Turbos - options.

[Jim Haseltine]

Judging from the prodigious quantities of oil accumulating in my intercooler hoses (approx 600mL in 4 weeks) and evidence inside the turbo outlet pipes I suspect that the seals in my turbos are no longer at their best. Not surprising as the car has now over 110K on it.
I can see I've got a number of choices:
1 rebuild mine - cons being a) their condition is unknown so it might not be possible and b) the length of time the engine will be out of the car
2 source and rebuild used units - cons being a) as above re condition and b) they aren't easy to find
3 new OE or similar units
4 some sort of upgrade
Choices 2, 3 & 4 have the slight edge of reducing the overall time for the job as I won't have to wait for the units to be rebuilt.

So: advice/options/opinions?

[IanH755]

Time wise, Turbo Dynamics said they can rebuild OEM turbos within a week when I asked back in late '15 or upgrade them for slightly better internals (costs a bit more) within the same time-frame.

Either way an upgrade will be a few weeks and cost around £1k minimum (OEM) to £5k (TTE's) just for the turbos and it'd be rare to find brand new turbos for under £5k.

[welwynnick]

Rebuilding turbos isn't as difficult or expensive as you might think.
The difficult bit is getting them in and out.
The core part of rebuilding is cleaning the burnt oil off, and oven cleaner can help with that.
However, while you're in there you should replace all the seals and bearings anyway, as they only cost a few tens of pounds for stock turbos.
Turbos don't have seals in the same sense as pumps do. They have what are described as "piston rings" on the shaft, and they stop high pressure exhaust gas from blowing by into the bearing chamber, and filling the crankcase.
Oil sealing is done by a thrower ring, but if the oil burns, it progressively fills up the drain until it reaches the level of the shaft, and then it leaks right out.
You need a puller for getting the compressor off, and a special torque wrench for the compressor bolt. That's usually low torque, reverse tightened and very critical.
The materials and the tolerances in there are amazing.
You have to take care to re-assemble correctly - there's nothing to stop you putting the bearing housing on upside-down, for example.
You don't usually have to have it re-balanced on re-assembly.

Regards, Nick

[Jim Haseltine]

With most turbo cars the turbo drains down when the engine isn't running because gravity pulls the oil down into the sump. On the RS the oil is sucked out by the rear section of the oil pump, but only when the engine is running so the turbos have quite a bit of oil when it isn't and that's the stuff that leaks out. And it's also leaking into the exhaust side of the housing judging from the short-lived James Bondesque clouds of blue smoke that I've had every 3-4 starts from cold this week.
I'll have go at most things but I'd rather leave turbo rebuilds to experts.
I'm in JCT600 tomorrow to collect some bits & pieces, I might have giggle and ask how much a pair of turbos would rush me.

[welwynnick]

OK, but remember the thing that needs rebuilding is the Centre Housing and Rotating Assembly (CHRA), and you can often buy them reconditioned quite economically.

It's quite likely that the RS6 shares it's CHRA with several other cars, so there should be a good supply if you can work it out. I'm not there yet.

Nick

[Jim Haseltine]

I'm in JCT600 tomorrow to collect some bits & pieces, I might have giggle and ask how much a pair of turbos would rush me.

For those who might be curious - a touch under 2.5K per side, although that does include a number of ancillary parts.

[Toady1]

Cheaper than a set of TTE850's, but what are the upgrades? just a 360 deg thrust bearing? Compressor wheels the same size?

[welwynnick]

Cheaper than a set of TTE850's,

Sadly you can't buy those any more - it has to be TTE1000's instead.

Nick

[Toady1]

So probably even more cheaper then!

[S4Player]

Cheaper than a set of TTE850's,

Sadly you can't buy those any more - it has to be TTE1000's instead.

Nick

Results from mines end of next week hopefully

[welwynnick]

Results from mines end of next week hopefully

Oh - I'm looking forward to hearing about that!

What's the rest of the spec?

Nick

[S4Player]

Results from mines end of next week hopefully

Oh - I'm looking forward to hearing about that!

What's the rest of the spec?

Nick

Loads, done pretty much everything I can other than build the engine. Dp’s +exhaust, upgraded intercoolers, upgraded injectors, modified air boxes, sportmile gearbox. Upgraded all the suspension and have full ceramics as well. Made 1000 odd ps on the 850’s so keen to see what these new turbos do

[Jim Haseltine]

short-lived James Bondesque clouds of blue smoke

Not so short lived tonight. Clouds of blue smoke until the fast idle ended then a lot more than I'd like to see for the next couple of minutes. Strangely, it was parked up for the same length of time (8 hours) overnight but there was next to nothing this morning.

[welwynnick]

Loads, done pretty much everything I can other than build the engine.
Dp’s +exhaust,
upgraded intercoolers,
upgraded injectors,
modified air boxes,
sportmile gearbox.
Upgraded all the suspension and have full ceramics as well.
Made 1000 odd ps on the 850’s so keen to see what these new turbos do

I should have results this week, unfortunately we had a hold up on the exhaust side of things.
I’ve went full 3.5” from the turbos back, I wanted to retain some level of quiet.
Opted for 5” silencers and the wrong size came, so we lost a couple of days waiting on new ones.
Exhaust is now finished and the car will be back at Mrc tomorrow for a week of testing and mapping.
As said TTEs rep suggests we should do 1000hp minimum especially with my spec.
My car ran 880ps and 1200nms on the 850’s on a mild map and 1008ps on race fuel. I’m hoping the new turbos do 1050+ps on 99 and upwards of 1150 on race.
I think the curve will move slightly to the right as it’s a bigger turbine wheel, I’m hoping we don’t lose too much spool as the 850’s were incredible in that sense.
Will post all findings good and bad throughout next week

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Cats are gone mate, dyno chart is on Mrc Facebook page I don’t have a copy on my phone. Car was stupidly fast on the 850’s, mid to top end was mind blowingly fast for such a big car

You won’t be able to release the full potential without doing the gearbox . Mrc are having a new dyno installed, dougs cleared a full two weeks to work on mines. The turbos aren’t doing what we expected hence there being delays with my figures, I’m also changing my exhaust spec to exactly what iainH has suggested. 3.5” into 3” with X pipe

Also seen someone mention torque, my car made 1440nms on the 850’s

1.45 bar mines peaked at and tapered to 1.3 on the tte 850’s

Running the marston intercoolers yes mate and aqua mist water meth kit with the biggest nozzles available. Hoping by the end of this month we will have the car done, I really wanna do vmax in it before I sell it

Now I remember - was it 1440 Nm on race fuel? You must have been peaking around 2 bar to get that.

1.45 bar peak boost on race fuel it was, yes selling to build a TT R8. Doesn’t bother me, someone will get an amazing c6 out of it. Plus my b5 is nearly finished, Mrs would leave me if I keep them all

Modified airboxes? Is yours the car with "vertical" cylindrical air filters sitting in the stock air boxes?

I remember reading about those, but I was never able to find the thread again. Do you have a link or a picture to whatever your car has?

Cheers, Nick

[welwynnick]

Not so short lived tonight. Clouds of blue smoke until the fast idle ended then a lot more than I'd like to see for the next couple of minutes. Strangely, it was parked up for the same length of time (8 hours) overnight but there was next to nothing this morning.

My Mondeo TDCI daily driver was doing the same thing. Only difference is it's not worth fixing, and is not long for this world.

One of the nice things about RS6's is that they do tend to get looked after properly.

Nick