BUL with K03 Turbo , why not a BUL with K04 that is the question.

Charlie Farley

Charlie Farley

Chilling out.
Staff member
Moderator
VCDS Map User
Joined
Jun 13, 2014
Messages
25,598
Reaction score
11,740
Points
113
Location
At Home
On another totally rubbish day I had a while to just sit down and have a read for a change I was thinking about the following.
The TFSI power plant in the DTM and special editions is the BUL code engine , which is fitted with the K03 turbo ,now why didn't they fit the K04 as standard , after all it was fitted to the TT and S3 etc .
As the BUL was only fitted to a the DTM and tfsi special edition , why not use the K04 , any thoughts chaps.
 
Last edited:
Did our b7s come before the s3s with k04 setup, new technology maybe?

Strangely despite it only being a different turbo, its a rather intensive job to do a conversion if im correct.
 
The k04 was fitted to the 225 bhp TT's upto 2005 , engine codes ,AMU, APX, BAM, BEA , maybe be others aswell as S3.
 
Alex Holmes said:
Did our b7s come before the s3s with k04 setup, new technology maybe?

Strangely despite it only being a different turbo, its a rather intensive job to do a conversion if im correct.
Click to expand...

If there was a straight bolt on version that would run on exisiting setup without the need to do a shed load of other mods i'd be straight in there for one.
 
May have to look into it a bit more, BBT are only a 20 min drive away from me so maybe worth a visit to them in the flesh .
 
My buddy @Beardymat started a ko4 conversion build. He did his homework and is a clued up about it more than most. Could be worth giving him a shout.
 
Indeedy.
I had a chat with AET turbo's this afternoon, seem to know there stuff and very helpful.
I'm going to get them to build me a suitable turbo upgrade in the next few weeks, need to find a few extra bit's now aswell.
I had decided a while back that I wasn't going this route, but since i'm already too far into changing bits on the old bus, might aswell go a bit further.
 
Last edited:
Just Rob. said:
Indeedy.
I had a chat with AET turbo's this afternoon, seem to know there stuff and very helpful.
I'm going to get them to build me a suitable turbo upgrade in the next few weeks, need to find a few extra bit's now aswell.
I had decided a while back that I wasn't going this route, but since i'm already too far into changing bits on the old bus, might aswell go a bit further.
Click to expand...
It’s well worth doing a bigger turbo if you like to have the power when you want it rob, the only downside to it is fuel cost, I have only been running mine to work and back for a few days and can see a massive difference in mpg however I might have it on the limiter too much and enjoying the power increase.
 
Toying the idea of using a donor engine again.
I bought a BUL engine some time ago for this very project but shelved it and let the engine go, but maybe the way to go and preserve the factory fit unit .

I have a few things in mind this time around, and allready have a decent FMIC still boxed ready to be used .
Could swap over my 034 cat and large bore tapered downpipe too, don't think i'd need to go any further with a full system , also have a HPFP upgrade kit still unused.
 
Just Rob. said:
Toying the idea of using a donor engine again.
I bought a BUL engine some time ago for this very project but shelved it and let the engine go, but maybe the way to go and preserve the factory fit unit .

I have a few things in mind this time around, and allready have a decent FMIC still boxed ready to be used .
Could swap over my 034 cat and large bore tapered downpipe too, don't think i'd need to go any further with a full system , also have a HPFP upgrade kit still unused.
Click to expand...

What does FMIC mean? Would having forged rods and piston head be over the top? I have just rebuilt my engine and put a hybrid KO4 turbo on the BUL engine and wondering and thinking I should have forged the pistons and rods.

C
 
FMIC , Front Mounted Inter Cooler.
Depends on how far you intend going performance wise.
 
Had a few quotes for parts etc , probably north of £5k to get it sorted , maybe that was why I shelved the idea last time round.
 
Just Rob. said:
Had a few quotes for parts etc , probably north of £5k to get it sorted , maybe that was why I shelved the idea last time round.
Click to expand...

I am in the process of completing my KO4 turbo upgrade and the budget has been blown to pieces. I mean the KO4 conversion has been much expensive there expected. I had decide not to go for the APR KO4 conversion kit as wanted a more custom KO4 turbo upgrade. I had decide to go for a the hybrid Warnborg Ko4 turbo made by turbo developments that alone cost me £1300, Airtech intercooler £567, ECS induction kit £311, upgraded to a tfsi 2.0 performance clutch kit £950, S3 injectors £400 and autotech HPFP upgrade at £350 and the mapping to do be done by MRC tuning. There is also the RS4 in tank pump to purchase, forging the piston rods and piston head and upgrading the brakes. I have not done those yet.

A lot to consider when going for the Ko4 upgrade.

C
 
Just Rob. said:
Toying the idea of using a donor engine again.
I bought a BUL engine some time ago for this very project but shelved it and let the engine go, but maybe the way to go and preserve the factory fit unit .

