Hybrid turbocharger k04 build

further up is a picture saying 'modified rs6 ko4 to fit standard ko4 fitment'. is it not possible to fit the ko4 off an rs6? surely this is the simplest and best way as its larger hotside is better than any hybrid. after all, the only difference is the hotside.
 
superkarl said:
further up is a picture saying 'modified rs6 ko4 to fit standard ko4 fitment'. is it not possible to fit the ko4 off an rs6? surely this is the simplest and best way as its larger hotside is better than any hybrid. after all, the only difference is the hotside.
Click to expand...

In theory yes, but the fact is you can't buy exhaust housings on there own, not even the main rebuild companies can hence why they use copies( apparently) The only way to get an rs6 exhaust housing is to buy a complete unit and at €2000+ it's not really a good option!
 
Cant you just buy a second hand rs6 ko4 then rebuild that and fit?
 
audi upgrades
Not sure. Firstly they aren't common, secondly the are mounted differently on an rs6 thirdly they are hugely expensive, so really not a practical option. Anything is possible though.
 
So was karl just meaning why dont you use a rs6 ko4 exhaust housing and not the whole turbo?
 
To be fair I think he meant the whole turbo. I have no idea if it would work. I think and only a guess as the v6 they come from is longitudinally mounted like the a4 they might not bolt straight up, that's only a guess though. I'd be surprised if the fitted without a lot of work.
 
As you say anything is possible.
I just imagined what if. you could modify a complete rs6 turbo. I mean obv its mounted differently but the housings can be turned to an extent and flanges modified. It would be great if it were just as an affordable option as the conventional ko4 hybrid. It would just take it to that next level.
Obv that's in an ideal world.

What your doing is great, its good to know the extent of work turbo companies go to.
 
Yeah like chris said, stupid iphone mate lol, meant to click thanks lol.
 
The RS6 flanges are totally wrong for any 1.8T manifold.

It would work if you made a custom manifold for it, but i doubt theres any point in going to those lengths, you'd be better to spend the money on a "Big" Turbo.

They're also ludicrously expensive due to the RS tax. You'll pay £400 or more for completely ruined units requiring a full rebuild.
 
So a little Friday night update for anyone coming in from the pub!

I took the turbo's to the machine shop today to get the housings done. I use a small machine shop in Woking that I've used in the past for head skimming. Couple of old boys with what looks like a workshop from the bowels of the Titanic but they are very good. I had already got a quote from another shop and they wanted £120 a turbo for the work as they said it would be tricky! Needless to say the shop I went today are going to charge £20 a housing or £40 a turbo! I think this is a really good result as it means the price is being kept well within check.

As with all turbo's there is a required clearance between the housing and blades. This has to allow for heat expansion and centrifugal forces that might cause the blades to touch the housing. Also the clearance has to be tight enough to maximise the airflow and enough to minimise the contact possibility.

Having read Bills post he kindly put up on page 1 from seatcupra.net and measuring the original turbo I had (0.48mm) the clearance of 0.50mm has been decided on and the housing are going to be machined to this.

I hope Bill doesn't mind me quoting him but this is a bit he wrote on the other forum.
I make a call to CR to confirm whats deemed the correct/acceptable clearance.. 0.020", give or take 0.05" - which is 0.508mm clearance, plus or minus 0.127mm (min 0.381mm max 0.635mm) These are Barn Door Tolerances... and exceeded anyhow.
rolleyes.gif







Now the thing to bear in mind this clearance factor doesn't allow for the surge proctection afforded by some hybrid makers, and as I'm not using a cutback blade I have decided to take another approach. This is going to be a little bit of a trial but as this turbo is a project believe it's a good place to try this, who knows it may be good option. I have borrowed a design used in jet engines which smoothes air flow through a jet engine in order to prevent surge. The only thing I can't do is use Vanes and stators, which smooth the air flow making it more efficient but I can use a design which will allow increase airflow around the turbine blades at high pressure but wont reduce the clearance around the housing and turbine blades.

