Sam's build thread

[sambb]

Well mixed results on the turbo swap. Prick of a job if I'm to be honest but one of those things where you'd do it in half the time if you have to do it again ........... which I will soon. Everything was going great until I went to tighten the water inlet banjo tower fitting. New bolt, new washers, I'd cleaned out the thread at work with some brake cleaner and running a bolt through it. All looked good and no reason to suspect there'd be a problem. When I tighten critical bolts I've learnt from work to always step up bit by bit with the torque wrench just in case its been dropped or whatever so that you don't accidentally overtighten. The spec on the bolt is 35Nm and I was only 25Nm when I just felt the first smidge of the thread letting go. Before anyone says I threaded it (and if you do I will punch you through your screen) I didn't - there is no way you could cross thread that sucker with the tall banjo fitting and it was free as anything before it started to tighten. I remember when I pulled it out of my old engine that the washers used either side of the banjo were really thick. I think what might have happened is that when I first got the turbo done (paid for due to babies etc) these washers meant that too few threads were engaged and it was probably overtightened. So because there was still plenty of torque on there and new washers and the water line is braced to the block I went ahead and left it in there. Its not leaking but f&^*k me - all that effort and I cant feel excited about it because I'll just have no trust that its going to hold together. If it hasn't started to leak before Bathurst then I'll still take it but if it does I'll double drive my mates Clio. So I'm driving around in my ported K03s on a ported manifold with turbosmart wastegate actuator and the de-silencer compressor inlet. All that put together properly kicks the standard K03s by a long shot and has a real compressor surge flutter without the silencer on lift off and is generally a bit louder on the induction side of things. But now I immediately have to be thinking about the next step so that I'm ready to go when the first coolant drips appear.
So these are my options:

1. get the CHRA of the standard K03s I pulled out refurbed so that its ready to swap in when the time comes
2. buy a genuine K04-001 that will be plug and play and work with a straight flash or better yet a flash/pump/MAF/injectors. A K04-001 with no other hardware and a flash wouldn't beat what I have in there now but with injectors etc it still would I think.
3. go for a K03s/K04 hybrid with the above hardware but would then definitely have to sort a custom tune.
3. I've been told a GT2554 is mine to have if I choose so I could organise manifold, lines, exhaust adapter, TIP and induction pipes for that.

That's all ascending order of difficulty and $ but if anyone has applicable parts available that may help a decision to be made I'm keen to hear about it.

[sambb]

could anyone who has a genuine borg-warner K04-001 sitting around maybe give me the part numbers. GCG turbos cant quote on one without the manufacturer and borg warner placard part numbers (they have no idea what a K04 is)?

[sambb]

GT2554R specs are on this page:
Garrett GT25R - GT2554R - 60 TRIM - 270 HP ✈ Turbocharger Specs

[Stuwey]

I bought my K04 from ECS, search under mk4 Golf.

[simon k]

I remember when I pulled it out of my old engine that the washers used either side of the banjo were really thick. I think what might have happened is that when I first got the turbo done (paid for due to babies etc) these washers meant that too few threads were engaged and it was probably overtightened. So because there was still plenty of torque on there and new washers and the water line is braced to the block I went ahead and left it in there. Its not leaking but f&^*k me - all that effort and I cant feel excited about it because I'll just have no trust that its going to hold together. If it hasn't started to leak before Bathurst then I'll still take it but if it does I'll double drive my mates Clio.

I betcha the mob that did the work had normal washers in it, did it up too tight, damaged the thread and then decided the bolt was OK and put the thick washers in...

I'd be taking it apart again and running a tap into that thread with a new bolt, if you don't trust it now, you never will. Even if it doesn't leak

[Sydneykid]

GT2554R specs are on this page:
Garrett GT25R - GT2554R - 60 TRIM - 270 HP ✈ Turbocharger Specs

Something rare for me, I can't remember ever suggesting to anyone that their choice of turbo is a bit small. I'm normally the guy counselling on not going too big in the turbo. A pair of 2554's on a 2.6 litre Nissan (ie; 1.3 litres each) is a lag free, instant throttle combo, what I'd consider a good street car set up. For a combo road and track 2.6 litre a pair of 2560's leans a bit more towards track work but is still virtually lag free. One of those on a 1.8 litre would give around 300 bhp at ~1 bar of boost and have plenty enough throttle response. They are rated to 140,000 shaft rpm and at 300/1 bar shouldn't see more than 115,000 rpm, so plenty of durability scope. At 0.75 bar they still make 250'ish bhp at under 100,000 rpm, right in the middle of high 70%'s efficiency island. So not a lot of intercooler required.

