# The Audi A3 K04 Turbo Upgrade Thread



## biff2bart (Dec 5, 2011)

There seem to be quite a few A3 drivers installing K04 turbos in 2.0 TSI engines lately, so why not have a single thread to consolidate as much information about this reasonably cost effective upgrade that transforms our cars into mini-super cars!


For the money, there is nothing that can really compete with the power performance upgrade of a K04 turbo charger and ECU tune on the 2.0 TSI engine: 



Stock HP: listed as 200 HP with K03 turbo, will be upgraded to around 350 - 360 HP range after K04 upgrade
Stock TQ: listed as 207 ft-lbs with K03 turbo, will be up in the 370-380 ft-lbs range after K04 upgrade


And, this is on 91 octane pump gas!


Combined in many cases with the Quattro AWD platform and also the quick shifting DSG transmission, the K04 upgrade can get the small and agile Audi A3 into Sub 5 second 0-100 kph times, on pretty much any reasonable road condition. It can also make the A3 competitive with pretty much most high performance sports cars at sane driving speeds (and even on the track) due to the power to weight ratio of the car, the AWD platform and the DSG transmission. While it may not compete with an Audi R8 V10, Ferrari 458, or Lamborghini Gallardo, it _will_ be competitive with an Audi R8 V8, BWM M3 / M5 and many models of Porsches, not to mention destroying Civics and going head to head with stock WRX STIs and Evos. Get into less than ideal road conditions, and half of those cars have no chance against the K04 mod'ed Quattro A3. And, it can do all of this while hauling skis, bikes, a baby seat, your spouse, a baby stroller and a week's worth of groceries. Maybe even the dog too, if he's not too big 


This puts the K04 upgraded A3 into a pretty unique category: a high performance car that maintains all of the versatility and functionality of a hatchback daily driver.


The goal of this thread is to discuss individual installations, costs, performance, troubleshooting and supporting mods of Audi A3 K04 upgraded vehicles. It should also be a great place to help future K04 owners understand the upgrade path and costs of this fantastic performance modification.


*Typical K04 parts costs:*

_Mandatory Parts:_


K04 Turbocharger, Manifold, ECU Software and supporting equipment (usually sold in kit form): $2000 - $2600 USD
Approximately 4 hours of labour for skilled technician​


_Highly Recommended Supporting Mods_


Down Pipe w/ high flow 100 - 200 cell Catalytic Converter: $300 - $500 USD
Approximately 1 hour of labour for skilled technician​


_Beneficial Additional Mods:_


Aftermarket CAI (Cold Air Intake): $250 - $600 USD
Approximately 0.5 - 1 hour of labour for skilled technician​
Aftermarket Full Exhaust: $400 - $1000 USD additional beyond Down Pipe
Approximately 3 - 5 hours of labour for skilled technician​
Aftermarket FMIC (Front Mounted Inter Cooler): $350 - $1000 USD
Approximately 3 - 5 hours of labour for skilled technician​


This puts the K04 upgrade at an entry price of about $3000 USD and around $3500 once a down pipe is added. Please note that these are list costs: many companies have sales (APR for instance seems to have frequent sales - at least quarterly) and often retailers will have free or reduced installation costs as well.


Note that due to the substantial power increase from the K04 upgrade, additional (safety!) modifications should be considered:



Upgraded brakes, comprising a minimum of upgraded rotors and pads front and rear (probably with stainless steel lines for improved feel).
Upgraded suspension, depending upon how the vehicle came from the factory: some of the upgraded Audi Sport Suspension packages may have suitable spring and damper rates, while other vehicles will highly benefit from _at least_ an aftermarket cup and coil kit, if not coilover damper / spring setups and perhaps with anti-sway bars depending upon how aggressively the vehicle is to be driven.
Tires should also - of course - be at least sport performance all seasons and be speed rated appropriately.



I think we all know this youtube video: it gives a good idea of the K04's performance potential:
http://www.youtube.com/watch?v=-tPWSH3tyM4


We can also use this thread to see what subtle tuning differences can be made - i.e.:



91 vs 93 vs 100 octane
Launch control: DSG Manual mode vs Sport mode
DSG: reprogramming: I think the factory launch mode is for ~3200 RMP, whereas the HPA DSG II launch mode is at 4750 RMP
Different tires / brakes / wheels (i.e. reduced inertial load when accelerating)
Other mods...


