Gamezilla

Is there any real difference other than the mazdaspeed one has replacable friction discs?

Gamezilla

So should I spend the extra money or is the ACT good enough?

Julian

iTrader: (14)

Racing Beat also has replaceable friction surface Alum Flywheel, resonable price I have been using for about 4 years

JaNusSolSumnus

I second the Racing Beat model, good price and the replacable disc is a nice option. My only complaint was the bolts/nuts to attach the flywheel to the clutch, could of been done a better way for the sake of install but once installed its nice and secure.

~Kris

ACTman

These are some of my thoughts on it taken from a similar thread on the EvoM forum:

... I don't want to bag on anyone's product. Personally I don't care for aluminum flywheels for a host of reasons. Most of these reasons are more in principle than common problems. I say this right up front so hopefully you don't get the wrong idea. I don't want to come off with make-believe scare tactics...

Here are some of the main reasons ACT perfers to manufacture only forged chrome-moly flywheels:

Chrome-moly is much stronger, harder, and resists fatigue better than aluminum. Chrome-moly can be heat treated to suit the need where aluminum cannot.
Chrome-moly is three times more rigid than aluminum (Youngs modulus of elasticity).
Chrome-moly can serve all purposes at the same time: friction surface, gear teeth, and structural all in one piece.
One piece flywheels can be machined perfectly flat. Bolted on steel inserts are never perfectly flat to begin with and they warp easily. The more fasteners used = the smaller the bumps will be between the bolts.
One piece design will transmit heat more evenly and effeciently from the disc than muliple pieces.
One piece design allows more liberty to machine to the most optimum shape.
One piece design prevents anything like ring gears, bolts, etc. from ever coming loose.
Thermal expansion rate of aluminum is much different than steel. One piece = one thermal expansion rate.
Threads, bolt surfaces and critical dimensions wear quickly in aluminum compared to chrome-moly.
Our flywheels are less likely to need resurfacing compared to the need to replace the insert on the multipiece equivilent. This is because the surface the disc is riding against is probably three times as thick as the typical insert and much harder.
Resurfacing is economical: When necessary, it cost half the price of an insert, and usually no shipping costs.
Chrome-moly steel has a higher coeffecient of friction than aluminum so it adheres to the crankshaft better. On high hp cars, the flywheel has more difficulty staying on.

WarspeedFD

Well put ACTMan. When you want to buy Fried chicken you go to KFC, not Burger King. Buy it from the people that specialized in it.