Which turbo for my Mk iv 1.8T

[prt57]

Hi,
I have a mk iv 1.8T with an agu engine and k03 turbo. I bought the car new in 1998 and at the moment 83500 miles are shown on the clock. It has a full VW service history.
Last year we had R-Tech remap the car to stage 1.
The output was only raised to 183 bhp but there was a massive increase in torque that produces a real shove in the back at approx 3000 rpm. This is like a spike and the chaps at R-Tech suggested that the turbo actuator was weak and so the headline bhp figures were lower than I was expecting. I know that I could have a forge actuator supplied and fitted for approx £250.

This morning, we went up to Midland VW to have an oil leak on my son's Mk V R32 investigated and so I got chatting about what to do about the weak actuator on the 1.8T. It was suggested that I look for a KO3S turbo from an Octavia VRS, a Leon Cupra (not R) or the later mk iv golfs with 180 bhp as standard and have that turbo fitted instead.
The fitting cost will be similar to the actuator as I understand the turbo has to come off to fit the actuator anyway.
Are there any other donor vehicles that have not been mentioned?

The big worry is that I do not want to buy something with play in the shaft or has a cracked housing and so it will not be worth fitting.

 I do not intend to start spending too much it may be foolish to spend lots of money on a 16 year old car in spite of the fact that you would struggle to find a car in better condition for it's age.

So what would you do and does anyone know of the whereabouts of a pre-used mint condition K03S or another turbo that will be a straight bolt on fit for my agu engine?

Thanks for your thoughts,
Peter

[mcgee9t2]

k03s turbos can be picked up cheep nower days, and iirc there is no difference between the k03s thats on the 180bhp golfs and the 150bhp golfs (some 150s had the k03 and some had the k03s) and the ibiza cupras i belive had k03s but i could be wrong.

best bet is to browse the forum clasifieds, pop up all the time in there.

[Kruga]

I have an AGU with K03, last weekend i picked up a K03S Hybrid

Look on ebay for k03s or ko3s sometimes people mispell it haha and while your at it get a forge actuator!

[Wazzzer]

The turbo you want can come from the AUM or AUQ engined Golfs, The Leon Cupra (also AUQ) Skoda Octavia (AUQ) or Audi A3 (AUM)

If you have a good condition K03 which has no signs of cracks in the housing then it's possible to swap your housing to a K03s should it have a crack. Balancing isn't necessary for the swap.

The only problem is unless you start to modify other parts of the engine such as the exhaust, possibly decat etc (and so begins the slippery slope) you will probably only see another 10-15bhp although it will change the way it delivers the power. Budget in another £150 odd for a new map along with parts to fit the turbo plus labour (if you don't want to do the job yourself, it's a bit of a pig) and you're already looking at around £600 for just 15bhp tops.

Not that I want to put you off modifying your car but if you don't want to spend a lot of money on it and get proper value for money maybe your best course of action would just be to get a new actuator. The turbo doesn't need to come off completely to fit a new one, just the manifold but the turbo will need to be dropped down. It can be left on the manifold to do this though

[prt57]

Thank you for your replies, most interesting and very helpful. Whilst it would be rewarding to get my golf running at the max I am keen to balance up power increase with cost. I also have an S3 2.0 L running at about 310 bhp and so that gives the high speed thrills. However, it would be good fun to give my old friend a new lease of life.
P.