simon's learning what to do with the polo thread

[simon k]

yep, I have the manual - about the only thing it doesn't say to replace are the copper washers on the banjo bolts! I'll replace them anyway

Have you replaced the manifold-turbo bolts with high tensile cap screws or have you kept the originals?

I keep finding references to those bolts coming loose once they've been disturbed, and Eddy talking about welding them on, but can't find any pictures.

Do you have nordlocks on the turbo inlet AND outlet? (7 in total)

Is the 'high temperature paste' they talk about *just* copper anti-seize, or is it something special?

[sambb]

On exhaust mani to turbo I used 12.9 tensile cap heads. I chased the threads inside the turbo right through and ran much longer bolts. The VW ones go in only 1/3rd of the way possible. The bigger O.D nordlocks that are available (standard ones are too small) need to be used and I torqued mine up to 60Nm. I cut off a ball head allen key to make a bit to access those cap heads with a torque wrench and left the heat shield off so that I can check them easily at the track if the dreaded whistle sound starts. Its taken a hiding and has stayed firm. Just normal washers on the turbo exit. Yeah I used silver grade anti seize. Not sure if its the same thing.
Was it you that I sent the nordlocks to?

[simon k]

On exhaust mani to turbo I used 12.9 tensile cap heads. I chased the threads inside the turbo right through and ran much longer bolts. The VW ones go in only 1/3rd of the way possible. The bigger O.D nordlocks that are available (standard ones are too small) need to be used and I torqued mine up to 60Nm. I cut off a ball head allen key to make a bit to access those cap heads with a torque wrench and left the heat shield off so that I can check them easily at the track if the dreaded whistle sound starts. Its taken a hiding and has stayed firm. Just normal washers on the turbo exit. Yeah I used silver grade anti seize. Not sure if its the same thing.

gotcha... it's all apart now, the turbo is sitting on the driveshaft ready to drop down after I undo it tomorrow night. Does the driveshaft need to come all the way out?

I've left the water and oil inlet hoses attached like you said, but I reckon it'll be awkward to get it all down through the hole... we'll see

the turbo to manifold gasket is cracked in 2 places too, so maybe it wasn't going to be long before it was going to come out anyway

Was it you that I sent the nordlocks to?

YES YOU DID!!! I forgot all about them, they're in with the gasket set I got from Europe! legend, thanks very much (again I hope!)

[sambb]

The inlet hoses are on the top of the turbo and have to come off for you to get it out from memory. The steel hardline inlet that has a tall post that the bolt goes down through, the coolant one, is the one that stripped for me. Make sure you use a nice thin washer on it so you've got lots of threads engaged. That was part of the cause of mine stripping I think, that and dirty threads - stupid. Still ****s me that I did tha but it hasn't leaked yet!! The outlet lines are on the bottom of the core and can stay on I think and it'll save you re-gasketing those. I got my turbo out through the top cos I didn't want to remove the driveshaft, but yes the manual says to remove it and it would be a more straight forward job with it out of the way........assuming nothing goes wrong when you remove it!........which is why I left mine in. I put some anti seize between the faces of the nordlocks too.

[sambb]

Also if you use cap heads on the 3 mani to turbo bolts, if the gasket does go and assuming you make up a ball head drive bit and don't have the heat shield in the way , you can easily access the bolts, remove a torched gasket and replace it with another by sliding it in/out from the side. With hex heads and a heat shield you are a) basically screwed trying to get back there and b) having any chance of re torqueing them properly afterwards.

[simon k]

got it - thanks Sam - your advice is much appreciated.

I went to VW this morning and they'll have all of the nuts, washers, studs etc. ready for me tomorrow. I also ordered another manifold-turbo gasket

I'm with you on the cap screws, I'll definitely do that.

oh! you know what else!?! one of the 6mm bolts that go into the clamp for the turbo outlet pipe broke! little bastard...

[sambb]

I pray for your threads. Everything is just a little messed up by decades of heat back there hey.

[simon k]

quick update - I pushed on past bedtime and both studs are out. One came out with welding on a nut, the other still wouldn't budge (welds broke) so I drilled the guts out of it and unscrewed with vice grips. The thread in one of them isn't flash but should dress up OK

Turbo came out from the bottom - remove inner CV bolts, steering all the way to the left, undo balljoint and swing strut forward, driveshaft drops to the ground. My bony arms aren't strong enough to lift the turbo out from the top and wrangle it past whatever gets in the way

[sambb]

Good on you. Now you can get back to making actual progress on it.

[simon k]

thanks to a LOT of advice from Sam I've been driving around "Stage 2" for a few weeks now - very quick, smooth, and I reckon fuel economy has improved.. there is a little lean spike (only very slightly lean) in the logs that I'll try to clean up when I have spare brain cycles but otherwise I'm happy.

I ended up putting recoils in all 4 of the turbo stud holes, the threads for the two that had broken were too badly damaged to trust, and since I was recoiling those I figured I should do the others too.

You can also see here that the threads had pulled up a little bit - I usually oilstone any mounting faces like this, and the shiny spots are where it wasn't flat.


Here's a picture looking down my turbo - I gather it's not uncommon for turbos to crack like this and it'll probably last another 100,000km - is that right?

[sambb]

Good stuff Simon. I've looked down the guts of 3 of them and they were all worse than that so I wouldn't worry. There's a tonne of meat behind that spot too so that crack has to travel miles before it'd become a leak too.

[simon k]

Had a sprint at the local track today. They put me in one of the rookie groups, probably because they could trust me not to do anything too silly, but it was hard to get a clean lap in... but I was hoping to get under a minute which I did, taking 4 seconds off my previous time, down to tyres and more power.

My fastest lap was during the 2nd session, and the front-right tyre (A050) delaminated, massive pieces of tread ripped off it and a flat spot where it was down to the wire... oopsie. I assume I overheated it, it shouldn't have had much more than 30psi in it, but there was no tread left anyway. I had taken a pair of wheels with NT-01s on them just in case so put them on for the rest of the day but didn't get under 1:01 - they felt quite greasy.

The car still picks up its inside rear wheel way too much, they tell me its easily 8"... does that simply mean stiffer front springs required? current springs are 275lb/4.9kg

edit: no video, the gopro didn't work, SD card error

[sambb]

Shame about your deceased A050's. Good to know that even as they literally fall to pieces, they stick better than most other semis. Your 275lb front springs are about 220lb at the wheel which is pretty light duty compared to those rear springs and beefy rear bar you have. Did you ever get your rears spring rate tested? You still have a stock front bar yeah? You are running good front dampers so yeah I'd be thinking you need to go stiffer at the front. Whether or not that means more front bar or more front spring I'm not sure - I'd suspect you'd need a bit more front spring cos even with a heavier front bar the car will still be pitched forward at turn in more compared to if you had stiffer springs.

[Sydneykid]

I agree with Sam, I'd add around 75 lbs to the front spring rate, to around 350 lbs/inch (285 at the tyre) works pretty well with A050's.


Cheers
Gary

[simon k]

thanks guys

I've been told where I can get 2nd hand slicks for a good price, and given I'm in the same class as some cars that are basically out-and-out race cars on semi-slicks it doesn't really matter if I put myself into the race car class. I just want to go faster... is 350lb in the right ballpark for them too? does a stickier tyre require a stiffer spring?

Daughter took some really poor photos; this is a reasonably flat corner where the inside rear doesn't pick up as much as the big sweeper. I think it also shows that I do need more rear camber, something I've been putting off