M7 Rev Match Tutorial Needed
10-22-2017, 01:57 AM
#21
E-Ray, 3LZ, ZER, LIFT
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I bought a September 2013 built C7 Z51 and drove it for 3 1/2 years using rev match 95% of the time. Now have a Grand Sport and also use it 95% of the time. Been driving only standard shifts for my DD for over 55 years. (My 1st car was a “3 on the floor” ‘41 Opera Coupe I stuffed in a bored out ‘50 Olds I assembled from parts!) Very good at heal-toe when driving in anger and downshifting when the rpm will be very high in the lower gear. Lots of good info mentioned as to the benefits in that situation so you are assured on not upsetting the car with a not perfect match.
But I also used it when making turns in everyday driving in town or when leaving an Interstate, for example, where direct drive 4th is best for an off-ramp and after! In the C7, just shift from 7th at ~1300 rpm directly to 4th! Why go through two other overdrives, 6th and 5th! In fact the shifter springs will bring you to 4th with an easy pull back on the shift lever with no side pressure. I also do that when passing an 18 wheeler fast to minimize exposure to it’s tires throwing rocks! Then back directly to 7th. ( A month after getting my 2014 had one throw a rock that hit near the passenger windshield wiper- was able to repair the small pit.)
Same when making a turn in town or on the rural roads where I live. Typically drive in 5th and when turning I shift directly to 3rd. In town that might be from 45 mph or where I mostly drive on rural roads 55/60 mph when making a turn to another rural road. Why bother with 4th when I want to be in 3rd after the turn. Rev Match matches perfectly at these lower rpms where modulating the throttle is harder than when downshifting one gear when being more aggressive as when racing. IMO, Rev Match is the best thing since synchromesh!
I even heel-toed my modified S10 Stepside truck when between Vettes and the most difficult part was those slower speed turns with the not so well positioned brake/throttle pedal position as it is in the Vette! Have a bit of a unique spot I deal with every day. The 25 mph street I live on starts as a single lane around a large fountain from a 60 mph speed limit 4 lane highway. Have to leave the highway and enter our slow speed limit street so in the Vette and truck that was, downshift two gears and carefully modulate the throttle. Got it close to perfect even in the S10 half the time! Better with my C6 Z51 but not perfect all the time. With Rev Match in the 2014 and my current Grand Sport it’s perfect 100% of the time!
SOME TRICKS
There is some good advice as outlined in other posts and the Owner’s Manual.
Here is another not covered, I found when testing why some complain about overreving. Appears to me related to not following what must be done to be sure Rev Match works correctly, like being sure the shift lever is placed “only” in the intended next gear and even just the gate when in neutral. I’ll explain:
When in the neutral gate, if the shift lever is moved even slightly toward say the 1st/2nd gate when the intent is to downshift to 3rd, the engine will overrev to match what would be needed for 2nd gear rpm. The shift lever poisition sensors are trying to anticipate where you will be shifting even before the lever is placed in that gear slot!
Another is a habit I had to break. If skipping a gear when downshifting would often, with the clutch depressed, put the lever in the gear being skipped. It spools up the gear cluster. Can’t do that with Rev Match. Put the lever only in the gear where you will engage the clutch or you confuse the computer anticipating your desires! The Tremic M7 has triple syncros in most gears, one carbon faced. Let them deal with managing the gear cluster rpm changes required!
PS: Upshifts with Rev Match is different. Frankly I generally shift fast enough that I don’t perceive Rev Match doing anything different than in my C6 Z51 without it and with every other DD I have owned, all of which were standard shifts! I take my foot off the accelerator when shifting. Rev Match does nothing differently to slow the engine rpm than having the throttle butterfly closed. In a test, I did find if shifting very slowly where the engine rpm would reduce below that needed for the next higher gear, it would hold the correct rpm for perhaps 2 seconds. Never shift that slow!
Hope all that helps, Enjoy!
