2G South Bend clutch slipping, surely I'm not hitting 400 ft. lbs?

[randman2011]

I have ~2700 miles on the South Bend Stage 3 "Daily" clutch that I installed in October of 2019. A new Competition Clutch flywheel was installed at the same time. I have had no clutch problems since then until I noticed on a drive in January that the clutch would slip only in 5th gear and only at ~3200 RPM at WOT. I couldn't instigate slip in any other gear and can't reasonably test above that threshold in 5th because that's like 90 mph, but if I floor it in 5th, when peak torque hits it would break the clutch loose every time.

South Bend rates this clutch for 400 ft. lbs. and I just can't believe that my 2.0L is making enough torque to overwhelm it given my mild build. FP1 cams, 9:1 compression, ~20 psi of boost from an HTA68 V1. I turned the boost down a half turn on the MBC in case it is, but I haven't driven the car since other than to the store and back.

I've been singing praises for this SBC for how light it feels but if this is all that it can handle, I'm a bit disappointed. Or maybe I'm just underestimating this 4G63?

 

[twicks69]

Which exact model clutch do you have?? Stage 3 doesn't mean anything. What pressure plate (HD, SS, SSX), which disk (O organic, TZ kevlar, TZ/B kevlar/ceramic, B Ceramic full face, B Ceramic 6-puck)?

Where do you have your pedal disengagement range at? It should be around 0-2" from the floor, if you are above that, you could be pre-loading the clutch and causing partial disengagement enough to make it slip.

 

[randman2011]

The SBC part number is K05048-SS-O, so SS pressure plate and organic disk.

That's a good question. It should be pretty close to the floor since that's where my previous clutch disengaged and the new one didn't feel any different when I first installed it but I haven't driven the car in about a month. Let me confirm that.

 

[twicks69]

The SS-O should handle around 400tq at the crank. Maybe a bit more. Check to make sure you are not over-adjusted.