M6 vs high stall A4 question.
03-20-2017, 01:07 PM
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M6 vs high stall A4 question. Gentlemen, l keep reading various threads of how a high stall A4 may have traction issues. When I drive my M6, from a dead stop. Going wot to redline. Before I shift. I have no wheel spin. Using 17x9 275/45/17 tires.?
03-20-2017, 01:12 PM
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The torque multiplication from the converter creates acceleration, and you need a tire to control it. If you (m6) can go wot in first you are leaving off idle. Most m6 cars that are competitive drop the clutch as high as 6500 rpms. If you did that you'd have either acceleration or wheel spin. The bottom line is, you dont have traction problems bc you arent leaving the line very hard.
03-20-2017, 02:05 PM
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A high RPM stall converter is doing 2 things:
1) allowing the engine to rev quickly from idle and hit a certain RPM before it hydraulically couples and begins to apply torque to the transmission and everything behind it
2) based on the converter internals it's basically multiplying the above mentioned torque to over double (on a dyno this can be seen if the car is improperly run and the car is allowed to flash the torque converter...it will show a much higher torque reading than what the engine is actually producing)
So it sounds like you are comparing leaving lightly at likely under 1,500 rpms to a high stalled auto which is going to nearly free rev up to 3,600-4,200rpm and apply the equivalent of over 700 ft/lbs of torque to the transmission input shaft.
As 01ssreda4 said a better comparison would be a high RPM clutch dump...but then you are likely to break either the driveshaft, u-joints, or stock 10 bolt rear end if it even tries to hook instead of boil the tires. A stalled auto is still a softer hit than a clutch dump. It's a very quick hydraulic couple of turbines instead of an instant mechanical grab of the clutch material to the flywheel surface.
1) allowing the engine to rev quickly from idle and hit a certain RPM before it hydraulically couples and begins to apply torque to the transmission and everything behind it
2) based on the converter internals it's basically multiplying the above mentioned torque to over double (on a dyno this can be seen if the car is improperly run and the car is allowed to flash the torque converter...it will show a much higher torque reading than what the engine is actually producing)
So it sounds like you are comparing leaving lightly at likely under 1,500 rpms to a high stalled auto which is going to nearly free rev up to 3,600-4,200rpm and apply the equivalent of over 700 ft/lbs of torque to the transmission input shaft.
As 01ssreda4 said a better comparison would be a high RPM clutch dump...but then you are likely to break either the driveshaft, u-joints, or stock 10 bolt rear end if it even tries to hook instead of boil the tires. A stalled auto is still a softer hit than a clutch dump. It's a very quick hydraulic couple of turbines instead of an instant mechanical grab of the clutch material to the flywheel surface.
03-20-2017, 04:08 PM
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Some great answers above, but there really isn't any need for yet another thread that essentially covers the same traction related concerns that your other current thread has evolved into covering:
https://ls1tech.com/forums/gears-axl...-concerns.html
https://ls1tech.com/forums/gears-axl...-concerns.html