fanbanlo

I asked a good friend of mine and he said the stock crank pulley is a harmonic balancer, and it's not a good idea to mess with changing to the UR pulley set.

Is this true?

JTso

iTrader: (2)

Some stock crank pulley might be a harmonic balancer such as those found on certain domestic engines, but it's not true for the TSX. The pulley itself is balanced as a rotating unit however.

fanbanlo

Thanks JTso. 1 more Q...

If I get the shorter belt (CRV), any other down side of this mod?

fanbanlo

Should I also replace the OE battery to maybe something beefier?

JTso

iTrader: (2)

IMO, the stock battery should be replaced with a better one even if you're not doing the pulley mod.

The downside is slight voltage drop under certain load condition. The lowest voltage is everything turned on.

curls

Since performing this mod I have not once noticed a problem with battery voltage, and that includes cold starts in temps well below -25*C (about -25*F), where a battery usually has very very low CCA's. Obviously the charging system is getting enough juice while the car is running or else that battery would never have lasted a few winters.

JTso - I recall the oem crank pulley has a layer of rubber between the inner and outer pieces (like a ring). Isn't that basically a harmonic damper by default? That being said, my UR pulleys have been on for over a year and many others have had them on longer without any problems - I wouldn't hesitate to run them in most/all cars I own.

JTso

iTrader: (2)

The term "harmonic balancer" has been used very loosely when referencing the crank pulley and it's function. The crank pulley on an externally balanced engine does serve the purpose of keeping the rotating assembly balanced. However, it's not the case for an internally balanced engine. The TSX crank pulley does have an elastomer band to absorb operating noises such as the drive belt, but it doesn't serve the same "balancing" task.

If you think about what goes on the ends of a crankshaft, one would worry more about installing clutch, lightweight flywheel or dumping the clutch during hard launches than a lightweight crank pulley on an internally balanced engine.

Having said that, an aftermarket clutch, flywheel, or crank pulley should be correctly balanced during the manufacturing process to avoid any potential vibration issues.

Here's an article on engine balance and harmonic balancers.

http://www.carcraft.com/howto/ccrp_0...l_balance.html

curls

So there is a definite difference between harmonic balancer (not needed in our car as much), and a harmonic damper (useful for all cars but not 100% imperative for operation)? If so, the rubber ring on the stock pulley is the latter -- a damper, and because the engine is internally balanced using dual balance shafts, we should be ok providing the replacement pulley is balanced properly when manufactured.

feuss2

iTrader: (1)

This is an old topic, discussed at legnth in several threads here, for example:

https://acurazine.com/forums/1g-tsx-performance-parts-modifications-126/danger-power-pulleys-understanding-harmonic-damper-678092/