If I was to change the turbo on my gti from a ko3 to a ko4 would I need anything else but the turbo and would this just go straight on. Would I be able to notice a difference in power or wouldn't it make much different I'm also thinking remap after turbo change if I keep my car. Thanks in advance
You need a diverter valve relocate kit as the dv is mounted onto the K03 but not onto the K04. Also, I don't know of anyone who tried mounting a K04 onto a K03 exhaust manifold, so you need some heads up where that is concerned. You would get a bit more power with just the turbo, but not more than a K03 with a remap, intake, and downpipe would net. The turbo alone will not compare to what you would net if/when you were to remap it, upgrade to the remaps accommodating S3 or RS4 injectors, and upgraded the rail hpfp. I believe you would also need to customize the remap if you only add the turbo as no one has a remap for just adding a K04 to the K03 configuration.
You cant bolt the K04 turbo onto a K03 manifold. Both the K03 and K04 turbos come ready made with their own manifold that a completely plug and play.
This is something I will be doing myself if i come back to a 2.0TFSI, which is looking like it might be a possibility. If you were to upgrade from a K03 to a K04 turbo onto a 2.0TFSI you are effectively making an Ed30 engine (different compression ratios and cams amongst other niff nav and trivia) but ultimately, if you bolt on a K04 turbo along with the injectors and DV relocatiion kit whilst running the stock exhaust, stock HPFP and stock intake, you will effectively have the same output, or as near as dammit, to a stage 1 Ed30.
To get a K03 TFSI to run at 280hp, you are looking at TBE, Intake, Intercooler, Discharge/Charge pipes, HPFP and a stage 2+ remap which will cost approx £3k if purchased new. Bear in mind thats the maximum safe output on that turbo and is running pretty aggressive to pull those figures.
If you just add the K04 Turbo, Injectors and small ancillaries you will be looking at 280-300Hp for approx £1.5-2k because the intercooler/TBE/intake/HPFP arent needed for that output and you will be running less boost and lower fueling etc.
Me personally, I would go
K04 turbo/injectors
Uprated HPFP,
OEM downpipe with pre-cat removed
Custom map from R-Tec ( or APR as they also offer this map). Thats should net 300-315hp IMO and from the outside listening or looking in, no one would even know you had done any of this (whichis kind of what my aim will be this time. Power and handling but in a pure stealth manner)
