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K14 Wastegate Question
by
jasonsansfleece
on 01 Jan, 2008 19:04
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So I'm preparing an Eco motor to put in an 85 na. This evening I pulled the exhaust manifold and turbo. The manifold to be drilled for an egt probe and the turbo for some wastegate attention.
I would like to get all the boost available (fuel will be supplied)
Is it enough to turn the WG adjusting screw in all the way and will this hold the WG closed?
How about the feed from the compressor to the WG? Can I control the WG by blocking/removing this line or is the adjustment screw enough.
I see some people put a boost control in this line but as I can expect no more than 20lbs boost I figure the right foot should supply all the control needed.
Whilst every thing is on the bench should I remove the WG and check the seating of the valve? Can it be lapped? I imagine a gas tight seal would be advantageous.
Anyway, any K14 advise appreciated.
And whilst we are at it, the nuts holding on the exhaust manifold are of a locking type. An reason why plain grade 8 replacements properly torqued would not suffice?
Thanks,
Guy
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#1
by
vanagonturbo
on 01 Jan, 2008 19:18
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Well, O dont have a K14 on my cars, but I do have a K24 on the rocco. I have the wastegate line disconnect and plugged on both ends. I also have the DV plugged. I get about 20psi on WOT. I know this doesnt directly answer your question but I hope it helps a bit.
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#2
by
BioDieselVW
on 04 Jan, 2008 15:20
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So I have a Eco Motor w/ a k14. If i screw the wastegate closed all the way screw in. It will make 20 psi boost. Is any one running this? If its adjusted in but not all the way will it increase boost also? Also 20 psi is safe correct. I do have a pp downpipe and intercooler and max fuel screw up. Thanks Paul
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#3
by
jasonsansfleece
on 04 Jan, 2008 19:46
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I've got the turbo in the vice and i'm working on the wastegate.
The three mounting screws are out ( well, one of them sheared off!)
The WG lifts up 3/8" or so then fetches up.
Through the 3/8" gap I can see the valve stem and it passes through what seems to be a thin hard steel disc.
I'm guessing the head of the valve is fetching up on this disc.
I resisted a strong urge to pry up against the WG body and came in to ask the proper way,
advise appreciated
Guy
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#4
by
jasonsansfleece
on 04 Jan, 2008 20:32
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Thank you Andrew, it's marinading in PBbuster overnight,
Guy
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#5
by
jimfoo
on 04 Jan, 2008 20:47
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Just out of curiosity, I thought max RPM's were important on a turbo, but no one seems to say anything about that when blocking off the wastegate. Why is that? Do EGT's climb quickly enough that heat will destroy it first if the operator doesn't let off?
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#6
by
burn_your_money
on 04 Jan, 2008 23:50
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I was just going to mention that Jim. You are going to wear the turbo out a lot faster the faster you make it spin (higher boost)
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#7
by
jasonsansfleece
on 05 Jan, 2008 09:54
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So the wastegate is out. The diaphram actuates and pumps air but the valve stem is bent.
The valve seat is corroded and looks the same as its surroundings. I doubt its held pressure in a while.
There is a rabbet in the base of the WG. For a gasket/O ring? There is nothing there now.
The valve is going to have to come out to be trued up or replaced ( can they be bought) and lapping into its seat. How?
There is a hex key socket in the head of the valve but it just turns it with out unscrewing. Am I to open the WG by uncrimping the cap? Is it possible to reclose it?
Guy