Turbo Impeller Clearance

[Sowler]

I have few questions regarding turbos which are one my turbo CRX, I am no expert and I've tried googleing the answer to no avail.

I have two turbos. One was bought as supposedly as a ' Garrett Super 60' whether it is or not I have no idea. The other was an eBay special T3/T04E (I think)

Now the A/R specs of both turbos (housings?) are as follows:

Garrett
Inlet A/R 42
Exhaust A/R 63

eBay
Inlet A/R 50
Exhaust A/R 63

What the wheel trims are of either, I don't know.

Now I would really like to use the Garrett turbo as the spool on the eBay one is a little late for my likings and I am hoping, the smaller A/R of the Garrett will help this. However the clearance around the exhaust impellor on the Garrett seems rather large to me? But I am no expert. Thoughts.





eBay



Garrett



Regarding only one housing, the eBay one came with a 5 bolt exhaust housing, still a A/R 63 it fits exactly the same clearance wise etc as the 4 bolt one that came with the Garrett and my down pipe is 4 bolt. As you can see the Garrett is a little gapy IMO but whether this is a problem I don't know. The screwdriver is just gently placed in there as a size reference.

John

[stevieturbo]

So you're trying to fit a turbine housing to a turbo core/turbine wheel it was never intended for ?

And as you see it does not fit correctly ?

[Boosted LS1]

The blades should be as close to the housing as possible but not touching, otherwise air flow will most likely be crap. Imagine if your water pump had a massive clearance around the blades.

[Sowler]

stevieturbo said:

So you're trying to fit a turbine housing to a turbo core/turbine wheel it was never intended for ?

And as you see it does not fit correctly ?

The Garrett came (to me second hand) with the housing you see me putting on it! Ie the one with loads of gap.

Boosted LS1 said:

The blades should be as close to the housing as possible but not touching, otherwise air flow will most likely be crap. Imagine if your water pump had a massive clearance around the blades.

Yes I understand this, however what I don't know is what should the clearances be and what is normal.

[Boosted LS1]

Sowler said:

stevieturbo said:

So you're trying to fit a turbine housing to a turbo core/turbine wheel it was never intended for ?

And as you see it does not fit correctly ?

The Garrett came (to me second hand) with the housing you see me putting on it! Ie the one with loads of gap.

Boosted LS1 said:

The blades should be as close to the housing as possible but not touching, otherwise air flow will most likely be crap. Imagine if your water pump had a massive clearance around the blades.

Yes I understand this, however what I don't know is what should the clearances be and what is normal.

If you hold the shaft at both ends and check for radial movement the blades shouldn't touch the housing. Pull both ends together, push both together. The gap should be tiny. You will feel a smidgen of free movement which is normal.

[stevieturbo]

Sowler said:

Yes I understand this, however what I don't know is what should the clearances be and what is normal.

So you're saying the "Garrett" came to you as a complete turbocharger that had never been apart and with a huge gap around the turbine wheel ?

If so, you've been sold a lemon.