Is my turbine and compressor wheels too small?

[rabbitman]

Ok, I've got a bunch of pics and measurement for ya'lls amusement.

Don't go by the dial reading seen in the pics, I just held it there so you'd see were I measured.
Everything is in inches.

Turbine housing: 1.45"

Turbine wheel: big side, 1.677"


As close to the tips as I could get: 1.282"


Compressor housing: 1.315"


Compressor wheel: Big side, 1.932"


Tip: 1.236"


By doing the math here the clearance between the turbine housing and fan: .084"

Compressor housing and fan clearance looks like: .0395".

The compressor blades all looked like somebody cleaned them with something too scratchy.

Both housings are very smooth and round.

Bearing is good and the oil I've been finding in the intake is also in the hose that goes filter to turbo so it must be from the breather rather than the turbo seals.

Thanks

[Rabbit on Roids]

wow, that thing is wasted. better go with a new center section.

[OM617]

Yes, that thing is junked.

[rabbitman]

  Well at least now I know what will fix it

[rabbitman]

I just measured a Euro VNT15 I have here and the housing measurements were the same as what you gave.  Your wheels are what is messed up.  Maybe someone can confirm that a US spec VNT15 is the same aside from the integral manifold.  If that is confirmed, then any decent VNT15 center section will cure your ills.

Thanks Andrew, that's what I was hoping was wrong.
I emailed prothe who sells both Euro and US vnt15 centers to find out what the difference is, here's his reply:

HI, the only difference is the location of the VNT actuator on the turbo cartridge housing.  Besides that they are identical.  The wastegate actuator has nuts to adjust it.  Have you tried adjusting them?  Pete

I hadn't yet told him this was on a rabbit. Anyways the lever is part of the center so I think I'll need a euro center or else the lever and the notch in the vane ring might not line up.

[rabbitman]

Well I ordered a center from prothe......payed yesterday and got an email this morning saying it's in the mail

I hope real bad that this'll fix it , I still have the non working one on the car and it is soooo gutless, cruising at 55-60mph gets me 650-900F EGTs. Top speed before I worry about the pistons is like 70 and not for very long . The EGTs used to be 450F at 55-60, and it had lots more power.

I'll let ya'll know what happens....(duh)

[rabbitman]

Here's what I bought: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=390061609253

I found in the ad where it says the part #, 128145702H so I "knew" it would fit.

Got it today and it looks pretty good, the wheels measure to what they should be, BUT......

It is not drilled for the alignment pins that the vane ring rides on, I could fix that, BUT......

In this picture of my old center, the blue diameter of the new one doesn't fit in the exhaust housing, the missing holes are circled in red.



So I'm thinkin' I could either grind away on it 'till it fits in the housing and mess around drilling holes, OR I could put the shaft, fans and bearing into my center piece, doing any of this will probably void the one year warranty.

What do yall think?

I really...really want to get it working today.... .or last month.....

[rabbitman]

Grinding it or swapping over the shaft would likely void any warranty.

How far off is the plate?  Those turbos spin VERY fast.  I'd be reluctant to remove the shaft as you will need to upset the balance of the unit...

Well, I would for sure mark the wheels before removal so the balance wouldn't be affected.

EDIT, got some better numbers,  The plate diameters are:
Old: 4.135"
New: 4.182"
Exhaust housing: 4.139"

Prothe's pictures show the plate without the pin holes so I don't know what he was planning for people to do about it.

It looks like my options are: 1: send it back, 2: void the warranty, then grind the plate and drill pin holes, 3: Void it and use the new wheels in my old center.

Waddya think?

[Rabbit on Roids]

i would just send it back and get a NORMAL vnt15 turbo center section from prothe. then if it works, let me know, cause i might be following your route.

[rabbitman]

That's a tough call as to what to do.  Drilling the holes for the pins shouldn't be difficult and certainly shouldn't void any warranty as they need to be there.  Any way to grid the exhaust housing larger instead of the center section?  That way if you ever need to replace the center section again in the future you wouldn't have to grind again.

Anyone have an integral manifold vnt-15 to measure?

I guess that's what I should've done is gring the housing and drill the holes, instead I swapped the internals over, fans, bearings and the compressor side plate so I could use the seal without disassembling the actual seal. The exhaust fan hit the housing just a bit so since the pins the center it go into the vane holder I had to move it some, the clearance is very small now both intake and exhaust.

i would just send it back and get a NORMAL vnt15 turbo center section from prothe. then if it works, let me know, cause i might be following your route.

A normal center won't work since the control lever in different locations, mine is on the side closest to the engine and normal ones are farthest from the engine.

Anyways I got it all put together and now I get maybe 4psi I am getting so sick of messing with this, I almost wish I'd left it NA.

So now I wonder if I need to check exhaust mani pressure to see if it's too low, isn't a 1:1 ratio of intake/exhaust manifold pressure ideal?
So if I'm only getting 4psi exhaust then 4psi is all I'd get on the intake side......I don't have any exhaust leaks, I have some after the turbo and it's black everywere the smoke touches.

The only thing I can think of is I need to close the vanes partway what else could it be? If air couldn't get to the turbo good enough would that cause a lack of boost? Like if my feed hose was kinking?

Feel free to input any ideas you got, I ran out long ago .

[Rabbit on Roids]

the turbo is not your problem, or your exhaust. you either have an epic boost leak, or your turbo is still way messed up. my turbo throws down lots of boost with the vanes wide open. or your valves may be adjusted way way too tight. or your fuel pump is turned down so far that it just simply cant operate the turbo. crank your fuel pump up till you adjust the idle with the max fuel screw. if you still cant get boost out of it, then there is something seriously wrong. oh yea, since you have a VNT, you could probably get 4psi exhaust pressure without a center section or turbine wheels in your turbo. i dont see how you get 4psi at wide ass open throttle. i get 4psi off idle. lol.

[rabbitman]

What are you using from air cleaner to compressor inlet.  Pics?

It's a piece of airoduct, you can kinda see it in this pic,

Here's some more,



In this pic you can see other stuff, drain, thermocouple and stuff.....


EDIT: Forgot some stuff. The airoduct is 2 1/8 dia silicone, it has wire wound inside it to prevent collapsing, I cut the wire out of it right where it connects to the turbo so it could neck down to the 1 11/16(?) turbo inlet.
The ugly tape around it is so it doesn't rub on anything and get a hole.

Does injection timing affect the turbo? Mine is slightly retarded, runs fine it just misses some on startup but clears up once it's ran for a minute.

My next plan was to put the TD intake mani on so I can use the controller, with this turbo the controller sticks above the turbo rather than straight down like the US spec VNTs, my gasser intake will interfere big time .

This is wearing me down........

[rabbitman]

Will it work to block off my turbo close to the outlet and put the boost gauge there to see if I'm somehow loosing flow/pressure? Thanks

[Rabbit on Roids]

no, it wont really work.
cause the turbo has nowhere for the boost to go, so it makes some boost, then surges until it can catch back up with its self. run a boost pipe from the turbo directly to the manifold. make it with hoses you know are good and have no holes in them. then run it again. you should have more than 4 psi.

[MouseGTD]

i was only getting 4psi on my old gtd engine, it turned out that the actuator wasn't bolted to the turbo so the exhaust valve thing in the turbo housing (can't think what its called) was just blowing wide open. not sure if this could help you in any way but it might be worth looking into to see if there's any issues with this.


also my pump timing was out a fair bit on that engine and i still got 18 psi with it.