Active Rev Match
 

I do not recall this issue being previously addressed on the forum. ARM is fine and it certainly saves wear and tear on the transmission and adds to the driving experience, but I feel that the algorithm for this feature on the Corvette is horrible. In my opinion it severely over revs the engine. I have driven several m7s and they have all been the same. I am certainly not the most proficient at manual double clutching (heal and toe or otherwise), but when done properly there should be only a slight and imperceptible throttle blip. Instead, with ARM we get what appears to be a very annoying and obnoxious over rev of the engine. This does not harm the engine, but I would be embarrassed to have a passenger in the car with me, particularly someone who was knowledgable about cars and how to properly shift a manual transmission. I was recently at Spring Mountain, and brought this up with Rick Malone: his response was a smile and a shrug of the shoulders and no comment. Comments anyone?

If the engine is actually "over-reving" then it would not be rev-matching and your car is malfunctioning. I suspect you mean that ARM punches the throttle more aggressively than you would like and makes too much noise. I rather like the effect, but if my exhaust is in quiet mode I don't think the sound would offend anybody.

ARM has been discussed many, MANY times here on the forum!!:yesnod:


I learned to drive on my dad's '57 VW Beetle a looong time ago, and my wife and I have never had anything but manual cars until I bought my F-150 as a tow vehicle in 2013.

I've been heel-and-toe downshifting since those early VW days when I learned to heel-and-toe and double-clutch that sucker into the straight cut 1st gear with a perfect rev match blip.

Every time I ride my Harley I downshift with a throttle blip to use engine braking.

And I LUV doing downshifting with my own rev matching throttle blip in my C7 Z06.

So....do I do the throttle blip myself???:confused2:

NO!!!!


The ARM is SOOOOOO good that I click the paddle to turn it on every time I get in the car!!!

As far as I'm concerned, the ARM rev match is virtually PERFECT!!! It really does know exactly how much of a blip to give you for a perfectly smooth downshift with no jerking of the drivetrain or upsetting the dynamics of the car.

I'm not sure why you don't like it, because it really is just about perfect!!!:steering:

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No overrevving on mine. Jumps right up to the appropriate RPM, no higher. No need to double clutch a car with synchros.

I appreciate that you think the rev match is "virtually perfect," but perhaps if you rode with someone who really does know how to properly manually execute a double clutch heal and tow downshift you would see an awesome difference. I experienced this at Spring Mountain when I rode with one of the instructors who demonstrated this art form to me.
What a difference! I do not feel that the m7 ARM is virtually perfect.
Maybe it is virtually perfect for those who do not know better or been exposed to the real thing.

I think the difference with ARM vs manual double clutching is that the ARM system accelerates much faster to the proper RPM than when done manually. I have also noticed an associated rasping noise that accompanies the RPM increase that may add to the noise.

Over revving is a problem. Get it checked out. :thumbs:

Yes, ARM has been discussed ad nauseam here. I'm virtually certain the problem is not the car, but it's you, OP.

ARM is as close to perfection as it's possible to get in a manual transmission. It provides a far better and a completely consistent rev match than any human will ever be capable of reproducing time, and time again. I've spent years honing my heel/toe and rev-matching skills on both track and street. I was very, very good at it, but ARM is better.

Any over-rev you may think you're experiencing is either operator error or misperception. You may be leaving your foot on the throttle and/or shifting too slowly. The manual clearly states rev match will only work properly with foot completely lifted off the throttle, and if you're not shifting quickly enough, it can't match a lazy shift.

To quote Jim Comey: "Oh Lordy!!!":smash:

First of all, for the second time I'll emphasize the proper spelling of heel and toe in heell-and-toe, i.e., it's talking about the heel of your foot, even though in virtually all modern cars you use the ball of your right foot on the brake pedal and the right side of your foot on the accelerator pedal.

Second of all, I've been to Spring Mt 3 times - twice when I bought my C6 ZR1 (once for the Owner School, and once for Level 2); and last Feb for the Owner School for my C7 Z06.

When I went to Spring Mt the first time in the spring of 2010 when they were running the C6, they did A LOT of heel-and-toe practice.

When I went to Spring Mt last year they had the C7, and they did ZERO heel-and-toe practice because of ARM. We just clicked on the ARM every time we started the car and let ARM do the throttle blip.

Third of all, to use your own quote, as I tried to explain in my first response, I am "someone who really does know how to properly manually execute a double clutch heal (sic) and tow (sic) downshift".

I've been instructing for a number of different track day organizing groups for many years, so I've driven with A LOT of drivers, and I must admit that most all of the beginner/novice group drivers of manual transmission cars really don't know how to rev match at all. Most all of the high intermediate/advanced group drivers that I ride with (usually just simply to check them out on a new track before turning them loose solo) do know how to rev match quite well.

