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I'm curious how the vf8 compares to our vf11. I know its bigger, but I'm curious where full boost comes on and how it pulls, and stuff like that. How do you like the general characteristics of the turbo?

-Ryan

I'm also curious about how it fits under the hood too.

I sits the same as a VF10, VF12, or 16G. Your best bet for comparison would be to look at Manual JDM Legacy RS's and see how it goes on there, then estimate how much the added displacement will change things.

Are the coolant and oil lines similarly placed? That's really what I meant to ask.

All your stock oil and coolant lines should fit right up to a VF8.

So it's basically plug n play, cool. I'll have to look into that some.

Well, not quite. The compressor outlet is angled the same way as all the turbos Hardy mentioned, which is different from how the stock one is angled. So you'll probably have to modify your plumbing between the turbo and the intercooler.

Our stock turbo looks like this:

http://www.graphics.cornell.edu/~v/pics ... harger.png

The VF8 looks like this:

http://www.graphics.cornell.edu/~v/pics ... harger.png

Plus the coolant supply line's pointing towards the front passenger side area instead of the the driverside strut tower.

All that stuff can be changed. You can swap over the oil lines, as well as coolant lines, and you can reclock the inlet to match the vf11.

Outlet you mean? Would it really be worth it to reclock it? The stock tubing wouldn't fit, or whatever tubing you were using.

reclocking would probably not be worth it unless you also were able to reduce the size of the outlet. Frankly, I like the idea that it is all ready to go for a JDM intercooler, of which I have one.

I just want to know what the drivability difference is when it is in the car. How does it compare to the stock one?

Matt - Yeah, but, like I was saying, you can swap those over. The clocking is the only nontrivial difference in terms of mounting.

Josh - Reclocking is not quite as simple as it may seem at first glance; you'd have to figure out a way to mount the compressor inlet elbow and the wastegate actuator correctly.

Ryan and Hardy - I thought the outer diameter of the compressor outlet was the same on both turbos. Is that not the case?

The VF11 has the smallest outlet of any new gen turbo.

Hardy's right. I have a samco hose that fits to a, what is it, ver 2 sti intercooler (I think?) and it is larger than what the stock turbo outlet is. I believe the vf10 even has a larger outlet. Isn't that true Hardy?

It's looking like all new gen turbos have the same size compressor outlet except the VF11.

vrg3 wrote:Matt - Yeah, but, like I was saying, you can swap those over. The clocking is the only nontrivial difference in terms of mounting.

All your stock oil and coolant lines should fit right up to a VF8.

This is what I was referring to. It's a super easy fix but the coolant supply line on the turbo needs turned around (may involve cutting the tab that holds it and the return line together) and the coolant supply line that comes from the coolant fill tank might need reran.

I meant the metal lines... they can be moved from the VF11 onto the VF8 so the stock hoses will fit correctly. No machining or anything. =)

Did you do that on your 16G? I ask because when I did mine, the VF11 banjo bolt is smaller then the 16G's. To use the VF11 coolant supply line or return line (the metal ones on the turbo) you would have to drill them out to fit the larger banjo bolt for the 16G. This could cause issues (leaking) that I didn't want to worry about.

I don't know what size the banjo bolts are on the VF8, 10 and 12 though but if they are the same size as the 16G's I think just turning it around is much easier. It would make sense though that all the early IHI VF series turbos would have the same size banjo in which case just swapping them over, like you said, would be better.

Hmm, don't mean to go off into left field here, but all this coolant talk has me thinking. Is the outlet clocking the reason our cooling system is different from every other subaru? What with the expansion tank being behind the #4 runner? It seems like the coolant return line would run into the compressor outlet, so they decided to turn it the other way, and throw the expansion tank to that side aswell. Is that right? Or is there another reason?

vrg3 wrote:Josh - Reclocking is not quite as simple as it may seem at first glance; you'd have to figure out a way to mount the compressor inlet elbow and the wastegate actuator correctly

Gotcha

good stuff on the geometry of the layout.

What's the difference between the vf11 and the 8?

Subtle( with a TWGN that needs a bigger T)

In boost characteristics ---that is

Matt - The banjo bolts are identical on the VF11 and VF8. Both turbos are IHI RHB5s, after all; they just have different turbine and compressor wheels and housings. You're right that the 16G uses larger banjo fittings, but the VF8 uses the same size as stock.

Hardy - Huh, I think you may be right. We could confirm it by trying to install a stock VF8 coolant line on a VF11 to see if it fits.

I think the turbine wheel is the same on all the RHB5's, so far all I take apart are.

Oh, only the housings are different?