Turbo/exhaust

[Osd0212]

Evening all

The turbo actuator arm has snapped on my Mk5 gti (2005) I’ve been pondering on what to do. I’m torn between ko3 hybrid turbo and a full ko4 conversion. There’s a few things in not sure of. With ko3 hybrid is it just a straight remove and refit with no modifications to manifold? Could it be possible to send my turbo off for repair and the hybrid turbo mod? Or is it something I would just have to purchase as a unit.  I’m not sure what is involved with the ko4 conversion and was hoping for a bit of an insight! Does it include replacement of inter cooler etc?

My exhaust is also blowing, everything is standard atm and as things go wrong or require replacement I’m using that as an incentive to upgrade! I was just wondering if anyones got any suggestions for an exhaust system they rate highly!

I’ll also attach an image of my broken turbo actuator arm! I’ve seen it’s quite common, those who have the issue seem to have an ongoing problem with them!

Many thanks

Owen

[breeze]

Evening all

The turbo actuator arm has snapped on my Mk5 gti (2005) I’ve been pondering on what to do. I’m torn between ko3 hybrid turbo and a full ko4 conversion. There’s a few things in not sure of. With ko3 hybrid is it just a straight remove and refit with no modifications to manifold? Could it be possible to send my turbo off for repair and the hybrid turbo mod? Or is it something I would just have to purchase as a unit.  I’m not sure what is involved with the ko4 conversion and was hoping for a bit of an insight! Does it include replacement of inter cooler etc?

My exhaust is also blowing, everything is standard atm and as things go wrong or require replacement I’m using that as an incentive to upgrade! I was just wondering if anyones got any suggestions for an exhaust system they rate highly!

I’ll also attach an image of my broken turbo actuator arm! I’ve seen it’s quite common, those who have the issue seem to have an ongoing problem with them!

Many thanks

Owen

Do you have an overall power goal in mind? You can end up spending quite a bit of money upgrading the turbo and you’ll probably need a clutch too if manual. If you aren’t going to keep the car for long I’d think carefully about spend, because generally you won’t get it back.

If fitting parts yourself:
- Replacement K03 turbo (used) upwards of £150. Same power
- Replacement K04 turbo, piping etc and injectors (used) upwards of £1000 for parts and remap 310bhp / 310lbft ish. General safe limit is in the 350/350 range or a bit more for your engine, but that will require more parts.

To both of the above you can add supporting modifications and additional tuning. Costs climb quite significantly and obviously more if you are paying somebody else to do the work. Others will have numbers but I suspect a performance clutch is in the £1000-£1250 range fitted.

The basic K04 conversion doesn’t require anything other than the turbo, injectors, pipe work and tuning. No intercooler intake required. The problem is you may end up tuning more than once. Hence asking about your overall goal.

One option you have is a K04-lite upgrade. A K04 turbo and keeping your K03 injectors. Mallory Performance has a couple of YT videos where they do that. Obviously you would still need the tune. Mallory made similar figures to a full K04 conversion, however the injectors are obviously being worked harder and would need to be replaced if you wanted more.

To add, I believe a K03 hybrid would be a direct swap. On these cars the turbo and manifold are a single unit.

[bacillus]

I've got a used low mileage ko3 turbo with forge actuator that was removed from my car. I'm open to an offer.

[Osd0212]

@breeze

Thanks for your reply!

Im not too fussed about massive power gains if I’m honest! The cars done 140k miles and I’m thinking about offloading it within the next year. I paid £2800 for it a year ago and they’re going for around £4000/£4500 atm. I’ve contemplated so much! I’ve gone back and forth so much with selling it and then keeping it and just going all out on it! I wanted to get a lower mileage one ages ago but this one was in very good condition considering the miles. So yeah I’m not looking to gain so much power that it warrants clutch changes etc. I’m not sure what the boundaries for that would be? Maybe around 300bhp?

Im a mechanic for landrover aswell so I can do all of the work myself!

Many thanks

Owen

[LC5F]

Hybrid K03/04 tends to be straight swap without any mucking around finding the extra K04 parts, remove old and replace with the new.
You will need a remap, but you would also need to do that with K04 swap, consider bigger injectors and fuelling upgrades.

Advantage of Hybrid is also that it retains the K03 better spool up than K04 with not much difference in power.
Turbo Technics do a hybrid K03/04

[breeze]

@breeze

Thanks for your reply!

Im not too fussed about massive power gains if I’m honest! The cars done 140k miles and I’m thinking about offloading it within the next year. I paid £2800 for it a year ago and they’re going for around £4000/£4500 atm. I’ve contemplated so much! I’ve gone back and forth so much with selling it and then keeping it and just going all out on it! I wanted to get a lower mileage one ages ago but this one was in very good condition considering the miles. So yeah I’m not looking to gain so much power that it warrants clutch changes etc. I’m not sure what the boundaries for that would be? Maybe around 300bhp?

Im a mechanic for landrover aswell so I can do all of the work myself!

Many thanks

Owen

Must say if you are keeping it for a year, replacing with a good used K03 is sensible. It isn’t the power but the torque that kills a clutch. A stage 1 tune on a standard turbo will give a big boost but even that might polish off a worn clutch.

Torque jumps to around 300 lbft unless you go for a torque limited map. Last time I checked, Superchips had a lower torque map, but the thing is it is the torque that makes it so much fun. K03 runs out of puff at the top end but is can be strong in the mid range, which is great for a daily.