[Norm Peterson]

Originally Posted by lt4camaro

Norm, rev match is primarily for down shifting and only works if you keep your foot off the gas so you do not interrupt the throttle blip.
NLS is for full throttle upshifts (powershifts) only with gas to the floor

What I'm talking about is the rev matching that the driver does for himself, where the same concern about the revs being spiked up to fuel cut at least exists. The difference being that a driver doing this for himself can't blame the software or some sensor malfunction when the revs run past the tach's redline.

But auto rev-match and NLS could have a rev limit in common, different from fuel cut. And rev-match could hold the revs at whatever rpm long enough for the clutch to be let out in the lower gear, which would essentially be NLS logic.


Norm

[Norm Peterson]

Originally Posted by BMWM.D.

I see a big difference between manual (i.e. driver initiated) power-shifting and rev-matching on a downshift as far as risk is concerned. If you miss a power-shift in a modern car, the various methods the ECM uses to control rev limit are going to prevent the engine speed from going above a safe level. It probably won't hurt a thing. If you misjudge a downshift (i.e. going too fast for selected gear), you are going to force the engine into a mechanical over-rev. No rev limiter is going to save you. Valve float and related damage are possible.

I'm fully aware of all this.

I've had a manual trans car (or two) in my garage/driveway for as long as I've been driving. I really don't think I'll have a problem using NLS in a new car. It just takes a little faith in technology. I power-shifted my '68 Camaro the last time I had it out at the strip. I didn't find it too tough mentally. It was definitely harder on my drivetrain, though. The beauty of a modern NLS system is that it can make the car faster while being relatively kind to the drivetrain.

I've been driving MT cars for about 53 years now, and almost exclusively for the past 45. But as I posted before, my drag racing experience is almost nil. So the whole idea of powershifting (and by extension NLS) is very much an alien concept. While I can intellectually picture how it could work, holding the throttle pedal on the floor with the clutch disengaged is too far removed from what it's always taken to "drive hard but drive smoothly" and to avoid breaking drivetrain components.

Those with substantial MT drag racing experience would almost certainly have little or no trouble adapting. So I wonder where the "average driver" who buys a MT car today falls in terms of drag racing experience.


Norm

[SSDan]

Originally Posted by Norm Peterson

Those with substantial MT drag racing experience would almost certainly have little or no trouble adapting. So I wonder where the "average driver" who buys a MT car today falls in terms of drag racing experience.

I think I fall into the average driver category for being a MT driver who has been to a drag strip a couple of times (total of 5 passes down the strip). On those runs I did shift as quickly as I could but did not "power shift" with no lift of the gas pedal. Its debated whether my 6th gen has NLS or not but if there - I am not sure I'd be successful using it anyway.

After 40 years of "speed shifting" (quick but slight throttle lift) whenever I wanted to do some spirited driving - I think my muscle memory is too engrained to be successful with NLS. I see my right foot twitching no matter what. I'm just wired to do it that way. I doubt I will ever go true drag racing enough to retrain the brain and muscles. So NLS is a novelty feature for me just like the rev match. Cool ideas I don't see me using much if at all.

[TransAmx2]

Originally Posted by SSDan

After 40 years of "speed shifting" (quick but slight throttle lift) whenever I wanted to do some spirited driving - I think my muscle memory is too engrained to be successful with NLS. I see my right foot twitching no matter what. I'm just wired to do it that way. I doubt I will ever go true drag racing enough to retrain the brain and muscles. So NLS is a novelty feature for me just like the rev match. Cool ideas I don't see me using much if at all.

Hell, My left foot moves when I drive my Automatic Expedition, I find myself pushing on the left foot rest at lights and constantly have to touch the shift lever with my right hand. Thankfully that's about as bad as I have gotten, haven't shifted the automatic while moving....yet.

[SSDan]

Originally Posted by TransAmx2

Hell, My left foot moves when I drive my Automatic Expedition, I find myself pushing on the left foot rest at lights and constantly have to touch the shift lever with my right hand. Thankfully that's about as bad as I have gotten, haven't shifted the automatic while moving....yet.

