patience that is needed/required!

I decided not to use the naca ducts on my car, because we routed the air intake down the driver's side fender; so it wouldn't have done anything for me.

Jason

Jason