It will be easier to show the finished item than try to describe it so as soon as it's done I will post but it's a very simple modification.

In my quest to build this turbo I have come up with a few questions based on other hybrid builders specifications.

1st. It seems that most builders, in their specs, use a 360degree thrust bearing. This is sold in some cases as an upgrade. I don't really understand this as all BW K03/K04 turbos use a 360 thrust bearing as stock. Seems a little odd. Are there different types of 360degree thrust bearings?

2nd a lot is made of lightened shaft wheels, which are sold as a faster spooling turbo. My only problem with this is that while it may spool quicker it also spools down quicker and also doesn't have as much potential energy stored, which in my mind can only increase the likely hood of surge due having less energy to fight the compressor stall. It's much the same as having a lightened flywheel in your car, it's great for 0-60 but rubbish when you need that stored energy when you go up hills etc and preventing stalling.
As you can see from the photo below there is a good chuck of metal removed from the end of the turbine shaft compared with the RS6 shaft I posted on the 1st page.
photo-34.jpg


I hoping maybe someone can answer the questions above or at least offer some explanation to them, I am not critising any one elses design just curious. Appreciate the chances of getting answers is pretty small as it's all closely guarded!


As I'm making 2 turbo's up I have also been speaking to andyc-s3 with regards to him possibly using one of them in his car as another test bed, this will all depend on whether we can sort something out, but as I am still on the look out for a project car myself it may be a possibility

So how much has it cost me so far?

Well.. If we exclude the donor K04 as this can be one you already have or buy

RS6 turbine wheel, 2283 S3 compressor wheel, Full balance and full rebuild kit £270 delivered

Machining of both housings £40

Total so far £310

Obviously this is just the parts and doesn't include rebuild costs, but it's not bad considering you can spend more on low milage 2nd K04's!
 
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A stock RS6 turbo is nowhere near as potent as the one envisioned by the OP. The 2283 compressor wheel is a big leap forward. And the RS6 turbine wheel will work best NOT clipped. If you are worried about "surge"; don't. I know it's a bugaboo among us hybrid-ers, but I am pretty skeptical that it even exists.

FYI, here is a better video of the "surge"-like symptoms we're discussing. The fluttering sound audible at ~3800rpms is the suspect.



You'll note the video title references "surge". But I am almost certain the sound you're hearing is boost pressure burping past the DV piston. And that's a benign behavior. The air, already metered, is just recirculating.
 
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slappy_dunbar said:
A stock RS6 turbo is nowhere near as potent as the one envisioned by the OP. The 2283 compressor wheel is a big leap forward. And the RS6 turbine wheel will work best NOT clipped. If you are worried about "surge"; don't. I know it's a bugaboo among us hybrid-ers, but I am pretty skeptical that it even exists.

FYI, here is a better video of the "surge"-like symptoms we're discussing. The fluttering sound audible at ~3800rpms is the suspect.



You'll note the video title references "surge". But I am almost certain the sound you're hearing is boost pressure burping past the DV piston. And that's a benign behavior. The air, already metered, is just recirculating.
Click to expand...


Hi what is the spec of the F23 compared to the likes of turbo dynamics stage 4 hybrid and CR turbos ? are there any differences ?
 
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bench mark a level of spec first vs tune you intend to run it at.... before pre-judging what may occur surge wise perhaps.
Dougs DV experiment of eliminating the flutter we all considered was surge (and I do suspect some of this noise is surge) is significant. Changes the thoughts we all had on them.
nice read as usual
keep up the good work
 
****** iPads! Just spent 20 minutes typing an update and it deleted it..

Oh well

Thanks Bill I will bare that in mind and just go ahead with the build and see how things go with the surge if we get any.

