924Board.org

bnoon · Posted: Sun Feb 21, 2010 12:27 pm Post subject: S1 custom air intake, worth it?

Seems like the stock air box is large enough for this engine. Is there any gain to putting a conical style filter and custom inlet? Seems like the air meter is more of a restriction than the box would be. Perhaps just a K&N drop in filter for more surface area in that case? I see by searching some have done it, but it seems like the majority are still stock intakes...
_________________
'80 924 Turbo - SOLD!
1986 Porsche 944 Turbo - SOLD!
Porscheless

Paul · Posted: Sun Feb 21, 2010 3:05 pm Post subject:

The stock box works pretty well plus it draws cold air already.
_________________
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.

mikebola · Joined: 07 Sep 2009 Posts: 361 Location: Parkside, PA

Something I learned while playing with cars is a lot of air boxes are designed more to dampen the sound of the air intake, and less to restrict it. most of the time the TB is the most restricting point of the intake (after the stock air cleaner)
_________________
proud owner of a 1979 924 Sebring Edition with a 931 trans that looks horrible but somehow runs...

931Owner · Joined: 14 Feb 2009 Posts: 352 Location: Chicago NW Suburbs

I am no expert but what I do understand is that the colder (therefore denser) air is better for fuel ignition, yada... yada... yada! (this has come up with the old Fiat 600 intake which has it's intake pointing down to the exhaust manifold compared to the Fiat 850 intake which points to the rear of the car [these Fiats are rear engined if you didn't know])

This also why you get better performance with an inter-cooler than without an inter cooler it's all about air density.

The key problem I have seen with the cone filter intakes is that they are ingesting the warmer engine bay air rather than the cooler air from outside the engine bay. IMHO a better air filter would be the best bet with the std intake. If you do want to go with a cone filter you need to make sure it is getting cool air channeled to it therefore isolating it from the warmer engine bay air.
_________________
1980 Turbo
-too many cars and too many motobikes

Rich H · Posted: Fri Apr 02, 2010 5:38 pm Post subject:

I was at a rolling road day when this was tried back to back.
Removing the 'horn' from the front of the airbox and replacing with a smooth intake gained ~1hp at the top end but lost ~1hp mid range.
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

Vince Ponz · Joined: 02 Nov 2002 Posts: 3581 Location: Florida

I think the main problem with the turbos at least is that the air cleaner rests over the radiator. I think the next mod [I have been lax in doing this] is to elimiate the box where it is now. Go to Home Depot and buy the correct size plastic tube, run it either left or right to the area behind the headlight. I would insulate the tube in order for heat not to effect the air going through the tube. Attache a cone filter on the end of it.

You will have to make arrangements for the other tube which is easy.
_________________
"Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock