To jetex or not to jetex that is the question!

Customboy

Registered User
Hi there all I got a bit of a head scratching moment and thought I would ask u gurus here to stop this itch lol, right I used to have fitted to my a3 turbo a smoothed and drilled airbox with a pipercross panel filter fitted, then I took the plunge and fitted a induction kit similar to the bmc cda ones but found that the car didn't boost anywhere as good as it used to I left it for a few days and see if it would change, but sadly the car never felt as strong as it was so right I thought off with the induction kit and back to the airbox! And low and behold the car ran better then ever boosting just over 1bar and pulled so well but I have seen everyone with jetex filters and was thinking are they any good? Or just stick with what I have? The car has following mods

Rtech remap
forge 007p dv
3 inch downpipe and decat stainless steel exhaust system
forge hoses

Will be fitting my forge fmic soon and then will be fitting my new k03s turbo then up to rtech for a custom map so should I buy the large jetex cone filter or just leave things the way they are even with the mods coming up? Just don't want to spend good money and see no gains any advice would be great

Thankx for reading

Customboy :)
 

S3featesV9

Registered User
I love my Jetex filter! Love it that much I threw my old air box away as I knew I'd never want it back in place
 

Customboy

Registered User
Did it make a big difference over the airbox? And I guess u have a s3 Im only running a remapped 150bhp aum engine so will it help or should I just leave it, I'm planning on fitting a cold air feed pipe from the front bumper this week and have the pipe ready but still into minds wether to buy the massive 80mm filter or just stick with the good ol airbox!! I'm going mad lol
 

smokiedee

Registered User
i had the bmc cda and have gone back to my airbox but i defo will be getting the jetex after seeing the differenve it made on my mates a3. i'm sure i've seen your car a couple days ago
 

Customboy

Registered User
Whereabouts are u smokiedee? Where did u spot me ? Also Craig I think I made a mistake about engine codes they always get me in a twist my car is a v reg 1999 150 bhp sport so not a aum but forgotten what it is lol
 

16Klappe

Man Boost!
Supporter
Whereabouts are u smokiedee? Where did u spot me ? Also Craig I think I made a mistake about engine codes they always get me in a twist my car is a v reg 1999 150 bhp sport so not a aum but forgotten what it is lol

AGU, it's written on the top of the engine just to the right of the pulleys on a tab if you want to check.

I have a Jetex and the only real difference is the noise, before I had a smoothed airbox with an upgraded filter. There is no power difference on the two, going by feel and datalogs.

A smoothed airbox is more than ok for a stage two car.

Jetex filters look better though...

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Customboy

Registered User
Thanks 16klappe that's a great help least I now know my engine haha and for the moment guess I will stick with my airbox cheers everyone
 
I saw a rise in peak airflow readings of 10g/s after replacing my pipercross filter with the jetex and b5 tip, although not sure the filter alone will make much difference
 

Alais DJA

Registered User
Carbonio?
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
Its all hype imo.

Theres no doubting the Badger5 Tip works on tuned S3's, but fancy air filters on standard engines? nah!

On the B5, Audi used the same filter on every model from the base spec 1.6 to the 380hp RS4. If that filter can happily flow enough air to satisfy a 380hp motor, it can flow enough air to satisfy my 200hp 1.8T, and i know it'll do so without damaging my MAF and without risking crap getting into my engine due to poor filtration.

I guess its possible that the A3 airbox is smaller or more restrictive than the B5 one, though looking at the photos there certainly isnt much in it...

You've also got the issue of removing the velocity stack, and the effect that has on the MAF readings, though i'm sure most folk nailing on a cone filter wouldnt even think twice about that funny trumpet stuck on the front of the MAF in the standard installation... As a result of this, its entirely possible to see more g/sec after removing the stock airbox and fitting a cone, but not because you're flowing more air, instead because you've altered the airflow through the MAF enough to screw up its readings.
 

16Klappe

Man Boost!
Supporter
Carbonio?

Personally speaking, not a fan for performance reasons as well as how stupidly over price they are.

With the filter mounted in that position it halves the life of the filter, is open for all the road crap, salts, grit and water. They were cool 5 years ago, but tech has moved on. It does offer cooler temps, but because it is pre turbo it is of little if any effect.

I used to run one, my girlfriends A3 (which is the same spec as yours but with PCV/N249 delete) and Prawn used to run one...In fact everybody I know who HAD a CAI now runs a MAF mounted filter in place of the air box. Good flow and much more sound :)

The other option is having a bit of both and going for the Tuffty patented Conebox.

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badger5

www.badger5.co.uk
Site Sponsor
FACTs are, Jetex cones with heatshield do flow more real air and make more power as measured on the dyno... over the stock airbox

filter for filter its not wow gains, noise it is, but performance is raised a little even on stockers.. Add a TIP to k04's and the rest is well documented now...
 

