 |
924Board.org
Discussion Forum of 924.org
|
| View previous topic :: View next topic |
| Author |
Message |
924CS
Joined: 23 Mar 2007
Posts: 14
Location: Grenoble in French Alps
|
 Posted: Fri Apr 20, 2007 10:55 pm Post subject: efficient direct air admission (job finish) |
 |
|
naca air duct
in french (for the moment, please wait for english translation)
cold air is necessary for a good air/fuel ratio
part 1 intake
find an 924 turbo airduct ant cut it with an 2' margin
with paint tape delimitate 1,5 ' around duct, be careful the air entry are not paralel to the cut. The finition work is very important, one hour mini
faites ensuite un gabarit en carton, c'est celui ci qui vous servira à la découpe du capot, voir plus étroit que large, vous ajusterez ensuite.
avec du scotch a masquer, balisez le bord et positionnez vos trous our les rivets, env 10 cm à 1 cm du bord pour des rivets de 4,2 x 8mm
capot ouvert tendez des la corde à l'emplacement ou vous voulez votre prise d'air et laissez autant de ficelle pendre, vous allez vite comprendre ensuite. prendre en considération la renfort du capot.
avec le reste de la corde restante, tendez là vers votre poinds d'origine en vertical comme en horizontal. avec cette méthode pas d'erreur de mesure, ne pas oublier que c'est one shot, pas de seconde chance
un essai de positionnement, pil poil passons aux choses sérieuses, fixez le gabarit
le tracé de découpe, les choses sérieuses commencent
ça y est, reste a ajuster, y aller mollo, très mollo même.
1er essai à blanc, cool faire les trous, foet de 3, puis 4,5
prêt à etre posé
un coup de peinture, n'oubliez pas de peindre la tête des rivets
ça y est, bien cool comme look, pour ne pas flinguer la tete des rivets, ammorcer avec la pince et donner un coup sec tout en donnant un cous sec en arrière afin de ne pas risquer de rayer le bouzin.
épisode 2 bientôt : isoler le filtre et canaliser l'air frais
bonne route
youngtimer with babies before hard drive night in mountains :
_________________
Race is Life
Last edited by 924CS on Mon May 14, 2007 8:56 pm; edited 1 time in total |
|
| Back to top |
|
 |
ideola
Joined: 01 Oct 2004
Posts: 15550
Location: Spring Lake MI
|
| Posted: Sat Apr 21, 2007 1:05 am Post subject: |
|
|
| Quote: | | please wait for english translation |
ooh, ooh, let me try!
Cold air is denser than the hot air, which provides a favorable air/fuel mixture. Without getting into a discussion about incredible claims of HP increases by gadget vendors, a setup that provides direct admission of air will optimize the flow while creating a nice audible effect.
Episode 1: Air Intake
Find a 931 hood with naca duct in order to stick with genuine Porsche dimensions, and cut out the naca duct leaving sufficient margin on each side (about 5 cm)
With masking tape, demarcate the shape to be cut, taking into account that the duct will not be exactly parallel to the mating surface. Use a fine blade jigsaw to cut a curved outline within this margin of 3 cm. Take your time; expect a good hour of work to complete the filing and sanding for nice results.
Next, make a template out of paperboard, which you will use to cut the hole in the hood. If you see that the template is too narrow or wide, you can adjust it [before cutting the hood].
Apply scotch tape to the Naca duct and mark the location for your rivets, spaced about 10 cm apart, and about 1 cm from the edge, for 4.2x8mm rivets.
Open the hood, and draw a string across the location where you want to position the air intake, leaving extra string that can be used to determine where the hood reinforcements are.
With the remaining string, tighten it at the edges of the hood to provide vertical and horizontal guides. With this method, it is less likely to make an incorrect measurement; don't forget, this is a one shot deal, there are no second chances [once you start cutting].
After testing the position, it is now time for us to move on to serious matters: affixing the template.
Trace the template onto the hood. Now it's time for the serious work to begin!
Once it's in place, all that's left is to adjust it. Take it easy, very very easy!
First do a trial to make the holes, first a set of 3mm, then 4.5mm
Ready to fit
Apply a coat of paint, and don't forget to paint the rivet heads
There it is. To avoid wrecking the heads of the rivets, start with the grip, blow off the rivet, making sure the neck of the rivet is dry.
Episode 2 (soon): Insulating the filter and channeling the fresh air
Bon voyage!
_________________
erstwhile owner of just about every 924 variant ever made
Last edited by ideola on Sat Apr 21, 2007 1:45 am; edited 1 time in total |
|
| Back to top |
|
|
924CS
Joined: 23 Mar 2007
Posts: 14
Location: Grenoble in French Alps
|
| Posted: Sat Apr 21, 2007 1:22 am Post subject: |
|
|
many thanks, i will never better translate.
a dream team is born
prêt à etre posé ?????? ready to fit
_________________
Race is Life |
|
| Back to top |
|
|
Nobbi
Joined: 24 Aug 2006
Posts: 1396
Location: Germany
|
| Posted: Thu Apr 26, 2007 11:24 pm Post subject: |
|
|
Hello ami,
when i remember right the air duct, is not providing fresh air, it is designed to suck - out the hot air from under the hood!!
