j89justin

Ive been reading the forum archives about ram-air setups and im looking to create my own

my biggest concern is what to do with the airbox since im using a cone filter

i currently integrated mine into a heat shield for my cone filter, so i cut open the inlet where the maf would connect and run my filter with velocity stack inside it

from the posts ive read it seems that people running ram air are using a completely sealed airbox?

would it still be beneficial to run a ram air duct to my airbox even though its not completely sealed on the top side? or does it defeat the purpose of building a "posotive pressure" area?


thanks in advance..

Lago Blue

Almost no one enhances the warm air intake system that comes from the factory. There may be a reason for that.

Even the OEM warm-air intake has a thermostat to shut it off; once the engine is warm. There may be a reason for that.

The factory put a really good sealed box around the original paper filter, a design that was hardly changed, even for the Porsche powered RS2 versions of this chassis. There may be a reason for that.

Most car manufacturer's spec paper filters on even their most expensive engines; despite the available alternatives. There may be a reason for that.

Audi put a cold air intake onto the OEM filter-box. Even the mighty IMSA 90 had a cold-air intake in the same spot. There may be a reason for that.

It's not difficult to improve <i>slightly</i> on what the factory did, but it is also easy to do worse. It may help if you have a particular goal in mind first. You may have already answered your own question.

I want:

- cool air,
- a paper filter,
- laminar flow over the MAF sensor,
- no air leaks; &
- quiet.

I'm keeping the stock filter-box, it's just not exactly stock; but nearly.

It usually takes more testing than wrenching to beat the stock set-up. Here is the beginning of a really interesting article on actually making improvements to the air intake system:

http://autospeed.com.au/cms/article.html?&A=0629

Here's what I did:

https://www.audiworld.com/forums/sho...highlight=tour

VAP

Lots of people have some very strange ideas on what "ram air" is and tend to create Rube Goldberg innovations that couldn't be less ram air by definition or function.

Ram Air is simply a "sealed system" from its cold air inlet mounted "outside" the vehicle on one of the clean/unobstructed "frontal surfaces" to the throttle body/carbuerator. If ANY one of these requirements are omitted/compromised it's not ram air. You're either ram air or your not. Done really REALLY right its incredible! Done half-assed or low-bucks its laughable/pitiful.

j89justin

alright
now its beginning to make more sense

so being sealed is the key

im looking to convert from my ram air/vs setup to an oem box

im wondering if i should try to implement a vs into it (i currently have a blox 3inch vs w/filter)

but would gains be found from retrofitting back to the oem box with no VS
versus a short ram setup with heatshield and velocity stack?

VAP

You don't have a ram air setup now. You have a cone filter with a heat shield and nothing more. As I said above "ram-air" is ONLY possible with a "sealed system" from its cold-air intake "outside" the car and to the throttle body. A cone filter sitting inside a heat shield with cold air blowing on it is NOT a sealed system or ram-air! All your intake air is "pulled" via vacuum of the pistons downward travel thru the intake valves. NOTHING is currently being "forced" into the cylinders for combustion!

Now incorporate your cone filter "inside" a sealed intake tract with only 2 openings, ie; one inlet located outside the car and one outlet sealed to the throttle body and you have ram air. But even then only "slight" ram air unless you incorporate an inlet the size of a house and were doing well over 100MPH. Only then could you start to "compress" air. But ram air will allow "slight" higher-than-atmospheric pressures at even low speeds provided the inlet diameter is large. And by large I mean "at least" in the neighborhood of a single headlight diameter that's COMPLETELY unobstructed on the frontal surface of the vehicle and ideally shaped like a velocity stack with a 10-12" diameter OD with a 6-8" ID. Anything less won't even be measurable except with the most sophisticated/sensitive equipment.

jimmys2.8

don't mistake what he is saying by thinking he is describing a cold air intake. He is not decribing a system where the filter is located at the front of the car i believe. you could keep your filter at a traditional ram air position but it isn't really "ram air" unless the entire system is sealed from your filter all the way to the front of the car. you will also avoid heatsoak this way right?

correct me please VAP if i am mistaken in any way i was just trying to shed some light on the point you were making

VAP

Well, let's take a look specifically at what he did say and not put any words in his mouth or presume he might mean something he didn't say and see what turns up, shall we?


"im looking to convert from my ram air/vs setup to an oem box"


Now where exactly is the mistake you were warning me about not making regarding what he has said or meant?

jimmys2.8

oh sorry i should have been more clear. i was clarifying on the point that you made in response to him. my post wasn't directed to anyone in particular. infact it was more directed towards other AW users who don't understand as much as some users such as yourself do. I was simplifying what you said so that noobs like myself would not get confused.

jimmys2.8

so what i should have said was this, Don't mistake what VAP is saying by thinking he is desribing a cold air intake. and once again my response was geared towards users other than yourself. I apologize for the confusion

VAP

No worries! Sometimes trying to make things simpler just confuses the issue, compounds or makes it worse.