5th Gen Legacy GT Turbo Upgrade Options

After lots of searching through various threads i havent been able to find many options for turbo upgrades on 5th gen Legacy GT's.

 

Those of you that know , please post hear. Maybe we can formalize a list and get it stickied.

I'm not up on all the lingo, but I want the turbo to kick in early, but still allow me to get good mileage on the freeway.

 

From a gentleman that has rebuilt thousands of Subie Turbos. I asked him his thoughts on what turbo is best for the Legacy. Here is what he told me:

 

"I'd go a vf52. I'm not a fan of the 18g. All it is is a 16g with a 20 g compressor wheel. Lots of lag because that small turbine has a hard time spinning thay big comp wheel"

There is an 18g or 20g upgrade to the stock vf54 and those are your options. And fwiw there is barely any lag in normal driving. Power comes on much faster than other subarus with the high mounted turbo.

 

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Here is the short-and-skinny. The VF54 in the 5th gen LGTs has a different housing and setup than any other turbo'd Subaru. Further, nobody is casting OEM-compatible turbo housings for the 5th gen so, unless you want to completely fab up your own setup (which could include, e.g., exhaust header, downpipes, mounts for the turbo, etc.) for different-styled turbos, you are stuck with stock turbo retro-fits (e.g., milling out stock turbo housings for larger compressor wheels and turbines).

 

The problem with the VF54 is that the geometry of the exhaust housing really doesn't flow great, and thus, is limiting. Generally, the VF54 is limited to a TD05 or equivalent turbine.

 

Thus, when retrofitting the VF54 with a larger compressor, you must consider that you are stuck with a TD05 that probably doesn't flow as well as a TD05 in more traditional subaru turbos.

 

The sweet spot seems to be 18G-sized compressor wheels (billet, if possible) matched with the TD05.

 

Additionally, 5th Gen LGTs are limited by the exhaust cams, which you can read about in a couple places on this forum.

 

That being said, I believe BNR will retro-fit your stock turbo or a stock core (if he has any or your source your own). Additionally, Kinugawa appears to have retro-fitted some VF54s with 20G/TD05 setups, which you can find on eBay. Also, Steamspeed as retro-fitted some VF54s with their own compressor wheels/TD05.

 

Also, I failed to mention that turbo upgrades on this platform seem to have a higher propensity for boost creep, so port the hell out of your internal waste gates, people, OR pay somebody to fab up an exhaust manifold with external waste gates.

 

Sources: I have spent a lot of time this forum, and followed the progression of many folks setups. Fahr Side is the go-to source for knowledge (probably in the world) when it comes to 5th Gen LGTs, and most of this knowledge/wisdom comes from him. Additionally, Gteaser can probably steer your in the right direction as well. You are probably right -- we probably need a quick-and-dirty unabomber-style FAQ regarding 5th Gen turbos and other enhancements....

After lots of searching through various threads i havent been able to find many options for turbo upgrades on 5th gen Legacy GT's.

 

Those of you that know , please post hear. Maybe we can formalize a list and get it stickied.

 

Read my build thread and you can get a good sense of what the options are like and what else is needed to make them work properly

 

FYI, you'll probably want to have a six-pack handy...

jackal8788 - Wow what an experience!! I have to confess, I skipped to the end and looked over your dyno comparison chart. It looks like you found that the 18g works best on our cars due to the wimpy exhaust cams and the restrictive size of the VF54 housing.

 

Any chance you would be willing to put together a brief summary of your experience, what specific turbo you used, where you sourced it, and the supporting mods required for success?

The only turbo you can use is the one in the car from the factory...there are a couple places who will upgrade it to the 18g or 20g compressor wheel.

 

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jackal8788 - Wow what an experience!! I have to confess, I skipped to the end and looked over your dyno comparison chart. It looks like you found that the 18g works best on our cars due to the wimpy exhaust cams and the restrictive size of the VF54 housing.

 

Any chance you would be willing to put together a brief summary of your experience, what specific turbo you used, where you sourced it, and the supporting mods required for success?

 

I would suggest to take the time out and read that thread from beginning to end. Quite a lot of knowledge to be learnt.

jackal8788 - Wow what an experience!! I have to confess, I skipped to the end and looked over your dyno comparison chart. It looks like you found that the 18g works best on our cars due to the wimpy exhaust cams and the restrictive size of the VF54 housing.

 

Any chance you would be willing to put together a brief summary of your experience, what specific turbo you used, where you sourced it, and the supporting mods required for success?

 

Yeah, it's been a wild ride I'm very happy with the car now and it really makes my daily drive satisfying and fun so I'm not complaining.

 

In my build thread, I do have as my very first post, a current and updated list of all the mods to date. I actually picked my turbo up from fahr_side (who, if you read my thread, is a tuning sage and eminent source of wisdom in our happy fifth gen family). BNR also offers a billet 18G option with a modified VF54 housing.

 

If you have more specific questions though, shoot me a PM and I'll be glad to share my opinions/experiences.

anyone in here ever used this? I think I saw somezero run it with nothing negative to say

 

https://www.tomiokaracing.com/collections/turbos/products/hybrid-vf54-turbo-for-2010-subaru-legacy-gt

Edited April 18, 2019 by SJGT

Has anyone had recent experience with BNR upgrading their VF54? I am ready for the 18G upgrade but have not gotten a response from them via email or phone... Makes me a bit nervous about the whole process versus spending the extra money for the Tomioka 20G. I just don't want the 20G based on dyno results with stock exhaust fans.

Has anyone had recent experience with BNR upgrading their VF54? I am ready for the 18G upgrade but have not gotten a response from them via email or phone... Makes me a bit nervous about the whole process versus spending the extra money for the Tomioka 20G. I just don't want the 20G based on dyno results with stock exhaust fans.

 

Contact Adrien @ Hill Country Forced Induction, he emails back quickly.

 

I will be sending my turbo to him for a 18g build soon.

 

http://hillcountryforcedinductions.com/

Has anyone had recent experience with BNR upgrading their VF54? I am ready for the 18G upgrade but have not gotten a response from them via email or phone... Makes me a bit nervous about the whole process versus spending the extra money for the Tomioka 20G. I just don't want the 20G based on dyno results with stock exhaust fans.

 

Did you try Lachute Performance in Quebec, they can do it as well.

Fwiw I ran the steamspeed20g on my car. Keep in mind I had significant upgrades which I believe was the perfect combo. Car pulled great to redline, quick spool compared to other big power Subarus I've been in, and made the car feel like a v6