So this is really an update for anyone with an A3 I picked up the k03s housings today from the machine shop. The turbine housing has been done to accommodate the k04-020 turbine, this was a little more tricky as it needed the excluder as well as inducer machine to allow the shell to fit. While I was there I got them to machine the k03s housing to fit a k04-020 compressor wheel (2275) but as I feared while it worked it has been done to an inch of its life and the metal on the outlet is, in my mind, just to thin! So plan is to stick with a k03s comp wheel and k04-020 turbine with the aim of 250bhp. Compared with the hybrid k04 this is a bit easier as its only one housing to machine. My next plan for the k03s is to mate a k04 comp housing with the outlet from the k03s so I can get the outlet around the manifold and use the stock header, in theory this will be a k04 as we have on the S3/TT so potentially 270bhp. In a complete ridiculous form you could then also fit the 2283 comp wheel I'm using in the k04 hybrid on this as well. I think that's for another rainy day... Run before you can walk springs to mind!

I have now got 3 hybrids being made up. 2 our mine and the 3rd I have an ASN member who is prepared just to buy the components off me and build the turbo himself, as he is confident in his abilities and wanted to experiment himself. One of the ones I have I will be using and am going to look at a cheap TT this week as my test bed and Andy-c is going to run the other one on his s3 at some stage.

So I am hoping by the end of this week/ early next week to have a unit to show and also a k03s hybrid as well, which all being well is to be fitted onto my brothers A3 in the new year. There will be some tweaking to be done before they can used, like the waste gate being ported but in essence they will be ready to go. I will also be posting the all in important how to rebuild the turbo very shortly as well.

I've literally just got an email from my supplier to say I have bought the last 3 compressor wheels in the uk so it's going to be a while before they get some more in.
 
Some photos of the machining, as well as a description of what actually needs done to make the wheels fit would be useful?

Good work so far though.

I'm toying with the idea of getting a complete K04-020 and fitting a machined out K03-005/029 turbine housing to it so it will fit a longitudinal engine...
 
aragorn said:
Some photos of the machining, as well as a description of what actually needs done to make the wheels fit would be useful?

Good work so far though.

I'm toying with the idea of getting a complete K04-020 and fitting a machined out K03-005/029 turbine housing to it so it will fit a longitudinal engine...
Click to expand...

You'd be better off buying new turbine/compressor, bearing housing and compressor housing and just machining your old exhaust housing.

It would work out not much more than buying a used k04 that has x amount of miles on it.

If you need any help with the parts or maching let me know,

I will get pictures of the machine work when I pick the housing up.
 
buying all new housings, shaft and compressor is surely going to get pricey, vs getting a complete K04-020 and giving it a new bearing, thrust washer, rings and seals?

I'd need the K04 compressor housing and backplate, turbine/shaft and compressor wheel, as well as a rebuild kit?

A quick google/ebay suggests the turbine/shaft alone is £100 for an RS6/Z20LEH item, and i've no idea if thats actually a decent one, or chocolate junk!
If i were going down that route, i could potentially use a "K06" 2277 wheel again from the Z20LEH, which again appears on ebay for ~£60 for one that may or may not be chocolate.

If i could pickup a complete K04-020 for £100ish, that would get me the housings, shaft and compressor and i could just rebuild it?
 
aragorn said:
buying all new housings, shaft and compressor is surely going to get pricey, vs getting a complete K04-020 and giving it a new bearing, thrust washer, rings and seals?

I'd need the K04 compressor housing and backplate, turbine/shaft and compressor wheel, as well as a rebuild kit?

A quick google/ebay suggests the turbine/shaft alone is £100 for an RS6/Z20LEH item, and i've no idea if thats actually a decent one, or chocolate junk!
If i were going down that route, i could potentially use a "K06" 2277 wheel again from the Z20LEH, which again appears on ebay for ~£60 for one that may or may not be chocolate.

If i could pickup a complete K04-020 for £100ish, that would get me the housings, shaft and compressor and i could just rebuild it?
Click to expand...