But I also used it when making turns in everyday driving in town or when leaving an Interstate, for example, where direct drive 4th is best for an off-ramp and after! In the C7, just shift from 7th at ~1300 rpm directly to 4th! Why go through two other overdrives, 6th and 5th! In fact the shifter springs will bring you to 4th with an easy pull back on the shift lever with no side pressure. I also do that when passing an 18 wheeler fast to minimize exposure to it’s tires throwing rocks! Then back directly to 7th. ( A month after getting my 2014 had one throw a rock that hit near the passenger windshield wiper- was able to repair the small pit.)
Same when making a turn in town or on the rural roads where I live. Typically drive in 5th and when turning I shift directly to 3rd. In town that might be from 45 mph or where I mostly drive on rural roads 55/60 mph when making a turn to another rural road. Why bother with 4th when I want to be in 3rd after the turn. Rev Match matches perfectly at these lower rpms where modulating the throttle is harder than when downshifting one gear when being more aggressive as when racing. IMO, Rev Match is the best thing since synchromesh!
I even heel-toed my modified S10 Stepside truck when between Vettes and the most difficult part was those slower speed turns with the not so well positioned brake/throttle pedal position as it is in the Vette! Have a bit of a unique spot I deal with every day. The 25 mph street I live on starts as a single lane around a large fountain from a 60 mph speed limit 4 lane highway. Have to leave the highway and enter our slow speed limit street so in the Vette and truck that was, downshift two gears and carefully modulate the throttle. Got it close to perfect even in the S10 half the time! Better with my C6 Z51 but not perfect all the time. With Rev Match in the 2014 and my current Grand Sport it’s perfect 100% of the time!
SOME TRICKS
There is some good advice as outlined in other posts and the Owner’s Manual.
Here is another not covered, I found when testing why some complain about overreving. Appears to me related to not following what must be done to be sure Rev Match works correctly, like being sure the shift lever is placed “only” in the intended next gear and even just the gate when in neutral. I’ll explain:
When in the neutral gate, if the shift lever is moved even slightly toward say the 1st/2nd gate when the intent is to downshift to 3rd, the engine will overrev to match what would be needed for 2nd gear rpm. The shift lever poisition sensors are trying to anticipate where you will be shifting even before the lever is placed in that gear slot!
Another is a habit I had to break. If skipping a gear when downshifting would often, with the clutch depressed, put the lever in the gear being skipped. It spools up the gear cluster. Can’t do that with Rev Match. Put the lever only in the gear where you will engage the clutch or you confuse the computer anticipating your desires! The Tremic M7 has triple syncros in most gears, one carbon faced. Let them deal with managing the gear cluster rpm changes required!
PS: Upshifts with Rev Match is different. Frankly I generally shift fast enough that I don’t perceive Rev Match doing anything different than in my C6 Z51 without it and with every other DD I have owned, all of which were standard shifts! I take my foot off the accelerator when shifting. Rev Match does nothing differently to slow the engine rpm than having the throttle butterfly closed. In a test, I did find if shifting very slowly where the engine rpm would reduce below that needed for the next higher gear, it would hold the correct rpm for perhaps 2 seconds. Never shift that slow!
Hope all that helps, Enjoy!
Last edited by JerryU; 10-22-2017 at 03:02 AM.
10-22-2017, 04:27 PM
#22
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This does bring up a curiosity I've had. I've pretty much only owned manuals for the 20+ years I've been driving, but never had a need to learn proper heel/toe for just street driving. With the advent of ARM, do the driving schools like Spring Mountain still teach and/or expect heel/toe when driving a manual in beginners courses like the Owners School, or do they just use ARM during the during sessions?
Last edited by DWS44; 10-22-2017 at 04:34 PM.