Let me know of any corrections that I should make to the above information.
Let's go ahead and build a K04 tuning Database for the A3!


----------



## biff2bart (Dec 5, 2011)

My Setup:

Base Car: 2010 Audi A3 Quattro S-Line w/ DSG and 2.0 TSI engine

K-04 Related Mods:


APR "Golf R" Quattro Down Pipe
APR K04 Kit
Carbonio Stage 2 Intake
ECU Programs: 91 and 93 Octane (primarily driving on 91 most of the time)


Currently No FMIC (hoping to add this next spring).

Golf R Downpipe is not an exact fit: mid "subframe" bracket alignment is not perfect as apparently the location is slightly different between A3 and Golf R. Currently not using this bracket and downpipe seems solid. Will modify bracket to ensure that it can be used to attach the down pipe to the car's subframe.

However, this adds another entry into the "Quattro Downpipe" mix, which has far fewer offerings than FWD down pipes.


----------



## GunKata (Apr 4, 2006)

My Setup:

Base Car: 2011Audi A3 Quattro S-Line w/ DSG and 2.0 TSI engine

K-04 Related Mods:

Billy Boat catted and resonated Quattro Down Pipe (they used to make them for APR, believe it is now Corsa)
APR K04 Kit
Modshack Intake
ECU Programs: 93 Octane, 100 Octane 
FMIC: S3 Intercooler, stock hoses

To be installed : R8 coilpacks, new NGK plugs from HS Tuning. (check these guys out if you are anywhere near Ohio, they have SICK pricing on installs, $2700 installed on a K04!!)

Personally, I do not recommend the stage 2 portion of the intake piping from APR/carbonio, mine leaked on my GTI, and I know a guy with a K04 GTI that had to make some repairs as a result of the same thing. 

On a Mustang dyno, my car did 252whp/267wtq. A stock RS4 put down 300whp/270wtq on the same dyno. It is a heartbreaker... my car was about equal to a APR stage 1 Golf R, that put down 253whp/280wtq, iirc. Of note, most stock STI's and Evo's usually dyno at 235-240whp on a Mustang. I am looking to dyno on a different one soon to compare it to more cars. Also, I had a coilpack blow not too far after this, so not sure if that was affecting the power output.


----------



## empivw (Apr 15, 2003)

So do u guys think it would be too much for a FWD car? I have a 2011 FWD 2.0T with APR ECU 91 93 and valet. I ALSO upgraded my inter cooler to an S3 unit. With the ECU upgrade the wheels break loose I'm sure with K04 it would be even more. Thoughts?


----------



## GunKata (Apr 4, 2006)

empivw said:


> So do u guys think it would be too much for a FWD car? I have a 2011 FWD 2.0T with APR ECU 91 93 and valet. I ALSO upgraded my inter cooler to an S3 unit. With the ECU upgrade the wheels break loose I'm sure with K04 it would be even more. Thoughts?


GTI's run it all the time, and are FWD. Usually, its just about getting good summer tires and possibly considering an LSD down the line, otherwise, most of those guys don't have a problem with it, but you can chirp through 3rd gear no problem :laugh::thumbup:


----------



## empivw (Apr 15, 2003)

GunKata said:


> GTI's run it all the time, and are FWD. Usually, its just about getting good summer tires and possibly considering an LSD down the line, otherwise, most of those guys don't have a problem with it, but you can chirp through 3rd gear no problem :laugh::thumbup:


Thanks. I read your posts in your build thread. Is it possible to get a video clip of how your car sounds? I'm like u I don't like the annoying loud exhaust sounds.


----------



## GunKata (Apr 4, 2006)

empivw said:


> Thanks. I read your posts in your build thread. Is it possible to get a video clip of how your car sounds? I'm like u I don't like the annoying loud exhaust sounds.


Its not even worth recording honestly, haha.. its that quiet. I will probably do a vid after the Milltek goes on though. But my wife didn't notice it the dp when it was added and its really not noticeable at all.


