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Need wastegate help


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I have a T4/T4 60 trim available to me in great condition for a great price. But, I will need an external wastegate. What would be the best way to run one with the stock exhaust manifold?

 

Could I get by without one for a while with the factory pop-off valve on the intake manifold set at 8psi?

 

Could I use the housing with the internal wastegate on the factory turo and rebuild the other using it to have an internal wastegate?

 

Thanks. I am a little green on turbos with Z cars, and non industrial applications.

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I may have mis-read that but the auction looks to be t3 to t3, not t3 to t4 if the turbo he has, has a t4 flange. I think the application of that part is just for adding a wastegate using a t3 flanged turbo.

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Typo... I meant T3/T4 hybrid. Not T4/T4..

 

I think that space would work, but I would have to go to aftermarket boost hose and fittings. I can get that easy enough though.

 

Thanks.

 

Would I get by with the factory pop-off valve on the intake manifold being set at 8psi and no wastegate on a T3/T4? I should not get much boost creep, but the turbo would be going nuts... I might do it, drive it easy, see what happens. I will get the turbo Thursday, but the other parts would have to wait till I have the fundage.

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^^ I agree

 

1) The safety pop valve probably can't evacuate that much flow to keep the boost low enough

 

2) If you're using the factory EFI, then that is metered air escaping so you'll be running way rich in boost

 

Is the turbine housing just missing the internal wastegate housing, or does it have a 3" V-band flange?

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I wouldn't do it. You could rely on the pop-off valve in emergencies, but you would probably have to drive at no more than %50 throttle all the time. The wastegate lets quite a bit of air bypass, and I don't think the pop-off valve can match that, so you are still at risk of over-boosting. The pop-off valve works differently than the wastegate since it is on the intake track, not in the exhaust. And without a bypass in the exhaust you are still at risk of overspinning the turbo, overpressurizing the intake, and overboosting your motor.

Not the best situation. I would wait till you have the wastegate setup before putting the turbo on. Also, another option is having the exhaust manifold modified and having a flange welded on there for the wastegate.

This is an option, you can modify the stock exhaust manifold in several ways to fit a wastegate, like this:

lew56.jpg

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Well. I am missing the impeller nut... Going to take off my intake manifold tonight anyway to make sure there are no fragments in the intake, and do a leak down to make sure that I didn't already lose a valve. Although the engine ran great except for the butt plug of a seized turbo. lol

 

When I take the exhaust and intake off I will probably just go ahead and weld on an adapter for the wastegate. I don't really like welding on cast iron even when done properly. The changes in heat expansion between the two metal types normally will cause a crack after enough time. Seems cheaper than going the other route for now.

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^^ I agree

 

1) The safety pop valve probably can't evacuate that much flow to keep the boost low enough

 

2) If you're using the factory EFI, then that is metered air escaping so you'll be running way rich in boost

 

Is the turbine housing just missing the internal wastegate housing, or does it have a 3" V-band flange?

 

I blew my BOV off, yes off, at the track and drove home without one. Could still produce over 5psi of boost!!! Flow in wastegate and compressor side or totally differant. A 1.5" hole before the turbo in the manifold and there is pretty much no way you are going to build any boost. Same hole in the intake side and depending on the turbo you may still be able to boost the crap out of it.

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I blew my BOV off, yes off, at the track and drove home without one. Could still produce over 5psi of boost!!! Flow in wastegate and compressor side or totally differant. A 1.5" hole before the turbo in the manifold and there is pretty much no way you are going to build any boost. Same hole in the intake side and depending on the turbo you may still be able to boost the crap out of it.

 

That's really bad for your turbo, as it was probably overrevving since it had no pressure to keep the RPMs from building up.

 

I've seen the a similar spacer as posted used and works good. It's not the best way to route a wastegate, but it works. I believe the have T4 flanged ones as well.

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Ever seen a turbo with a malfunctioning wastegate? I don't know how high the one I had (GT35R) fail went (TiAL with a pinched diaphragm). My boost gauge reads to 2.5 bar and the needle stop was at about 2.9'ish. It pegged the stop on the peak hold. I knew it might be bad and let out of the throttle right away. Didn't save my rod bearings, though.

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FYI, blowoff valves don't technically have a rating. They aren't there to manage boost. BOV's use a spring assist along with boost pressure to stay shut. They'll typically hold 1.5X standard boost at a minimum. A good one wouldn't start leaking (READ: not open, just leak) at 40 psi. Your turbo will lunch your bearings way before that.

You definitely can't swap turbines from one turbo to another for the time being. Keep it apart until you get all the bits you need.

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WigenOut, it seems like cutting and welding cast iron would be a little troublesome. How did you go about it? Shop? What?

 

Thanks, and it looks great.

 

read this:

 

The Datsun exhaust manifold is not cast iron. It's cast steel, and welds beautifully with ER70S wire in the hands of a decent MIG welder.
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