And then it is installed in the very wrong place.
But it still looks cool ( Even if the smoke is comming out)
Nobbi  |
|
| Back to top |
|
|
ideola
Joined: 01 Oct 2004
Posts: 15550
Location: Spring Lake MI
|
| Posted: Fri Apr 27, 2007 12:54 am Post subject: |
|
|
Actually, the NACA duct is designed to draw cooler outside air in thru the hood / bonnet and down over the hot exhaust manifold, and out the bottom of the engine bay.
_________________
erstwhile owner of just about every 924 variant ever made |
|
| Back to top |
|
|
924CS
Joined: 23 Mar 2007
Posts: 14
Location: Grenoble in French Alps
|
| Posted: Fri Apr 27, 2007 4:45 am Post subject: |
|
|
| Nobbi wrote: | Hello ami,
when i remember right the air duct, is not providing fresh air, it is designed to suck - out the hot air from under the hood!!
And then it is installed in the very wrong place.
But it still looks cool ( Even if the smoke is comming out)
Nobbi |
i understand the original application, but when my admission are closed fresh air down to admission well.
suck out, yes, but with fresh air, i dont want to invent the whell but just applicate physical rules.
i stop smoking, 12 years ago,
_________________
Race is Life |
|
| Back to top |
|
|
924CS
Joined: 23 Mar 2007
Posts: 14
Location: Grenoble in French Alps
|
| Posted: Mon May 14, 2007 8:56 pm Post subject: |
|
|
the job is finish
finally the channel between debitmeter and filter are too long and heavy.
i have make 4 holes to refresh air filter and the naca with inside derivation to refresh the admission.
i have close the direct admission in a stainles stell box home made
the température results : - 25° in the direct admission and - 20° on the admission pipe
yesteray in my alps :
http://www.dailymotion.com/outlaws_racing/video/x1z0zy_le-vercors-en-924cs-vol-1/1
_________________
Race is Life |
|
| Back to top |
|
|
morghen
Joined: 21 Jan 2005
Posts: 9095
Location: Romania
|
| Posted: Mon May 14, 2007 11:49 pm Post subject: |
|
|
good driving  nice roads.
_________________
Supercharger and EFI kits
https://www.the924.com |
|
| Back to top |
|
|
impreza749
Joined: 29 Jan 2007
Posts: 36
|
| Posted: Sun May 20, 2007 6:06 pm Post subject: |
|
|
| This is a great write up! I am seriously considering doing this, I wish they made some sort of an after market hood for us with this scoop setup! I like what you did with the air box, what did you use to go about making it? and what is the deal with the MAF sensor upside down! |
|
| Back to top |
|
|
Paul
Joined: 02 Nov 2002
Posts: 9491
Location: Southeast Wisconsin
|
| Posted: Mon May 21, 2007 2:31 am Post subject: |
|
|
Might be a problem while driving in heavy rains.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy. |
|
| Back to top |
|
|
Joes924Racer
Joined: 03 Nov 2002
Posts: 11964
Location: Oregon, Denver Colorado native!
|
| Posted: Mon May 21, 2007 4:26 am Post subject: |
|
|
Nice work Id like to see the air box.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo. |
|
| Back to top |
|
|
impreza749
Joined: 29 Jan 2007
Posts: 36
|
| Posted: Mon May 21, 2007 8:55 am Post subject: |
|
|
| Paul wrote: | | Might be a problem while driving in heavy rains. |
my experiences with cold air intake is you won't have a problem as long as you don't completely submerge the filter, then you will hydro lock, or you could throw a by pass valve in there if you were really paranoid, I was thinking of improving my air intake, I have having trouble finding a good place to run the piping, I plan to make the piping out of a hard plastic, I also would like to create a replacement hard pipe for the flex hose that connects the MAF sensor to the TB,I would like the filter to sit either down in the back of the engine bay (con the oil pan heat) or up by the front bumper, I also want to run a 2.5 in pipe, my experience with intakes is with most NA 4cyl engines you will have a drop in intake viscosity with a 3in pipe that most "cone intake" kits come with, any input? |
|
| Back to top |
|
|
Joes924Racer
Joined: 03 Nov 2002
Posts: 11964
Location: Oregon, Denver Colorado native!
|
| Posted: Mon May 21, 2007 9:15 am Post subject: |
|
|
hydro-lock  popped a head gasket once a while ago yrs to be exact and
experienced hydro locking first hand.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo. |
|
| Back to top |
|
|
924CS
Joined: 23 Mar 2007
Posts: 14
Location: Grenoble in French Alps
|
| Posted: Mon May 21, 2007 6:20 pm Post subject: |
|
|
i have running last week in a mountain thunder storm without problems.
and i leave in a dry weather country.
_________________
Race is Life |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
924 FAQ (Technical)