----------



## FinderRO (Sep 17, 2012)

biff2bart said:


> There seem to be quite a few A3 drivers installing K04 turbos in 2.0 TSI engines lately, so why not have a single thread to consolidate as much information about this reasonably cost effective upgrade that transforms our cars into mini-super cars!
> 
> 
> For the money, there is nothing that can really compete with the power performance upgrade of a K04 turbo charger and ECU tune on the 2.0 TSI engine:
> ...


You forgot the injectors and fuel pump upgrades. Both are mandatory..


----------



## GunKata (Apr 4, 2006)

FinderRO said:


> You forgot the injectors and fuel pump upgrades. Both are mandatory..



true only on FSI, not on TSI/TFSI 09+


----------



## empivw (Apr 15, 2003)

GunKata said:


> Its not even worth recording honestly, haha.. its that quiet. I will probably do a vid after the Milltek goes on though. But my wife didn't notice it the dp when it was added and its really not noticeable at all.


That is proof enough for me! I would be curious how it sounds with exhaust though


----------



## NYCameron (Nov 17, 2010)

GunKata said:


> GTI's run it all the time, and are FWD. Usually, its just about getting good summer tires and possibly considering an LSD down the line, otherwise, most of those guys don't have a problem with it, but you can chirp through 3rd gear no problem :laugh::thumbup:


I have a K04 on my FSI (so it's FWD only) and I'm running continental extremecontact DW's
maybe it is because it is a little colder out (although I did try this after car had been warmed up and I had been driving for a while so my tires were also a little warmer) and I was spinning from high end second into third gear


----------



## biff2bart (Dec 5, 2011)

GunKata said:


> GTI's run it all the time, and are FWD. Usually, its just about getting good summer tires and possibly considering an LSD down the line, otherwise, most of those guys don't have a problem with it, but you can chirp through 3rd gear no problem :laugh::thumbup:



empivw:

As Gunkata mentions above, an LSD makes a big difference in getting power down to the front wheels. If you have a manual transmission, www.wavetrac.net will be your friend for any FWD install!

The Wavetrac LSD makes a _huge_ difference in high powered FWD cars.


----------



## QMoney (Jul 27, 2014)

*K04 packages*

Thanks for all the info on supporting mods... It seems like it makes sense to pick a company and at least stay consistent getting both the hardware and ecu tune from the same guys. Does anyone have a strong opinion on the best package??? Im looking at Uni and Apr because I have apr software with the unitronic cai. Any experiences would be greatly appreciated.


----------



## skotti (Sep 27, 2005)

QMoney said:


> Thanks for all the info on supporting mods... It seems like it makes sense to pick a company and at least stay consistent getting both the hardware and ecu tune from the same guys. Does anyone have a strong opinion on the best package??? Im looking at Uni and Apr because I have apr software with the unitronic cai. Any experiences would be greatly appreciated.


Funny, I have the opposite thought. I am thinking about a K04/stage 3 tune. I am currently stage 2, DP, CAI, new transmission mount (for me, most bang for the buck- local shop makes them). Just bought the do88 FMIC, to be installed in next couple of weeks. Will source injectors and HPFP next. Doing bit by bit, not spending mad money all at once. I also have to budget for my timing belt/water pump replacement this year.
I have a Revo tune, but I no longer have a Revo dealer locally, so may go with Driver Motorsport, as my shop is a distributor for them. APR dealer is 2 hours away, nearest Revo is an hour but I don't like the shop.


----------



## dannyace (Nov 9, 2000)

I need some advice. I'm in the market for a K04 kit but have a few questions. Kit wise, I'm looking at APR/Spulen or buying the stock oem k04 amd peicing together the rest. Regardless, besides the turbo kit and tune and DV relocation, what else is a must for the k04 on my 06 FSI DSG, fwd? 

Upgraded injectors? HPFP? Downpipe? Or are these techincally optional?


----------



## RedLineRob (Feb 8, 2009)

dannyace said:


> I need some advice. I'm in the market for a K04 kit but have a few questions. Kit wise, I'm looking at APR/Spulen or buying the stock oem k04 amd peicing together the rest. Regardless, besides the turbo kit and tune and DV relocation, what else is a must for the k04 on my 06 FSI DSG, fwd?
> 
> Upgraded injectors? HPFP? Downpipe? Or are these techincally optional?



I would highly recommend the APR k04 kit its put together great and comes with software. Not to mention its been tested now for years and is holding up really well. 

