Garrett GT20 Project

[306Puggy]

Did the cabin not fill up with fumes though? I think the angle might be too severe on the turbo for that, we'll see what the others think and then go from there. Thanks for the idea

Edit:

Decided since I had to clock the chra that I would remove the housings for a closer look at the chra. There is a load of grey gunk on the housings and chra, do I have to clean it off? I have squirted brake cleaner on it and it won't budge, I could use sandpaper but I don't want to make it uneven and cause it not to seal? Here is what I mean:

[306Puggy]

Just found this:

http://www.audi-sport.net/vb/a3-s3-sport...boost.html

Says to use a wire wheel on the housing, but doesn't mention the sealing surfaces? Don't really wanna bugger it up. I heard it is just to stop exhaust gases going to the compressor side but still? Edit: On the thread another person has mentioned dropping both housings in cleaner and leaving to soak. But what kind of cleaner? Caustic Soda? White Spirit? Coca-Cola? That seems like the safest option rather than scrubbing it with a metal brush

[Tom]

I'd just use some wet and dry if it bothers you like that, it will be fine left alone though.

[Piggy]

tbh it looks damn clean in there!

[306Puggy]

Okay well I will remove the crusty looking bits and leave the rest of it well alone as long as it is not gonna be an issue. Next thing I am gonna do is cut out the blanking plate for the recirculation valve and then drill and tap the hole in the mani for the EGT gauge. Most sensors are 1/8NPT, from what I have read it's about 8.5mm, obviously I will only get one shot at drilling the hole so I don't want to get the wrong size and junk the mani, can anyone confirm what size hole I need to drill to tap for a 1/8NPT sensor? Thanks.

[306Puggy]

Right, time for a major update! Decided to get my arse in gear and even though I had been told not to, clean the mating surfaces of the turbo:





They're not totally clean looking but they are nice and smooth. Still not sure of the reason not to do this? As long as you use a fine enough grade of sandpaper (>400) then I can't see how it could cause problems. Surely the carbon will just build up a natural seal if there are any leaks, on the exhaust side at least.

Next job on the list was to remove all the exhaust studs from the turbine exhaust housing:



This proved to be easier said than done. Using heat, candle wax and leverage I got two of the three out. The third one was a right bitch to do however. I got molegrips on and managed to get a tiny bit of movement in the stud. With that, I swung to build up momentum, a similar motion to using a ratchet in a confined space. With every swing it was turning the stud just a tiny bit.

Eventually I got it out, along with most of the thread. This is going to hold me up as I need to save up and buy a decent quality tap to tap a new thread now.

I also decided to drill some new holes for the adapter plate, so that I could put the turbo on straight. Now the adapter plate is wonky to compensate for the turbo mounting studs being wonky as a result of not having a straight flange to line up. A bit of a bodge I know but I have no choice!



Bloody thing looks ugly as anything now as well:



Hey at least the turbo is straight now!



Then decided to start work on the exhaust elbow adapter plate:



I decided to go for a 70mm/2 3/4th inch hole because I wanted to leave some leeway for error. Good thing I did decide to do that as well, not sure if it might be a tad too big still though? Reckon firegum might be able to seal it up?



The reason I haven't cut it in the middle was to reduce the amount of medal I will have to hack off to get it to fit.

Stupidly though I drilled holes for the blank off plate for the compressor housing in the plate that I was going to use for the exhaust elbow adapter. As it happens I didn't need to make a blank off plate for the compressor housing recirculation valve after all!

Find out why below:

This was my bodge to save money:

Thread a screw into the hole with threadlock and then use quick metal over the top of it:



Probably overkill, but there's no way that is gonna leak any boost!

Chuck some firegum on the comp housing and then stick the empty recirculation plate back on:



Lubricate the silicone seal with oil and then put it back onto the CHRA:



Then get the comp housing back on and it starts to look like a turbo again!

I had to cut a slot on the adapter plate to allow the wastegate arm to move freely. I am still not sure if there is enough clearance for the rod to move or not:



The arm has enough space but I won't know about the rod until I can get it all back together to mock it up. Well, that's it for now chaps! The amount of time and money I have put into this so far is astounding. Just hope it works when it goes on, but it all seems so far away! There are so many problems to sort out before it can get anywhere near ready to bolt on.

Next week I will order the taps and then I can get some progress on the exhaust elbow adapter plate.

[Dum-Dum]

good update mate. getting there

[306Puggy]

Right people, slight update and query:

I have got the studs in and the holes drilled for the exhaust elbow adapter plate. The hole size of 2 3/4 inches is near perfect, but there is a slight gap on all sides even though the metal plate has been pushed all the way down and the holes chiseled and sanded after drilling.

Here's how it looks from the top view:



Pretty even all the way around.

But this is the biggest part of the gap:



Sorry that pic is terrible, camera ran out. My plan is to simply gum it up with copious amounts of firegum which I am hoping will work, I know it's pretty epic stuff. Yes it is a big of a bodge but I don't know what is causing this gap, I cleaned the surface with 400 grit so a fine grade of paper and I used a piece of wood to keep it relatively flat.

Anyone had this problem with their builds? Edit: Just to remind people this gap is all the way around, I could gum it from both the inside and the outside as well.

[Jenkosowls]

Fire fuming a gap that big you'll have turbo off in a week do it properly first time see what the problem is

[Jonny81191]

It's resting on something then, find it and work out how to make the plate fit flush, you'd be kicking yourself if it didn't seal.

[martyn92]

Thats quite a big gap ! I dont think the paste would seal it tbh, its very brittle when it sets.
It may even be worth doing another plate? taking it apart again a week later to fix it wont be fun
Good work so far!

