"Cold-air intakes" and "high-flow air filter" FAQ

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
Spent the last few hours reading this entire thread. Great info. I appreciate all of the discussion. Especially those from those who have studied the data.

I'm currently running a KermaTDI tune and couldn't be happier. Came here before spending money elsewhere under the hood and glad I did.

Thanks.
That's fantastic. The more you read here the more you will find good info on quality parts and what counts and what is fine.
 

rhill2901

Active member
Joined
Feb 10, 2020
Location
Nashville, TN
TDI
2014 VW Jetta
I decided to go with an aftermarket cai, mainly because I needed the room under my hood to put in a oil catch can. The stock filter just takes up too much real estate under the hood. I went with a APR PEX CAI, which btw, wasn't designed for the diesel, but connected up just fine. The bottom of the filter had a hole, and I just put in a 3/16 inch grommet in it, and inserted a 3/16 elbow air fitting for the N75 valve and it looks good, not that I care, but it takes up 1/2 of the space, and leaves plenty of room for my oil catch can. I keep seeing oil on the input of the turbo, and know that can't be good. This is the one I put in:


I think for a perfect fit, the retaining bracket spacer needs another 1/4 inch spacer. But still works as is.
 

klburton22

Member
Joined
Feb 13, 2020
Location
Lake Labish Oregon
TDI
2014 Passat TDI SEL Prem
I've had my Passat for 14 months now and tonight I was looking into maybe installing a cold air system from Rawtek. While doing some reading on how to install Rawtek's cold air setup I discovered my car was missing a part, the intake air duct cover. I had no idea it was missing, I thought that the open duct was normal. I always have about a 2-4 MPG difference in fuel economy in my early morning drive to work as I do in my evening drive. I now see that without that cover air is being pulled from the engine compartment, which in the morning is much cooler that the evening. I just finished ordering the cover for less than $20. I'm curious to see if my fuel economy equalizes between my morning and evening commute. Also, after reading through much of this thread I'll be staying with the factory air intake.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
I've had my Passat for 14 months now and tonight I was looking into maybe installing a cold air system from Rawtek. While doing some reading on how to install Rawtek's cold air setup I discovered my car was missing a part, the intake air duct cover. I had no idea it was missing, I thought that the open duct was normal. I always have about a 2-4 MPG difference in fuel economy in my early morning drive to work as I do in my evening drive. I now see that without that cover air is being pulled from the engine compartment, which in the morning is much cooler that the evening. I just finished ordering the cover for less than $20. I'm curious to see if my fuel economy equalizes between my morning and evening commute. Also, after reading through much of this thread I'll be staying with the factory air intake.
Good to hear.
Don't think you will see a difference though. Would love to see results. Keep us posted.
 

Lenard

Active member
Joined
Apr 26, 2017
Location
Lake Mills, WI
TDI
02 Beetle "skeetle" Previously: 98 ahu jetta, 05 bew jetta, 97 1z b4 sedan, 2004 bhw passat, 02 alh jetta, 2005 bhw passat, 97 b4v glx 1z swapped, another 98 jetta. Honorable mention: 81 jetta coupe 1.6d
People here are going to hate what I have to say. But, if you're anything like me and have had a crap ton of volkswagens (not just TDIs), and have a ton of parts laying around....grab one of those mk3/b4 MAFs you've had laying around, smash the guts out, and jam the sucker over the top of your mk4 MAF. Viola, zero cost adapter kit to have a mini-BHAF mod.
 

Doug Jr

Member
Joined
Sep 27, 2020
Location
31419
TDI
2011 Sportwagen
Glad I read this thread, stock with factory authorized parts are just fine. Want a hot-rod? Build it from the ground up for a specific purpose then go have fun! Good info here, glad I joined.
Doug
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
People here are going to hate what I have to say. But, if you're anything like me and have had a crap ton of volkswagens (not just TDIs), and have a ton of parts laying around....grab one of those mk3/b4 MAFs you've had laying around, smash the guts out, and jam the sucker over the top of your mk4 MAF. Viola, zero cost adapter kit to have a mini-BHAF mod.
You just made no sense what to ever.
I can't even start to explain how illogical the choice of words you used here are.
 

rhill2901

Active member
Joined
Feb 10, 2020
Location
Nashville, TN
TDI
2014 VW Jetta
Glad I read this thread, stock with factory authorized parts are just fine. Want a hot-rod? Build it from the ground up for a specific purpose then go have fun! Good info here, glad I joined.
Doug
Its always a good plan. but once bitten by the MOD bug, you just can't stop lol...

My jetta tdi gets over 50 mpg highway, and has over 200 ponies and 390 torque at the wheels. It completely transforms the car. Sure. I can go drive my audi r8 for the performance, but not at 51mpg. At best, my stock jetta tdi got 43mpg. Not interested in a hot rod, if i was, I would build one up. The cost is way higher though.
 
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Doug Jr

Member
Joined
Sep 27, 2020
Location
31419
TDI
2011 Sportwagen
Its always a good plan. but once bitten by the MOD bug, you just can't stop lol...

