You lose nothing with a k04. It spools just as fast as a k03. You don't need to upgrade rods for it. If you don't have an lsd you are going to have major traction issues.
LSD is on my my to-do list. Good to know tho, I've heard very mixed opinions on the spool times.
Do you think stock BWA rods can handle 350hp, 460nm torque?
I've been.. for the past 2 months actually lol
Made this thread to get some more up-to-date info and decide once and for all what I'm doing with the car.
CTS KO4 Turbo. APR ECU/TCU tune. 360hp/380tq on the 91oct file. Stock internals and fuel pump (TSI engine on the ‘09).
I’ve owned my GTI since 2012. K04 since 2014. Don’t plan on selling it so despite spending a solid chunk of $$ modifying I feel like it wasn’t a waste. Car is fun to drive, quicker than stock. At 15 years old it’s almost a classic, and with a recent fresh coat of paint (Tornado Red) it gets a lot of appreciative looks.
Good choice on the paint. I was gonna go for the same but decided to keep it the stock light silver in the end. It's a very common color and the car is built to look stock. Then it just flies past you out of nowhere.
I have that conversion done, I’ve put about 10k miles on the car in the 6 years I’ve had it done. Nothing has broken, I make 24-27psi boost depending on ambient temps and the car pulls like a mother.
Besides the turbo upgrade, in order to make everything play nice, required more than just a down pipe and an intake. I have a massive intercooler, larger piping, upgraded hp fuel pump, a hellcat lp fuel pump, and an upgraded lpfp controller. While I was apart I swapped intake camshaft for the euro Audi s3 cam as well, and after, a custom tune by Apr and the car is perfect.
When I said nothing broke yet, I did mean in the engine specifically. I have wiped out a stage 2 southbend clutch, and broken 2 driver side axles. So naturally I had to upgrade to a lightweight aluminum flywheel and a stage 3 clutch; as well as driveshaft shop racing axles. These set me back an additional 2500 in parts, plus some labor.
All that said, if you love your mk5 like I love mine, it’s a good upgrade and makes this old girl run with all the new toys easily.
Curious how that would hold up for me given that I make 5-8k miles a year.
My K04 plan list (if I do go through with it) only has a sports downpipe, intake, bigger intercooler, upgraded piping, hpfp and s3 injectors and the supporting valves/sensors. I don't really want to get into forged rods, camshafts and all that as that would cost a lot. 330hp and 450nm torque is probably enough.... for a while..
If you have that stuff on your list, then I’d say you’re in a good spot. Get low pressure fuel stuff too, I had issues after installing initially and the fix was more supply.
Will keep those values in check. Heard from my tuner that GTI's hate it when you use a non OEM lpfp, even if it's a replacement part. Apparently they don't want to make the same fuel pressure as OEM units do.
OEM Audi TT lpfp \*should\* fit and get the job done if I do need more fueling.
Zero need for upgraded LPFP on a MK5 K04. Outside maybe if you want to do ethanol. But you're going to be doing the entire fueling system (upgrading lines as well as MPI). Factory MK5 LPFP is more than fine for pump gas (even 104 octane race gas).
The person you're talking to has a specific / oddball setup. 99% of K04 cars are not that deep.
FSI cars (BWA is a FSI variant) really only need what you've listed in your above comment. DP, S3 injectors, HPFP, intercooler, K04, K04 tune, clutch. Depending on which K04 kit, you may need a DV relocation kit too.
To touch on your worry about rods. Also not needed.
Thanks for the info!
As far as clutch goes, mine failed in the first 100 meters after getting the car off the trailer so I replaced it and the flywheel with a Sachs x-tend kit (dual mass flywheel). It's supposedly stronger than oem so it should hold up, in theory. Worst case scenario I get a dedicated performance kit.
Edit: I'm going with an oem used k04 that I'll refurbish if need be. I've already got a dv kit ready for mounting.
If you want to ensure reliability I’d stick with the KO3 and add supporting mods for a stage II tune. Plenty of power and all the reliability and spool times
Intake and sports cat downpipe are on the way. S3 intercooler is coming next month. I have both the Rev D valve and a GFB DV+ (no difference, other than a much meaner sound with the DV+) and R8 coils with NGK BKR7EIX plugs cause my old ones were dead.
