4 Speed Flywheel vs. 3 Speed Flywheel (2 Viewers)

[pb4ugo]

I think the number one reason Toyota went to a diaphragm clutch was the lower pedal pressure. In most cases a three finger can
provide better clamping pressures but you can overcome that with a larger diameter diaphragm clutch. Most of my clutch swapping
has been with V-8 conversions because the power differences from one V-8 to the next are wide. The FJ40 is pretty much figured out
by Toyota. Most people will be happy with the stock clutch and it's ability to harness the modest amount of torque and horsepower.
I have, on the other hand personally played with the variety of other clutches in V-8s with 2-400hp. I had a 3 finger 4500lb "racing"
clutch in one setup that slipped annoyingly, especially when it got wet. I replaced it with a 12" 1600 lb and the pedal got lighter and it
never slipped again. The other problem with the heavy pedal clutches is they wear out the thrust bearings on the crankshaft. Every time
you step on the clutch you are pushing that crankshaft forward. The 4500lb clutch wore the crank bearings down in about 25,000 miles

I had the same problem with clutch slippage and a 450+ sbc many yrs ago.
I then i went to a ceramic style clutch with pads instead of a disc. I currently run a relatively stk sbc and an organic/ceramic mix with a stk pp plate. My pedal is scary easy to push and no slippage.

 

[lcwizard]

I had the same problem with clutch slippage and a 450+ sbc many yrs ago.
I then i went to a ceramic style clutch with pads instead of a disc. I currently run a relatively stk sbc and an organic/ceramic mix with a stk pp plate. My pedal is scary easy to push and no slippage.

The other advantage of a larger clutch is better heat dissipation leading to less long term flywheel damage and longer clutch life