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Upshifting with syncro-rev

Old May 2, 2009 | 06:09 AM
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Question Upshifting with syncro-rev

What's the purpose of syncro-rev when upshifting. It just seems like it would reduce performance. I can see the purpose for it when downshifting & hard braking right before a turn. Do some people really take that long to upshift for the RPM's to drop low enough to possible cause shift lock?
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Old May 2, 2009 | 06:20 AM
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It's supposed to be for smoother shifts. Some people, especially those new to manual transmissions, have trouble making smooths shifts because they either overrev or take too long and the RPMs drop. That causes the car to buck during the gear change.

Sure, it's not the best thing for performance but that's not the intent.
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Old May 2, 2009 | 06:54 AM
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Originally Posted by DavesZ#3
It's supposed to be for smoother shifts. Some people, especially those new to manual transmissions, have trouble making smooths shifts because they either overrev or take too long and the RPMs drop. That causes the car to buck during the gear change.

Sure, it's not the best thing for performance but that's not the intent.
I don't think it would be ideal for track use since it wouldn't give full power when attempting to accelerate as fast as you can through the gears. Too bad you can't turn the upshift portion off & leave the downshift on. It's either all or nothing, right? Just something I thought it would end up on the G37 instead of a high performance car like the 370Z.
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Old May 2, 2009 | 07:17 AM
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To be smooth while accelerating hard you want to start letting the clutch out a little early anyway. That brief second while your RPM are perfectly matched and you are off the gas = engine braking. It's more for downshifting and allowing people who aren't at that skill level to have perfect downshifts, especially in heal-toe situations. While it will still match RPM for up-shifts, it is rather unobtrusive.
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Old May 2, 2009 | 07:20 AM
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Originally Posted by ZR_Yancy
What's the purpose of syncro-rev when upshifting. It just seems like it would reduce performance. I can see the purpose for it when downshifting & hard braking right before a turn. Do some people really take that long to upshift for the RPM's to drop low enough to possible cause shift lock?
I believe there is a button to turn it off tho,!! Rev Match up shifting barely makes sense to me

Last edited by BeeAyche; May 2, 2009 at 07:27 AM.
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Old May 2, 2009 | 07:49 AM
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Ultimately, we won't know if it's a benefit or detriment on the track until somebody gets out and lays down some laps with it on and off and we see results.

I also suspect that in a performance driving situation, most of us can shift faster than the rev-match will be able keep up and have much effect on.

Last edited by DavesZ#3; May 2, 2009 at 10:10 AM.
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Old May 2, 2009 | 09:23 AM
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i thought the sycro rev only worked for downshifts...
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Old May 2, 2009 | 10:24 AM
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From my thread, my thoughts on this feature:



Before I tried it, I thought I would hate it and never use it. I'm a bit of a purist, and love heel-toe downshifting. Being able to do it properly, whenever you want, in whatever situation calls for it, is not only a skill but an art. After I started playing with the new feature, I have yet to turn it off. It matches the RPM perfectly every time. It's pretty damn cool to say the least. My only concern is what kind of bad habits it may lead to, on or off the track. I also wonder how this feature will be affected when a lightweight flywheel is used.

Last edited by roast; May 2, 2009 at 11:15 AM.
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Old May 2, 2009 | 12:22 PM
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How does it keep up with quick up-shifts? I know under track conditions I can shift from 1-2 and 3-4 pretty quickly.
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Old May 2, 2009 | 12:26 PM
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I don't think that it rev matches on upshits. I have been driving mine for a week now and don't notice a rpm match when shiting from 1-2-3-4. I believe it rev matches only on down shifting. Correct me if I am wrong, but I don't notice any change of RPM on upshifts.
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Old May 2, 2009 | 01:06 PM
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It's really designed for downshifting. If you're speed shifting it doesn't do a thing. You aren't giving the RPM a chance to fall low enough where gas would need to be supplied to keep the engine speed at the right RPM.

If you up shift.... and hold the clutch in... the RPM will drop at the normal rate, right to the point where the RPM need to be at. Then it will hold the RPM there until you decide to release the clutch pedal.

You will never notice the feature when upshifting, unless you wait too long to release the clutch.

I'll make a video of it in action. Be back in a bit.
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Old May 2, 2009 | 01:25 PM
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Originally Posted by roast
I'll make a video of it in action. Be back in a bit.
Try to get 2 runs it. One with syncrorev on & one with it off. When up shifting, speed shift like you are drag racing. Make sure you turn VDC off. I'm going to assume syncrorev will also stop wheel spin like VDC so you're not going to be barking the tires when up shifting.

