DIY Hybrid IHI turbos

Matt Monson · Post by **Matt Monson** » Mon Apr 05, 2004 8:33 pm

Ok,
I have had a couple of thought running through my mind recently. I have access to a cheap dead VF-8 turbo. I also have in my possesion a recently serviced VF-29 turbo. I am looking for a way to get more power out of the turbo on my soon to be installed EJ20G w/Vf-10.
So, I am thinking about two things:

1. I can pick up this VF-8 turbo and use it's P18 exhaust housing to up the power on my vf-10. I know that this would be a relatively easy swap over and I shouldn't need to buy any parts to make it work since I have a fully functional VF-10 to work with.

2. Or, and here's the question, can I use the RHB52 compressor housing from my vf-10 and mate it to the p18 housing off of the VF-29 and convert it over to the newer bearing design while I am at it? Any thoughts?

boostjunkie · Post by **boostjunkie** » Mon Apr 05, 2004 8:49 pm

Have you been able to test fit the vf-29 into the stock location? You might be better off running custom intake for the turbo, if there's enough clearance. Afterall, the turbo's just been serviced, and is probably in better condition than the other vf-series turbos. Don't need to break open a perfectly good turbo if you don't have to (then you'd have to send it off again to be rebalanced, etc).

I'm assuming you have a v2 intercooler? The intercooler hoses should line up. I'm pretty sure the turbo outlets are the same between the years.

Matt Monson · Post by **Matt Monson** » Mon Apr 05, 2004 8:57 pm

I haven't test fit the VF-29, but I have the whole stock intake assembly and am looking to do this build for the least $$$ possible. It is a '93 EJ20G out of a Legacy GT, so it has the good old 90 degree inlet that I was trying to work with. As for the intercooler, it is the stock AWIC unit...

boostjunkie · Post by **boostjunkie** » Mon Apr 05, 2004 9:10 pm

How much does it cost to send off an balance a turbo? $100? I'm sure a custom DIY intake (you'd only be swapping out the rubber turbo outlet) would be considerably less. I'd see if you can find any radiator hoses that would work first before taking apart the turbo. That's just my 2 cents.

boostjunkie · Post by **boostjunkie** » Mon Apr 05, 2004 11:08 pm

Oh, I see. I've never been able to see an AWIC up close.

Matt Monson · Post by **Matt Monson** » Mon Apr 05, 2004 11:15 pm

It's not that simple on an engine fitted with the factory AWIC. The BOV runs right from the base of the line between the turbo and AWIC over to dump right into the inlet stream of the turbo. It is not a simple rubber elbow like on the USDM Legacies. It is a bit of an octopus that has several lines feeding into the elbow, like the vents off the heads, in addition to the BOV. I'll get some pics up manana when my gurl gets back in town. Modifiying the inlet is not an option. That is why I want to use the stock compressor. If I can't get away without sending the rebuilt turbo out for rebalancing (which is easy to do locally since the Co. that made Marc Rameriz's turbo is 25 miles away in Golden) then I am going to have to pass on the mod all together. Why must I get it balanced?

vrg3 · Post by **vrg3** » Mon Apr 05, 2004 11:27 pm

The USDM compressor inlet elbow is, I think, the same as the JDM/UKDM/ADM one. It has three fittings on it -- two for PCV and one for the blowoff valve. Look at the PCV diagram on this page:

http://www.graphics.cornell.edu/~v/vacuum/

If you were making your own intake tubing, you could put all three of those fittings a little further upstream. Like maybe do the coffee mug mod but add these three fittings to it. The blowoff valve line is 19mm, so 3/4" ought to do there. The PCV lines are 12mm, so 1/2" should work for those.

Matt Monson · Post by **Matt Monson** » Tue Apr 06, 2004 12:43 am

I pulled up an old picture I have of my Legacy's engine bay, and the elbow is definitely different, though you are correct that those lines do all feed into the USDM elbow as well. But ultimately, this does not change the fact that I am not going to the time or effort to make a new elbow. If rebuilding the turbo is unfeasible, then I am not going to do it at all. That is what this topic is about, not intake mods.

