ko4-015?

[boost-addict]

firstly, car is a a4 1.8t quattro sport 1999

has a ajl enigne, and its a shame it has a ko3 and not a ko3s

so am i right i saying the ko4-015 is a direct swap over to a k03?

ive decided for now a gt28r/s isnt going to be viable for me at the moment.

for which reasons do the other ko4's not fit?

as i have a tqs the fuel pump is good for 300bhp, but do i need injectors or are the stock ones good to?

fmic, decat and remap is a must, exhaust is 2.5 i believe so worth having a decat or leave stock cat?

i have searched but just nothing available to me that answers the question

 

[aragorn]

The k04-015 is overpriced for what it is. Its not that much larger.

The other K04's dont fit because the housings are a different shape. They're designed for transverse engined cars where the turbos mounted the other way round.

I'd suggest you get a hybrid built, either something like mine (s3 turbine, RS4 or 2.0TFSI compressor) squeezed into the stock housings.

Alternatively, if you want a bit more, then i think a complete K04-020 from an S3, with the turbine housing swapped for a machined out A4 part should work quite well. I dont think anyones actually tried it yet, but i cant see why it wouldnt work, and you know the turbos capable of 260-270ish.

Theres a bloke on the forum (beachbuggy) who built a few pretty cheaply for people on here, so might be worth giving him a PM.

As for other mods, it really depends what you want to do going forward. You can spend a lot of money on K03/K04 specific parts like downpipe/manifold which will help you to get the most out of the hybrid turbo, but will end up in the bin should you upgrade to a GT28 later. An FMIC is fairly universal obviously.

Injectors are a must, the stock ones will barely flow enough for 220hp. You'll also need a bigger MAF if you plan to exceed 230hp.

If if were mine, minimising wasted money and maximising performance for minimal spend, i'd do something like this:

Used K04-020, with an A4 K03 turbine housing modified to fit.
3" downpipe from turbo to 200cell cat, 2.5" system from there
FMIC
larger injectors (SAAB reds will probably do, they're 350cc vs the 220cc of the originals)
3" MAF housing
Ported standard exhaust manifold
Custom map from someone like R-Tech who knows these older ECU's well.

Probably talking not much change from £1500 to do all of that, if you shop around and get cheap bits etc.

If you wanted to spend a bit more, then you could rebuild the K04 or even hybridise it with a 2280 wheel or similar, add a large bore aftermarket manifold, and if your very lucky you might see 280hp.

 

[boost-addict]

sounds good. can i use a 023, if im right by what ive read it fits right on with only the housing needing spinning round 90 degree.

also as per 3" maf i found a alloy maf housing which was 3" would that work or best to stick to a vr6 maf with my sensor

 

[aragorn]

023 can be used in place of the 020, but neither of them fit as they come, flange is totally different orientation. You will need to use the K03 turbine housing, machined out to fit the K04 turbine.

 

[boost-addict]

so you cant spin the housing to suit?

 

[aragorn]

the flange where it bolts to the manifold is different, so no, its not possible to turn or tweak or manipulate the existing housing, the only way would be to fit the turbine housing from the A4 K03 turbo, and doing that requires the A4 housing to be machined out to take the larger turbine.

 

[boost-addict]

yer i read that mate, im just trying to figure out why others say the 023 is direct fit to a a4 1,8t.

is there a k04 thatll fit with minimal hassle. for the time being i dont have loads of cash,
things ill consider,
go bt and build the parts up, problem with that is if any thing happens to the car or something changes then im stuck with a part built kit.
or try to find a k04-015 or other wise thatll fit and use with the map i have, as im peaking 18psi though 3k to 12/13 at 5k

i know it proberly dosnt make sence to do it that way but for now i wanted to know which k04 fits to manifold and decat/cat

 

[aragorn]

The only K04 that will bolt directly on, is the -015. Problem is they're rare, i've never seen one come up second hand in years and they're over a grand new.

Your cheapest option will either be hybridising a K03, or using a K04-02x like i described above with an appropriately modified turbine housing.

I suggest you give beachbuggy a PM, as he has already done the mods required to fit the K04-02x to an A4, and he should be able to let you know the costs. As a rough guide though, you should be able to put a budget hybrid together for around 3-400quid.

Also, realise that keeping your existing map will mean that you wont see any extra power, as the M3.8 ECU is governed entirely by mass air flow. Fit a larger turbo and it will simply turn down the boost so you have the same airflow as you do at the moment. My hybrid is on a standard map and peaks 12psi and quickly drops to 10, tapering down to 8psi, and the peak airflow and power figures are exactly the same as they were on the stock K03 turbo.

 

[boost-addict]

ok i see, yer ill give him a pm, so because i think im dumb which k04 would i be on the look out for to start with?
you said 02x which one specificity?

 

[Lee Goodall]

Are you tuning to suit your new setup? If not then as Aragorn said you won't see any realistic gains.

