Aftermarket turbo need a tune?

[Phosoup253]

Bought my 2005 Legacy GT with an “oem style” turbo replacement. 
Not exactly sure how the last turbo failed, but previous owner paid $1300 for what he thought was an OEM IHI Vf42 turbo only to find out later that it was not. 
Car spun a bearing only few hundred miles later which is why I’m making this post.
I got a replacement motor and instead of a brand new oem turbo, I found what’s seems to be an “oem style replacement”.  After dealing with some other issues I had non related to this topic, I finally got it all buttoned up and took it for its first long test drive. Car drove absolutely fine, but I will say, it feels “sluggish”. Threw some octane booster because it did sat for a few months so we can rule out bad fuel. 
Car is bone stock and I intend to keep that way until I can source a vf52  along with a few other of the supporting mods and a real tune. 
My question is, do I need a tune asap or am I fine running it this way? 

 

Edited October 18, 2022 by Phosoup253

[KZJonny]

Turbo is installed now, so it’ll be harder getting measurements…. It that is just a pattern replica of a VF40 you should be fine, although off-brand turbos in those frames have a bad reputation around here.

If it’s anything but a ‘VF40’, I would at least consider getting a used AP and chucking a Stage 1 tune on, they’re reputedly a but richer than needed, which would at least give you a little safety margin, and even the OTS maps are better than the stock one.

Better to get a real tune, I think. The last owner used a non VF-40 and the engine died right? You’re now using maybe a non VF-40….. how much did that engine cost?

Unless you are dead set on a VF-52, it may be worth considering having JMP see if he can make a Custom VF40 out of the other turbo you have. If you want max power at red line, if might not satisfy you, but I’ve got one in my GT, and it’s a pretty huge difference from stock. Doesn’t require a full fuel system either…. 

Edited September 26, 2022 by KZJonny

[Max Capacity]

Is there a boost pill in that short hose off the compressor housing ? There should be a white dot on that short hose, and you should be able to feel the pill inside.

If you're not sure, get the car tuned.  Agree, Cobb AP is great. JMP6889928 may have a clue about that turbo, PM him.

 

Have you asked google to search for that turbo p/n ?

[KZJonny]

Google suggests it is this one, at least the logo looks about the same:

https://jmturbo.com/subaru/subaru-vf46-legacy-gt-outback-xt-2-5l-turbocharger.html

So, if that can be confirmed (maybe call/email the company and ask?) then you'd be safe on that guy without a tune, since it's just a replica VF46, pretty much the exact same turbo as the VF40, except for some marketing hype and a new part number. Still check for a restrictor pill as suggested by MaxCapacity.

Willing to be wrong, if there are people who can report on having some relatively high miles on off-brand turbos, but I wouldn't personally use anything but a turbo from one of the more reputable builders. (JMP, BNR, Blouche, it's a short list, though should probably also include some of the better Tiawanese ones, like Kinugawa etc... Farh Side goes through the options in the turbo wiki....) At least, I wouldn't use one for a long time, or push it too hard constantly.

[Max Capacity]

Just saying, the new vf52 I got from Mike at AZPinstalls.com back in early Aug 2011 is still running great after some 160,000+ miles. Sometimes, you get what you pay for.

[kzr750r1]

Get a tune.

Or as Mike would say, "Stay stock and stay happy".

You need a tune on the "changes" you have made.

Lean is not a good thing for ringlands. Pushing it will only make it fail faster.

[NORULZleggy]

You no want boom boom short block time. Got to pay to play.

[JmP6889928]

Chinese VF46 copy.  Not all bad parts and based on what the condition of it looks like, it seems like it probably runs fine.  They are definitely a crap shoot though as to whether or not they will last.