I would have to agree with you, and in theory you are correct.
My only problem is, and only from experience is that I have recently bought 3 £100 turbo's and non of them I would use the internals, mainly because they are all being sold because of oil leaks and damage. Now whether you get lucky and get one which isn't I don't know and if you do then you are correct it will work out considerably cheaper. You could for instance buy a K04 to use, and end up having to scrap the turbine wheel, bearing housing, backplate and compressor wheel as they're tat so you end up with a K04 compressor housing that's cost you £100 when you can by them for £25 at the moment new!

I admit it's always going to be more expensive but the reality is you are getting new, fully balanced parts. What's more expensive an extra £150 in turbo parts or £1000 on a new engine that's just eaten your turbo?

On another point, all these chocolate turbo parts, aren't actually that bad, what makes them bad is the complete lack of balancing and I mean lack of!!! Also original BW aren't that much more expensive if at all so not really that much point in buying chocolate parts.

Give me 24hrs and i'll put together a realistic price list for what you plan on doing.. Just to give you an idea.

Also If you want I have a collection of K04 turbines and compressor wheels that I've stripped from the turbo's so let me know if they'd be any good, I'm sure we can come to some arrangement.
 
Hi BB very intresting thread thats got my cogs working, so in regards to the k03s hybrid your are showing us A3 mob, you are basically mounting a k04 turbine to a k03s compressor turbine? Then sticking it back in the k03s housing? Have you had to machine the housing to accomodate the ko4 turbine? And how do you mate the two turbines together? I assure you that i have no clue what im goin on about lol but i think iv got my head round it if my questions make sense to you?lol.

Keep up the good work mate, looking forward to the how to and costing, and hopefully having ago myself :)
 
camscockle20vT said:
Hi BB very intresting thread thats got my cogs working, so in regards to the k03s hybrid your are showing us A3 mob, you are basically mounting a k04 turbine to a k03s compressor turbine? Then sticking it back in the k03s housing? Have you had to machine the housing to accomodate the ko4 turbine? And how do you mate the two turbines together? I assure you that i have no clue what im goin on about lol but i think iv got my head round it if my questions make sense to you?lol.

Keep up the good work mate, looking forward to the how to and costing, and hopefully having ago myself :)
Click to expand...

Yes, that's exactly what I'm doing. Yes, the k03s housing was machined to get the required clearances. They are mated exactly the same way a stock turbo parts are done, nothing special is required as all k03 and k04 turbos share the same shaft specifications with regards diameter and length. They just bolt together literally. The only thing that has to be done is to get the parts balanced to ensure they don't vibrate themselves to bits. This is vital to make the turbo last.

The good news is that in this spec the build is cheaper than the k04!

I hope that when I post the build it thread your see how it all comes together. I think it will answer a lot of questions people have.
 
beachbuggy said:
I would have to agree with you, and in theory you are correct.
My only problem is, and only from experience is that I have recently bought 3 £100 turbo's and non of them I would use the internals, mainly because they are all being sold because of oil leaks and damage. Now whether you get lucky and get one which isn't I don't know and if you do then you are correct it will work out considerably cheaper. You could for instance buy a K04 to use, and end up having to scrap the turbine wheel, bearing housing, backplate and compressor wheel as they're tat so you end up with a K04 compressor housing that's cost you £100 when you can by them for £25 at the moment new!

I admit it's always going to be more expensive but the reality is you are getting new, fully balanced parts. What's more expensive an extra £150 in turbo parts or £1000 on a new engine that's just eaten your turbo?

On another point, all these chocolate turbo parts, aren't actually that bad, what makes them bad is the complete lack of balancing and I mean lack of!!! Also original BW aren't that much more expensive if at all so not really that much point in buying chocolate parts.

Give me 24hrs and i'll put together a realistic price list for what you plan on doing.. Just to give you an idea.

Also If you want I have a collection of K04 turbines and compressor wheels that I've stripped from the turbo's so let me know if they'd be any good, I'm sure we can come to some arrangement.
Click to expand...

