Racelogic Traction Control

phunk

See I am on top of the theory of it all, but what I am trying to say is that: just because the no-lift shift box has cut fuel or spark doesnt mean the engine is immediately at the lower speed. It will still take a moment for the mass of the crank and flywheel to decelerate, and with the throttles wide open there isnt even any manifold vacuum to help. If you are shifting as fast as you are physically able, which I assume is pretty fast if you are experienced and confident, the engine isnt going to have enough time to decelerate to 5500rpm.

Of course, the way I am doing it, the engine is staying at redline the entire shift, working the synchros a little more, but my transmission does not complain, it shifts just fine and hasnt started to grind or anything and that is 60,000 miles on it and it is still on the factory fill trans fluid and all. I had the same experience with my 350z, however that car did break its transmission a couple months after I sold it (but it was 10 years old by then and been through hell, and a new trans isnt even expensive enough to worry about). To have it at redline as I release clutch in the next gear also gives me a nice little jerk of power as the inertial energy of the flywheel and crankshaft at 7500rpm gets blasted into the drivetrain to decelerate it to the next gears speed.

If you watch my in-car vids, you will notice that the car only taps the limiter the first time and you cant even hear it because the shift is already over. You use that first cut as your no-load chance to slam that shifter. Only on my slower/miss-timed shifts do you notice that it hit the limiter.

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Chuck33079

No ****? Wow. I'd love to see an analysis and see what weight it's sheared down to after the abuse you put it through.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

victorofhavoc

Oh I see what you're saying now. Well From my experience with it on a boosted engine, not the Z's, it has always fallen as fast, if not a tad faster, than the time it has taken me to push in the clutch shift to the next gear and release the clutch. Especially on 2-3 4-5 shifts. I may not be as fast as a DSG auto, but the .5 sec it takes me to shift is enough time for RPMs to fall enough to where it matters. And of course peak range for torque is more efficient this way.

EDIT: I'm sure a lightweight flywheel would also help it fall faster, when it's not holding the same intertia

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Had a 2010 WRX- boy was it quick in a straight line, got a 2014 Z- man is she grippy in the corners-- then left the Z and later got a GTI, now back in an 09 racecar Z!

phunk

peak torque and turbo efficiency and all that have nothing to do with it... gearing is gearing, and once the clutch is re-engaged the engine speed will match the wheel speed per the selected ratios and thats what you have to work with. the most a wot-box can do is help keep a big turbo spinning faster by burning the fuel in the exhaust mani, but we dont need that, turbos on Z's arent laggy anyway and the car has enough natural power to propel itself quickly even if it did loose boost for a split second.

my car has a twin disk clutch and light flywheel... it still isnt gonna fall quick enough that i want to wait for it!

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victorofhavoc

Haha, fair enough. The whole process is more useful on 4cyl cars by far, and especially for awd where gear to engine speed management is important to not break things. If you're not spinning you wheels every shift, not experiencing an absurd shock, and shifting before your rev limiter you're most likely good to go anyway

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Had a 2010 WRX- boy was it quick in a straight line, got a 2014 Z- man is she grippy in the corners-- then left the Z and later got a GTI, now back in an 09 racecar Z!