VF 40 for VF46 swap

Hello,

 

I have a couple questions.

 

I have an 05 LGT 5MT. From what I have read it seems the turbos are prone to have oil seal failures, particularly around 100k miles.

 

I have also read there are some changes (improvements?) to the VF46 turbo vs the VF40.

 

Is it beneficial to install a VF46 rather than the original VF40 turbo? Is a VF46 more robust?

 

I also read that the compressor wheel and housing shape on the VF46 is slightly different than the VF40. Is there an obvious benefit such as quicker spool rate? It would be nice to slightly improve low end torque.

 

Thank you for any information you can provide.

You can pretty easily (unless everything is rusted on) pull your downpipe and check your turbos health.

 

1. are you burning oil?

2. Is there excessive amounts of oil in the downpipe / intercooler

3. Is there excessive amounts of shaft play in the VF40?

4. Have you removed your Banjo bolt filters (http://legacygt.com/forums/showthread.php/2-5gt-turbo-oil-supply-banjo-bolt-filter-removal-62371.html)

 

Anecdotally it seems that less VF46s fail compared to VF40s, but that might just be due to age of the of the VF40 (05)

Thank you for the response.

 

I do have excessive oil in my intercooler and burn approximately a quart of oil every 1000- 1500 miles.

 

I have not yet removed the banjo bolt filter however am aware of the issue. I just purchased a new oil feed line and banjo bolts with larger oil supply holes.

 

I was thinking the same thing in regards to the vf46 just being newer. There was an interesting webpage about this comparison but doesn't really discuss durability issues.

 

http://pretuning.com/2012/06/ihi-vf40-and-vf46-turbo-comparison/

 

 

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With that kind of oil loss I would throw in a compression check and pcv valve. Definitely pull the down pipe and check to see if the turbo seals are blown. The vf46 is a better turbo then the vf40. How much better? That is an open debate. Not 100% certain it is direct plug and play though. I would consult a tuner and think about a stage one map anyways.

With that kind of oil loss I would throw in a compression check and pcv valve. Definitely pull the down pipe and check to see if the turbo seals are blown. The vf46 is a better turbo then the vf40. How much better? That is an open debate. Not 100% certain it is direct plug and play though. I would consult a tuner and think about a stage one map anyways.

 

Hello Gex,

 

Thanks for the advice. I did do a compression test and got approximately 130 dry on cylinder 4, which I believe is the one most prone to the ringland failures. Thats not too bad, correct?

 

I also purchased a PCV, just have to install. Hopefully I will get to it soon.

 

Thanks for the input people. Please keep it coming.

Also, I have been reading about the "bulletproof" kit for the OEM TMIC. Is that something worth getting? Does it only prevent leaking, so it makes sense to install on a TMIC in good working order or does it fix leaks?

Also, I have been reading about the "bulletproof" kit for the OEM TMIC. Is that something worth getting? Does it only prevent leaking, so it makes sense to install on a TMIC in good working order or does it fix leaks?

 

Yes. it stops boost leaks.

 

Get a vf52, don't waste your money on a vf46. Then get the car tuned. You should replaces the catted up pipe with a catless one.

 

Where do you live ? We can send you to a good Tuner.

 

Read some of th e sticky's at the top of the forums here, lots of good info.

Yes. it stops boost leaks.

 

Get a vf52, don't waste your money on a vf46. Then get the car tuned. You should replaces the catted up pipe with a catless one.

 

Where do you live ? We can send you to a good Tuner.

 

Read some of th e sticky's at the top of the forums here, lots of good info.

 

Thanks for the response.

 

I live in southeastern michigan.

 

I prefer not to increase the power output by much, particularly because of the potential ringland issue and that the vehicle is my daily driver. I am more looking for robustness. In that case is a VF52 still a better decision over the VF40 or VF46?

Thanks for the response.

 

I live in southeastern michigan.

