FE Series Engines
(3/5SFE / 4/7AFE / 4/5EFE /
1ZZFE / and V6 / V8s)
various FE series engines (using the FE head design) are the most thoroughly
developed and purpose tuned Toyota power plants.
In the USA, 98% of current models Toyotas use this engine/head design.
The FE 4 valve per cylinder, narrow-angle Twin Cam heads (on the various
Toyota blocks) are the reason for the amazing response and smoothness of the
current generation Toyota motors. The
high torque characteristic designed into these engines give the driver all the
advantages of the Twin Cam head design- plus low-end torque and fuel economy.
Torque is the reason why these engines respond quickly and smoothly.
The performance band has been engineered to provide power from low RPM to
the designated redline.
There has been a lot of
requests for parts and modifications for these engines, but unfortunately trying
to raise the RPM band (or changing cams) will negate all the built-in attributes
of these engines. A camshaft change
to raise the power band higher, will result in the loss of low-end torque and
idling problems. Drivability will
suffer and the trade off will leave the customer with a compromised engine,
trying to work against the ECU program and engine design.
By comparison, the
performance oriented GE versions of the same series engines, (if available on
the sporty models)- offer about a 20% horsepower advantage- but at a loss in low
RPM response and torque. The GE
heads are more of the true Twin Cam design: wide-angle valves, long duration
cams- suited for high RPM and high output- but at the sacrifice of throttle
response in the lower RPM levels.
There are improvements that
can be made to the FE engines- but the Toyota engineered power band should not
be altered. The ECU program and
Camshaft profiles, if changed will result in a loss of drivability and risk
internal damage. You cannot do a
better job than Toyota on coaxing power from these series engines, and needless
to say, stay street-legal.
Upgrading these engines, is
of course still possible: intake
systems, exhaust components, ignition upgrades all help in fine-tuning these
engines. The rule to follow and
keep in mind is that all modifications are basically external in nature.
The only exception being pistons- to increase or decrease compression-
within the same RPM band. Turbocharging
and/or supercharging will help- but keep in mind that based on the design
parameters (again) these engines were designed for response- meaning lightweight
internals: con rods/crankshaft (as compared to the sportier GE series engines).
The short answer is- if you
are seeking a true high performance engine and high HP outputs- upgrade to the
GE version of your engine (if available).
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