Best turbo upgrade for mk4 gti

I was wondering what the next upgrade to a standard turbo for the mk4 gti would be? mine is the AGU Engine.. Also what car would i get this uprated turbo from? more boost for little cash?

Thanks
Dave

 

AGU has the KO3 turbo, so you can bolt on a KO3s with a remap and get an easy 220bhp, with anything up to 250bhp these days. Not sure how to get to 250bhp though, I never ran over 230bhp on mine.

To get a reliable 220/230bhp, you'll need a performance filter, upgraded TIP, decent dump valve and a decent exhaust.

If you want more than that, you can get a KO4, but then you need to change oil lines, inlet pipes, and other stuff. More expensive, but you should see a comfortable 270ish out of that.

 

redline mag, a few months ago, showed a cone filter lost 10bhp (or it might have been more) with they modded a TT

 

look into a ko4 setup from tt 225 or lcr 225 s3 225 etc

 

whats required with the k04 set up?

 

tip?

Wats a TIP?

 

Turbo inlet pipe iirc.

 

Correct. Runs from the airbox to the turbo.

 

consider your k03 being hybrided with k04 internals for 280bhp level.
also need larger injectors and larger maf tube to suit
Or
cheaper but less power slap a k03s on

 

K04's command silly money

 

I would either go K03S and get some little power, or go big...
I bought everything for the K04-023 (S3), and I feel I should have gone bigger
If I had to do it all again, I would go GT3071R

 

Cheers for that info guys. Im looking to get between 200 and 250 brake, at a decent price. the K03s is tempting me but looking for more info.
Is there any other bits i would need for the K03s setup, ive dun some search on here, but not found much,

My car is basically standard but has Forge 007 DV and a KnN airfilter.

 

Just to dispell any myths here, a dump valve will do nothing to increase the bhp - it's purely there to vent any charged air, to prevent the turbo from stalling when you lift off the throttle. The standard Bosch DVs are rubbish, so get a decent one like a Forge. They're about 90 from Forge.

If you've already got a K&N panel filter, throw it away - they make feck all difference.

As above, all you'll need is a K03S turbo and a decent remap. You'll pay anything from 300 to 600 for a remap - a lot depends on experience of the tuner plus whether they use a rolling road to apply and test the output of the engine once the remap's been applied.

Definitely get an uprated exhaust. Milltek is your best bet, although you'll find them more expensive than some of the low end market stuff. Expect to pay around 600 for a Milltek cat-back system and about the same again to get a Milltek high-flow 200 cpi catalytic converter (the standard cat is between 400 and 500 cpi (cells per inch).

With just the K03S, a remap and a Milltek cat-back, you should get around 220-230bhp. With the Milltek cat, you'll get up to 250bhp, but again, this all depends on who does your remap.

Depending on where in the UK you are, I can't recommend www.autops.co.uk in Brackley highly enough. They've done work on a lot of my old 1.8Ts with standard ECUs, my R32 and my S4.

HTH

 

Thanks for that, very informative, Will look into that.

 

hybrid..

i bought a k04 for 200
nothing silly about that

 

tha'd be a reasonable price, i've seen them for 500+

 

yours for 499

 

you get as 20bhp gain from a high flow cat??

 

k03s

I have recently done a k03s upgrade to my mk2 golf agu, the parts I needed were:-

Turbo: k03s, 90
Turbo intake pipe: mine came free with the turbo
Injectors, fuel rail: s3 225 bhp, 50
Piggy bank remap: free from qpeng

Most mappers say that you do not need to change in injectors for a k03s, because you can get away with just changing your fpr from 3 bar to 4 bar. But qpeng said that for their map I would have to change the injectors.

It is worth mentioning that agu's will handle up to 270ish bhp with standard con rods, I do not know from experience but rather from research.

For me, the k03s is a perfect upgrade because it kicks in earlier then my k03 did and the power upgrade is also very satisfactory (230 bhp it has been rolling roaded).

As mentioned on other posts, for a k03s upgrade you need: turbo, tip, 4 bar fpr and remap.
For a k04 upgrade you need: turbo, tip, injectors, new downpipe, oil/water lines (I think).

 

k03s hybrid only needs new TIP (forge) injectors MAF and remap for 280bhp, but would want supporting mods of fmic, downpipe, exhaust etc etc

if you already have those, then happy days