Second-hand Japanese turbochargers are a great way to add power to an engine.
It doesn’t matter if you’ve got an atmo engine you want to boost or you want to
step up to a bigger huffer on your factory turbomotor - second-hand Japanese
turbos are extremely cost-effective.
But what range of turbos is available, you ask?
Well, here we scour a local import wrecker and uncover everything from a tiny
Kei-class turbo to a big Toyota ‘charger capable of 206kW in
factory guise. And don’t think you’re limited to an engine output of around
206kW. There’s nothing to stop you installing multiple turbos to an engine – a
pair of those 206kW Toyotaturbos
would be ideal to turbocharge a big-cube V8 to around 450kW!
In this two-part series we give you the specs of thirteen Japanese-import
turbochargers. Let’s go!
Meet the Turbos...
IHI RHB31
The smallest turbocharger we’ve seen fitted to a production engine is the IHI
RHB31. This turbo is used on various Japanese Kei-class cars including Suzuki
and Daihatsu.
We’re told this particular turbocharger comes from a Suzuki 660cc engine
which, like all Kei-class engines, is limited to 47kW. Experience tells us this
turbo can be wound up to more than 1.0 Bar of boost and about 75kW – but don’t
expect it to last very long. These very small turbos aren’t particularly
durable, despite having a water-cooled core.
The compressor inlet of this little ‘un is less than 30mm and the discharge
nozzle measures 26mm diameter. A 2-bolt flange is used at the compressor inlet
and discharge nozzle – there are no slip-over hose joints. The turbine wheel is
fed exhaust gasses through a 24mm diameter passage in the triangular mounting
flange. Three bolts attach the turbine to the exhaust manifold and four bolts
connect the dump pipe.
The extremely compact dimensions of this turbocharger allow it to be mounted
in very tight spaces. If you’re keen, you could probably squeeze a pair of these turbos under the bonnet
of a N12 Nissan Pulsar/EXA turbo. Alternatively, you might have a
small-to-medium size motorcycle you want to turbocharge...
IHI RHB5 VJ11
Another IHI manufactured turbocharger is the RHB5 VJ11, as fitted to the
Mazda F2 2.2 litre engine. This engine is employed in the Mazda MX-6/626 and the
Ford TX-5 cousin.
Despite displacing a considerable 2.2 litres, the F2 engine has a relatively
low power output of 108kW. Not surprisingly, the F2’s turbocharger is quite
small in comparison to other engines of similar capacity. We suggest the
effective limit of this turbocharger is about 140kW.
The IHI RHB5 VJ11 draws induction air through a 45mm compressor inlet and
blows it out through a 43mm discharge nozzle. A slip-over hose joint is used at
each side of the compressor. Exhaust gasses enter the 44mm turbine passage and
the 4-bolt mounting flange measures 74mm square. The dump pipe is a 5 bolter.
Note that the IHI RHB5 turbo is factory fitted to various engines and there
are several subtle variations. These variations might come in handy if you want
to mix and match IHI parts to create a unique compressor/turbine combo.
IHI RHF5 VJ26
We’re not 100 percent sure on the origin of this turbo but it appears to be
from the Japanese-market Mazda Familia GT-R (essentially a STi or Evo equivalent
of the Mazda’s Familia AWD turbo). The turbocharger is identified as an IHI RHF5
VJ26.
In factory form, the Familia GT-R’s 1.8 litre engine is rated at 154kW and
the turbocharger is sized to give rally teams scope for more power. Two-hundred
kilowatts is reliably within reach of this turbocharger. Note that the core
features a ball bearing for enhanced boost response and strength. The core is
also water-cooled.
The RHF5 VJ26’s compressor inlet is 45mm diameter and the discharge nozzle is
43mm (the same as the above RHB5 VJ11). We were unable to measure the diameter
of the turbine passage because the exhaust manifold was still attached but we
can tell you the 4-bolt flange is 74mm square. Note that this flange appears
identical to the RHB5 turbo sampled above. The dump pipe also needs 4 bolts.
This is a great, medium-size roller bearing turbocharger. It’s a pity there
aren’t many around.
Nissan/Garrett RB25DET (T3
style)
The Garrett T3-based turbocharger from Nissan’s RB25DET engine is one of the
biggest OE Japanese turbos you can buy. They’re also relatively easy to find
because they’re factory fitment to the ever-popular R33 Skyline GTS25T.
One of the biggest attractions of this turbo is its sophisticated design – it
uses a water-cooled core with a roller bearing, ceramic turbine and lightweight
compressor. These factors contribute to a very fast spool-up time.