I still haven't heard why I need to re-balance the turbo after rebuilding it. Can someone please help me understand what I really want to know?

boostjunkie · Post by **boostjunkie** » Tue Apr 06, 2004 2:33 am

Whenever the turbo is disassembled it has to be REBALANCED. An unbalanced turbo spinning at 10,000 or more rpm will not last too long.

vrg3 · Post by **vrg3** » Tue Apr 06, 2004 2:55 am

More like 100,000 rpm...

But I've heard of many people doing turbo rebuilds or building hybrid turbos in their garage and then dropping them right into their cars. I don't know how long they lasted, but I don't remember hearing of any spectacular failures.

What spinning part of the turbo wouldn't already be balanced from the factory? Or, what kind of acceptable damage could cause it to go out of balance? I can't imagine any damage to either wheel being acceptable.

legacy92ej22t · Post by **legacy92ej22t** » Tue Apr 06, 2004 2:59 am

Matt Monson wrote:
1. I can pick up this VF-8 turbo and use it's P18 exhaust housing to up the power on my vf-10.

Hmm...I must be totally misinformed. I thought the vf8 was the turbo in the GL turbos and 1.8T's. The one with the 4 bolt DP pattern. Is this wrong? I just want to know for future reference.

boostjunkie · Post by **boostjunkie** » Tue Apr 06, 2004 3:28 am

vrg3 wrote:More like 100,000 rpm...

But I've heard of many people doing turbo rebuilds or building hybrid turbos in their garage and then dropping them right into their cars. I don't know how long they lasted, but I don't remember hearing of any spectacular failures.

What spinning part of the turbo wouldn't already be balanced from the factory? Or, what kind of acceptable damage could cause it to go out of balance? I can't imagine any damage to either wheel being acceptable.

I'd rather be safe than sorry. The last thing anyone needs is a turbo falling apart and wasting other parts in the intake and/or exhaust path.

Matt Monson · Post by **Matt Monson** » Tue Apr 06, 2004 4:13 am

legacy92ej22t wrote:
Matt Monson wrote:
1. I can pick up this VF-8 turbo and use it's P18 exhaust housing to up the power on my vf-10.

Hmm...I must be totally misinformed. I thought the vf8 was the turbo in the GL turbos and 1.8T's. The one with the 4 bolt DP pattern. Is this wrong? I just want to know for future reference.

I don't know about the GL's, but the VF-8 was the standard turbo on 89-93 JDM Legacy RS's w/ 5spd. It has the same compressor as the VF-10's and VF-11's. but use the bigger P18 Exhaust housing (vs. the P15 on the other two.)

VRG and Boost, thanks for the replies. I thought I had heard of guys taking their chances. And since I know of several cheap junkyard VF-10's the only real risk would be a fouled turbo. I'll have to think on this a bit more as well as seeing what others may have to say over the next few days...

DOA · Post by **DOA** » Wed Apr 07, 2004 10:28 pm

If your only going to do the job to test out the theory first then dont bother balancing the rotor, just be VERY carefull with it. If you plan on only doing it once then get it balanced anyway and have ALL the bits refurbed profesionally on common sense grounds.

Jaxx · Post by **Jaxx** » Mon Apr 12, 2004 10:23 pm

hmmm .. is that the turbo from flordia??

Matt Monson · Post by **Matt Monson** » Tue Apr 13, 2004 2:35 am

Jaxx wrote:hmmm .. is that the turbo from flordia??

Why, did he sell it to you?

-K- · Post by **-K-** » Fri May 14, 2004 3:50 pm

I ame one of the garage hybrid guys. I found that every part that spins in the IHI turbo is balanced seperatley. I have to had any problems but you could get it balanced for peace of mind.

legacy92ej22t · Post by **legacy92ej22t** » Fri May 14, 2004 3:55 pm

K! How are things? Are you deployed yet or are you home?

-K- · Post by **-K-** » Tue Jul 06, 2004 9:11 am

I'm in Bagdad. I get on the internet once in a while. I have to see what is up in the subaru world. I'll let you guys and girls now, how I'm doing sometime.

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DIY Hybrid IHI turbos

DIY Hybrid IHI turbos

Re: DIY Hybrid IHI turbos

Re: DIY Hybrid IHI turbos