KO4 would need relocation of DV + new discharge pipe but theoretically it should work as long as you limit the boost, but then you wouldn't be running K04 specific software so it wont try and hold the boost for that long anyway.
....Surely fitting a K04 without the rest of the package would result in turbo lag. It's swings vs roundabouts (assuming you know the expression).
On a standard car, maybe. Comparing a standard K03 to a standard K04, then the K03 can provide peak boost from about 1750rpms, whereas the K04 peaks from around 2250rpms. But with a remap, you should be able to negate some of the lag.
....As I think any of us performance freaks here would be likely to do, I have considered the K04 option but it doesn't make sense unless I take the whole package of injectors, fuel pump, S3 intercooler, Revo2+ remap etc. Most of these components are VAG oem but the result on my GTI would be about 300 neddies at my front wheels. Yes, I love driving and I love the opportunity to drive very enthusiastically when I consider it safe, but I'm 61yo and not 18 and my balance of power, suspension, brakes, etc with Revo2 (probably around 250 bhp) feels perfect for me, personally. It's a feckin sweet ride!!
As Kev at Revo says, you have to draw your own line in the sand and decide what is enough. Otherwise it's never ending.
Coincidentally, Kev also knows the car my replacement turbo has come off and said that the owner had decided to do the K04 conversion immediately. Kev, like JKM, and TT here, would very strongly advise against a used turbo but this one is virtually only run-in, and knowing the car, can be recommended. The risk is very small indeed.
Need I remind anyone that the whole package costs £4K.
Where does the £4k come from?
....It's the "Basic K04 Upgrade" -
http://www.jkm.org.uk/performance/jkmtfsi-K04-upgrade.htmActually, because I already have Revo Stage2 I now realise it would cost me £3,355 inc vat. So less than £4,000 - I was mistaken. But if my K03 turbo transplant is successful on Friday it will be likely to have cost me around £800 including previous diagnostics/checks etc. But the bottom line is that I really don't want 300 bhp or to spend about £3.5K + £1.5K suspension + Monza powdercoating = £5.5K on top of what (don't ask!!!!) I've already spent on my car. I have to draw the line somewhere.
Besides, I wanna upgrade my big desktop Mac system and buy my daughter a MacBook Pro laptop for Uni.