I have it on my A3 and the car feels amazing:thumbup:

like my friends tell me do it right the first time :laugh:


----------



## TBomb (Sep 23, 2009)

dannyace said:


> I need some advice. I'm in the market for a K04 kit but have a few questions. Kit wise, I'm looking at APR/Spulen or buying the stock oem k04 amd peicing together the rest. Regardless, besides the turbo kit and tune and DV relocation, what else is a must for the k04 on my 06 FSI DSG, fwd?
> 
> Upgraded injectors? HPFP? Downpipe? Or are these techincally optional?


Generally speaking, yes, with most K04 tunes you will need S3 injectors or possibly RS4 injectors depending on the tuner, upgraded HPFP, and a downpipe. There are some tuners out there who will actually tune for a K04 on stock injectors (Unitronic, for one) and I believe at least one person on here has had a K04 tune written for him with a stock downpipe. In any case, I figure if you're going to spend the money on a K04 setup you might as well get as much out of it as you can and throw in all the supporting mods.

As far as kits go, the latest APR setup is pretty slick as it does not require the DV relocation and I am pretty sure it comes with S3 injectors. You might as well clean your intake valves when you replace the injectors, especially if you've never done it on your 2006. :thumbup:


----------



## RedLineRob (Feb 8, 2009)

My setup:

2012 Audi A3 quattro titanium package

APR K04 Kit
APR new 3inch down pipe
OEM air intake 
APR K04 tune wo/DSG flash 

things to do:
install a Miltek 3inch RS3 cat back , requires some custom tubing and hanger relocations.


----------



## AudiA3Plus (Sep 21, 2015)

RedLineRob said:


> My setup:
> 
> 2012 Audi A3 quattro titanium package
> 
> ...


RedLineRob, have you had your car on a dyno with these mods? What do you have at the wheels? thanks,


----------



## RedLineRob (Feb 8, 2009)

not yet currently figuring out how to get my DSG flashed with APR 

I need to get them my box code ASAP 

OEM DSG software with K04 no good, car feels like its loosing power.


----------



## everfresh59 (Jul 26, 2010)

235/40/18 is your best friend with FWD K04 upgrade; significant reduction in wheel spin.


----------



## RedLineRob (Feb 8, 2009)

everfresh59 said:


> 235/40/18 is your best friend with FWD K04 upgrade; significant reduction in wheel spin.


Im running that same size on my quattro :thumbup:


----------



## easthk (Oct 10, 2004)

How's the rubbing with 235's? and what wheel tire combo? 


My setup:

- APR K04 - installed at least 2 years ago, no issues 
- APR software- still running version 1.2...not motivated enough to go get version 3.1 yet
- APR intercooler
- APR carbonio intake
- Milltek 3" turboback resonated - catalyst packed spacer
- redtop coils
- HPA DSG software
- Pedalbox - great mod, despite all the negators out there...
- 034 catch can 

Been outta of the vortex loop for awhile (kids) but gearing up for a track day at the new Palmer, MA track in a few weeks. Will put the OPS system to work...and finally testing out the Team Dynamics/g-force Rivals that have been sitting in my garage for about 2 years.


----------



## AudiA3Plus (Sep 21, 2015)

*United Motorsport A3 Quattro tune*

Our 2012 A3 Quattro was upgraded by DoubleJ Motorwerks in Portland, Oregon. 
Here's what they recommended and did for us. Pretty happy with the result: 
313 whp @ 5000rpm
350 wtrq @ 4200rpm
(I hope the link to image of the dyno chart below works)

K04 Turbo OEM
UM combo tune (ECU, DSG, Haldex)
3" Billyboat downpipe
IE front mount intercooler
Techtonics Tuning cat back exhaust
H&R sway bar

https://photos.google.com/search/_tra_/photo/AF1QipM-rtZ6bDbUXCQVFyxT11ymdmk80Dd_riIWG3PX


----------



## skotti (Sep 27, 2005)

AudiA3Plus said:


> Our 2012 A3 Quattro was upgraded by DoubleJ Motorwerks in Portland, Oregon.
> Here's what they recommended and did for us. Pretty happy with the result:
> 313 whp @ 5000rpm
> 350 wtrq @ 4200rpm
> ...