I have a few things in mind this time around, and allready have a decent FMIC still boxed ready to be used .
Could swap over my 034 cat and large bore tapered downpipe too, don't think i'd need to go any further with a full system , also have a HPFP upgrade kit still unused.
Click to expand...

What else do you have in that magical store Rob? Haha

Do you know if anyone has tried a 5pot lump conversion from a TTRS into a B7? Now that would be interesting.... that noise and that power. I guess there would be so many alterations to make - what a project though.


Sent from my iPhone using Tapatalk
 
Alex Holmes said:
My buddy @Beardymat started a ko4 conversion build. He did his homework and is a clued up about it more than most. Could be worth giving him a shout.
Click to expand...

It's still all in the garage at the moment Alex but it's on the list with a few things to part company with as I have an impending house move on the way.

I bought a used K04 turbo and altered the exhaust stud pattern to match the B7 exhaust flange. I also bought a new Chra (turbo core) and every gasket and seal I could find at tps and I also bought a doner B7 Ko3 turbo for the compressor housing and all the pipework. The next stage was to get the compressor housing machined to go over the K04 compressor wheel for which I was quoted (I thought) a very reasonable £75. Then it would be a case of bolting the whole lot together with a slight modification of the actuator bracket and creating a drop in K04. No need to mess around with custom pipework or remote diverter valves, just whack it in with some S3 injectors (other brands available) and a decent map and away you go or add a hpfp for more power still.

Unfortunately I didn't get as far as getting the housing machined before the S4 purchase negated the need to finish it and although the S4 is basically none tunable I cant see me returning to the TFSI so someone will get a bargain when I pull my finger out and advertise it.
 
  • Like
Reactions: Charlie Farley
Just Rob. said:
On another totally rubbish day I had a while to just sit down and have a read for a change I was thinking about the following.
The TFSI power plant in the DTM and special editions is the BUL code engine , which is fitted with the K03 turbo ,now why didn't they fit the K04 as standard , after all it was fitted to the TT and S3 etc .
As the BUL was only fitted to a the DTM and tfsi special edition , why not use the K04 , any thoughts chaps.
Click to expand...

What's the spool difference between the two turbos, coupled with the weight difference between the mentioned cars? I don't know, just a thought. I'm thinking the A4 would be more laggy/boggy. That's unless you tune it a little, but that's a different conversation.
 
Beardymat said:
It's still all in the garage at the moment Alex but it's on the list with a few things to part company with as I have an impending house move on the way.

I bought a used K04 turbo and altered the exhaust stud pattern to match the B7 exhaust flange. I also bought a new Chra (turbo core) and every gasket and seal I could find at tps and I also bought a doner B7 Ko3 turbo for the compressor housing and all the pipework. The next stage was to get the compressor housing machined to go over the K04 compressor wheel for which I was quoted (I thought) a very reasonable £75. Then it would be a case of bolting the whole lot together with a slight modification of the actuator bracket and creating a drop in K04. No need to mess around with custom pipework or remote diverter valves, just whack it in with some S3 injectors (other brands available) and a decent map and away you go or add a hpfp for more power still.

Unfortunately I didn't get as far as getting the housing machined before the S4 purchase negated the need to finish it and although the S4 is basically none tunable I cant see me returning to the TFSI so someone will get a bargain when I pull my finger out and advertise it.
Click to expand...

Very Interesting !!

how easy to modify the exhaust flange any pics at all ?

this is also gutting to hear as i scrapped a K03 comp/exhaust housing not so long back ....

i was thinking this recently if this method would be the same as the Frankenturbo F23-L and ebay copies ?
 
Is there any guides to k04’ing a b7? I like beardymats idea with a modified compressor housing, will the k04 fit onto it?

have many people done this conversion? I’ve currently got a mk1 TT track car for sale as I’m just too big for it (6’6”) and been contemplating a b7 quattro as a track car.

I know there is some better options out there, but I’d like to be comfortable too.
 
2.0T A4's were never designed to be rocketships, like it or not they're the compromise on economy and performance between diesels and S/RS models, plenty of tuning potential for anything with a turbo and that's why aftermarket companies love them but they were designed as a cheaper "sporty" Audi rather than an expensive neck snapping "powerhouse" Audi.
 
  • Like
Reactions: Sidrick
You must log in or register to reply here.

Similar threads

A
K03 S in the "special edition(s)" BUL engine???
Replies
20
Views
12K
antwan64og
A
R
Help with thermostat replacement TFSI BUL
Replies
5
Views
5K
Baka
Baka
Marius87
BUL turbo in BWE
Replies
0
Views
783
Marius87
Marius87
Jammymancan
Is the fuel pump on my BUL engine not a 'HPFP'?
Replies
8
Views
2K
Rob Avant
Rob Avant
Stu_b7
BUL thermostat replacement??
Replies
2
Views
827
Luke Smith A4 2.0T
Luke Smith A4 2.0T
Top
Back