 

I prefer not to increase the power output by much, particularly because of the potential ringland issue and that the vehicle is my daily driver. I am more looking for robustness. In that case is a VF52 still a better decision over the VF40 or VF46?

 

yes, absolutely. it's still a stock subaru turbo, just not stock for the leggy... even though it should have been. without fueling it'll have to be a mild tune anyways. just a really nice, entirely streetable and daily driveable bump in power and some good peace of mind. love the vf52.

What he said ^ You can run it at the stock psi.

Awesome. Thanks for the input. I will look into a vf52.

 

 

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I ordered mine from Mike at www.AZPinstall.com I had it the next day.

 

Look in my click here link you'll see where I bolted the turbo on. Much easier to line up the inlet, "new oil return hose" and up pipe. Your not fighting the studs.

 

Hint, those bolts are the same ones that mount the up pipe bracket to the block, the dealer has them.

 

 

Be careful with the turbo inlet hose, it cuts very easy.

Thanks for the info.

 

Is the link correct? I got directed to a flat screen installer.

Do you know of a good tuner in south eastern MI?

 

Also, my intercooler is leaking at the seam near the turbo. Would it make sense to just purchase the "bulletproof" kit or does a fix usually entail a new intercooler?

I believe there is a decent tuner in Toledo, but if you can make the trip, Dom at turn in concepts in Cincinnati is one of the best in the US

PM, BMB for that answer. that's his gig...

 

Check the local forum or over on NASIOC for that too.

 

The only contact I have in MI is from back in the Honda day's. http://www.lovefab.com/About.aspx

Cody may know someone if you contact him. Tell him the guy with the single cam yellow Civic sent you. My son and Cody talked a lot back in the day. There is alway's Devin Pierce at AEM...

Installed correctly, a bulletproof kit will fix an intercooler that is leaking slightly.

 

 

Thank you for the input.

 

Where could I order the bulletproof upgrade?

 

 

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I think you click on the link in his sig ?

Sorry to resurrect a long dead post but I would like to inquire a little more about the VF46 turbo. I feel this discussion veered away from it without answering any questions other than "vf52 being a better upgrade path"

I had my vf40 blow a while back and due to financial restrictions i had to put a cheaper generic vf40 in the car. The entire time ive owned the car its burned oil. Ive gotten the head gaskets done, PCV done and several other things to stop this. Ive come to 2 conclusions. Either my piston rings are going, my cheap turbo is buring a ton of oil, or (and very possible) both. I have a warranty that should cover the engine and im going to get a compression and leakdown test for the engine but either way i have to get that cheap turbo out of the car as ive noticed it smoking a bit recently.

 

Bottom line. I need a new turbo. Ive been told the VF40 and VF46 are basically the same with the VF46 having minor improvements and a better track record. Due to the budget i dont have extra cash for a tune. So to answer the ultimate question. Is VF46 a good bolt on replacement for the VF40 and does it require a tune? I plan on running it at stock PSI. (at least for now)

I'm guessing the vf46 is what you want.

 

Talk with Mike from , www.tuningalliance.com or tuningalliance@gmail.com as he's a vendor here and see what he can do for you. He'll know the best way to go. He's kept both my cars happy for years.

Thanks i shot him an email. Ill share what i learn back here for future people seeking the same answer.

VF40 and VF46 are virtually identical in performance and they use exactly the same internal parts (turbine/shaft assembly, journal bearings, piston ring seals, thrust plates and washers) and center bearing support housing. The compressor wheel is very slightly different between the two but they are interchangeable internally between the two turbos.

 

The ONLY difference (and you won't really feel it) is you'll spool about 100 rpm sooner with the VF46 but it will run out at the other end about 100 rpm sooner than a VF40.

OTS tune no good for that, righ?

OTS tune no good for that, righ?

OTS tunes are not really ideal anyway, but people have done it by swapping the wastegate actuator and boost pill from their old VF40 to the VF46.