I would build the parts up for your ideal build over time or you'll never be happy with the outcome; that way you'll only need to pay for one custom map too which could save you £600 or more.

 

[aragorn]

020 022 and 023 are all much the same turbo, as fitted to the TT225/S3/Leon CupraR, any of them would do as a basis.

 

[boost-addict]

ok so decided to go hybrid (i think) i dont need a massive turbo and want some thing over stock/chipped/remapped on the k03

ok so shortly after making a list for a k04 hybrid or gt28rs/t3 i lost my job, so im now part time with overtime so now defently going k04 hybrid route.

so sorry its been a while but was a massive set back in june when i get sacked!


so seen this turbos

belive tihs is a 020? or 020 varriant as its from the 225 tt states 06a



Audi TT MK1 225 Turbo K04 06A 145 704M or 020BG5010527 k04 Turbo APX | eBay


then 350cc injectors, was im i right by saying the a4 quattro sport model has a 4bar pump already?
BOSCH Green Giant Fuel Injectors 0280155968 audi A4 S3,k04,leon,skoda,vw,r32,S4 | eBay

can get 3" maf from s3 or v6 golf.

will get a atp manifold or just port this one,

going 200cell cat, or maybe even the 3" decat pipe i have. to 3" downpipe which i have got ready to make. then 2.5" back to a single straight though rear box, again i have the rear box in a 2.25" form and can fabriacate my own exhaust as have mig, plus mate has tig for the downpipe,
any way am going to use the shell of the rear box as its s/s put in a 2.5" perforated tube and need glass pack. not sure how much to use but will have to be a guess for the first time, can open back uyp and put more or less depending how loud/quite it becomes

then all pipes fmic are easy to do,

so if i go for that k04, ill then buy a k03 so i can continue to use my car/turbo right up untill i swap it all over

would any machine shop be able to machine the k03 hot side to fit? and what tolerances do i need to stick to? just so i can relay this to the machine shop.

 

[Broken Byzan]

Turbo won't fit, it's for a transverse engined car

 

[aragorn]

If you get it cheap enough, you could fit the CHRA to a bored out K03 turbine housing though...

 

[Broken Byzan]

If you get it cheap enough, you could fit the CHRA to a bored out K03 turbine housing though...

True, he has stated he wants to be able to swap it in when the time comes, so that assumes its a direct fit which it isn't

 

[aragorn]

Aye. Certainly not a bolt on.

 

[boost-addict]

Aye. Certainly not a bolt on.

I'm confussed because i thought by having the k03 hot side machined to fit the k04 turbine then this allows The hybrid to fitted back in stock location. Isn't that's what you said further up the page aragorn

 

[aragorn]

yeh, if you get a A4 K03 housing and have it machined, the TT K04 will fit.

Speak to beachbuggy about the machining, he did mine.

 

[boost-addict]

Thanks yer that's what I mean. Ok I'll get on to him. Any tying else other then remap or even a 225 tuned chip?

 

[aragorn]

225 ECU's are completely different.

You'll need to find someone that can properly tune the older ECU's in these cars. RTech and i believe Unicorn can do this for instance but a lot of tuners cant.

 

[jcb]

can they do DBC ECU's?

 

[aragorn]

Yep RTech have done many M3.8 ECU's like the ones in our car. A quick browse of the A3 section will find you quite a few folk who've used them for tuning over the recent months.

 

[boost-addict]

Yer that's a problem I noticed the ecu that's attached to the all and other such engines are hard to tune. But if I go k04 surely rtech will have enough info on that front due to Audi tt and cupra r's So running 310cc injectors. K04 and exhaust work what figures are to be expected?Also can you tell me if the quarto sport models came with the s4 pump? Also while I'm acumilatig a list is there any thing else to stick in other then a forge 007 and fmic? Do larger tb's make a diffence? Cheers

 

[HibiscusS4]

Can you do the same with S4 Turbos? I have seen hybrid units with K03 hot sides and RS4 compressors but they need a new inlet pipt to be compatible. Could I manufacture a pair of hybrid turbo's from my stock S4 units using TT225/s3 internals or is it not worth it.

I have been looking at the Frankenturbos but $1200 plus duty for Chinees copies worries me. I only plan on pulling the motor once so I want to fit something thats going to work and I dont plan on putting it back in with the standard units as they have covered 140k+.

 

[aragorn]

The issue with the S4 turbos is the compressor housing inlet is very small, a lot smaller than even the tiny 1.8T item.

To get any decent sized internals in there, you need to use the K04 compressor housing, which are rare and hard to get hold of, and ofcourse need the inlet pipe changing.

You can build a mild hybrid using standard S4 housings, but its not that much better than stock, allowing maybe 380hp maxed out rather than 350.

 

[boost-addict]

so on my front im still after a k04-02x

oh also does the waste gate on the k03 hot side need changing or does it flow well enough?