K04 Upgrade

[moktoya]

Can someone shed some light on the issue of K04 upgrade on an S4. I'm interested but due to budget constraints would like to take it step by step.... Pls highlight what actual priorities should be, beyond having a pair of K04s. Thx

[snbS4]

Having had this carried out earlier this year, I'm not sure which areas can be successfully performed without 'overlapping' costs meaning the overall result is much more expensive. It depends on what state of tune you are running presently.
I already had a Milltek cat-back exhaust, Forge diverters and Samco hoses (precautionary measures but worth having in place for reliability) and was running AMD's 326bhp programme. This saved me a bit on the K04 conversion although it's hard to tell since I also had a new clutch, cambelt with tensioners etc and water pump at the same time the engine was out.
GBP1,200 (+ VAT) of the cost of works relates to removal & refit of the engine.
Should you choose to only have the K04's fitted (GBP750 each + VAT), plus the modified pipes, on their own then I doubt you would gain any real benefit until the rest of the engine works were finished to optimise. The exhaust could be fitted after (with Milltek downpipes). The final remapping and R/R session can only really be carried out once everything is done.
The final product is quite astonishing and produces quite a noticeable difference over the 326bhp previously enjoyed.
The complete details are listed on the AMD web-site but remember there will be probably be 'extras' on the way!!
HTH, Simon

K04's, Tanoga, full Milltek, Forge DV's, H&R, Samco TBB&F!

[Olly_K]

including brakes ! been thinking about this myself.
snbs4, where can you get the k04 turbo's for 750GBP each ?
i've been looking at ebay over in the states and they sell em on there brand new for about 1300 quid.
plus shipping of course !

[moktoya]

Thx Simon,

I fact I'm presently running a similar setup to your pre-K04 days, plus Milltek downpipes and a CAI. So i take it that if I decide to go for K04, should get everything done in 1 go to realize full benefits.... I was hoping to initially get by with the turbos and maybe the fuel injector only...maybe not. Thx

[Morpheous]

Check with VAG parts, they were about £550. plus the vat.

[Nige_RS4]

I was hoping to initially get by with the turbos and maybe the fuel injector only...

I would be wary of just changing the turbos and injectors - it is not quite as easy as that. If you go the injector route, you need to consider an enlarged MAF, if you go RS4 injectors you will need the RS4 injector manifold, also a 4 or 5 bar FPR atc.....

You can see it gets quite complicated (not to mention fecking expensive). If I were you, I would bolt the K04's on and run with stage 1 or 2 K03 software until you can afford a remap. Be aware that fueling is maxed out using the std S4 injectors at high revs.

Nige.

[moktoya]

So what u r saying is i can run bare K04 fine, but need to be careful with high revs to avoid fuel supply problems. But if i update my MTM ECU to K04 specs, will the rest of the engine still run fine? Or are u saying that once i mess with the ECU to stage 3, I would need to upgrade the rest of the peripherals to make it all work? Thx.

<I'm the IC guy BTW.>

[snbS4]

Guys,

snbs4, where can you get the k04 turbo's for 750GBP each ?

All of the conversion work was carried out by AMD and that's how much they charge. Scott also pointed out that they buy them in new and then have them stripped and balanced so that they are absolutely spot on before fitting them to their modified intake tubes to give more torque than the RS4 items.

So i take it that if I decide to go for K04, should get everything done in 1 go to realize full benefits.... I was hoping to initially get by with the turbos and maybe the fuel injector only...maybe not. Thx

I have not had the next stage with injectors and RS4 MAF etc. There is a lot of info on this Forum on reliability and the standard fuelling being on the limit with 400bhp. Having said that, AMD have carried out many conversions now and are are confident with this setup.
I can't honestly say that I use all of the power all of the time on the roads so mine is definitely not flat out! The injector conversion adds another 30bhp and costs GBP2,250 (I think). Ideally, if you were to decide on the fuelling as well, I think you would be better off having it done at the same time and then remapped to suit.
One of the great attractions to me about this conversion is that the characteristics of the engine are not changed from being very torquey and driveable - it's just there is so much more at all engine speeds.
Also, my car had 43.5K miles on it and K03's have a shorter lifespan than K04's and while the engine was out, K04's seemed a sensible route rather than changing the turbos in a years time. They have much bigger shafts, oil-lines etc and I will be keeping the car as my daily driver.
I think it unlikely that I will go for the fuelling mods and am definitely very pleased with what I have had done.
HTH, Simon

K04's, Tanoga, full Milltek, Forge DV's, H&R, Samco TBB&F!

