Porting the stock VNT-15 compressor housing and ASV. Why not? (Pics coming)

Randomhomelesstdibeetlegu

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I am not exactly sure WHY I am doing this. It is probably because I have not had anything worthy of porting and have not had my fix of modifying anything cool for years.

Yet here I am doing it. We will start with the compressor housing, inlet and outlet.

After that the factory ASV is getting it's turn.

I'm sure it will yield mouse power level benefits but... Yeah. Just feel like doing it.

Whenever anyone lets me borrow a car I usually return it with some things ported and worked because I get bored. I also like grinding metals.

🤷‍♂️
 

Andyinchville1

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HI,

It's a shame you don't live closer to me .... you could port to your hearts content!

Sounds like an interesting project .... I believe every little bit helps.

It'll be interesting to see (hopefully plenty of pics) and hear what the results are ....

Do you have baseline power and MPG numbers before porting ?

Andrew
 

Mongler98

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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
no gains... only spending time and $
porting is one of those things that after a cam, massive boost, and all the bells and whistles are done... porting can help but a light blend is all that is needed.
post pictures...
i fully support this though. good practice,
 

Randomhomelesstdibeetlegu

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HI,

It's a shame you don't live closer to me .... you could port to your hearts content!

Sounds like an interesting project .... I believe every little bit helps.

It'll be interesting to see (hopefully plenty of pics) and hear what the results are ....

Do you have baseline power and MPG numbers before porting ?

Andrew

Not at all. The car is sort of a pile waiting on a new N75.

Its more of a "I am bored and miss having fast stuff so I am going to pretend this will make a difference."

What I do suspect is it will be marginal if anything.

It was way too hot earlier to do this. Waiting out the heat a bit.

I am going to pull the compressor cover off my auto parts store special which is probably a china charger and get busy. Then the factory ASV.

The chinacharger hot side was gasket matched to the fel pro gasket. Very surprising.

I'll do the extremely scientific test drive after for placebo effect before I jam a 3 bar MAP into the car with a 2.5 bar MAP tune for extra chinacharger exploding boost.

I would like to pretend this porting will do something. At a minimum it will be entertaining. Everything is so small....... You know.
 

Mongler98

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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
dont remove much if at all... just smooth it out, blend things, casting etc... and gasket match the ports
 

Randomhomelesstdibeetlegu

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no gains... only spending time and $
porting is one of those things that after a cam, massive boost, and all the bells and whistles are done... porting can help but a light blend is all that is needed.
post pictures...
i fully support this though. good practice,
I should dig up photos from the past life....... But I really just want to do go fast stuff that I can with right nows budget. Even if it doesn't make it faster.


Not too distant futures budget will have a larger turbo, lots of supporting goodies and a Frank06 top end. Possibly a Frank06 bottom end unless I just ring, bearing and shoestring polish journals on a good used block. Fab intake manifold with some plenum volume. I don't want to girdle and go nuts but some more top end would be nice.

Tomorrow morning the Wuhan whirly cold side comes off and ASV. I'll grab the starrett dial caliper and measure as well while I do it.

When I had the intake manifold off for the turbo explosion extravaganza it was dead on to the fel pro intake manifold gasket. So.... Was not worth it. Same with the new auto parts store special turbo it was basically dead on.

I can't find a used good head for cheap local. 😶
 

Randomhomelesstdibeetlegu

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Ok. I had to finish quick because of garage access. Only took a few early photos.

The end result is much less smoke and the car rips way harder at any throttle position. That is when it is not misfiring with the quantity injection control deviation code. The turbo is moving more air you can hear it at any throttle position. Grey haze at WOT sometimes a little black compared to solid thick black before.

Just doing my part for the environment.

It still has an anti shudder anti runaway valve.

I took 0 pictures of the compressor housing. I will say the factory Garrett compressor has a much wider mouth and better inlet angle to the tips of the compressor wheel. I took out a ton of material to angle that inlet and the casting was junk on the outlet.



















Sort of self explanatory. I would still do it to a Garrett housing and if you have a knock off I would 100% do it because there was gobs and gobs of **** removed.
 

JELLOWSUBMARINE

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I hope I'm not throwing $$ out the window but I opted this with Ceramic on my k14 being done,,,

How does it feel now relative to pre gut?
 

Randomhomelesstdibeetlegu

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I hope I'm not throwing $$ out the window but I opted this with Ceramic on my k14 being done,,,

How does it feel now relative to pre gut?

It actually did make a decent difference even on a stock turbo. Less smoke and it sounds more throaty(when it runs right). I have a china charger knock off from an auto parts store but even the OEM core I have around could lose some material but it is a much better casting.
 

Nevada_TDI

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I am confused at all of this...Garrett specs clearance at 0.010 from blade edge to housing.
In my experience working with high power commercial fans, the distance between the edge of the fan and the housing is critical to produce the proper amount of pressure and volume at a given RPM.
Please explain exactly where you were porting in the compressor housing.
 

Randomhomelesstdibeetlegu

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I am confused at all of this...Garrett specs clearance at 0.010 from blade edge to housing.
In my experience working with high power commercial fans, the distance between the edge of the fan and the housing is critical to produce the proper amount of pressure and volume at a given RPM.
Please explain exactly where you were porting in the compressor housing.

Not there. Funnel the inlet to right before the blades. Common sense.
 

Randomhomelesstdibeetlegu

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I believe you are probably right: opening up the inlet and no farther in the housing could produce positive results.

It did. There is less smoke for sure ..... WHEN IT RUNS RIGHT 😂. But really when I looked at China charger vs OEM Garrett the OEM had less material and a better funnel angle to the compressor inlet blade area you speak of. So less material to remove a good bit less but gains to be had none the less. The outlet was better too the china charger I'd say I removed about 5mm of material deep inside to where it became a static size per se.
 

Randomhomelesstdibeetlegu

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It's difficult to blend out the hump for the EGR plunger seat even after removing the steel insert. The casting is a pain. I got it close enough and said whatever. I also opened up the area around the ASV blade a hair to see light through and blended that lip. I did not do as much as I wanted because of time and later on I remembered I hadn't some nice TI carbide cutters that would have made it easier and cut time off. Brain eating immune diseases suck.

Either way that made a difference with ye ole butt dyno later the compressor housing made more off a difference.

Core shift can be a pain so don't expect perfection.

I'll see about snapping a pic of ASV inlet. Goal was achieved to increase flow and keep the ASV/Anti runaway valve. I still feel confident it would stop a runaway.

Would do it all again especially if you have an 11mm and nozzles plus a "stage 3" tune.

I didn't smoke out people on bicycles I had to pass. I don't like that roll coal crap personally I want FE and power when needed.
 
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