Airbox-->Cone

Started by MRVR6, January 28, 2005, 09:09:18 AM

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MRVR6

I guess I start this as new topic so that people will not have to read it under "VR6 Exhaust"  ;)

For you all that enthusiast to take the cone out of your airbox and wonder why you should do that in the first place.
Go to this website and look under "Air Management/Airbox"

In fact this website contain a lot of useful info.

Enjoy 8)

MRVR6


orggti

V interesting tho i dont belive it tells the whole story. Im not so sure what i think is true either but here goes, On the earlier K-jet motors people chop out the side of the airbox and say it gives better throttle response and sounds better. However methinks that whilst it does let air in slightly faster thus giving the better response and noise it actually makes it"dump" soon after and dosent allow a more constant vacume in the inlet hoses by making it a little harder to get air in below the air flap thus making the flap drop down again making the car run lean, im positive that is why Nastnas car launches well but then craps out and has poor part throttle running. It may work better slightly in a race car where you are on and off full throttle for shorter times.
I also think that on later cars hot wire systems you will also get a similar effect. On hot wire you will get the air flowwing more but slower thus limiting its cooling effect therefore making it run lean.
Making a car go fast is about making it get the correct amount of fuel as much if not more than simply getting more air. And seeing as all fuel systems get there "orders" from the air flow i think its best to leave things alone as if you belive what im saying more air is not nessisarily more fuel as well. Not unless you remap your computer.
Whilst i agree that some parts on cars are just to make them quieter it is very important to know excacly what your doing when mucking around with anything in front of the motor. Exausts are good -chopping airboxes is bad.
Air flow is the most tricky thing to understand and is the thing they are trying to improve the most now withg variable lenght intakes and such.
Theres lots of articals saying that small air intakes are best cause they keep good air speed. Our golfs have non crossflow heads and small valves making for good torque and economy as opposed to a fiat that has big valves and crossflow good power high up but no torque. I like torque.

OOOO

Nice one Jem...so taking what you say into account what are your thoughts on running a direct hose from the intake box of the Audi 200 out to the front grill?...instead of that trumpet type thing.  The main aim being to lower incoming air temp rather than air flow.
2014 Audi A8 4.2TDI
2013 VW Golf 2.0TDI
2009 Audi A3 quattro

orggti

If its a simple thing to do like that try it and see.  I think they could have easily done this at audi if it was much better tho and on lots of cars there is a summer/winter lever on the air filter as you actually need some warm air to get them to run good when its cold. I think the audi one is where it is cause it gets nice warm air from the maniflod whilst its idling but then would get plenty of cold when the car is running along.
They all do it in those fast four mags and stuff and yes it in the end with a great big whopping turbo would give a few more CCs of cold air but none of those cars run good on a light throttle...........or do they? Its a bloody difficult area of thought as there are so many ideals. Bit like life really. :D

Dub_luver

yeah i used 2 screwdrivers and mines out, not dat difficult.

dubstar

With the cut k-jet airboxs, if you make the mixture slightly richer, would the disadvantages would be counteracted?

I also don't know if the vacuum inside the airbox would be enough to alter the movement of the plate.  And if it did, there would be less vacuum in the airbox causing a greater pressure differential between the box and the intake pipe, thus the position of the plate is going to be slightly higher than when the airbox is intact, but no other change.
"I am so clever that sometimes I don't understand a single word of what I am saying."

Period_Correct_

when i cut my airbox, i noticed better throttle response, also the max speed was 180km/h and struggled to get there... i've recently closed it and now the throttle response isn't as good but the top speed is bout 190km/h then the motor dies...

1971 Porsche 911T | 1990 Audi Quattro Turbo | 2003 Audi RS6 Avant | 2009 Renault Megane R26

mk3 gti

I have just got back from doing some Dyno runs on the GTi and have tried few things

First run    Stock air filter nothing changed in the air box or anything 100Kw@wheels @around 5800rpm

second run
    Pod filter cold air intake 102.4Kw@wheels  @ around 6500rpm

This was at torque performance today so unless you are going to be up in the very high rpm the difference is nothing
as the power curves are excatly the same except the very top end 

I am very happy with power output though  I will put the dyno chats up tommrrow

orggti

Quote from: dubstar on February 16, 2005, 04:11:32 PM
With the cut k-jet airboxs, if you make the mixture slightly richer, would the disadvantages would be counteracted?