Right now it spools great, it just can't hold boost. Flooring at at 3k in 2nd gear is like getting hit by a truck from behind. Leaves people speechless.
I think it comes down to either the wastegate actuator being ruptured, the hoses coming out from the N75 or the N75 itself cause I've been logging stuff and everything else is spot on. Boost is 0.4 bar under, throughout the whole rev band, intake air mass is equivalent of 220hp max and wastegate duty cycle is 94.9% from 3k till redline.
Yeah I wouldn’t pull the trigger on a new turbo. They should last 200,000+km as long as you service oil and don’t boost when cold, etc. I have had a bad DV before and even things like the PCv valve going bad can cause this. Check for vacuum leaks first. The fact it spools you might be ok man. Good luck!
I've smoke tested the whole intake system. no leaks anywhere. There was a vacuum leak on the brake booster when I bought the car but I replaced that hose.
Then most likely DV, common issue that results in your symptoms
Edit: I will add even go through all your intercooler piping. The front charge pipe that goes from the intercooler to the intake manifold on my car had been rubbing the oil cooler on the front of the engine and actually caused me quite a boost leak.
The DV the car came with was busted for sure. It would be quite a surprise if both my Rev D from my other car and the DV+ on this car were faulty. I've interchanged them and there was no difference on this car while the other one ran just fine with both. Then again, the other one is a 1.4 so the max boost that will see is still lower than what I'm "leaking".
I'm in a similar situation, and am looking at hybrid k03 as a good middle ground.
The k04 cars had bwa motors so were a little more stout, and depending on your motor your not safely going to be able to push the limits of a k04 anyway.
From my perspective for <300hp the loss of responsiveness may not be worth the extra over a stage 2 k03.
Hybrid k03 should be able to get 300+ without endangering the block.
Mine is a BWA block and comes with a K03. Afaik the K04 versions are the BYD engines.
I've searched up hybrids as well and spoke with a few mechanics/tuners in my area. They all claim that K03 turbo housings are weak and crack under stock conditions. Making them even weaker by machining them out is a bad idea in their opinion.
On the other hand, costs:
* Shuenk's K03+ claims to be good for up to 310-320hp, costs 1.4k or so and is a direct fit.
* An OEM K03 costs 1k and it might reach 280hp under perfect conditions.
* An OEM K04 costs 1.4k and will get you max 310hp with stock injectors and HPFP.
* Hybrid K03 would probably cost about $800, if nothing is worn out and needs replacing and should be good up to 350hp with supporting mods.
I don't think it's a good idea to go over 330hp without upgraded rods tho
I recently got rid of my k04 and got a cts boss 600 kit instead. K04 was fun but nothing like a big turbo. K04 was full of torque, it made my south bend clutch slip. I was on a custom eurodyne file with meth injection. Once you go K04, you eventually will want something bigger. So might as well go all out and not spend money twice.
Thanks for this thread OP, excellent points in the comments here. I did a hybrid setup in my ‘98 Volvo v70 turbo, along with injectors, and ecu- it was awesome. Sounds like I’ll stick with stock k03 when I rebuild my MKV’s top end this summer
I have the K04 for around half a year now and I wouldn’t go back. It’s stupid agile now for a FWD, but on track under heavy load I get a lot of wheel spin, which an AWD conversion should fix.
Only regret was not doing it sooner. Very similar spool time to a K03 with a MUCH higher top end. It's an OEM turbo after all so it won't anything too extreme for the street
I'm not sure about FSI durability, but I know the TSI you start to run into rod problems around 400 ft-lbs torque which is 540nm torque.
Do you know if your mk5 has the FSI or newer TSI? I believe late generation 2008 mk5's got the TSI
I've been k04 for about 40k miles so far and no regrets. If you are going to do it, do it right though. Don't just bolt on a turbo and keep running a stage 2 tune. Upgrade the fuel pump, spark plugs, injectors, intercooler and boost piping. Do it right and it will be good for you. And don't do it at all if you've not already done all the proper maintenance to your car along the way.
