BLOW-OFF
VALVE
(Re-circulation
MX7760
type) MX7960(F)
When the throttle closes, the pressurized air from the turbo has no where to go and is
forced back towards the turbo. This puts significant stress on the compressor wheel and in
some instances can be enough to stall it all together. To prevent this, a blow-off valve is
installed between the turbo and throttle to recirculate the air to between the MAF and turbo.
However, using a stock blow off valve for high boost setups will cause it to relief the
boost prematurely, resulting in reduced response and power. Therefore it is highly recommended
that you upgrade the blow-off valve to a high performance unit. It should be noted that whilst both
vent-to-atmosphere type and recirculation type blow-off valve setups serve the same function
of relieving boost, the former will often cause the MAF to give false readings. For this reason
it is recommended that you recirculate the excess boost.
EXHAUST
MANIFOLD
MX7760
MX7960(F)
MX8265
With the increased exhaust pressure from upgrading the camshafts, a high flow exhaust manifold
is needed to efficiently route the exhaust gases to the turbine wheel. This helps improve turbo
spool and performance.
However, on an EJ engine, the exhaust ports on the cylinder head and the turbo are far apart.
This means that an exhaust manifold with pipes too wide will have an adverse effect on performance.
When changing from an unequal to equal length exhaust manifold, changing to the respective
type oil pan is also recommended. Failing to do so may result in reduced performance as the
equal length pipes are longer and have more bends.
TURBO OUTLET
CATALYTIC
MX7760
CONVERTER
MX7960(F)
FRONT PIPE
The stock turbo outlet/front pipe isn't capable of expunging the exhaust gasses efficiently.
Especially at high rpms with higher boost, the confined exhaust gasses are unable to flow efficiently
through the turbo, causing unstable boost. Upgrading the turbo outlet/front pipe to one with a larger
opening helps solve this issue, providing improved turbo spool and stable boost.
Upgrading to a metal catalytic converter greatly reduces exhaust flow resistance whist
maintaining it's core function of reducing toxic gasses.
MX8265
High performance type
(not vent to atmosphere)
STOCK ENGINE
TUNED ENGINE
(e.g. 2.2/2.5l stroker)
Upgrade recommended
Upgrade required
STOCK ENGINE
TUNED ENGINE
(e.g. 2.2/2.5l stroker)
Metal type, around φ70〜φ75
MX8265
Metal type,
Metal type, around φ70〜φ75
CATEGORY
RECOMMENDATION
STOCK ENGINE
TUNED ENGINE
(e.g. 2.2/2.5l stroker)
High performance type (not vent to atmosphere)
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