Btw what holesaw's have you got? looks like they did a really good job

[Jonny81191]

Martyn, any decent holesaw will do, even the ones designed for wood believe it or not! Just go slow and use plenty of lubrication (giggity)

[ginge191]

Start a thread as to what the issue could be? Let people guess with a limited amount of information, have a few arguments on the way, get banned then come back with a solution. That's the way, right?

[Piggy]

ginge.. stop winding him up.

my suggestion, and what I would do is, weld that plate on. then make another plate to bolt to it and weld to downpipe.

then you got two perfect flat surfaces to work with. find thr right size triangular gasket and it be proper job done

[306Puggy]

Good suggestion piggy. I hadn't thought of using a plate on a plate before. I think I will go with that, hopefully then I can get to the exciting stuff afterwards! Not sure on the gasket though, they seem really hard to find on eGay. Would it be possible to sand both surfaces smoothly to help them to seal without a gasket? Thanks.

[Piggy]

no.
need a gasket.
you want something like this
http://pages.ebay.com/link/?nav=item.vie...0816190423

but you will want to obviously measure between the studs on your turbo then find out what would match that.

to be honest mate, you do need to dig/search a bit more...I spent 10seconds on ebay to find that!

[306Puggy]

I have looked for gaskets on eGay before. Normally I put in "GT2052s exhaust gasket" and nothing comes up. I would never have though to look for a Rover one, not sure how you got the idea but good find anyway.

[Poodle]

Think laterally - it probably won't be labelled as a garrett gt2052s gasket, more likely to be a freelander turbo gasket, or whatever vehicle it originally came on.

[Tom]

Is the plate resting on the open wastegate?.. As per gaskets fuckem i just used firegum and nothing leaks on mine.

[Piggy]

I have looked for gaskets on eGay before. Normally I put in "GT2052s exhaust gasket" and nothing comes up. I would never have though to look for a Rover one, not sure how you got the idea but good find anyway.

I searched for turbo gasket. then start finding measurements

[306Puggy]

Right, turns out my welding guy is on holiday for a month, so I won't be able to get anything done involving welding. I have decided to crack on with the rest of the downpipe fabrication, everything that I can do without welding.

[Dum-Dum]

Not sure if im being an utter div or not but is that gap on a presurised part or is it the downpipe flange cos if its the downpipe flange you might get away with pasting it up especially if you use a large diameter down pipe (less system pressure)

Get a straight edge and work out why it isn't straight.

[306Puggy]

Right then, update time!

Subject: EGT Sensor

The exhaust manifold started life like this:



20 minutes later:





Concerns:

The EGT sensor is shrouded by the adapter and the adapter itself only barely makes it into the mani:

Sensor in adapter



Adapter in mani:



So yeah, didn't even realise about that problem, thought the temperature probe would stick out way more than it did. And I went for the middle of the mani because 1. it's the middle and I like even things; and 2. it was nice and thick which gives the adapter threads a lot of material to grip into and therefore it won't leak.

Oh yeah and although you are supposed to use a 10.5mm drill bit for an M12 thread I got away with using a 10mm it was harder to turn the tap but the threads went in a treat and the adapter threads in and tightens nicely.

But yeah, couldn't find a 1/8th NPT tap for love nor money so from searching the XUD section I found MattCheese31 asked the same question and someone suggested this adapter which was what I went for.

Assuming I get away with the EGT sensor, the next little bit I need to tackle is the wastegate bracket, which I have no idea how to do other than get an off cut of steel welded to the comp housing and then get the wastegate actuator welded to that, which I can't do until I can get the exhaust housing elbow adapter faceplate (let's call it that) welded onto the exhaust housing which I can't get done until the welding guy comes back next week!

[Piggy]

could get the egt adapter welded in...thats what I did

[Dum-Dum]

Id cut the adapter down on the hex bit ti get the probe further through it.

Oh there is 1/8 NPT taps on ebay relatively cheap. Shame really if you cant get the probe out in the gas flow cos that is pretty much the perfect place for it

[306Puggy]

Good idea Dum-Dum. I will get the clamp and hacksaw out and have a go. I did look into tapping a 1/8th NPT thread but I seem to remember I couldn't find a "straight" answer as to what drill size to use even though loads of threads on enthusiast type car forums came up.

Right, just gone and cut the adapter down, took about 60% off but then realised it wasn't threaded all the way down, now it looks like I will have to get that 1/8th NPT tap afterall Or just get it welded and waste the £6 odd quid that I spent on the poxy adapter? This is the kind of thing that ends up making these kinds of projects cost a fapping fortune!

Sorry if I missed it but is this turbo off a Saab? I am just waiting for my GT2052S (diesel derived) too come through the post

No it's not but it's off a Vauxhall which is owned by GM and it's off a Z20NET engine if that means anything to you? I have no idea how the serial numbers work or anything.

Edit: Umm, Dum, what did you type in to find those cheap 1/8th NPT taps on eGay? Because I have just searched "1/8th NPT tap" on eGay and the cheapest is about £15 if you include delivery from the US?

That's a lot of money wasted on one thing:

M12x1.5 taps: £9 quid
M12x1.5 to 1/8NPT adapter: £6 quid 84 p

£15 quid wasted on fitting the EGT gauge and counting!

[strictly_perv]

Sorry if I missed it but is this turbo off a Saab? I am just waiting for my GT2052S (diesel derived) too come through the post

[Poodle]

Slow down dude, don't run in hacking at stuff, just sit there and look at it for a bit first, this could have been avoided. Besides, look on the bright side - next time you need an m12x1.5 tap you're sorted.

That turbo will be from a vectra or zafira or something similar then, petrol turbo.

[strictly_perv]

Yeah they share the same engine I believe poodle

[Piggy]

£15 wasted fitting a custom turbo and egt....you can start moaning when its closer to £150!!!