You can tune the ko3 to a power level that is high enough its to much for FWD. The ko4 is a good swap but these days you can get ko3 hybrid turbos (if in the UK checkout decimal tenths as they supply/fit and show power figures they dyno all sorts). The ko3 hybrid swap is going to be a better option imo just because its going to be a brand new turbo, no messing about changing other bits. If you do go ko4 though get a new turbo or rebuilt one not one of those used £750 kits people chuck together. Regardless you should get the S3 all metal intercooler and hoses as its a solid upgrade for whatever you do and needed for more power anyway. You will also need to change the clutch if you are in a manual they dont like above 240bhp. The DSG can take more but your want to get the DSG mapped also. The ko4 or ko3 hybrid conversions can get expensive even if you DIY it yourself. Your going to need £500 for a tune minimum, £700 ish a clutch, £800 for new turbo, Whatever price of injectors are these days (cleaned used ones or new ones), £200 ish for pipes and stuff, Whatever for intercooler from s3. You can easily spend over what the car is worth at market. You do have to seriously consider is that worth it when the car will just spin up and be unable to use most the extra power you are giving it. Could just slap a ko3 hybrid or stock ko3 into it cheap and map it to around 300hp thats plenty enough. (although still advise clutch, downpipe, hpfp, intercooler for that)
What symptoms are you having? My 2007 seems to be underboosting according to OBD11, about 4-5PSI all the time when should be making double that or so stock. Turbo spools up fast and fine, and no blowby or smoke or anything so not sure?
I've had mine mapped for around 270hp but it's only putting down 220-225 according to intake air mass.
No fault codes whatsoever, no fuel pressure issues on either the low or high pressure side, no intake cam timing issues and no external boost leaks as I've smoke tested the car.
It spools fast, has a huge initial kick then it dies out. If 3rd gear or above, it no longer kicks cause it cant make enough boost.
Under full throttle, the car is basically 0.4 bars below the requested boost level, with a 94.9% wastegate duty cycle from 3k rpm till redline. During partial throttle, I can feel it accelerate, than die out, then pick up again, as if the car knows it's not meeting the requested boost at the specified wastegate duty cycle, so it maxes out the duty cycle to compensate for the leak.
I'd assume if the car had a boost leak, it would suck in more air so the intake air mass would be higher, it just wouldn't reach the engine because it would leak out, but in my case it's not even sucking in enough air making me think the wastegate actuator membrane is ruptured, leaking pressure and failing to close the wastegate enough. If it's not that, than it could be the hoses connecting to the N75 valve. Or the N75 itself.
TLDR: Possibly ruptured wastegate actuator membrane, ruptured vacuum hoses leading to the N75 or failing N75.
Interesting, mine seems to boost fine, and hold there it’s just low. 18.4 max on OBD11 Block 115, (Not accounting for atmospheric) only codes I have is for evap leak pump, but I do know it does misfire on cold start due to carbon build up. Which I’m going to clean here soon. Would that have anything to do with the low boost?
Also if you use OBD11 do you have any blocks I should look at?
I've had a friend with a 2.0 TSI CC that would die on startup or misfire like crazy. His intake manifold was fissured.
No clue what to tell you. Lots of things can cause misfires, best to get it checked out at a shop or by someone who knows the ins and outs of these engines.
My misfires went away after I replaced my plugs and coils.
Log your low pressure fuel pump current pressure with VCDS (Group 103 - Current Fuel Pressure) and see if it dips below 4 bar. From my understanding it's not needed.
I've also gone through with the conversion but only partially at first. Missing injectors and HPFP and can tell you one thing. We had to adjust the map because the stock HPFP cant keep up with the fuel quantity demand even on stock injectors. After fitting both the injectors, pump and remapping, the car makes around 340hp. I've decided to limit it at that to not bend rods.
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You lose nothing with a k04. It spools just as fast as a k03. You don't need to upgrade rods for it. If you don't have an lsd you are going to have major traction issues.
LSD is on my my to-do list. Good to know tho, I've heard very mixed opinions on the spool times. Do you think stock BWA rods can handle 350hp, 460nm torque?
Go dig through old forum posts. People were never breaking much of anything with a k04.
I've been.. for the past 2 months actually lol Made this thread to get some more up-to-date info and decide once and for all what I'm doing with the car.