10-22-2017, 04:54 PM
#23
As I mentioned in post #14, when I first went to Spring Mt. 11-12 years ago for both Level 1 and Level 2 courses, there was a heavy emphasis on heel/toe, and a lot of practice sessions. In those days, instructors would be standing at corner entries, often radioing to students, "nice blip" or "work on your rev match."
Since the advent of the C7 w/ ARM they recommend using it and don't focus on heel/toe anymore.
Since the advent of the C7 w/ ARM they recommend using it and don't focus on heel/toe anymore.
Last edited by Foosh; 10-22-2017 at 04:58 PM.
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DWS44 (10-22-2017)
10-22-2017, 05:47 PM
#24
Race Director
I went to Spring Mt after I got my C6 ZR1 about 7 or 8 years ago and there was a big emphasis on heel-n-toe with a bunch of exercises working on it.After getting my C7 Z06 I went back in Feb this year. Not even any mention of doing anything but activating ARM and driving!!
.
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DWS44 (10-22-2017)
10-22-2017, 06:23 PM
#25
It Works Great!
I use it all the time. When using it don’t over think it. 
10-22-2017, 06:57 PM
#26
LOL . . . you're appear to be one of the fortunate who don't have to over-think it because your technique must be compatible with the way it works. But those who keep their foot on the throttle during downshifts are having problems, which is the source of so many complaints.
It's those some of us are trying to help.
It's those some of us are trying to help.
Last edited by Foosh; 10-22-2017 at 11:48 PM.
10-22-2017, 07:12 PM
#27
LOL . . . you're appear to be one of the fortunate few who don't have to over-think it because your technique must be compatible with the way it works. But those keep their foot on the throttle during downshifts are having problems, which is the source of so many complaints.
It's those some of us are trying to help.
It's those some of us are trying to help.
10-23-2017, 01:48 PM
#29
LOL . . . you're appear to be one of the fortunate who don't have to over-think it because your technique must be compatible with the way it works. But those who keep their foot on the throttle during downshifts are having problems, which is the source of so many complaints.
It's those some of us are trying to help.
It's those some of us are trying to help.
I don't get that. I thought most people never touched the throttle when shifting. Even heel toe, you blip the throttle so your foot is off during the shift. No lift shift has changed this under some circumstances for up shifts, but down shift behavior would be the same.
10-23-2017, 01:53 PM
#30
Le Mans Master
You are absolutely, positively, 100% correct - brake and downshift before corner entry so you're in the correct gear for initial track-out!!!!
Screwing around with downshifting in the corner will only mess with the balance of the car. You can see Aryton may be modulating the throttle and steering during the turn, and I see he does a quick tap of the brake during one of the turns (commonly done to balance the car, or shift a little weight forward onto the front wheels during the turn), but you sure don't see him downshifting in the turn.
When using rev matching (or just doing your own throttle blip) let the clutch out immediately after the engine revs. If you hold the clutch pedal down and wait before letting it up to engage the clutch, you're defeating the rev matching as the revs can drop and when you do let the clutch out you'll get a jerk of the drive train that upsets the car.
You can see in that video of Aryton, he NEVER pushes the clutch in and holds the pedal down!!!
The only time you should ever need to do that is when coming to a complete stop.
I can heel-and-toe almost as good as Aryton, and I've been driving nothing but manual transmission cars for more than 57 years. I could double-clutch/heel-n-toe my Dad's old '57 VW and "snick" those straight cut gears down into 1st gear at anything under 15 mph (max speed at redline in 1st). My wife and I have never had a vehicle with any automatic transmission until I got an F-150 four years ago to tow my trailer to track events - and you can't even get a manual transmission in one anymore.
Butt...unlike a couple others that have commented, I LUV the rev-matching feature in the C7!!!!!!!!!!!!!
Whether driving on the track or the street, throughout almost 6 decades of driving/riding manual transmissions, I almost always downshift and use engine braking when slowing down. In my C6's and now C7, or on my Harleys, I hardly ever go down into 1st until coming to a stop, but quite commonly am down into 2nd, but I NEVER push the clutch pedal down (or pull the clutch lever in on the Harley) and hold it unless coming to a complete stop is imminent.
