[dmboone25]

Originally Posted by yourfriend

Exactly, I really don't care what is faster. Sometimes I'm slow with shifting manuals--so slow that a corolla will beat me off the line while I am driving my dad's 911.

If I need to shift really fast to show him/her who's boss, I suppose I could (and sometimes I do when a Prius inevitably decides it wants a "race", race in quotations because of how laughable that idea is--why do they all seem to want to race anyway?)--but I don't care! It just feels SO good to be shifting the car myself either way. People care too much about numbers, and it's making cars way more boring.

Totally agreed - it's what I miss from my past cars more than anything. The shifting...I think that's one of the reasons I like my bike so much - the shifting and the feel, sound of the thing. Just so much more fun - and yes, slower...a although it feels faster.

[wat2win]

Originally Posted by Greenkirby21

I believe when you shift in a 6MT the boost is lost and the turbo has to respool (kinda like a type of turbo lag)

Whereas in an auto the boost is kept constant while it shifts

So theoretically in a manual you have to rebuild boost, which that slight delay causes you to loose some time

Don't ask me the technical parts of it because I have no idea! I'm assuming because of the clutch

I thought as long as u shift and if rpm stays above 1250(for28i) isnt the turbo is spinning fast enough? All you need is boost back isnt it??

I might be wrong bc i really do not understand the boost part ppl talk about.... Even in tuning....

[DrFranknFurter]

The question of Boost is really not rocket science. Basically between gear changes the amount of boost or forced induction of air into the engine reduces. There are 2 reasons why this happens;

1. As you change gear you lift off the gas pedal when you depress the clutch. This in turn causes the RPM of the engine to drop rapidly as the engine is no longer connected to the gearbox and the gas pedal is at idle position. Whilst this happens the exhaust gas is greatly reduced and it is this exhaust gas that drives the Turbo Turbine that spins the Turbo Compressor that pressurises induction air into the engine (loss of boost) this can be mittigated to some degree but Rev/RPM matching, that is to hold the gas pedal at a position where the engine RPM will match the gearbox RPM. Obviously this is no standard everyday driving skill for most. The M235 ZF ruduces this in 2 ways, firstly the gear change is much quicker than a manual change especially for Mr Average. Secondly in Sport mode the ECU(engine management) will RPM match between gears.

2. One other advantage of the ZF/DCT is that RPM matching is not as important as the speed change since when the engine is under less load (engine not connected to gearbox) the exhaust gas is less and there for the Turbo Boost is also less. It's important to remember that engine RPM and Turbo RPM are completly different.

[Vervain]

Originally Posted by DrFranknFurter

The question of Boost is really not rocket science. Basically between gear changes the amount of boost or forced induction of air into the engine reduces. There are 2 reasons why this happens;

1. As you change gear you lift off the gas pedal when you depress the clutch. This in turn causes the RPM of the engine to drop rapidly as the engine is no longer connected to the gearbox and the gas pedal is at idle position. Whilst this happens the exhaust gas is greatly reduced and it is this exhaust gas that drives the Turbo Turbine that spins the Turbo Compressor that pressurises induction air into the engine (loss of boost) this can be mittigated to some degree but Rev/RPM matching, that is to hold the gas pedal at a position where the engine RPM will match the gearbox RPM. Obviously this is no standard everyday driving skill for most. The M235 ZF ruduces this in 2 ways, firstly the gear change is much quicker than a manual change especially for Mr Average. Secondly in Sport mode the ECU(engine management) will RPM match between gears.

2. One other advantage of the ZF/DCT is that RPM matching is not as important as the speed change since when the engine is under less load (engine not connected to gearbox) the exhaust gas is less and there for the Turbo Boost is also less. It's important to remember that engine RPM and Turbo RPM are completly different.

Great explanation.