RyanS3TT

Registered User
Badger could you please pm me info and cost for your tip to fit k26 turbo thanks
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
Bill, have you ever compared a tuned K04 with a B5 Tip/Jetex to a standard smoothed/opened up airbox with new paper filter and B5 Tip?

Any figures i can view?
 

Alais DJA

Registered User
FACTs are, Jetex cones with heatshield do flow more real air and make more power as measured on the dyno... over the stock airbox

filter for filter its not wow gains, noise it is, but performance is raised a little even on stockers.. Add a TIP to k04's and the rest is well documented now...

I've always liked the quoted gains on airfilters....

10 bhp from a K&N carburettor for MK2 golf was my favourite.

It's again down to opinions against fact.

Opinion is that the jetex works better as it "flows better", yet only really seen when put as a combination of mods on a dyno

However, heat rises. So surely an air filter at a higher position and nearer the engine is sucking in warmer air that a air filter down a foot lower with no heat and a direct air feed.
 

Paradox1

Registered User
With a cone filter, is bigger better? I've thought of changing my cone for a jetex or a larger cone
 

StaceyS3

Registered User
Ryan MTM I've made a custom 3" tip on my k26 MTM which I will be selling in a couple of months or if your interested in making one I've got pictures in my build thread :)

Shameless plug ;)
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
Stacey: why you selling the K26? havent you just got it all sorted?!
 

StaceyS3

Registered User
Yeah pretty much but runs to hot for my liking and when I bought the MTM kit plan was standard internals but now everything else is upgraded now looking at garrett in a k26 turbine housing which previously didn't know these hybrids existed ;)

Will be aiming to crack 400 Mark :whistle:
 

badger5

www.badger5.co.uk
Site Sponsor
I've always liked the quoted gains on airfilters....

10 bhp from a K&N carburettor for MK2 golf was my favourite.

It's again down to opinions against fact.

Opinion is that the jetex works better as it "flows better", yet only really seen when put as a combination of mods on a dyno

However, heat rises. So surely an air filter at a higher position and nearer the engine is sucking in warmer air that a air filter down a foot lower with no heat and a direct air feed.

thats why you can buy a full kit which includes heatshield...
b5-80mm-Induction_kit-1.jpg
 

Alais DJA

Registered User

S3featesV9

Registered User
Ok so looking at getting a replacement turbo. Obviously it's got to be k04 but does it matter what engine it came from? Mines BAM.

Or if anyone could help me out massively and actually point me at a turbo on eBay or something, would be great!
 

S3featesV9

Registered User
Sorry, posted in wrong thread haha.
 

Customboy

Registered User
Badger that tip and filter looks great wish they could work with my car :(
 

badger5

www.badger5.co.uk
Site Sponsor
Bill, have you ever compared a tuned K04 with a B5 Tip/Jetex to a standard smoothed/opened up airbox with new paper filter and B5 Tip?

Any figures i can view?

yes..
gains were seen...

I dont remember the cars reg to look it up tho. think it was an s3 tho
 

badger5

www.badger5.co.uk
Site Sponsor
Ok so looking at getting a replacement turbo. Obviously it's got to be k04 but does it matter what engine it came from? Mines BAM.

Or if anyone could help me out massively and actually point me at a turbo on eBay or something, would be great!


K04-023 with egt sensor for your bam
 

Reesy

Well-Known Member
VCDS Map User
yes..
gains were seen...

I dont remember the cars reg to look it up tho. think it was an s3 tho

I think westy went from a smoothed airbox to a jetex and I'm pretty sure the number he said was 7bhp.
 

Westy

Registered User
yes..
gains were seen...

I dont remember the cars reg to look it up tho. think it was an s3 tho

It was mine Bill. I turned up with B5 TIP but smooted airbox fitted. We did a run, fitted Jetex then run again and saw 7bhp.

Car reg would either be OE51HYB or S111NPW and would have been from July 2011.
 

Welly

335D Driver :-)
then I took the plunge and fitted a induction kit similar to the bmc cda ones but found that the car didn't boost anywhere as good

So.... what I read from this is that you bought and fitted a cheap induction kit off of ebay - Something along the lines of this: PERFORMANCE UNIVERSAL SPORTS CARBON FIBRE AIR FILTER COLD FEED INDUCTION KIT | eBay - and it didn't go as well.

The reason is that inside those enclosed things, there is a filter exactly the same size and flow capacity as a gnat's ****. They are no good for a 1.8T engine, as they need to be able to breath easily.

The reason that it didn't go as well post fitting is because the engine and turbo were having to fight harder for every cf/m of air coming in.

Buy a big, free flowing filter. Jetex is ideal.
 