Spending your money, right up with the best

Cheers
Gary

[sambb]

Simon K I think the problem now is that there's only 1 or 2 good threads at the bottom and a tap wont fix the ones above them. They werent threaded, they were pulled. I just paid 300 odd bucks to get that core re bearing'd and rebalaced too. An utter waste of $ and effort. I have another CHRA spare that I could put in its place , its more that now I'm not keen on going to all that effort all over again to put a 110,000km core in thats been oversped/tuned its whole life. Just kicking a can at the moment really but ill get over it. I could spend another 3-400 bucks on refurbing that too but at this stage that'll feel like dead money. Thats why if I'm going to double do it, I want something that I'll be happy with for the longterm but not too big to kill my cast conrod >100k km engine which is also why I'd not looked at a GT2860 but yeah I do suppose that from an efficiency/temperature point of view there's an advantage.
Its hard to go past a K0# turbo for bolt in convenience - its just which one? F21, K04, K03/K04. Short on dollars (al this years tyre money will have to go into this) which is why a K04 with the tune to go with it (+FPR) is a cheap easy way in and then later I can add the fuel pump, injectors 3in MAF, pre turbo WI injection and have scope for improvement. Anyone got a straight borg-warner K04 tune that doesn't cost APR money?

[simon k]

Simon K I think the problem now is that there's only 1 or 2 good threads at the bottom and a tap wont fix the ones above them. They werent threaded, they were pulled. I just paid 300 odd bucks to get that core re bearing'd and rebalaced too. An utter waste of $ and effort.

I see.... I guess you're not asking for solutions, but helicoil? tap it to the next thread size up?

though I don't even know where the 'water inlet tower banjo' bolt is, or what the metal is...

[sambb]

ha ha sorry didn't mean to sound gruff. No you're right though helicoil is an option. There's no room for a wider banjo so the question would be how much of the area under the washer would be taken away by the helicoil being under it and would that compromise the seal, and how to drill it without crap getting into the bearing journals.
What I'm actually thinking i'll do now is go for a turbo upgrade K04 'ish. Don't know where I'll find the money to do it first up but then i'll put the good (but 100,000km) core into the modified compressor and exhaust housings with a stock wastegate actuator and sell it. If there was a bit of interest I could get the un molested core refurbed so that it'd be a near new hotted up K03s that'll run on a stage 2/phase 2 tune but it'd be instantly more costly. That might help me recoup funds after the initial outlay.

anyone interested in a K03s:

compressor housing with de-silencer a la K04
exhaust housing ported out at the entry to the turbine and wastegate inc the wastegate tunnel
ceramic coated in and out exhaust housing.
option to have the core refurbed with fresh bearings and rebalanced
turbo to exhaust mani mounting surface linished flat
pics are a few pages back

On a stock 2.5in MAF it flows 190g/s which equates to about 240hp from what I've been told. Spools harder than a stock K03s but holds higher boost for longer so makes the 6000rpm part of the range usable rather than a waste of time. I've only ever used it with a ported stock manifold but it'd still be a good step up from a standard K03s even on a standard exhaust mani. Mani has to come off during the turbo swap though so while its out of the car its a good time to get that done too!!

[sambb]

Not a great looking turbo to exhaust mani gasket. Actually warped into an oval shape which suggests its moving around and split where they all seem to go.