I left foot brake in an auto trans. My left foot just has to get in the action!

[BMWM.D.]

Originally Posted by Norm Peterson

I'm fully aware of all this.


Those with substantial MT drag racing experience would almost certainly have little or no trouble adapting. So I wonder where the "average driver" who buys a MT car today falls in terms of drag racing experience.


Norm

I'm no hard core drag racer. I've been to the strip 5 times total with a few different cars. That said, I had no problem power-shifting at the track when I was looking to shave a few tenths from my ETs. I was even going to set up my supercharged C6 for no lift shift (can be done via tuning), but I decided it probably wasn't worth the risk given that I have methanol injection and cats. I think it would be great on this car, though.

Oh... and the only reason I mentioned the difference between manual power-shifting and manual rev-matching on a downshift was in response to you saying that you'd be nervous doing a no lift shift -- but shooting the revs up to near redline on a downshift doesn't bother you. Maybe that's not what you meant, but its how I read it. I'm much more nervous about forcing my engine into a mechanical over-rev than banging into the rev limiter at WOT.

[BMWM.D.]

Originally Posted by Norm Peterson

What I'm talking about is the rev matching that the driver does for himself, where the same concern about the revs being spiked up to fuel cut at least exists. The difference being that a driver doing this for himself can't blame the software or some sensor malfunction when the revs run past the tach's redline.



Norm

The only way that could happen would be if the driver were to force a mechanical over-rev by selecting the wrong gear. Even if something like the gear position sensor were to be inaccurate, it would simply blip the revs to the wrong rpm. Its not going to exceed the regular rev limit. There are a whole lot of fail-safes in place to prevent something like that, though.

[Norm Peterson]

Originally Posted by BMWM.D.

Oh... and the only reason I mentioned the difference between manual power-shifting and manual rev-matching on a downshift was in response to you saying that you'd be nervous doing a no lift shift -- but shooting the revs up to near redline on a downshift doesn't bother you.

That's exactly what I meant.

I'm very comfortable rev-matching a 4-3 downshift at 90 - 91 mph, when my 6000 rpm redline corresponds to 96 mph. My rev kick will make my 5900 rpm upshift indicator flash, but on the rev kick itself I've never run into what's supposed to be a 6250 fuel cut. IOW, I'm not needing any sort of rev limiting help. So far.

But I can't bring myself to not lift at least a little on the upshift.

Originally Posted by BMWM.D.

The only way that could happen would be if the driver were to force a mechanical over-rev by selecting the wrong gear. Even if something like the gear position sensor were to be inaccurate, it would simply blip the revs to the wrong rpm. Its not going to exceed the regular rev limit. There are a whole lot of fail-safes in place to prevent something like that, though.

It's a psychological thing based on long experience, something that the mere existence of a technological crutch cannot rewrite. No matter how good it might actually work.

In 45 years of rev-match downshifting MT cars I've mechanically pushed an engine past its limiter exactly once (fumbling for 4th from 5th with a vague OE shifter in a hard braking zone, not getting it, trying again and finding 2nd and somewhere north of 7000 before getting back on the clutch pedal . . . then having to coast through the upcoming 0.9g turn essentially in neutral . . . don't want to repeat that, ever again).

In the presence of a rev limiter, it's not fear of actually over-revving on the throttle so much as it is the dislike of actually running into the limiter. Means I just screwed up something I shouldn't have screwed up.


Norm

[Ian SS]

Originally Posted by clanky

Like I said I wish someone would confirm and show proof 100% that the SS does have no lift shift. I can't find it in the manual or I am just blind as a bat. I hope it does, but I don't want to just get my new car out there before it's 2nd oil change and try it ;p

I've done it on 3 different cars. It has it 100%. Even my tuner said it was already there when I asked him to set it up.

[lt4camaro]

Originally Posted by BMWM.D.