Customboy

Registered User
Thank welly for the advice but it was a Simota induction kit not ur cheap nasty eBay jobs but the car just didn't like it but now reading all these posts about jetex has got me wanting one oh decision decisions but I'm very happy with airbox and soon will be running a cold air Feed to it from lower front bumper just with all the other mods I have coming up would it be worth investing in one of these jetex cones
 

Westy

Registered User
Thank welly for the advice but it was a Simota induction kit not ur cheap nasty eBay jobs but the car just didn't like it but now reading all these posts about jetex has got me wanting one oh decision decisions but I'm very happy with airbox and soon will be running a cold air Feed to it from lower front bumper just with all the other mods I have coming up would it be worth investing in one of these jetex cones

I asked Bill if we could do the comparison runs on his rollers because I too was sceptical as to how much more a large cone would flow over the standard airbox (mine was also smoothed and had cold feed). We were both amazed at how much flow and power a Jetex gives over the box.
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
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It was mine Bill. I turned up with B5 TIP but smooted airbox fitted. We did a run, fitted Jetex then run again and saw 7bhp.

Car reg would either be OE51HYB or S111NPW and would have been from July 2011.

Standard paper filter in the airbox? New or old?

I'm just trying to get a comparison on a fair playing field. Replacing a 20k old paper filter with a jetex and gaining some power doesnt prove that much, as i'm sure you'll agree!

Personally i feel that OEM's use paper filters on their engines, irrespective of performance level, because its the only thing that actually filters the air properly. Aftermarket filters have a hugely reduced surface area, which means even to match the flow of a standard paper filter they need much larger holes due to this reduced area. To offer less restriction they need even bigger holes still. These huge holes simply dont filter the air properly, and most filter manufacturers then resort to soaking the elements in oil to try and capture more dirt.

So for the sake of a 5hp gain (which on a 260hp S3 engine is less than 2%, and ofcourse trying to measure such small differences with any accuracy on a chassis dyno is difficult at best) your risking MAF damage and letting your engine breathe badly filtered air.

I'll be sticking with my paper filter!
 

Welly

335D Driver :-)
Thank welly for the advice but it was a Simota induction kit not ur cheap nasty eBay jobs but the car just didn't like it but now reading all these posts about jetex has got me wanting one oh decision decisions but I'm very happy with airbox and soon will be running a cold air Feed to it from lower front bumper just with all the other mods I have coming up would it be worth investing in one of these jetex cones

Sweet, thats probably your best bet. All these enclosed induction kits seem to have a tiny filter inside annoyingly, even the BMC ones aren't very big.
 

Westy

Registered User
Standard paper filter in the airbox? New or old?

I'm just trying to get a comparison on a fair playing field. Replacing a 20k old paper filter with a jetex and gaining some power doesnt prove that much, as i'm sure you'll agree!

Personally i feel that OEM's use paper filters on their engines, irrespective of performance level, because its the only thing that actually filters the air properly. Aftermarket filters have a hugely reduced surface area, which means even to match the flow of a standard paper filter they need much larger holes due to this reduced area. To offer less restriction they need even bigger holes still. These huge holes simply dont filter the air properly, and most filter manufacturers then resort to soaking the elements in oil to try and capture more dirt.

So for the sake of a 5hp gain (which on a 260hp S3 engine is less than 2%, and ofcourse trying to measure such small differences with any accuracy on a chassis dyno is difficult at best) your risking MAF damage and letting your engine breathe badly filtered air.

I'll be sticking with my paper filter!

It was with a brand new paper filter as I'd had a service in June. It came fitted with a green cotton panel when I bought the car but I went back to paper on it's first service I had for it. I had also replaced the MAF with a brand new genuine one.

I've found the post in my thread with the graphs but can find any of the comparison runs so hopefully Bill has something:

http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/119353-w3stys-progress-thread-6.html#post1296054
 

Craig1.8t

Registered User
Whereabouts are u smokiedee? Where did u spot me ? Also Craig I think I made a mistake about engine codes they always get me in a twist my car is a v reg 1999 150 bhp sport so not a aum but forgotten what it is lol

Then as already said its the AGU engine, which only has a ko3 so a ko3s would be an upgrade ;)
 

Alais DJA

Registered User
Then as already said its the AGU engine, which only has a ko3 so a ko3s would be an upgrade ;)

KO3 Hybrid. Speak to "beachbuggy"
 

badger5

www.badger5.co.uk
Site Sponsor
I'll be sticking with my paper filter!

good for you. If that makes you happy.

The fact remains, as stated... The open Cone large Jetex did flow more and make more power, which is the goal for folks tuning their cars...

The lightly coated cotton gauze filters do filter... foams ones I am not a fan of, as on numerous occasions I have seen and felt the gritty dusty oily debris on maf's where dust had migrated thru them. Its a filter, and not fit and forget tho, so is subject to cleaning/replacing when required.

Changing paper filter in OE airbox for Green filter resulted in zero gains when I ran that test. I no longer sell panel filters unless asked to supply one specifically.
 
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