thanks I'll give it a try..

 

The new Audi TT with DSG gearbox contains double clutches and software that apparently preselects the next gear. So when accelerating, the second clutch with prepare the next gear before you select it, allowing for continuous power when the shift point is reached.

I wonder what happens if you trick the system and demand a downshift when it has prepared for an upshift? Kinda like branch misprediction cases on Pentium chips....

///Robin

 

[QUOTE]Originally posted by RazorV3

 

[QUOTE]Originally posted by johninator

 

The reason the 'Cup boys shift without the clutch has nothing to do with g forces and tranny experts, it has to do with their Jericho (sp?) transmission and massive straight cut gears. Ever seen those gears? Couldn't break 'em with a sledge hammer. They don't necessarily 'finesse' them into gear either

You can shift your S with out the clutch - up and down the tranny, but you'd better have an excellent feel going up the box, and REALLY match those revs coming down. The shifter does not come out of gear off load as easily as say my e36 for which it is effortless, but going up the box, it does go into gear easier than the above mentioned car. All that said, I just don't see where it is faster than a super quick shift with the clutch in our cars. If your timing is down, you can literally have the shifter moving before you fully depress the clutch, and the clutch pedal is already on the way up by the time you pass through the neutral gate and into gear. When rushing it, you can shift using the clutch and barely hear the revs drop - but I'm hard pressed to see how that isn't beating up the tranny.

 

[QUOTE]Originally posted by nutsack

 

Racecars have what is called constant mesh gearboxes. The gears on the layshaft are splined to the layshaft. The gears on the pinion shaft are NOT splined to the pinion shaft, therefore the gears are constantly meshed. A gear is selected via a shift fork with a dog ring that is splined to the pinion shaft.

When I raced Formula Mazda, I would upshift without the clutch. When I downshifted, I would push the clutch pedal in about 1/2 way down. The drivers that left foot braked (very few) would not use the clutch at all except leaving the pit or taking off after a spin. I am a right foot braker. I tried to left foot brake but I could not move my left foot from the clutch to the brake and vice versa. Even with the constant mesh gear box, it is VERY hard to downshift without the clutch without grinding the shit out of the gearbox. I found it more reliable to use the clutch to downshift. After all the difference could be winning or losing or having to pay for a gearbox that was destroyed due to driver error.

The S2K is NOT a racecar. If you want to destroy your transmission, that your business. Over the years, I have broken a clutch on about 4 or 5 cars. Street cars just cannot be shifted without disengaging the clutch, it's almost impossible, and impractical. I broke a clutch cable on a Honda XL600 and it was almost impossible and impractical to shift without disengaging the clutch.

 

[QUOTE]Originally posted by TrueDrezzer
The new Audi TT with DSG gearbox contains double clutches and software that apparently preselects the next gear.

 

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