924 Hood Modification & 968 Mirror Ideas
02-23-2009, 06:13 AM
#31
Rennlist Member
Ok, I thought Darwin was quoting someone else. Still a funny comment to have up your sleeve. 
02-23-2009, 06:16 PM
#32
Three Wheelin'
Join Date: Sep 2004
Location: Tennesee
Posts: 1,269
Likes: 0
Received 0 Likes
on
0 Posts
I'm not sure that I can agree, because I think we're talking about two different subjects.
To be more correct, the venting was used to cool the area, around the turbo, from which a lot of external heat is made. The turbo spool up wouldn't really be affected by that. The vent brings air into the area in an undirected, very general way. It really would only, perhaps, help to reduce heat soak of other components. It would take a heel of a lot of very narrowly focused air, to overcome the heat pouring through the crossover pipe and into the engine.
The idea worked really well for the LeMans cars, and that vent rammed area over both the turbo and the exhaust manifold.
In a street car, you're really only opening a hole to let radiant heat disipate, in city type driving.
To be more correct, the venting was used to cool the area, around the turbo, from which a lot of external heat is made. The turbo spool up wouldn't really be affected by that. The vent brings air into the area in an undirected, very general way. It really would only, perhaps, help to reduce heat soak of other components. It would take a heel of a lot of very narrowly focused air, to overcome the heat pouring through the crossover pipe and into the engine.
The idea worked really well for the LeMans cars, and that vent rammed area over both the turbo and the exhaust manifold.
In a street car, you're really only opening a hole to let radiant heat disipate, in city type driving.
The scoop on the 924GTS/LeMans fed air through the intercooler.
The NACA duct on the 924T fed air over the ducting from the turbo to the intake. At rest it allowed air to escape
from the engine bay.
On a 951 the naca duct or 924GTS scoop would act to cool the headers. The faster you go more cool air would be forced into the area of the headers cooling them.
Hotter exaust gas = quicker turbo spool.
For the 951 a scoop of some sort is the wrong way to go.
The car would benefit more from a vent allowing air out,
like the 968 TRS vent or like David Floyds mods.
02-23-2009, 06:24 PM
#33
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Well, I definitely agree with this,
"For the 951 a scoop of some sort is the wrong way to go.
The car would benefit more from a vent allowing air out,
like the 968 TRS vent or like David Floyds mods."
I'll have to go back and look at the LeMans cars again. The four inlet holes pulled air through the IC, as I understood it. The hood scoop wouldn't make sense for that purpose, due to it's location, but you may be right, that they did that.
"For the 951 a scoop of some sort is the wrong way to go.
The car would benefit more from a vent allowing air out,
like the 968 TRS vent or like David Floyds mods."
I'll have to go back and look at the LeMans cars again. The four inlet holes pulled air through the IC, as I understood it. The hood scoop wouldn't make sense for that purpose, due to it's location, but you may be right, that they did that.
02-23-2009, 06:28 PM
#34
Three Wheelin'
Join Date: Sep 2004
Location: Tennesee
Posts: 1,269
Likes: 0
Received 0 Likes
on
0 Posts
The four inlet holes let more air into the rad, like the 924T.
The intercooler on the GTS was mounted on top of the engine believe it or not. (I'm looking at a pic)
The intercooler on the GTS was mounted on top of the engine believe it or not. (I'm looking at a pic)
02-23-2009, 06:37 PM
#35
Nordschleife Master
This is a GT, note the headlights.
02-23-2009, 06:51 PM
#38
Nordschleife Master
Here is some info from 924.Org regarding the GTS..
"The hood scoop was retained for better engine compartment cooling. The fixed headlights were necessary to accommodate the larger intercooler, which was moved to the front."
02-23-2009, 07:06 PM
#41
Rennlist Member
The NACA duct shoots directly onto the exhaust manifold of a 931. The intake piping is more forward. It's purpose was to help keep the turbo cool do to it's placement and it's oil only cartridge in order to lengthen it's already somewhat short lifespan.
02-23-2009, 07:09 PM
#42
Nordschleife Master
I personally think the best method to do any type of hood venting are what David Floyd did or the D9 vents. I think heat extraction will be more useful than any extra air being crammed in personally. I would like to add vents to my own car, but my main concern is water draining onto the test port and near the headers (basically the spots behind the strut towers.. Not a big deal on a track car, but mine is daily driven from spring through fall.
02-23-2009, 07:48 PM
#44
Nordschleife Master
Here was my original plan for adding hood louvers. My friend John (WormHole) told me about these, he has them on his track car.
http://www.hoodlouvers.com/products.html
I was thinking about putting the medium sized, standard vents possibly right over the strut towers, and close to the edge of the hood if possible, or basically as far away from the headers and test port while still being symmetrical on both sides. Of course i would paint them to match the car, the only thing is the stainless steel rivets will stand out like a sore thumb i think. This can be remedied by repainting the entire hood with the rivets in place..but i would want to avoid having to repaint the hood if possible..although it could use a repaint! The other downside is i will need to cutout my very good condition silver hood pad..
.
http://www.hoodlouvers.com/products.html
I was thinking about putting the medium sized, standard vents possibly right over the strut towers, and close to the edge of the hood if possible, or basically as far away from the headers and test port while still being symmetrical on both sides. Of course i would paint them to match the car, the only thing is the stainless steel rivets will stand out like a sore thumb i think. This can be remedied by repainting the entire hood with the rivets in place..but i would want to avoid having to repaint the hood if possible..although it could use a repaint! The other downside is i will need to cutout my very good condition silver hood pad..
.
02-23-2009, 07:53 PM
#45
The Impaler
Rennlist Member
Rennlist Member
Here was my original plan for adding hood louvers. My friend John (WormHole) told me about these, he has them on his track car.
http://www.hoodlouvers.com/products.html
I was thinking about putting the medium sized, standard vents possibly right over the strut towers, and close to the edge of the hood if possible, or basically as far away from the headers and test port while still being symmetrical on both sides. Of course i would paint them to match the car, the only thing is the stainless steel rivets will stand out like a sore thumb i think. The other downside is i will need to cutout my very good condition silver hood pad...
http://www.hoodlouvers.com/products.html
I was thinking about putting the medium sized, standard vents possibly right over the strut towers, and close to the edge of the hood if possible, or basically as far away from the headers and test port while still being symmetrical on both sides. Of course i would paint them to match the car, the only thing is the stainless steel rivets will stand out like a sore thumb i think. The other downside is i will need to cutout my very good condition silver hood pad..
.You now have a quck disconnect power source for your MAF, and a blink tester built into the harness. It's also watertight so that would no longer be an issue.