Question for E90Fleet - BMW 3-Series (E90 E92) Forum

Socom · 11-04-2005, 08:46 AM

My latest issue of Roundal had a piece about a Dinan Z4. One of the mods had to do with the airbox. Dinan stated their airbox actually removes as much H20 (90%) as the OEM version but unlike the OEM airbox, theirs actually has ram air characteristics. The article said the BMW stock airbox has a slight vacum(sp?).

E90Fleet · 11-04-2005, 10:03 AM

Most non-turbo/supercharged engine intakes run under a slight vacume

Think of it : The piston goes down in the cylinder with the intake valve open, this downwards movement causes a bit of a vacume because it has to draw the air in past the throttle and valves.

You can measure this vacume in the intake, most piston aircraft have a instrument showing "manifold pressure"

At small throttle openings there is a pressure well below atmosperic pressure ( vacume )
At wide open throttle you just about get atmosperic pressure

The BMW intake gives this pressure, now the Dinan one must somehow allow air to be rammed into the intake creating a pressure above atmospheric at wide open throttle.

Turbos and superchargers work the similarly. They use a fan to push more air into the intake, making the pressure in the intake greater that atmospheric pressure

LEDZEP · 11-04-2005, 10:33 AM

E90Fleet

Socom · 11-04-2005, 10:48 AM

Quote:

Originally Posted by E90Fleet

Most non-turbo/supercharged engine intakes run under a slight vacume

Think of it : The piston goes down in the cylinder with the intake valve open, this downwards movement causes a bit of a vacume because it has to draw the air in past the throttle and valves.

You can measure this vacume in the intake, most piston aircraft have a instrument showing "manifold pressure"

At small throttle openings there is a pressure well below atmosperic pressure ( vacume )
At wide open throttle you just about get atmosperic pressure

The BMW intake gives this pressure, now the Dinan one must somehow allow air to be rammed into the intake creating a pressure above atmospheric at wide open throttle.

Turbos and superchargers work the similarly. They use a fan to push more air into the intake, making the pressure in the intake greater that atmospheric pressure

Clarification: I was under the impression from the Roundel article that the BMW airbox had a slight vacum pulling air away from the throttle body, not towards it. It didn't make sense to me, so I can only assume I misread the article. Thanks

tiga901 · 11-04-2005, 11:24 AM

E90Fleet, we salute you for your knowledge. Without you, this board will be just as boring at the other ones.

chris · 11-04-2005, 12:53 PM

e90fleet is a beast.

RichReg · 11-04-2005, 07:55 PM

"And on the 3rd day, God created E90Fleet"

coreslogic · 11-04-2005, 08:17 PM

"And on the 4th day, E90Fleet created turbo charger."

puck724 · 11-04-2005, 10:31 PM

i wonder how big his head is right now....YOU DA MAN!!!

tightie · 11-04-2005, 10:36 PM

< lost

visor · 11-04-2005, 11:35 PM

Quote:

Originally Posted by tightie

< lost

Just do a search of e90fleet's posts and you will see how much he has singlehandedly contributed to the collective knowledge on this board.

e90fleet on his throne

RichReg · 11-05-2005, 09:01 PM

Quote:

Originally Posted by visor

e90fleet on his throne

ShinyRedCar · 11-15-2005, 07:37 AM

Quote:

Originally Posted by coreslogic

"And on the 4th day, E90Fleet created turbo charger."

I LOVE THIS PLACE!

11-04-2005, 08:46 AM	#1
Socom Brigadier General Drives: 2010 335D Join Date: May 2005 Location: USA Posts: 3,308 iTrader: (0)	Question for E90Fleet My latest issue of Roundal had a piece about a Dinan Z4. One of the mods had to do with the airbox. Dinan stated their airbox actually removes as much H20 (90%) as the OEM version but unlike the OEM airbox, theirs actually has ram air characteristics. The article said the BMW stock airbox has a slight vacum(sp?).

11-04-2005, 10:33 AM	#3
LEDZEP Lieutenant General Drives: E90 & E91 Join Date: Jun 2005 Location: Area 51 Posts: 11,205 iTrader: (0) View LEDZEP's Garage	E90Fleet __________________ I think it is bad luck to be superstitious

11-04-2005, 08:17 PM	#8
coreslogic Captain Drives: e90 325i Join Date: Aug 2005 Location: Toronto, Canada Posts: 738 iTrader: (0) View coreslogic's Garage	"And on the 4th day, E90Fleet created turbo charger." __________________ e90 325i Jet Black / Sports Pkg / Auto

11-04-2005, 10:31 PM	#9
puck724 COLTS 4 LIFE!!! Drives: 2006 330i Join Date: Aug 2005 Location: california Posts: 1,455 iTrader: (1) View puck724's Garage	i wonder how big his head is right now....YOU DA MAN!!! __________________ 2006 330i --sapphire black--black leather --alumminum trim --premium package --cold weather package --park distace control --automatic transmission --navigation with iDrive

11-04-2005, 10:36 PM	#10
tightie JOSH SHOKRI. Drives: e ninety two em three. Join Date: Aug 2005 Location: i love LA Posts: 2,395 iTrader: (4) View tightie's Garage	< lost __________________ Under Construction... "The best is yet to come... "

11-04-2005, 10:03 AM	#2
E90Fleet Major General Drives: BMW Join Date: Apr 2005 Location: South Africa Posts: 6,515 iTrader: (0)	Most non-turbo/supercharged engine intakes run under a slight vacume Think of it : The piston goes down in the cylinder with the intake valve open, this downwards movement causes a bit of a vacume because it has to draw the air in past the throttle and valves. You can measure this vacume in the intake, most piston aircraft have a instrument showing "manifold pressure" At small throttle openings there is a pressure well below atmosperic pressure ( vacume ) At wide open throttle you just about get atmosperic pressure The BMW intake gives this pressure, now the Dinan one must somehow allow air to be rammed into the intake creating a pressure above atmospheric at wide open throttle. Turbos and superchargers work the similarly. They use a fan to push more air into the intake, making the pressure in the intake greater that atmospheric pressure

11-04-2005, 11:24 AM	#5
tiga901 First Lieutenant Drives: e90 330i, mt pp sp Join Date: Sep 2005 Location: Millbrae, CA Posts: 245 iTrader: (0)	E90Fleet, we salute you for your knowledge. Without you, this board will be just as boring at the other ones.

11-04-2005, 12:53 PM	#6
chris First Lieutenant Drives: Jet Black e90 330i Join Date: Aug 2005 Location: Bay Area, CA Posts: 280 iTrader: (0)	e90fleet is a beast.

11-04-2005, 07:55 PM	#7
RichReg Lieutenant Colonel Drives: 2006 330i Sport & 2000 323Ci. Join Date: Apr 2005 Location: New Jersey Posts: 1,745 iTrader: (0)	"And on the 3rd day, God created E90Fleet"