Bottom line - I don't want to be too arrogant about it, but I REALLY DO know how to heel-and-toe on my own and have been what you call "exposed to the real thing".

Below is a video of a few laps around VIR in the C7 Z06 last June with ARM on, and downshifting before the corners you can hear how the ARM does PERFECT rev matching:



Below is my old C6 Z06 doing a couple laps around the Rolex 24 roadcourse in Dec 2008, and you might be able to hear my own rev matching throttle blips during heel-and-toe downshifting:



When downshifting, it's imperative to get a good throttle blip in order that after you select the lower gear and pop the clutch you get NO jerk of the drivetrain at all - you want an absolutely smooth downshift so that the car isn't upset by any jerkiness.

Take a look at Ayrton Senna driving around Suzuka - you can hear significant throttle blips that are required to get the rpm's up to what is required for a smooth transition when downshifting:



Bottom line - the ARM does a FANTASTIC job!!! It really does do a virtually PERFECT match of rpm to what is required in the lower gear - even if you skip a gear or two (there's an example of that in my VIR video at about 1:57 where I go from 5th to 3rd).

Just go ahead and engage ARM and enjoy how great a job it does. When you downshift it will give you PRECISELY the rpm needed in the lower gear - even if you skip a gear or two!!:steering:


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I used to feel "self-conscious" about using rev-match, but now I paddle it on as soon as I have shifted into 1st. I think it has more benefit to the engine than otherwise.

The only time I have noticed it being a little fussy is on a cold engine, so I try to drive at least a half mile before I change many gears.

This is probably normal for Vettes whether you rev match or not, and I have, unfortunately, only been able to drive mine, almost always very cold, every 3 or 4 days because of my @#$%ing job and because it has been so @#$%ing cold lately, run-flat tires and all.

Jealous of you mother@#$%ers that get to drive your Vette every day.

/rant

Thought double clutching was an 18 wheeler, trucking term anyway?

BEZ06 - Thanks so much for the tutorial. I'll be picking up my 2019 GS M7 shortly and I feel much better about how I will be driving. It's been a long time since I've driven a manual transmission so ARM will make me look like I still have the skills!!

Ok, that was Senna at Suzuka not the Nurburgring...

Yeah, it's probably you, not the car, but you could always go to a corvette club meet and take a rise with someone else, or let them drive your, to get another opinion...

:iagree: This as been an occasional complaint, especially early on the Forum when I got my September 2013 built Z51. Since I never had the issue I tested a possible reason. I also had another issue and an old habit I had to break.

The Test:
A normal downshift I use frequently is when cruising in town at 45/50 mph I downshift to 3nd when making a turn. Have done that many hundred times and never an overrevd!

However, instead of carefully going from 5th directly to 3rd, while in the neutral gate I move the shift level toward the 1st/2nd gate. Note I DID NOT PUT The LEVER IN EITHER 1st or 2nd. The engine revved to what would have been 2nd gear! The Hall sensors that detect and the computer that anticipates where you want to shift do that as the shifter moved in the neutral gate! You must be careful where and how you shift. No issue for me as I have been driving an M7 for now 4 1/2 years, use Rev Match 98% of the time and overreving does NOT occur.

Habit I Had to Break: When skipping gears on downshifts in my C6 (and other cars, as I have ONLY driven a standard shift as my DD for ~60 years!) while the clutch was depressed I would put the shifter in the gear I was skipping. Spools up the cluster gears and makes less work for the syncro's! Can't do that with Rev Match as it confuses the computer as which gear you are going to!

IMO Rev Match is the best thing since syncromesh and I find it especially useful in low rpm downshifts where modulating the throttle to get a perfect match is much more difficult than heel-toe when driving in anger where the rpm in the lower gear is closer to redline!
The M7 has triple syncro's, one carbon faced, let them worry about spooling up the cluster gears! :yesnod:

I think the ARM blip is quite accurate. When I first got my Z, I tested it by leaving it off and blipping via heel/toe. Pretty much the same blip as ARM. I think it is simply the loud exhaust that deceives some into believing it is over-reving. Try this experiment. Do it old school and watch the tach (same mph, same gear shift) then turn on ARM and go through the shift again. If you have the PDF, record both methods and you’ll be able to truly determine if there is a significant difference.

Works fine, your perceptions on how it should operate are not.

:iagree:I think he is correct that he is the only one that has brought up how horrible the rev match is...and should let it go at that..
How much of a blip I hear seems to also depend on how fast I try to make the shift... I found it is better to shift a little slower and let the rev match do its job.:yesnod: