I have a question regarding the M7 transmission. I understand the rev matching feature and how it works. However, if the rev match is not engaged can the transmission be satisfactorily shifted. In other words is there a synchromesh feature and how well does it work without the ARM being engaged? I understand how either the ARM or heal and toe double clutching would be appropriate when pushing rev limits and during performance driving, but what about normal "street driving;" Is there a synchromesh feature that works. I personally drive the A6, so I cannot test this on my own car. When I was recently at Spring Mountain I pushed M7 that I drove to its limits so ARM and double clutching was obviously important, but what about "normal" driving.

 

Yes, has syncros just like any modern trans. Nothing weird happens if you don't use the ARM. I actually drive with the ARM off most of the time these days. It's fun but I feel a bit boy racer when it kicks in on down shifts. The gf uses ARM all the time.

 

I think it revs too much for me. Makes it sound like I'm trying to race people on the freeway.

 

I agree. I also feel that the ARM over revs, and that it should be reprogramed. When I manually double clutched I accomplished the same thing with only a very slight throttle bip.

 

Never use rev match with my M7...after 50 years, a blip of the throttle is all I know...As far as I'm concerned, rev match is much too quick for me...too old...

Ken

 

Having my new experience with the rev-matching. After many years of heal/toe on tracks and autox courses for 20+ years I would have to give my 2016 7-speed manny an A+. Works great, and matches beautifully both on upshifts and downshifts. I personally thinks it is terrific!
When the car arrived last week I did have to adjust a bit and keep my foot from prematurely pressing on the gas pedal or it cancels out the blip. Once I figured that out, it's been a hoot to use.

 

I love my rev-match....makes me look like i actually know what I am doing in twisty mountain roads! Excellent feature!

 

The Tremic trans with it's big gears and gear clusters has double and some triple syncro's in all gears! Some are carbon faced! Although rev match saves some wear and tear it's not needed to get a crunch free gear change.

I use it all the time. I've been driving essentially only standard shifts in my DD cars for 50+ years! I've used heel toe (or in my 3 other Vettes toe side of foot, the peddles are well positioned) and at higher rpm's am very good at getting a good rpm match. Even did that in cars that required more foot dexterity because the peddles where not placed perfectly! However at lower rpm's and when skipping gears at lower rpm's like when coming off a freeway in 7th and shifting to the logical 4th 1:1 for the off-ramp etc, modulating the throttle to get a perfect match is not as easy! Rev match does it perfectly every time! IMO with 3 overdrives it makes it very useful. Understand at a track it may not be as needed but around town and coming off even a rural road from say 60 mph in 5th and downshifting to 3rd when I make a turn to another rural road, it's ideal. (That's going from ~1900 rpm to 3700 rpm.)
I have not found it over revs and could care less what the cows think about the engine revving where I mostly drive or frankly in town! I do it because it makes the lower rpm matches perfect. To each his own but even a professional racer said he found it useful so he could concentrate on his braking spot, etc!
The one thing I have found, which is warned against, is I can't do what was a common practice in my C6 (and other cars) when skipping gears. I would often disengage the clutch and put the shift lever into an the next lower gear that I was skipping before going into the next lower gear where I was planning to reengage the clutch. Helped get the gear clusters up to speed. That confuses rev match and I read early on not to do that! Still occasionally happens by habit when I'm coming to a stop and then I can hear a some excess engine revs. To each his own.

 

 

The only time I use rev matching is when driving the twisties near home, the hill country has some nice roads for playing, as long as you stay in your own lane. The road from Austin to Volente Beach and out to Anderson Lane in Cedar Park is very curvy, some being extremely tight and the rev match does a wonderful job there. Makes it much easier to drive that road.
In town I don't use it as I feel a bit show offish, as it is a bit loud ( thankfully ) and does attract attention. The M7 shifts just fine without the use of the rev match feature. I have driven the car pretty hard and not used the feature, downshifting and breaking without blipping the throttle, never double clutching. It was not a problem. Remember this is not a 1950's transmission, they have incorporated a lot of tech that keeps you from destroying the M7, and the rest of the car.
There is an occasion where it may rev higher than one would want. That being when you drop from fourth to third and then decide to go to second, the rev match tries to adjust for this and rpm's do climb to a higher level, which sounds as though the system is over revving. It's just trying to match engine rpms to the cars speed to keep everything bolted together.
This is just another nannie that is easy to use, and like all the other nannies in the car it does not have to be used. But, unlike some of the others, it is not a safety feature. Won't save your bacon if you over correct in a corner, or encounter a bit of unnecessary wheel spin.

 

completely.

Even though I still heel and toe, whats the harm of a safety net? It's a fantastic tool available to us C7 guys. On an auto-x where speed and timing is of the essence, I've found that I can put somebody into my car and they go out and downshift like a pro with it activated.

My system has been tuned when i had it on the dyno. My system seems spot on now, it's right on the money on every down shift and has eliminated an lurch from poorly timed clutch releases.

It's so fun to be able to effortlessly downshift on an auto-x course. Thats something I've been lacking in the C4 I've competed in.

 

I think it is worth mentioning that still heel and toeing with the ARM active was a suggestion made to me by the Spring mountain instructing staff.

 

i agree i think it over revs

 

I've driven manuals almost my entire life, and can heel / toe, but won't claim I'm great at it. I use, and like ARM. I actually like the sound of it blipping the throttle. But I turn it off if my wife is in the car, and in places I want a quiet car (for example, when going to work in the morning I have ESM in Tour and ARM off).

My only real complaint about it is that it's not always quick enough. If I'm driving in a spirited manner, and shifting as quickly as I can, I can beat the rev match, and downshift before the engine has reached the correct rpm.

 

I don't think it over-revs in the 'classic' definition, just that the engine RPM you happen to be running at the time is significantly lower than the programmed 'optimal' shift point, so the ARM system boosts higher.

That's why I don't use it in day to day driving, but occasionally during 'spirited driving' is another story..

 

I have been using Rev Match 99% of the time for what will be 2 years this October. I only recall an over revving situation once and thought it might have been my fault. So ran a test today while driving into town!
I'm assuming you and others who have mentioned over revving are referring to downshifts as I can hardly tell as it operates on up-shifts. Appears just like normal since I always have my foot off the throttle at that point so the engine naturally reduces in rpm.
TEST: I was driving at 45 mph in 5th (~1400 rpm in my Z51) and went to down shift to 4th (should have raised the rpm to ~2000.) But instead of going straight to 4th, I first pulled the lever over to the 1st/2nd gate. I kept it in neutral and did not try to go into either gear. However the rpm increased significantly! I assume it was estimating I was going to shift to 2nd! That would be about 4000 rpm! I then went into 4th and it did not raise the rpm to ~2000 until I was actually in 4th! (The Rev Match computer algorithm must have figured I could't make up my mind so waited!) When at 2000 in 4th I downshifted to 3rd and it revved as it should to ~2800 rpm!
I knew the Hall Effect Sensor was said to anticipate the gear to be selected and it appears it will assume, even if still in neutral but in a gate slot it will rev to (I also assume) the highest numerical number of the two possible gears- if that makes sense.
But 99% of the time I downshift shift using Rev Match, if it was over revving I would feel a jump etc. I don't, it's just like doing a perfect heel/toe! As mentioned previously, at lower rpm's it is not as easy to modulate the throttle to achieve a perfect match as stabbing the throttle at higher rpms. IMO Rev Match does it perfectly each time.
For what it's worth.