Last edited by ZR_Yancy; May 2, 2009 at 01:29 PM.
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Old May 2, 2009 | 01:29 PM
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You guys that own a 370Z and don't know if it works during upshifts - ya'll should go read section 5-16 of your owners manuals.
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Old May 2, 2009 | 01:32 PM
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Originally Posted by STLZ
I don't think that it rev matches on upshits. I have been driving mine for a week now and don't notice a rpm match when shiting from 1-2-3-4. I believe it rev matches only on down shifting. Correct me if I am wrong, but I don't notice any change of RPM on upshifts.
Isn't this in your manual?:

"When Downshifting:
The engine speed is automatically increased to the target
engine speed befre the clutch engages.

When Upshifting:
The engine speed is automatically kept AFTER the engine speed lowers
to the target engine speed. Rapid clutch engagement before the engine
speed lowers to the target engine speed may cause shift shock."
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Old May 2, 2009 | 02:32 PM
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Originally Posted by ZR_Yancy
Try to get 2 runs it. One with syncrorev on & one with it off. When up shifting, speed shift like you are drag racing. Make sure you turn VDC off. I'm going to assume syncrorev will also stop wheel spin like VDC so you're not going to be barking the tires when up shifting.
Sorry, I already left before I read your post. The feature will not stop wheel spin... all it does is monitor your speed and the gear your in, and supply fuel to make the RPM match. So if you're speed shifting, like when drag racing, it doesn't do anything at all because you aren't giving the engine time to slow down enough where fuel would be required to match the RPM. It also does not slow the engine down at all. So if you are downshifting aggressively, you want to make sure you have enough gear... It will not save you from floating a valve. No, the system won't over-rev itself, but selecting too low of a gear will spin the engine past redline.... just like with any manual transmission.
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Old May 2, 2009 | 03:02 PM
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Originally Posted by roast
Sorry, I already left before I read your post. The feature will not stop wheel spin... all it does is monitor your speed and the gear your in, and supply fuel to make the RPM match. So if you're speed shifting, like when drag racing, it doesn't do anything at all because you aren't giving the engine time to slow down enough where fuel would be required to match the RPM. It also does not slow the engine down at all. So if you are downshifting aggressively, you want to make sure you have enough gear... It will not save you from floating a valve. No, the system won't over-rev itself, but selecting too low of a gear will spin the engine past redline.... just like with any manual transmission.
I'm still cornfused.

If syncrorev is supposed to make gear changing seamless, how does it not stop wheel spin if you are speed shifting.
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Old May 2, 2009 | 03:59 PM
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Originally Posted by ZR_Yancy
I'm still cornfused.

If syncrorev is supposed to make gear changing seamless, how does it not stop wheel spin if you are speed shifting.
..because all the system does is supply extra fuel to the engine when its needed to maintain a certain RPM. It doesn't cut fuel, slow the engine down, or apply the brakes.
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Old May 2, 2009 | 04:11 PM
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Originally Posted by roast
..because all the system does is supply extra fuel to the engine when its needed to maintain a certain RPM. It doesn't cut fuel, slow the engine down, or apply the brakes.
So... does the car override your input? Let's say you decide to do the heel/toe rev match manually. Will the car ignore your foot blipping the gas or will the syncrorev only engage if you don't touch the gas?

While up shifting, I know people don't let off the gas all the way when up shifting in a drag race. I'm wondering if the syncrorev will still rev match in that situation.

Last edited by ZR_Yancy; May 2, 2009 at 04:15 PM.
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Old May 2, 2009 | 04:25 PM
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http://www.youtube.com/watch?v=27gW9ZS0rkI
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Old May 2, 2009 | 04:33 PM
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Originally Posted by ZR_Yancy
So... does the car override your input? Let's say you decide to do the heel/toe rev match manually. Will the car ignore your foot blipping the gas or will the syncrorev only engage if you don't touch the gas?

While up shifting, I know people don't let off the gas all the way when up shifting in a drag race. I'm wondering if the syncrorev will still rev match in that situation.
There are sensors in the base of the shifter, so it knows which gear you are in or selecting. If you decided to rev match manually.... chances are it will beat you to it... all you would possibly do is apply too much throttle and over-rev... the same as you would have done if the system was off.
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