My jetta tdi gets over 50 mpg highway, and has over 200 ponies and 390 torque at the wheels. It completely transforms the car. Sure. I can go drive my audi r8 for the performance, but not at 51mpg. At best, my stock jetta tdi got 43mpg. Not interested in a hot rod, if i was, I would build one up. The cost is way higher though.
That's an impressive increase, I as well have torque monster toys but it comes nowhere close to the efficiency your TDI has. In-fact neither the 70 Yenko or Off road built Yukon( LS1 re-powered) set any efficiency records but both are in the 550+ hp & wheel torque scale.
I bought the TDI after a buck chasing 2 doe's quite literally jumped over & landed on the right front fender & hood area of the Mercedes causing excessive sheet-metal damage and breaking my heart, there was no way the paint on this car could ever be blended being 21 years old; garage kept highway missile, loved that car.
I was under the TDI to see what was needed to install a rear sway bar prior to buying one & was shocked to see one was already there, (neon green) attached to a multi link rear suspension. Strange considering I know the car's previous owner was the original owner, an elderly lady in West Palm Beach. Happy it's there I shifted my purchase to a big brake kit (front/rear) instead.
Perhaps at some point I may increase the exhaust pipe sizing while keeping it stone quiet but being a 2 wheel drive version coupled to the fact that I wanted a stock and efficient car that is fun to drive and comfortable on a daily basis, it will likely end there. Next stop is to remove the headliner and have it replaced with new material, it's typical German glue and Southern US shrinkage error.
I think a 4 Motion model might be fun, I had Quattro's in the early thru mid 80's until we started a family, then all went away to focus on raising children including my 930 which did not get driven much anyway, oddly don't really miss that car that much. As brutal as acceleration was for the era, that was about all it had going for it while the sale paid completely for the birth of my Daughter an excellent return on investment ha ha!
It's good speaking with you. I'm curious how the torque increased so dramatically and if any detrimental effect on the drive-train has been evident since the power increase.
Doug
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
2010 Touareg Tdi w/factory Tow PCKG
I have no idea what his point was.
He seems to be talking about a 'BHAF' mod, which I can't find out by a quick google search. It's something from the pickup truck diesel world, but I could not find a clear explanation. I landed on some Dodge forums, but no one says what it is.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
He seems to be talking about a 'BHAF' mod, which I can't find out by a quick google search. It's something from the pickup truck diesel world, but I could not find a clear explanation. I landed on some Dodge forums, but no one says what it is.
It just means a big air filter aka a pos cold air intake or any other variation of modifying from the stock or equivalent oem filter. More air flow bs.
The idea of smashing up a part of just tape or glue or even slap on to a totally different part is just asinine when the part is like $20 to get in the first place. I get what he is talking about but the proposal of such ghetto methods was perverse to my liking.
 

MY19Extreme

New member
Joined
May 25, 2020
Location
New Zealand
TDI
Amarok V6 (Stage 2)
I'm looking at installing a cone filter on my V6 Amarok, but unsure about it throwing codes and engine lights. I'm fairly new to diesels, have had a similar filter installed in a previous 2.0T Subaru and was a fan of the induction noise, even if there was no performance gain. Can't find a lot on fiddling with Amaroks, it's the same engine as in the older Touareg/Q7's.
For context, running a 3" exhaust (from the first cat that's directly after the turbo) straight to the back & tuned to suit.
Any help would be appreciated, but not fussed if it's entirely impossible.
This might link also: youtube.com/watch?v=IOzRT6ngVno
Thanks
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
I'm looking at installing a cone filter on my V6 Amarok, but unsure about it throwing codes and engine lights. I'm fairly new to diesels, have had a similar filter installed in a previous 2.0T Subaru and was a fan of the induction noise, even if there was no performance gain. Can't find a lot on fiddling with Amaroks, it's the same engine as in the older Touareg/Q7's.
For context, running a 3" exhaust (from the first cat that's directly after the turbo) straight to the back & tuned to suit.
Any help would be appreciated, but not fussed if it's entirely impossible.
This might link also: youtube.com/watch?v=IOzRT6ngVno
Thanks
Did you read the 1st page?
Dont
No need to and no gains to be had. Spend money elsewhere
 

MY19Extreme

New member
Joined
May 25, 2020
Location
New Zealand
TDI
Amarok V6 (Stage 2)
I did read it, and all power to yourself & all other contributors as this thread really is incredibly interesting.
I've spent money and got my pickup to where I want it to be power-wise, and as before there's hardly a thing on Amaroks online bar Darkside Developments.

Did you have a look at the link? Wouldn't mind that. Not worried that it doesn't increase horseys.
Thanks ✌
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
I did read it, and all power to yourself & all other contributors as this thread really is incredibly interesting.
I've spent money and got my pickup to where I want it to be power-wise, and as before there's hardly a thing on Amaroks online bar Darkside Developments.

Did you have a look at the link? Wouldn't mind that. Not worried that it doesn't increase horseys.
Thanks ✌
Your going to lose power and eventually damage internals.
 
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