Wow didnt realise the compressor housings were so cheap!

Get me some prices and i'll have a think!
 
massive credit to what you are doing. as people have said this is great info so people know exactly what goes on and whats required to hopefully make your own reliable hybrid.

i would be very very tempted to try this. it would give a great sense of achievement to be able to say 'i put this turbo together to get my 300 or so hp', thats the main appeal for me. i like to give things ago myself.

obv you plan on putting a ko4 comp housing onto a ko3 comp housing, creating the ultimate ko3 hybrid i suppose.

but would you consider doing a ko4 hybrid comp housing onto a ko3 turbine housing, and would a rs6 turbine blade fit into a ko3 turbine housing?
is this what bill has done on his lupo, i havent had a chance to read his thread on SCN yet. but this is the impression i get.

many people have said that ko3 fitment and manifold flows better than ko4, so would this be the ultimate ko4 hybrid for performance and reliability?
 
superkarl said:
massive credit to what you are doing. as people have said this is great info so people know exactly what goes on and whats required to hopefully make your own reliable hybrid.

i would be very very tempted to try this. it would give a great sense of achievement to be able to say 'i put this turbo together to get my 300 or so hp', thats the main appeal for me. i like to give things ago myself.

obv you plan on putting a ko4 comp housing onto a ko3 comp housing, creating the ultimate ko3 hybrid i suppose.

but would you consider doing a ko4 hybrid comp housing onto a ko3 turbine housing, and would a rs6 turbine blade fit into a ko3 turbine housing?
is this what bill has done on his lupo, i havent had a chance to read his thread on SCN yet. but this is the impression i get.

many people have said that ko3 fitment and manifold flows better than ko4, so would this be the ultimate ko4 hybrid for performance and reliability?
Click to expand...

I've heard this also, that that k03 manifold certainly flows better than the K04 but I have no idea about the actual exhaust housing its self but if it did then potentially then yes you can fit the Rs6 turbine and 2283 compressor onto the K03 exhaust housing.

The K03s exhaust housing I've just got back has been machined for the K04 turbine and the Rs6 wheel is only 3mm bigger so in theory, providing there is enough material left then it can be done. But it is more than possible to run the rs6 compressor wheel on the stock K04 turbine and still get near if not over the 300bhp mark... If this is what Bill has done then brilliant it shows it's possible and worth working on..

Unfortuantely at the moment I don't have the time I wish I had to put into it, A 16 month baby and a full time job ( nothing to do with cars ) means I get to concentrate on this in my spare time, but having said that I've had so much interest, that I'm going to continue with as much as I can, in the hope we get some decent results and very viable turbo's..
 
if memory serves me right bills ko4/ko3 fitment hybrid has made 315 or there abouts on his lupo.
im sure he'l see this and contribute.

its just since i've been on here its always been said the ko3 fitment manifold flows better. and heat is a big factor in running a reliable ko4 hybrid. so perhaps us s3 drivers converting to ko3 fitment with ko4 hybrid comp housing and internals would be the most efficient hybrid set up.

we all really hope you can continue with this as much as you can. just tell your wife your onto something thats nobel prize worthy:) thatl work
 
beachbuggy said:
The K03s exhaust housing I've just got back has been machined for the K04 turbine and the Rs6 wheel is only 3mm bigger so in theory, providing there is enough material left then it can be done. But it is more than possible to run the rs6 compressor wheel on the stock K04 turbine and still get near if not over the 300bhp mark... If this is what Bill has done then brilliant it shows it's possible and worth working on..
Click to expand...

BadgerBill has a 2283/RS6 wheel combo on a hybrid K03 turbo being tested on his Lupo project. The 2075/K04 wheel combo was marketed last decade as a Eurospec E05. It stunk.
 
Cheers Slappy

I read the E05 had a weak turbine shaft that snapped is that what you mean by stunk? Looking here it has a eurospec impeller does that mean cheap!? and with advent of the E05b they used original BW stuff?