Shows the throat of a standard K03s vs a ported K03s. The ported one on the right is devoid of the shrouding that runs around the top right edge and obscures the entrance to the wastegate tunnel (the pathway on the right). The standard one on the left is sporting a nasty crack that makes it pretty much a bin job too. You can also see where the gasket had cracked in the really thin spot. All in all I was going to have to do a turbo swap anyway since this one had had it, but luckily its core is in good nick without much freeplay.

first pic shows the gas guide that throws the gases from opposing sides downwards into the turbo. When I showed the aftermarket manifolds to my rainman fabricator mate he wasn't a fan because none of them had this feature. eg cylinders 1 and cylinder 4's gases would just shoot straight into each other from opposite sides of the collector with nothing to actually project them into the turbo. From what I've read if you want to port a mani the stocker is a good pic. It may not port out to the runner diameters you see in ATP's etc but they are reliable and don't crack as much as some aftermarket ones do and retain the gas guide in the collector. Mine was ported at 23,000km and at 108,000km is fresh as a daisy and crack free. My manifold is on the right though and shows how particularly cyl 3 has been opened up. In a stocker this runner is choked nearly to nothing.

[simon k]

ha ha sorry didn't mean to sound gruff. No you're right though helicoil is an option. There's no room for a wider banjo so the question would be how much of the area under the washer would be taken away by the helicoil being under it and would that compromise the seal, and how to drill it without crap getting into the bearing journals.

nah, you didn't sound gruff - I know what it's like when you've made up your mind about one thing, and people keep saying "but but but but" and you don't want to know about it...

however! helicoil wouldn't upset the seal, the amount of of material lost is negligible. Normally coat the drill with grease and run it slow, take it out often to clear the swarf. Do the same thing with the tap, coat it with grease and take it out often. If there's anything left in the hole when you're done it's easy to pick out with a bit of MIG wire

What's the upgraded turbo worth? I'm happy with the stock performance of my car, it's my daily and does a 70km round trip. Maintaining *reasonable* fuel economy is important so I don't think I'm going to do anything with tunes or upgrades any time soon. I know what you're talking about with the 6000rpm range though - it really does run out of puff over that... I've no idea where the limiter is, but it certainly doesn't drive like it wants to go bashing against it.

[Sydneykid]

I see.... I guess you're not asking for solutions, but helicoil?

I'm with Simon, I'd heli-coil it, but only if it is beyond liquid thread repair. Keeping in mind that water jacket bangos don't carry a lot of pressure, just a typical cooling systems 20 psi or so. As a result "a couple of threads" may well be enough. But just in case I'd look at something like Loctite Form-A-Thread, I've used it with great success a number of times. If I remember rightly it's now called Loctite PC3967.



Cheers
Gary

[sambb]

At work they were telling me that Loctite will cook and turn to powder in the turbo. Will that PC3967 work at turbo core temps? I'm starting to calm down now. I'm still going to explore all the costs of K04'ing (or the like) it but I think if I can just get to (and from!) Bathurst and if the car really does feel like a solid jump up on the track too, then I may look at a helicoiling it. Still stressing everywhere I drive - I was only at 20nm (of 35nm) when it let go so there's bugger all torque on there. Hopefully the fact that there's no movement whatsoever on that line/banjo will keep it good. Oh and out of interest - can you/would you Loctite a helicoil thread?

[Stuwey]

At work they were telling me that Loctite will cook and turn to powder in the turbo. Will that PC3967 work at turbo core temps?

Says it's good for 300*F, so probably not.

[sambb]

Alright alright I've properly calmed down now and have a bit of a last ditch plan. I have no idea where I could source one from but I'm going to try to hunt down a longer banjo bolt. Looking at the threads in the turbo I pulled off the car and looking at the length of the threads on the banjo bolt, there is nearly another 1/3 of unused threads inside the turbo core. I had a head fart before when I was in a bother and now that I think of it its a water jacket (not anything to do with the bearings) so I'll remove the exhaust manifold to reveal the top of the turbo, run a tap into the threads by hand just to clean it out like Simon K said, magnet any crap out that may have fallen in, and bung a longer banjo bolt in with some kind of paste (I'm sure there's something I can use) and the thinnest banjo washers I can find. That way I only need an exhaust to head gasket, exhaust to turbo gasket, a bit of coolant and not such a bad amount of time to achieve it - maybe even feasible to do it before Bathurst on march 3/4. Thanks all for talking me down.