Digitalfiend
New member
I have a question that has been bugging me all weekend with regards to tuning engagement for peak torque coming out of corners.
Every forum post on the subject of clutch engagement tuning seems to recommend tuning for just before peak torque. In theory, this makes sense: transfer peak torque to the sprocket/driver to accelerate the kart. But why does tuning for peak torque really matter coming out of a corner if the higher rpm engagement is going to result in slippage between the clutch and drum? Slippage is loss of torque: the clutch drum is connected to the axle via the chain/driver, so the engine can’t possibly instantly accelerate the mass of the kart; i.e. the clutch drum and clutch shoes will turn at different rates (until they sync up), resulting in slippage.
Since slippage means loss of transferred torque, then couldn’t it be possible that the actual torque transferred, after accounting for the temporary slippage, is similar to the torque the engine puts out at a lower rpm without slippage? I guess it depends on how much torque is lost through slippage and just how low-speed the corner is. If the corner would result in the engine running below 2500rpm, then setting the engagement to 3400rpm is probably beneficial. But if the corner is above 2500rpm, where the engine makes reasonable torque (8.5 lb-ft), then the actual torque applied at 3400rpm, after factoring in slippage, might not be any greater than if you just locked up at 2500rpm.
My question really only applies to whether tuning matters for corners. With regards to starting from a stand-still, I get why tuning would probably be important: the engine can likely accelerate the kart from a stand-still faster, even with the slippage, starting at peak torque (e.g. 3400rpm) vs idle (e.g. 1600rpm).
I've come to the conclusion that the only time I can see clutch engagement tuning being important is on a track with a really long straight and some really tight corners. You'd have to gear for the straight and that tall gear would likely drop the engine below 2500rpm in the corners, so tuning the clutch engagement for peak torque might result in better acceleration, even after factoring in the torque lost due to slippage (edit: this is likely incorrect thinking on my part and the clutch can probably still transfer the peak torque of the engine even when slipping. See my response below here). Otherwise, for tracks that don't have long straights and tight corners, clutch tuning probably doesn't matter that much.
Am I thinking about this the wrong way or missing something?
Every forum post on the subject of clutch engagement tuning seems to recommend tuning for just before peak torque. In theory, this makes sense: transfer peak torque to the sprocket/driver to accelerate the kart. But why does tuning for peak torque really matter coming out of a corner if the higher rpm engagement is going to result in slippage between the clutch and drum? Slippage is loss of torque: the clutch drum is connected to the axle via the chain/driver, so the engine can’t possibly instantly accelerate the mass of the kart; i.e. the clutch drum and clutch shoes will turn at different rates (until they sync up), resulting in slippage.
Since slippage means loss of transferred torque, then couldn’t it be possible that the actual torque transferred, after accounting for the temporary slippage, is similar to the torque the engine puts out at a lower rpm without slippage? I guess it depends on how much torque is lost through slippage and just how low-speed the corner is. If the corner would result in the engine running below 2500rpm, then setting the engagement to 3400rpm is probably beneficial. But if the corner is above 2500rpm, where the engine makes reasonable torque (8.5 lb-ft), then the actual torque applied at 3400rpm, after factoring in slippage, might not be any greater than if you just locked up at 2500rpm.
My question really only applies to whether tuning matters for corners. With regards to starting from a stand-still, I get why tuning would probably be important: the engine can likely accelerate the kart from a stand-still faster, even with the slippage, starting at peak torque (e.g. 3400rpm) vs idle (e.g. 1600rpm).
I've come to the conclusion that the only time I can see clutch engagement tuning being important is on a track with a really long straight and some really tight corners. You'd have to gear for the straight and that tall gear would likely drop the engine below 2500rpm in the corners, so tuning the clutch engagement for peak torque might result in better acceleration, even after factoring in the torque lost due to slippage (edit: this is likely incorrect thinking on my part and the clutch can probably still transfer the peak torque of the engine even when slipping. See my response below here). Otherwise, for tracks that don't have long straights and tight corners, clutch tuning probably doesn't matter that much.
Am I thinking about this the wrong way or missing something?
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