Here's a break down of what I found:


-k03
-k03sport = bigger cold side/k03 hot side
-k04/01 = k03 cold side/k04 hot side
-E05 = k03 cold side/k04 hot side w/eurospec impeller
-E05b = k03sport cold side/k04 hot side w/eurospec impeller & stronger shaft


The E05b is rated at 250bhp which is good power. So this is a good aiming point for me.

Rs6 turbines and the 2283 compressor wheels are also a good option that may be worth following up on for the k03s.
 
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aragorn said:
buying all new housings, shaft and compressor is surely going to get pricey, vs getting a complete K04-020 and giving it a new bearing, thrust washer, rings and seals?

I'd need the K04 compressor housing and backplate, turbine/shaft and compressor wheel, as well as a rebuild kit?

A quick google/ebay suggests the turbine/shaft alone is £100 for an RS6/Z20LEH item, and i've no idea if thats actually a decent one, or chocolate junk!
If i were going down that route, i could potentially use a "K06" 2277 wheel again from the Z20LEH, which again appears on ebay for ~£60 for one that may or may not be chocolate.

If i could pickup a complete K04-020 for £100ish, that would get me the housings, shaft and compressor and i could just rebuild it?
Click to expand...

I would just add: I have mapped a couple of VXR's running Z20LEH engine and they dont hold more thna 16psi boost after 5krpm maxing a max power (with all stage 3 bolt on VXR mods) of 270-275bhp - They run uber uber hot....
 
superkarl said:
but would you consider doing a ko4 hybrid comp housing onto a ko3 turbine housing, and would a rs6 turbine blade fit into a ko3 turbine housing?
is this what bill has done on his lupo, i havent had a chance to read his thread on SCN yet. but this is the impression i get.
Click to expand...

This is exactly what I have done many months ago on the lupo yes.
On it I decided to clip the turbine fearing surge as we see (thought we saw) on pukka k04 hybrids. No real change in spool because of it.
305-315bhp from 22-24psi boost on it.
 
badger5 said:
I would just add: I have mapped a couple of VXR's running Z20LEH engine and they dont hold more thna 16psi boost after 5krpm maxing a max power (with all stage 3 bolt on VXR mods) of 270-275bhp - They run uber uber hot....
Click to expand...

Thats pretty odd, but the Z20 cylinder head isnt the best flowing thing around, and they come with that manky exhaust manifold/turbine housing combined.

The turbine on the Z20LEH turbo is the same as the RS6 one that we're all familiar with, and the compressor is a 2277, ie a "k06" ETT wheel, thats a tiny bit larger than the standard S3 compressor wheel, albeit smaller than the 2283 used on the K04 hybrids. Given a stock S3 turbo will do 270ish absolutely maxed out, i'd imagine the slightly larger RS6 turbine and slightly bigger more modern compressor should mean a little more headroom.

I'd be limited by the A4 longitudinal turbine housing anyway, hence choosing the smaller 2277 wheel, the standard k03-005 has a 36mm! turbine exducer as standard, i'm not even sure theres enough metal in an 005 housing to take it out to use the RS6 turbine. I'd like to get my hands on a K04-015 housing to see how they compare.
 
beachbuggy said:
Cheers Slappy

I read the E05 had a weak turbine shaft that snapped is that what you mean by stunk? Looking here it has a eurospec impeller does that mean cheap!? and with advent of the E05b they used original BW stuff?
Click to expand...

That business about rotors snapping was baloney. My guess is one or two might have failed and suddenly the issue was judged to be chronic. I say it stunk because it was overpriced and underperformed. Retail on that thing was $3000. For a turbo that is only marginally better than an OEM K04-001? Nonsense.
 
$3000 Jesus! I knew it was expensive but ****** hell! No wonder it stunk...
 
Awesome work!!! Had to read a few bits two or three times to properly understand them, but it all pretty much sank in. Keep up the good work and updates. I'm looking forward to the next instalments!
 
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