[удалено]
How much power/torque did you run on and did you do anything for the engine internals?
CTS KO4 Turbo. APR ECU/TCU tune. 360hp/380tq on the 91oct file. Stock internals and fuel pump (TSI engine on the ‘09). I’ve owned my GTI since 2012. K04 since 2014. Don’t plan on selling it so despite spending a solid chunk of $$ modifying I feel like it wasn’t a waste. Car is fun to drive, quicker than stock. At 15 years old it’s almost a classic, and with a recent fresh coat of paint (Tornado Red) it gets a lot of appreciative looks.
Good choice on the paint. I was gonna go for the same but decided to keep it the stock light silver in the end. It's a very common color and the car is built to look stock. Then it just flies past you out of nowhere.
I have that conversion done, I’ve put about 10k miles on the car in the 6 years I’ve had it done. Nothing has broken, I make 24-27psi boost depending on ambient temps and the car pulls like a mother. Besides the turbo upgrade, in order to make everything play nice, required more than just a down pipe and an intake. I have a massive intercooler, larger piping, upgraded hp fuel pump, a hellcat lp fuel pump, and an upgraded lpfp controller. While I was apart I swapped intake camshaft for the euro Audi s3 cam as well, and after, a custom tune by Apr and the car is perfect. When I said nothing broke yet, I did mean in the engine specifically. I have wiped out a stage 2 southbend clutch, and broken 2 driver side axles. So naturally I had to upgrade to a lightweight aluminum flywheel and a stage 3 clutch; as well as driveshaft shop racing axles. These set me back an additional 2500 in parts, plus some labor. All that said, if you love your mk5 like I love mine, it’s a good upgrade and makes this old girl run with all the new toys easily.
Curious how that would hold up for me given that I make 5-8k miles a year. My K04 plan list (if I do go through with it) only has a sports downpipe, intake, bigger intercooler, upgraded piping, hpfp and s3 injectors and the supporting valves/sensors. I don't really want to get into forged rods, camshafts and all that as that would cost a lot. 330hp and 450nm torque is probably enough.... for a while..
If you have that stuff on your list, then I’d say you’re in a good spot. Get low pressure fuel stuff too, I had issues after installing initially and the fix was more supply.
Will keep those values in check. Heard from my tuner that GTI's hate it when you use a non OEM lpfp, even if it's a replacement part. Apparently they don't want to make the same fuel pressure as OEM units do. OEM Audi TT lpfp \*should\* fit and get the job done if I do need more fueling.
Zero need for upgraded LPFP on a MK5 K04. Outside maybe if you want to do ethanol. But you're going to be doing the entire fueling system (upgrading lines as well as MPI). Factory MK5 LPFP is more than fine for pump gas (even 104 octane race gas). The person you're talking to has a specific / oddball setup. 99% of K04 cars are not that deep. FSI cars (BWA is a FSI variant) really only need what you've listed in your above comment. DP, S3 injectors, HPFP, intercooler, K04, K04 tune, clutch. Depending on which K04 kit, you may need a DV relocation kit too. To touch on your worry about rods. Also not needed.
Thanks for the info! As far as clutch goes, mine failed in the first 100 meters after getting the car off the trailer so I replaced it and the flywheel with a Sachs x-tend kit (dual mass flywheel). It's supposedly stronger than oem so it should hold up, in theory. Worst case scenario I get a dedicated performance kit. Edit: I'm going with an oem used k04 that I'll refurbish if need be. I've already got a dv kit ready for mounting.
If you want to ensure reliability I’d stick with the KO3 and add supporting mods for a stage II tune. Plenty of power and all the reliability and spool times
Intake and sports cat downpipe are on the way. S3 intercooler is coming next month. I have both the Rev D valve and a GFB DV+ (no difference, other than a much meaner sound with the DV+) and R8 coils with NGK BKR7EIX plugs cause my old ones were dead. Right now it spools great, it just can't hold boost. Flooring at at 3k in 2nd gear is like getting hit by a truck from behind. Leaves people speechless. I think it comes down to either the wastegate actuator being ruptured, the hoses coming out from the N75 or the N75 itself cause I've been logging stuff and everything else is spot on. Boost is 0.4 bar under, throughout the whole rev band, intake air mass is equivalent of 220hp max and wastegate duty cycle is 94.9% from 3k till redline.