In standard form, the RB25DET engine generates 187kW and we have seen the
standard turbo pushed to around 250kW in some applications. At this output,
however, the ceramic turbine is likely to fail – especially when held at high
load for extended durations.
The RB25DET turbocharger employs a 60mm compressor inlet and a 38mm discharge
nozzle. The compressor housing is identified with a 0.40 A/R. On the exhaust
side, the turbine inlet passage is 65 x 45mm and the mounting flange measures
110 x 70mm. The turbo connects to the exhaust manifold with 4 bolts and the dump
pipe is attached by 6 bolts.
This is a great turbo for any engine making less than 250kW.
Nissan/Garrett VG30DET (T3
style)
In
Japan during the
early ‘90s, Nissan offered a range of large luxury sedans powered by a single
turbo version of the VG30 quad-cam V6 (aka VG30DET). These vehicles include the
Leopard, Laurel and Cima.
The VG30DET uses a large-frame T3-style turbocharger, similar to the unit on
the RB25DET. Factory output for the VG30DET is 187kW. Power can be increased to
more than 200kW but – like the RB25DET turbo - its ceramic turbine wheel can
fail under duress. The core uses only a conventional bearing but it does feature
water cooling.
The compressor inlet to this turbocharger measures 60mm diameter at its
mouth. The compressor outlet uses a 3-bolt flange arrangement but we were unable
to measure the nozzle diameter. However, if the RB25DET turbocharger is anything
to go by, we imagine the nozzle diameter is around 38mm. The turbine is fed
through a 65 x 45mm passage with a 110 x 70mm mounting flange. This is identical
to the RB25DET. Four bolts join the turbo to the exhaust manifold and 5 bolts
connect the dump pipe.
These often-overlooked turbos are very similar to the RB25DET turbocharger.
It is rumoured that late-model versions of the VG30DET turbocharger use a ball
bearing centre.
Nissan/Garrett RB26DETT (T28
style)
The Skyline GT-R engine uses a pair of T28 turbochargers to achieve its 206kW
claimed output.
Just one of these turbochargers can be employed on engines making about
120kW, so long as the ceramic turbine isn’t pushed beyond its limits. A single
R32 GT-R turbo is ideal for, say, a 1.5 litre four cylinder with a few breathing
mods.
The GT-R compressor inlet is 53mm diameter but, again, we were unable to
measure the discharge nozzle diameter. The compressor is marked with a 0.48 A/R
ratio. On the opposite side, the GT-R turbo uses a 38 x 50mm turbine passage and
a 63 x 93mm mounting flange. The turbine housing is also marked with a 0.54 A/R.
The mounting flange and dump pipe are 4-bolters.
Note that this turbocharger uses the same turbine mounting flange as the
S14/S15 200SX, Pulsar GTi-R and various other Nissan turbos. This makes
conversions easy.
Nissan/Garrett T2
One of the first turbocars to appear in
Australiais the Nissan Pulsar/EXA turbo.
Using a new generation ‘small frame’ Garrett T2 turbocharger, the E15ET
engine is factory rated at up to 86kW (in Australian guise). These turbos are
comfortable at well over standard boost (about 7 psi) and can capably be used
for around 110kW in a street application. Push the envelope to about 120kW and
its efficiency falls away dramatically. Note that early versions of this turbo
(as photographed) are air-cooled, but later versions use a water-cooled core for
improved durability.
The T2’s compressor inlet is 45mm diameter and the discharge nozzle is flared
to 52mm at the slip-on hose connection. The compressor housing is also marked
with a 0.48 A/R. Exhaust gas passes through a 50 x 39mm turbine passage and the
mounting flange is 63 x 93mm. The turbine and dump pipe both connect with 4 bolt
flanges.
Interestingly, the little T2 turbo uses the same turbine mounting flange as
some larger T25 and T28 turbochargers. This means Skyline GT-R, S13/S14/S15 and
Pulsar GTi-R turbos will bolt up to the same manifold.
T2 turbos are pretty easy to find and servicing parts are readily available.
If you have the choice, go for the longer-lasting water-cooled version.
Stay tuned – in Part Two we’ll check out more of these wonderful second-hand
Japanese turbos!
Correction
I started to read the
article Used Turbo Info - Part One
and there is one error that I noticed... The IHI VJ26 is a diesel turbo from an
Isuzu 4x4 - the Mazda Familia 1.8 GTR uses a VJ23. Both are BB turbos but the
exhaust AR is a lot bigger on the GTR turbo. The VJ26 is good for about 350hp
(261kW) on a gas engine were the GTR turbo the VJ23 is good for about 420hp
(313kW).
Jason
King
Barbados
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