Bottom line - ARM is a fantastic feature on our Vettes!! I use it all the time. When you downshift and get the rev increase, immediately select your lower gear (and I often go from 5th to 3rd a couple places on the Rolex 24 road course at Daytona) and quickly let the clutch out before the revs drop, and you'll have a perfectly smooth downshift.
Use it - you'll like it!!!
Screwing around with downshifting in the corner will only mess with the balance of the car. You can see Aryton may be modulating the throttle and steering during the turn, and I see he does a quick tap of the brake during one of the turns (commonly done to balance the car, or shift a little weight forward onto the front wheels during the turn), but you sure don't see him downshifting in the turn.
When using rev matching (or just doing your own throttle blip) let the clutch out immediately after the engine revs. If you hold the clutch pedal down and wait before letting it up to engage the clutch, you're defeating the rev matching as the revs can drop and when you do let the clutch out you'll get a jerk of the drive train that upsets the car.
You can see in that video of Aryton, he NEVER pushes the clutch in and holds the pedal down!!!
The only time you should ever need to do that is when coming to a complete stop.I can heel-and-toe almost as good as Aryton, and I've been driving nothing but manual transmission cars for more than 57 years. I could double-clutch/heel-n-toe my Dad's old '57 VW and "snick" those straight cut gears down into 1st gear at anything under 15 mph (max speed at redline in 1st). My wife and I have never had a vehicle with any automatic transmission until I got an F-150 four years ago to tow my trailer to track events - and you can't even get a manual transmission in one anymore.
Butt...unlike a couple others that have commented, I LUV the rev-matching feature in the C7!!!!!!!!!!!!!
Whether driving on the track or the street, throughout almost 6 decades of driving/riding manual transmissions, I almost always downshift and use engine braking when slowing down. In my C6's and now C7, or on my Harleys, I hardly ever go down into 1st until coming to a stop, but quite commonly am down into 2nd, but I NEVER push the clutch pedal down (or pull the clutch lever in on the Harley) and hold it unless coming to a complete stop is imminent.
Bottom line - ARM is a fantastic feature on our Vettes!! I use it all the time. When you downshift and get the rev increase, immediately select your lower gear (and I often go from 5th to 3rd a couple places on the Rolex 24 road course at Daytona) and quickly let the clutch out before the revs drop, and you'll have a perfectly smooth downshift.
Use it - you'll like it!!!
10-23-2017, 01:57 PM
#31
This is true. I tried it after that earlier post. It does not upset the car...still seems like a bad habit. You also had better not forget to turn rev match on.
10-23-2017, 01:59 PM
#32
Le Mans Master
The only downside of rev match is when you track a car without it.
10-23-2017, 02:32 PM
#33
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At VIR when I use 5th gear on the back straight as I am braking into the subsequent left right combo I downshift to 4th and then 3rd before letting the clutch out. I get two rev bumps as I am approaching the flagger on the left at the top of the roller coaster. I use rev match all the time and have pretty much forgotten how to heel/toe like I did for all of those years before.
As for shifting at the apex of a corner. I think it was Dick Turner who recommended doing that at an autocross. He didn't say to drive into the corner in neutral but he did say the best point to shift was when the car was going its slowest at the apex. That let non heel/toe drivers shift without disturbing the car too much. When I had HPDE students that couldn't heel/toe and they weren't driving a torque monster Corvette that could lap a course in 4th almost as fast as it would do when shifted I would have them shift at the apex to minimize car disturbance.
Bill
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LT1 Z51 (10-23-2017)
10-23-2017, 02:33 PM
#34
I don't get that. I thought most people never touched the throttle when shifting. Even heel toe, you blip the throttle so your foot is off during the shift. No lift shift has changed this under some circumstances for up shifts, but down shift behavior would be the same.