Like those numbers!
Did you also upgrade the HPFP and injectors?


----------



## AudiA3Plus (Sep 21, 2015)

skotti said:


> Like those numbers!
> Did you also upgrade the HPFP and injectors?


Nope. Left those stock. I asked about it and they said it was unnecessary.
The MAF sensor had to be upgraded to 3 bars.
They told me it is a 26psi tune. 
Replaced coil packs and plugs.


----------



## TBomb (Sep 23, 2009)

skotti said:


> Like those numbers!
> Did you also upgrade the HPFP and injectors?



The TSI doesn't really need any fueling upgrades until you are throwing a serious big turbo on it. Stock HPFP and injectors are good to over 400HP.


----------



## skotti (Sep 27, 2005)

TBomb said:


> The TSI doesn't really need any fueling upgrades until you are throwing a serious big turbo on it. Stock HPFP and injectors are good to over 400HP.


Does that hold true for the FSI as well, with a K04?


----------



## TBomb (Sep 23, 2009)

skotti said:


> Does that hold true for the FSI as well, with a K04?


Nope. With the FSI, you really need the HPFP upgrade even on a Stage 2 tune to avoid possible fuel cuts. Some companies offer a stock injector (with upgraded HPFP) tune on K04, like Unitronic, which claims ~330HP/~330ft-lbs on that file, but most will also require upgraded injectors to either S3 or RS4 depending on the tuner.


----------



## skotti (Sep 27, 2005)

TBomb said:


> Nope. With the FSI, you really need the HPFP upgrade even on a Stage 2 tune to avoid possible fuel cuts. Some companies offer a stock injector (with upgraded HPFP) tune on K04, like Unitronic, which claims ~330HP/~330ft-lbs on that file, but most will also require upgraded injectors to either S3 or RS4 depending on the tuner.


I just went back and looked at AudiA3Plus' post- he has a 2006, so FSI motor- and did not do injector or HPFP upgrades


----------



## AudiA3Plus (Sep 21, 2015)

skotti said:


> I just went back and looked at AudiA3Plus' post- he has a 2006, so FSI motor- and did not do injector or HPFP upgrades


Nope. I have a 2012 TFSI 2.0L. Maybe that helps resolve the confusion.


----------



## TBomb (Sep 23, 2009)

skotti said:


> I just went back and looked at AudiA3Plus' post- he has a 2006, so FSI motor- and did not do injector or HPFP upgrades


No? You have a 2006...he has a 2012...:screwy:


----------



## skotti (Sep 27, 2005)

AudiA3Plus said:


> Nope. I have a 2012 TFSI 2.0L. Maybe that helps resolve the confusion.


I swear your profile info said you had a 2012!
Need my reading glasses. Sucks getting old :vampire:


----------



## A3-Owner (Aug 10, 2015)

*K04 is a good upgrade*

The K04 is a good upgrade to our cars. 315 and 350 are good numbers. I went APR stage 1(270 HP/300 ft/lb) and then to APR stage 2(290/320 ft/lb). I decided to go with the APR stage 3 kit so I could get the most out of the TSI engine. I was able to get 390 HP and about the same torque to the wheels on the swd dyno from a shop close to me. The owner of the shop told me that you can get about 450 HP out of the stock fuel system on a TSI motor with a big turbo. APR says the TSI stock rods are good for 400 ft/lb of torque so you should upgrade the rods if you go for higher power.


----------



## gammerx (Nov 24, 2015)

A3-Owner said:


> The K04 is a good upgrade to our cars. 315 and 350 are good numbers. I went APR stage 1(270 HP/300 ft/lb) and then to APR stage 2(290/320 ft/lb). I decided to go with the APR stage 3 kit so I could get the most out of the TSI engine. I was able to get 390 HP and about the same torque to the wheels on the swd dyno from a shop close to me. The owner of the shop told me that you can get about 450 HP out of the stock fuel system on a TSI motor with a big turbo. APR says the TSI stock rods are good for 400 ft/lb of torque so you should upgrade the rods if you go for higher power.


I feel like stage 3 would be a bit much for the FWD guys. Is there a significant upgrade going with the K04 though? All I'm missing are the upgraded injectors and a LSD for power and I could upgrade the turbo. Wondering if it's worth it


----------

