is an aftermarket ballancer safe/better than stock for high hp?
03-07-2010, 03:39 PM
#1
is an aftermarket ballancer safe/better than stock for high hp? i have a g8, mild cam, twins. pushing 600+rwhp and close to 7000rpm.
saturday my ballancer nearly came off while at the track, it could have been ugly.
my plan is to pin the stock ballancer, new bolt, locktite and make sure i get it properly torqued. an after market sfi underdrive ballancer has been recomened. would there be any negative effects? will it absorb the harmonics like a stock ballancer? a few extra hp would be ok and since i am spining it higher than stock and pulling thru the rpms faster than stock maybe i should be looking at an aftermarket underdrive ballancer?
just dont want to spin a bearing or something silly after i get one and find out they have known issues.
saturday my ballancer nearly came off while at the track, it could have been ugly.
my plan is to pin the stock ballancer, new bolt, locktite and make sure i get it properly torqued. an after market sfi underdrive ballancer has been recomened. would there be any negative effects? will it absorb the harmonics like a stock ballancer? a few extra hp would be ok and since i am spining it higher than stock and pulling thru the rpms faster than stock maybe i should be looking at an aftermarket underdrive ballancer?
just dont want to spin a bearing or something silly after i get one and find out they have known issues.
03-07-2010, 08:33 PM
#2
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It's basically just a pulley. The motor is internally balanced, which is why they aren't keyed or pinned from the factory. I would get an underdrive pulley. They only show a few hp but it allows the motor to build rpm a little faster so is should reduce your et a little.
03-07-2010, 09:23 PM
#6
FI = pinned or keyed NA = not necessary. This is an interference fit which is not well suited to heavy torque loads. It can support low parasitic loads such as an A/C compressor, water pump, power steering pump and alternator, but not a big blower. That calls for additional clamping force an interference fit does not provide.
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03-11-2010, 06:19 AM
#8
i have an under drive ballancer on the way and am going to key it this time along with makeing sure that bolt is tight. then bump it up a little more
03-11-2010, 06:35 AM
#9
TECH Senior Member
There are some threads here where an underdrive pulley/dampener may be responsible for a broken timing chain... if it's too small it won't sufficiently dampen the harmonics.
03-11-2010, 06:37 AM
#10
TECH Senior Member
03-11-2010, 06:41 AM
#11
TECH Senior Member
I'm not sure what you're saying... you mean a solid balancer (i.e. inner and outer parts solidly connected, no rubber/elastomer)...? It won't have the ability to dampen crank harmonics... crank harmonics have to be absorbed somewhere otherwise damage will ensue... you already know this, right...?
03-11-2010, 09:49 AM
#14
I'm not sure what you're saying... you mean a solid balancer (i.e. inner and outer parts solidly connected, no rubber/elastomer)...? It won't have the ability to dampen crank harmonics... crank harmonics have to be absorbed somewhere otherwise damage will ensue... you already know this, right...?
there are plenty of solid balancers out there. as long as your engine is balanced correctly you wont have any problems. the reason for solid balancers is mainly for supercharged cars that have a high load on the belt system. if you use an elastomer bonded pulley/balancer, it will slip and break the bond. but they are used for high RPM engines as well to keep from slipping.
03-11-2010, 03:24 PM
#16
TECH Senior Member
i dont think you know what your talking about.
there are plenty of solid balancers out there. as long as your engine is balanced correctly you wont have any problems. the reason for solid balancers is mainly for supercharged cars that have a high load on the belt system. if you use an elastomer bonded pulley/balancer, it will slip and break the bond. but they are used for high RPM engines as well to keep from slipping.
there are plenty of solid balancers out there. as long as your engine is balanced correctly you wont have any problems. the reason for solid balancers is mainly for supercharged cars that have a high load on the belt system. if you use an elastomer bonded pulley/balancer, it will slip and break the bond. but they are used for high RPM engines as well to keep from slipping.
Why do you say "i dont think you know what your talking about. "...?
The harmonic balancer has nothing to do with internal balancing, it has to do with crank harmonics (with each ignition event, the crank twists/untwists, this motion has resonant frequencies (harmonics) where the crank twist/untwist oscillations get bigger... the harmonic balancer dampens these oscillations and/or moves those frequencies so they can't be achieved).
I am wondering what type of pulley/balancer is used in OEM SC applications...?