I'm no hard core drag racer. I've been to the strip 5 times total with a few different cars. That said, I had no problem power-shifting at the track when I was looking to shave a few tenths from my ETs. I was even going to set up my supercharged C6 for no lift shift (can be done via tuning), but I decided it probably wasn't worth the risk given that I have methanol injection and cats. I think it would be great on this car, though.

Oh... and the only reason I mentioned the difference between manual power-shifting and manual rev-matching on a downshift was in response to you saying that you'd be nervous doing a no lift shift -- but shooting the revs up to near redline on a downshift doesn't bother you. Maybe that's not what you meant, but its how I read it. I'm much more nervous about forcing my engine into a mechanical over-rev than banging into the rev limiter at WOT.

Rev Match has a rpm limit of 5500 rpm when down shifting, so unless you let the clutch out when downshifting into the wrong gear, you will never get a over rev.

[Arizona480]

Originally Posted by Iron Oak

First shift in the video is a no lift @ 0:24

1:45 questionable but sounds like it
same with the shift at 2:10

Then he does a couple more no lift shits at 3:10 and 3:20

He doesn't do it every time but more often than not.

I'm not a huge fan of no lift shift, it just seems like an accident waiting to happen.

Drive it like you stole it! Ha ha, cool video.

[Norm Peterson]

Originally Posted by lt4camaro

Rev Match has a rpm limit of 5500 rpm when down shifting, so unless you let the clutch out when downshifting into the wrong gear, you will never get a over rev.

Good to know . . . but they definitely left themselves some extra cushion there. It's not like any automated rev-matching is going to be too slow to let go of the wider throttle opening that runs the revs up (like a human might be from time to time).


Norm

[BMWM.D.]

Originally Posted by lt4camaro

Rev Match has a rpm limit of 5500 rpm when down shifting, so unless you let the clutch out when downshifting into the wrong gear, you will never get a over rev.

I was referring to manual rev-matching and power-shifting as for how they relate to the risk of over revving an engine. Stuffing the trans into the wrong gear at high rpm is pretty damn scary. I did it once in my '67 Camaro. Was trying to do a 3-4 upshift at 6500 rpm. Accidentally went into 2nd. Thankfully, I caught it before anything really bad happened -- but the revs definitely went higher than my limiter settings. How high, I'm not sure.

Interesting to know about the electronic Rev Match feature, though. So if I were going to downshift and select a gear that would put the revs at 6000 rpm, what would the system do? just hold the revs at 5500 instead?

[BMWM.D.]

Originally Posted by Norm Peterson

That's exactly what I meant.

I'm very comfortable rev-matching a 4-3 downshift at 90 - 91 mph, when my 6000 rpm redline corresponds to 96 mph. My rev kick will make my 5900 rpm upshift indicator flash, but on the rev kick itself I've never run into what's supposed to be a 6250 fuel cut. IOW, I'm not needing any sort of rev limiting help. So far.

But I can't bring myself to not lift at least a little on the upshift.



It's a psychological thing based on long experience, something that the mere existence of a technological crutch cannot rewrite. No matter how good it might actually work.

In 45 years of rev-match downshifting MT cars I've mechanically pushed an engine past its limiter exactly once (fumbling for 4th from 5th with a vague OE shifter in a hard braking zone, not getting it, trying again and finding 2nd and somewhere north of 7000 before getting back on the clutch pedal . . . then having to coast through the upcoming 0.9g turn essentially in neutral . . . don't want to repeat that, ever again).

In the presence of a rev limiter, it's not fear of actually over-revving on the throttle so much as it is the dislike of actually running into the limiter. Means I just screwed up something I shouldn't have screwed up.


Norm

I get the psychological thing. Habits can be hard to break. But there shouldn't be any anxiety about using something like a factory No Lift Shift system. Worrying about it malfunctioning is along the same lines as worrying that your ECM might miscalculate air-mass or fueling requirements when making a full throttle pull. Its extremely unlikely.

The truth is that we put a ton of faith in these systems, though most people take them for granted as what they do is mostly transparent. The difference with something like NLS is that its something tangible. Its much more obvious that the ECM is doing things for you. Really no different than anything else the ECM does -- just easier to see.