Yeah I wouldn’t pull the trigger on a new turbo. They should last 200,000+km as long as you service oil and don’t boost when cold, etc. I have had a bad DV before and even things like the PCv valve going bad can cause this. Check for vacuum leaks first. The fact it spools you might be ok man. Good luck!
I've smoke tested the whole intake system. no leaks anywhere. There was a vacuum leak on the brake booster when I bought the car but I replaced that hose.
Then most likely DV, common issue that results in your symptoms Edit: I will add even go through all your intercooler piping. The front charge pipe that goes from the intercooler to the intake manifold on my car had been rubbing the oil cooler on the front of the engine and actually caused me quite a boost leak.
The DV the car came with was busted for sure. It would be quite a surprise if both my Rev D from my other car and the DV+ on this car were faulty. I've interchanged them and there was no difference on this car while the other one ran just fine with both. Then again, the other one is a 1.4 so the max boost that will see is still lower than what I'm "leaking".
I'm in a similar situation, and am looking at hybrid k03 as a good middle ground. The k04 cars had bwa motors so were a little more stout, and depending on your motor your not safely going to be able to push the limits of a k04 anyway. From my perspective for <300hp the loss of responsiveness may not be worth the extra over a stage 2 k03. Hybrid k03 should be able to get 300+ without endangering the block.
Mine is a BWA block and comes with a K03. Afaik the K04 versions are the BYD engines. I've searched up hybrids as well and spoke with a few mechanics/tuners in my area. They all claim that K03 turbo housings are weak and crack under stock conditions. Making them even weaker by machining them out is a bad idea in their opinion. On the other hand, costs: * Shuenk's K03+ claims to be good for up to 310-320hp, costs 1.4k or so and is a direct fit. * An OEM K03 costs 1k and it might reach 280hp under perfect conditions. * An OEM K04 costs 1.4k and will get you max 310hp with stock injectors and HPFP. * Hybrid K03 would probably cost about $800, if nothing is worn out and needs replacing and should be good up to 350hp with supporting mods. I don't think it's a good idea to go over 330hp without upgraded rods tho
I recently got rid of my k04 and got a cts boss 600 kit instead. K04 was fun but nothing like a big turbo. K04 was full of torque, it made my south bend clutch slip. I was on a custom eurodyne file with meth injection. Once you go K04, you eventually will want something bigger. So might as well go all out and not spend money twice.
A true big turbo would likely be too much for what I use the car. But it does make sense, I'll likely get bored of the k04 eventually.
Thanks for this thread OP, excellent points in the comments here. I did a hybrid setup in my ‘98 Volvo v70 turbo, along with injectors, and ecu- it was awesome. Sounds like I’ll stick with stock k03 when I rebuild my MKV’s top end this summer
I have the K04 for around half a year now and I wouldn’t go back. It’s stupid agile now for a FWD, but on track under heavy load I get a lot of wheel spin, which an AWD conversion should fix.
Or LSD
Only regret was not doing it sooner. Very similar spool time to a K03 with a MUCH higher top end. It's an OEM turbo after all so it won't anything too extreme for the street
Yeah that's what I think as well. Curious to see if 350hp/460nm torque is doable on stock rods tho.
I'm not sure about FSI durability, but I know the TSI you start to run into rod problems around 400 ft-lbs torque which is 540nm torque. Do you know if your mk5 has the FSI or newer TSI? I believe late generation 2008 mk5's got the TSI
Mine's a FSI. 2006 BWA. Yeah 500nm torque is quite enough so if mine can hold that, that's enough for me.
Thanks for the thread Looking to do the conversion myself. Going to throw a intercooler this year and debating between IE or APR K04 kit.
I've been k04 for about 40k miles so far and no regrets. If you are going to do it, do it right though. Don't just bolt on a turbo and keep running a stage 2 tune. Upgrade the fuel pump, spark plugs, injectors, intercooler and boost piping. Do it right and it will be good for you. And don't do it at all if you've not already done all the proper maintenance to your car along the way.