[moktoya]

So Simon, let me try and see if i understand u correctly. U are running Stage 2 and K04s alone without any mods to the fuelling etc? If that's the case, i am ahead of you by a DP and behind you by a pair of K04s. So my question, should i decide to go with K04 only, is: what if there's no custom R/R session available? Would i run fine with my stage 1 MTM ECU? Also, do you know if MTM have programmes for K04 turbo alone, without fuelling mods......Thx

[S4RS4]

[/quote]
All of the conversion work was carried out by AMD and that's how much they charge. Scott also pointed out that they buy them in new and then have them stripped and balanced so that they are absolutely spot on before fitting them to their modified intake tubes to give more torque than the RS4 items.
[quote]
Why would they balance brand new turbo's that are balanced in the factory? How does this give more torque than the RS4 ones?

[snbS4]

So Simon, let me try and see if i understand u correctly. U are running Stage 2 and K04s alone without any mods to the fuelling etc? If that's the case, i am ahead of you by a DP and behind you by a pair of K04s. So my question, should i decide to go with K04 only, is: what if there's no custom R/R session available? Would i run fine with my stage 1 MTM ECU? Also, do you know if MTM have programmes for K04 turbo alone, without fuelling mods......Thx

I believe that I am indeed stage 2 without fuelling. I did have the Milltek downpipes fitted (to complement the cat-back system originally fitted) when the K04's were installed.
I must confess I have no experience of MTM actually themselves (other than a short drive in an MTM'd RS4) but would be very surprised if there was not a 'programme' to fully realise the potential if/when you have the K04's fitted.
I am not sure where you are located but do know that AMD have close links with MTM.
My main point is that the best time to have an R/R session is obviously after all of the kit you have chosen is installed. My understanding is that at AMD they start with a basic programme and then 'tweak' the final settings to suit the actual car. In this way they can 'fine tune' the performance to maximise the gains/potential. No two consecutive cars give identical power/torque graphs. Mine finished with 395.7bhp and 426 ft/lb torque.
You will notice that K04's pull much further into the rev range and the tailing off is not so pronounced over the K03's. It also comes in with much more of a wallop which is nice!
I think the MTM programme you have now will run with K04's but you will gain much more with a remap which I believe would be sensible to do at the same time. I would be surprised if AMD/MTM could not accommodate you. If you are intending to keep the car, their reliability is also a big plus.
HTH, Simon

K04's, Tanoga, full Milltek, Forge DV's, H&R, Samco TBB&F!

[snbS4]

Why would they balance brand new turbo's that are balanced in the factory? How does this give more torque than the RS4 ones?

I must confess to being a bit of sceptic when it comes to marketing differentiation but can see the logic in AMD buying mass produced turbos and sending them to a specialist to have them blueprinted. Not only should this make them more reliable by ensuring they meet exacting tolerances thus reducing the chance of failures meaning re-work by engine out under warranty by back-to-backing it with the specialist company but also where promised outputs are important then they should be able to squeeze a bit more out of them keeping the customer happy. If all you do is rebuild new turbos and your reputation depends on it, you have no excuses not to be good to stay in business for long!
Maybe the chances of failure are higher with certain types of car driver/enthusiastic owner? K04's are also used in other makes/models such as TT's, Bentleys and VW's which are probably not subjected to such high and continuous loads/strains. Track days etc may be more regular too!
Blueprinting is obviously an ideal but costly.
I did not intend to imply that blueprinting gave more torque (although it may through higher performance overall) but was referring to the alloy intake tubes fitted to the turbos. They have a smaller diameter than the RS4 items and the ends are enlarged to fit the larger impellor intake of the K04. Apparently the air speed along the tube is critical for low speed torque which the standard S4 has and (being cruel) the standard RS4 hasn't - I know even the std. RS4 is a different beast altogether and quite formidable!
HTH, Simon

K04's, Tanoga, full Milltek, Forge DV's, H&R, Samco TBB&F!

[Dippy]

AFAIK, blue printing does allow a turbo to give more torque, but you need to think about the WAY in which it produces that torque.

Most people think about peak figures all the time (as you do yourself Simon!), and this is misleading. To illustrate my point you car developed a peak of 426 lbft. My car developed a peak of 413 lbft and I have OEM K03 turbos!

You must always think about the torque curve. This is fundamentally driven by the boost curve (vs revs), which is determined by turbo efficiency. Blueprinting should allow the turbo to produce greater boost in some, if not all, parts of the range.

Of course someone correct me if I'm writing BS.

[moktoya]

I am not sure where you are located but do know that AMD have close links with MTM

Simon, I live a few thousand miles away in HK, and nobody here's 1/2 capable of doing custom ECU jobs due to a very limited install base. So all we are all left with is off-the-shelf stuff. I take your point of K04 pulling much stonger at the high end, as the RS4 I've driven felt like it had another turbo kicking in after ~4.5K; that's the main reason why i wanna go after the K04. Thx for your info anyway. Eric

[Verruckt]

If you want a turbo that pulls hard up top, please see the thread just below regarding other turbo options as well.