I also don't know if the vacuum inside the airbox would be enough to alter the movement of the plate.  And if it did, there would be less vacuum in the airbox causing a greater pressure differential between the box and the intake pipe, thus the position of the plate is going to be slightly higher than when the airbox is intact, but no other change.

You sure you thinking properly bout that dub?

dubstar

Quote from: NasTnaS on February 16, 2005, 04:35:08 PM
when i cut my airbox, i noticed better throttle response, also the max speed was 180km/h and struggled to get there... i've recently closed it and now the throttle response isn't as good but the top speed is bout 190km/h then the motor dies...



190km/h :o :o :o

Where can you safely drive that speed in Auckland?
"I am so clever that sometimes I don't understand a single word of what I am saying."

MRVR6

Strange. I always thought that VR6 can go up to 138mph (220Kmh). I guess that is the official figure.

RS ZWEI

Quote from: MRVR6 on February 17, 2005, 08:44:48 AM
Strange. I always thought that VR6 can go up to 138mph (220Kmh). I guess that is the official figure.

Ive read 140 mph.

The 190Km/h that is spoken of above is a Jetta with a 8V GTI engine in it.
1980 VW Golf GTI Track Car
1995 Audi RS2
2003 Mini Cooper S (Written off - rear ended)
2005 Mini Cooper S
2006 Skoda Octavia vRS Combi
2009 Renault Megane 230 R26 (Written off - rear ended)
2013 Renault Megane RS265 Redbull RB8

Period_Correct_

#13
Quote from: dubstar on February 17, 2005, 08:13:34 AM
Quote from: NasTnaS on February 16, 2005, 04:35:08 PM
when i cut my airbox, i noticed better throttle response, also the max speed was 180km/h and struggled to get there... i've recently closed it and now the throttle response isn't as good but the top speed is bout 190km/h then the motor dies...



190km/h :o :o :o

Where can you safely drive that speed in Auckland?

mostly early parts of the morning, heading home from my GF's place...

[ Kid's , Don't Try this At home, only on the motorway ]? :D
1971 Porsche 911T | 1990 Audi Quattro Turbo | 2003 Audi RS6 Avant | 2009 Renault Megane R26

bsting

I dont get how a Pod filter on a N/A right next to a hot engine makes any difference. ie vr6/2L.


RS ZWEI

Quote from: BSTING on February 17, 2005, 10:36:09 AM
I dont get how a Pod filter on a N/A right next to a hot engine makes any difference. ie vr6/2L.



Well you can if you have a cold box setup I guess.
1980 VW Golf GTI Track Car
1995 Audi RS2
2003 Mini Cooper S (Written off - rear ended)
2005 Mini Cooper S
2006 Skoda Octavia vRS Combi
2009 Renault Megane 230 R26 (Written off - rear ended)
2013 Renault Megane RS265 Redbull RB8

orggti

why did older cars have a summer/winter setting that allowed hot air into the filter on the winter possition if hot air is so bad? I mean i know it makes them run better when cold but on the winter setting it got warmed air all the time unless you poped the bonnet and changed it after you warmed up! i always put my one on summer. I know for ultimate power lots of cold air is best but what about driveability? max HP isnt always the best setting.

bsting

Quote from: orggti on February 17, 2005, 03:00:34 PM
why did older cars have a summer/winter setting that allowed hot air into the filter on the winter possition if hot air is so bad? I mean i know it makes them run better when cold but on the winter setting it got warmed air all the time unless you poped the bonnet and changed it after you warmed up! i always put my one on summer. I know for ultimate power lots of cold air is best but what about driveability? max HP isnt always the best setting.

Is that only for carbed engines ? Summer/winter setting.

orggti

so as per usual the summer/winter is a bit missleading. It should say normal/icey.
SO a fuel injected car never needs warmed air to make it run smoother? I thought tho you get more air density with it being cold, you got better vapourization with it being a bit warmer?

MRVR6

could it be that since it colder, it is denser and therefore more O2?