That's what I was talking about.
Last edited by Foosh; 10-23-2017 at 02:37 PM.
10-23-2017, 02:42 PM
#35
Since many who grew up on manual transmissions are used to rev-matching, they developed the habit of keeping their foot on the throttle during shifts in order blip the throttle during a downshift. Heel/toe also has heel on throttle pedal and toe on brake. Even inadvertent light pressure on the throttle can defeat the ARM system.
That's what I was talking about.
That's what I was talking about.
Yeah, I get it...just never heard of anyone doing that. I thought blipping was the way everyone did it.
10-23-2017, 02:58 PM
#36
Yes, that's precisely the issue! That's the way everyone used to do it.
The problem for some is ARM is now supposed to do the blipping, but they're having trouble breaking the old habit of resting foot on throttle in anticipation of doing the blip themselves.
The first week I had my car, I had to break myself of that habit when using ARM, because heel/toe and blipping had become 2nd nature over decades. Turn ARM off, and you can keep doing it the old-fashioned way.
The problem for some is ARM is now supposed to do the blipping, but they're having trouble breaking the old habit of resting foot on throttle in anticipation of doing the blip themselves.
The first week I had my car, I had to break myself of that habit when using ARM, because heel/toe and blipping had become 2nd nature over decades. Turn ARM off, and you can keep doing it the old-fashioned way.
Last edited by Foosh; 10-23-2017 at 03:02 PM.
10-23-2017, 03:17 PM
#37
Le Mans Master
Not true all the time. When I have been slow on executing the downshift at times the revs drop too much and I have to remember to be smooth on the clutch release or the car will jerk pretty badly. That happens in a lot less than 15 seconds even less than 2 seconds.
At VIR when I use 5th gear on the back straight as I am braking into the subsequent left right combo I downshift to 4th and then 3rd before letting the clutch out. I get two rev bumps as I am approaching the flagger on the left at the top of the roller coaster. I use rev match all the time and have pretty much forgotten how to heel/toe like I did for all of those years before.
As for shifting at the apex of a corner. I think it was Dick Turner who recommended doing that at an autocross. He didn't say to drive into the corner in neutral but he did say the best point to shift was when the car was going its slowest at the apex. That let non heel/toe drivers shift without disturbing the car too much. When I had HPDE students that couldn't heel/toe and they weren't driving a torque monster Corvette that could lap a course in 4th almost as fast as it would do when shifted I would have them shift at the apex to minimize car disturbance.
Bill
At VIR when I use 5th gear on the back straight as I am braking into the subsequent left right combo I downshift to 4th and then 3rd before letting the clutch out. I get two rev bumps as I am approaching the flagger on the left at the top of the roller coaster. I use rev match all the time and have pretty much forgotten how to heel/toe like I did for all of those years before.
As for shifting at the apex of a corner. I think it was Dick Turner who recommended doing that at an autocross. He didn't say to drive into the corner in neutral but he did say the best point to shift was when the car was going its slowest at the apex. That let non heel/toe drivers shift without disturbing the car too much. When I had HPDE students that couldn't heel/toe and they weren't driving a torque monster Corvette that could lap a course in 4th almost as fast as it would do when shifted I would have them shift at the apex to minimize car disturbance.
Bill
10-23-2017, 05:15 PM
#38
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I think I downshift way to early and don't engage the lower gear fast enough. So rev match doesn't work for me 50% of the time (as in I am too slow).
Lets say I'm coming up on a turn, I'm in 4th, I brake, then push in the clutch, then slow down more and shift to second, then release the clutch in the turn. I think I have this fear of stalling so I push in the clutch super early.
Lets say I'm coming up on a turn, I'm in 4th, I brake, then push in the clutch, then slow down more and shift to second, then release the clutch in the turn. I think I have this fear of stalling so I push in the clutch super early.