SONIC TECH NOTE SERIES:
SONiC TECH NOTE SERIES:
After market Light weight crankshaft pulleys
Flywheel/harmonic dampener and crank bolts coming loose, engine
Never remove the factory crank pulley on any engine to replace it with
performance pulley or light weight performance pulley. To replace
factory engineered pulley with something made by a person or company
does not understand the complete engine design will hurt the
performance/reliability of your engine not help it.
Toyota and many other manufactures such as BMW, Porsche, Mercedes all
dual mode damper pulley designs in all their engines. I have
a similar tech note on crank pulley's from Dinan Engineering (BMW
The factory stock pulley is designed to absorb both torsion and bending
lateral vibration from the crankshaft. This helps the crankshaft
high vibration in the 400 Hz range after the #1 piston fires.
has many benefits on the bottom end. It helps the crank deal
continuous loads as well as overall bearing life, not to mention overall
engine life. Also the drive-line will have a more pleasing sound
little 400Hz vibe's setting up.
See the following jpeg pictures from a Toyota engineering book discussing
A number of times I have personally seen bad side effects on street
track cars using these after market crank pulleys. Avoid them,
other good performance upgrades that will not hamper the reliability
I understand that this topic has seen many flame war's back and forth
of our supra club mail lists and other car lists around the country.
I personally don't mind this at all, I feel it is my responsibility
to tell our members
about correct and documented information such as this topic regardless
of the flame
wars it could result.
Please send any flame comments with regard to this directly to
email@example.com e-mail address so as not to bog down the list servers
this type of email.
There has been too much disregard the past year on all of our club web
with regard to erroneous information being given to many car club members
Our sites should only offer good upgrades for Toyotas. Upgrades
that will not hurt the
reliability of the car.
Written by Reg Riemer Copyright Sonic 1997 (free to distribute and copy
in this original format)
Supra Owner Network in Canada
See the SONiC web site @
Technology Is The Only Substitute For Cubic Inches
Information provided is given free of charge in good faith without
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See RCTS's 700 HP Supra running in the One Lap of America, picture