VJ-11 vs. VJ-14
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VJ-11 vs. VJ-14
Here's some pics for anyone interested in the IHI turbos. The VJ-11 (larger) was from a Ford Probe and the VJ-14 (smaller) was from a Mercury Capri. They look like the same turbine wheel but the VJ-11 has a larger turbine housing. VJ-14 has a smaller compressor wheel. The downpipe flanges are also different.
I've always wanted to compair the two myself but never had them side by side. Now I have the chance since I picked up a VJ-14 and mani for $20. I ran a VJ-11 on my Miata with a DIY mani. I could get 12-14psi all day but I could feel the power rolling off at the top end. I have a VJ-11 on the MX-3 now but it takes awhile to spool. I'll be putting the VJ-14 and mani on the MX-3 and let you know how that works out.
I've always wanted to compair the two myself but never had them side by side. Now I have the chance since I picked up a VJ-14 and mani for $20. I ran a VJ-11 on my Miata with a DIY mani. I could get 12-14psi all day but I could feel the power rolling off at the top end. I have a VJ-11 on the MX-3 now but it takes awhile to spool. I'll be putting the VJ-14 and mani on the MX-3 and let you know how that works out.
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ok ok ok
That mani is from the Capri. 1.6L (B6 I assume) but probably won't work on a Miata with the a/c and p/s in the way. I have the Probe mani also. It's for whatever that Probe had. 2.2L?
That mani is from the Capri. 1.6L (B6 I assume) but probably won't work on a Miata with the a/c and p/s in the way. I have the Probe mani also. It's for whatever that Probe had. 2.2L?
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Ford Probe VJ-11 compressor inlet ID at the wheel = ~39mm
Merc Capri VJ-14 compressor inlet ID at the wheel = ~37mm
The compressor housings look identical but the Capri compressor outlet (for the hose) is slightly longer.
Both turbine wheels are ~44mm at the opening of the turbine outlet.
Both turbine inlet flanges are ~45mm and the same 4-bolt symmetrical pattern.
I'm not going to tear them apart again and figure out the a/r and trims and all that. Although I'd love to I JUST put them back together. I can't measure the wheels exactly due to them having an odd number of blades. Just allow for housing clearance of the above measurements.
Merc Capri VJ-14 compressor inlet ID at the wheel = ~37mm
The compressor housings look identical but the Capri compressor outlet (for the hose) is slightly longer.
Both turbine wheels are ~44mm at the opening of the turbine outlet.
Both turbine inlet flanges are ~45mm and the same 4-bolt symmetrical pattern.
I'm not going to tear them apart again and figure out the a/r and trims and all that. Although I'd love to I JUST put them back together. I can't measure the wheels exactly due to them having an odd number of blades. Just allow for housing clearance of the above measurements.
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edit - make that 8-10psi. That's more realistic.
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I know the smaller turbine housing on the 14 lowers the a/r on that side. That should give higher velocity and faster spool in the turbine side of things. The smaller compressor wheel should give lower inertia as well. Together it should spool faster or at least at a lower rpm. I've seen how the larger compressor does make more power when I did the T4 compressor upgrade on my old T3 setup. Doesn't make sense though. Xpsi is Xpsi no matter how it's made and being that the T3 turbine/housing wasn't changed it shouldn't have had any effect on the exhaust restriction. It did take longer to spool the larger T4 wheel. Boost came on about the same time. Maybe the 14 turbine with the 11 compressor would work well together.
#13
The huge vj23 turbo I have on the GTR swapped 323 GTX is also a total dog until it gets to around 4500 rpm then it tries to rip all 4 tires off as you have instant boost come on like sombody hit a switch. The GT3071R I have on the 2.0l Miata is a thing of beauty though totally smooth and gobs of power everywhere.
Bob
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Bob
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Going from a vj14 to a vj11 on a 1.6l GTX I had made the car not much fun to drive at all. It made good power but no usible boost until very high in the rev range. It’s not really a big turbo but spools like a much bigger turbo than what it is. I dont know why but it sucks. The boost response on the 14 is instantaneous and it will make 16+psi from 2500 rpm to redline with a good exhaust. You wont get much more than about 200hp but it will work at 20psi.
The huge vj23 turbo I have on the GTR swapped 323 GTX is also a total dog until it gets to around 4500 rpm then it tries to rip all 4 tires off as you have instant boost come on like sombody hit a switch. The GT3071R I have on the 2.0l Miata is a thing of beauty though totally smooth and gobs of power everywhere.
Bob
The huge vj23 turbo I have on the GTR swapped 323 GTX is also a total dog until it gets to around 4500 rpm then it tries to rip all 4 tires off as you have instant boost come on like sombody hit a switch. The GT3071R I have on the 2.0l Miata is a thing of beauty though totally smooth and gobs of power everywhere.
Bob
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