Vnt-15 installation, slowly but surely.....almost

[rabbitman]

Wow I am sick of this, not a bit of change.

I started it and the idle was a little low so I used the max fuel screw to bump it up a bit.
When I drove it there was maaybe a half pound increase in boost and the egt hit 1250F easy, I think the extra boost and higher egt are from turning the fuel up that little bit. There's just a touch of smoke.

Before running it I checked to make sure my braze sealed it and it did, I also put ultra copper on all the gasket surfaces so I doubt they're leaky.

The turbo sounds good, at idle with the vanes opened I get a loud whistle

[Rabbit on Roids]

yea, but do you get 25+ psi like your supposed to?

[rabbitman]

yea, but do you get 25+ psi like your supposed to?

haha......I think I hit 4psi My egt probe was leaking a tiny bit so I fixed that too and now I'm messin' around trying to think of every possible thing that could mess up my boost so bad.........

[Rabbit on Roids]

ya know andrew, i was thinking the same thing. thats the only other thing i can think of.

[rabbitman]

I know you got a new center section but perhaps it does not fit your housing properly.

Could be, that would stink though since I paid almost 300$ with shipping. The turbine wheel does go into the housing far enough.....come to think of it I actually put the new wheels into my old center so the spacing "should" be right.

The other thing I'll fix first is the compressor intake hose, I think it could be pinching off and resticting airflow. I welded up an elbow yesterday but haven't installed it yet......

[Rabbit on Roids]

who knows if those wheels were made to go in a garrett center section tho. thats a chinese center you bought and it could have completely different dimensions.

[rabbitman]

I know you got a new center section but perhaps it does not fit your housing properly.

As near as I can tell by looking through the compressor inlet and turbine outlet it looks good, of course I can't see the larger diameter of the wheels though.

The other thing I'll fix first is the compressor intake hose, I think it could be pinching off and resticting airflow.

Well a few days ago I welded up an elbow for the compressor inlet and while I was installing it I discovered the airbox had about a pint of dog food in it . Dumb mouses. I had noticed an increase in egt about a week before that, it's only been a month or so since I've had the airbox out so it hasn't been full for long.

When I drove it, I was once again sorely disappointed 5-6psi, a slight increase.

It's weird, if I floor it the boost rises to 5ish and then kinda drops off at like 4200rpm (governor?) but the egt keeps going up . I get very little smoke in the upper rpm range.

I advanced the static timing 'till it rattles a bit but it didn't help at all

who knows if those wheels were made to go in a garrett center section tho. thats a chinese center you bought and it could have completely different dimensions.

It's advertised as a replacement for the stock center.

[Rabbit on Roids]

you already messed it up or took it apart or something didnt you? i cant remember what you did to it, didnt it not fit? i would never buy another turbo from prothe.

[rabbitman]

I just put the wheels from the new center into my old center and they fit perfect, no end to end or side to side play.
Prothe's center wouldn't fit without enlarging my exhaust housing and drilling the three alignment pin holes in the center section.

[Rabbit on Roids]

then appearently his center section isnt a direct bolt in piece like he claims. i would have mailed that thing right back to him. i want a VNT to fit and work right. whole reason i got a VNT. otherwise i would just K24 it.

[rabbitman]

then appearently his center section isnt a direct bolt in piece like he claims. i would have mailed that thing right back to him. i want a VNT to fit and work right. whole reason i got a VNT. otherwise i would just K24 it.

Now of course I wish I had sent it back since it didn't fix anything .

Last night I closed the vanes a little bit and at full power I can get 10psi and the egt max was about 1100F instead of 1250 @ 5psi, still not much power. I feel like scrapping this turbo and getting a k14(?) since I mainly want low end/midrange boost.

[rabbitman]

Well I turned the fuel all the way up and can get 12-13psi, very little smoke once the boost comes up, the egt still gets to 1250F easily . The vanes are just a little bit towards closed.

Today I was in a hurry so I cruised at 78-83mph for about 15 miles , the boost hung at 4psi and the egt was at 900-950F.

The power is MUCH better, I can actually feel the boost kick in . There's a hill here that starts at a T in the road so it's a good test. Back when I was NA I would be going 58-60mph at the top, now I can get up to 70mph without flooring it the whole way, (because of high egt).

This turbo is really confusing, I'm starting to think that the vanes open more on the euro vnt that a US spec one . Maybe I'll post a vid of how the boost acts........

[rabbitman]

All of the performance characteristics I have described before were with Euro non-integral manifold VNTs.  Here's a recap.  Stock fueling with vanes fully open EGTs never get above 1000°F and boost will easily shoot above 20 psi at higher rpms with no smoke what so ever.  Vanes fully open the turbo is a little faster acting than a K14 but with lower EGTs.  With vanes closed, boost happens pretty much instantly.  I'm sorry to say, but from what you are describing, it is still very much not right.

Rats, I thought I had it figured out .
So if boost can go past 20psi with stock fueling then how can you ever add more fueling without blowing up the turbo/over boosting?

I really wish there was a turbo guy around here I could bring it to.......

Maybe I should put my stock TD intake manifold on, I don't know why that would change anything though.

Yeah with the vanes closed I have hit 8-10psi in neutral. I wonder if the previous owner took the vanes out and somehow got 'em in wrong, I know he tried cleaning the wheels off so he for sure had it that far apart.

[rabbitman]

The stock air filter is big enough ain't it?

[rabbitman]

Well I am nearing the point of tears , so I'm coming up with all kinds of weird ideas, here's one.

Could my flywheels timing mark be slightly off from were it should be? That would mess up the cam timing and some have said that misajusted valves (that's sort of like an out of time cam ) can cause a lack of boost so it's possible......hopefully.
It does run good though, a bit clacky when cold but at running temp it sounds good. Thanks