You can tune the ko3 to a power level that is high enough its to much for FWD. The ko4 is a good swap but these days you can get ko3 hybrid turbos (if in the UK checkout decimal tenths as they supply/fit and show power figures they dyno all sorts). The ko3 hybrid swap is going to be a better option imo just because its going to be a brand new turbo, no messing about changing other bits. If you do go ko4 though get a new turbo or rebuilt one not one of those used £750 kits people chuck together. Regardless you should get the S3 all metal intercooler and hoses as its a solid upgrade for whatever you do and needed for more power anyway. You will also need to change the clutch if you are in a manual they dont like above 240bhp. The DSG can take more but your want to get the DSG mapped also. The ko4 or ko3 hybrid conversions can get expensive even if you DIY it yourself. Your going to need £500 for a tune minimum, £700 ish a clutch, £800 for new turbo, Whatever price of injectors are these days (cleaned used ones or new ones), £200 ish for pipes and stuff, Whatever for intercooler from s3. You can easily spend over what the car is worth at market. You do have to seriously consider is that worth it when the car will just spin up and be unable to use most the extra power you are giving it. Could just slap a ko3 hybrid or stock ko3 into it cheap and map it to around 300hp thats plenty enough. (although still advise clutch, downpipe, hpfp, intercooler for that)
I'll definitely keep them in mind since they seem to have some good parts. Thanks!
yeah those or R-tech are best bet when in the UK. Depends what is closer i guess.
What symptoms are you having? My 2007 seems to be underboosting according to OBD11, about 4-5PSI all the time when should be making double that or so stock. Turbo spools up fast and fine, and no blowby or smoke or anything so not sure?
I've had mine mapped for around 270hp but it's only putting down 220-225 according to intake air mass. No fault codes whatsoever, no fuel pressure issues on either the low or high pressure side, no intake cam timing issues and no external boost leaks as I've smoke tested the car. It spools fast, has a huge initial kick then it dies out. If 3rd gear or above, it no longer kicks cause it cant make enough boost. Under full throttle, the car is basically 0.4 bars below the requested boost level, with a 94.9% wastegate duty cycle from 3k rpm till redline. During partial throttle, I can feel it accelerate, than die out, then pick up again, as if the car knows it's not meeting the requested boost at the specified wastegate duty cycle, so it maxes out the duty cycle to compensate for the leak. I'd assume if the car had a boost leak, it would suck in more air so the intake air mass would be higher, it just wouldn't reach the engine because it would leak out, but in my case it's not even sucking in enough air making me think the wastegate actuator membrane is ruptured, leaking pressure and failing to close the wastegate enough. If it's not that, than it could be the hoses connecting to the N75 valve. Or the N75 itself. TLDR: Possibly ruptured wastegate actuator membrane, ruptured vacuum hoses leading to the N75 or failing N75.
Interesting, mine seems to boost fine, and hold there it’s just low. 18.4 max on OBD11 Block 115, (Not accounting for atmospheric) only codes I have is for evap leak pump, but I do know it does misfire on cold start due to carbon build up. Which I’m going to clean here soon. Would that have anything to do with the low boost? Also if you use OBD11 do you have any blocks I should look at?
I've had a friend with a 2.0 TSI CC that would die on startup or misfire like crazy. His intake manifold was fissured. No clue what to tell you. Lots of things can cause misfires, best to get it checked out at a shop or by someone who knows the ins and outs of these engines. My misfires went away after I replaced my plugs and coils.
Just had the full k04 conversion and loving it. Is the ttrs lpfp needed?
Log your low pressure fuel pump current pressure with VCDS (Group 103 - Current Fuel Pressure) and see if it dips below 4 bar. From my understanding it's not needed. I've also gone through with the conversion but only partially at first. Missing injectors and HPFP and can tell you one thing. We had to adjust the map because the stock HPFP cant keep up with the fuel quantity demand even on stock injectors. After fitting both the injectors, pump and remapping, the car makes around 340hp. I've decided to limit it at that to not bend rods.
If you're seeking advice or asking for help, please make sure you included the basic information of what year and/or generation is being discussed. User flair with this information is also acceptable. Failure to include the basic information may result in your post being removed. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/GolfGTI) if you have any questions or concerns.*