Rev Matching in an Auto
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Joined: Mar 2014
Posts: 173
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From: USA
Kleemann C55, C32
Rev Matching in an Auto
Coming from a driving history of only manual cars, manual rev-matching has become engrained in my driving, but after switching to the auto in the C55,I was sorely missing that wonderful rev-matching sound and satisfaction when nailing rev-matches perfectly. I started reading around the web to if there are any tuners that can program auto-rev matching for our tranny. Unfortunately, there isn’t any feasible and simple solutions for this, so I began toying with my down-shifts and gas pedal. After a few backstreet runs, I was able to simulate the rev-matching sound and function like those of a manual car or new auto-trannies with auto-rev match feature like seen in the 370Z, ISF, and C63. What a total satisfaction it was to revmatch in the C55. Very much like in manual cars, the timing will have to be perfect to get the seamless and smooth down-shift from rev-matching. Blipping the gas pedal a second too late or soon will cause the car to have an unhealthy lunge and jerk (…imagine the shock to the engine and tranny mounts).
I later had my brother drive besides me in another car tolisten as I rev-matched from 5 to 4, 4 to 3, and 3 to 2. His comments were “OMG,that sound is vicious and so sweet! It actually sounds like how the 370Z auto rev matches on downshifts (my wife drives a 370Z), except with a big V8 bark to it.” I’m thinking now how cool it wouldbe if I had an exhaust setup to compliment the sweet rev-matching sound.
Just curious if anyone else get the joy and satisfaction of rev-matching in their C55.
I later had my brother drive besides me in another car tolisten as I rev-matched from 5 to 4, 4 to 3, and 3 to 2. His comments were “OMG,that sound is vicious and so sweet! It actually sounds like how the 370Z auto rev matches on downshifts (my wife drives a 370Z), except with a big V8 bark to it.” I’m thinking now how cool it wouldbe if I had an exhaust setup to compliment the sweet rev-matching sound.
Just curious if anyone else get the joy and satisfaction of rev-matching in their C55.
Last edited by Vette Moto; Jun 10, 2014 at 04:49 PM.
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Joined: Nov 2012
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From: San Diego, CA
2005 C55 black on black aka DVS C55, 2007 C230 sport silver on black for the boss
How are you rev matching?
Heel/toe but tap the gas when you expect the downshift?
Two feet at work?
Manual mode only?
Renntech just came out with a module for the 722.9, hopefully others will follow suit and also make one for the 722.6
Last edited by EDgineered; Jun 10, 2014 at 05:56 PM.
Thread Starter
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Joined: Mar 2014
Posts: 173
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From: USA
Kleemann C55, C32
Cool, Ill have to keep an eye out on the renntech developments.
The left foot is idle. Right foot and left finger are the only things in action. The moment I press the downshift button, I count "1 second" , then blip the gas pedal with the right foot to jump the revs anywhere from 300 - 1,000 rpms depending on the speed. I noticed the higher the mph during downshift, the more revs that is required to get a smooth rev matching downshift.
The left foot is idle. Right foot and left finger are the only things in action. The moment I press the downshift button, I count "1 second" , then blip the gas pedal with the right foot to jump the revs anywhere from 300 - 1,000 rpms depending on the speed. I noticed the higher the mph during downshift, the more revs that is required to get a smooth rev matching downshift.
Last edited by Vette Moto; Jun 10, 2014 at 09:59 PM.
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From: USA
Kleemann C55, C32
It can be done in any mode. I do it in S mode, but find that M mode is convenient for that 1st downshift since M mode shows the exact gear I'm in. At times when I am in S mode, for example, I think that I am in 4th gear so I blip the throttle accordingly for a 3rd gear downshift, but in reality I was actually in 3rd going to 2nd, so that causes a botched rev match.
Last edited by Vette Moto; Jun 10, 2014 at 06:19 PM.
Thread Starter
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Joined: Mar 2014
Posts: 173
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From: USA
Kleemann C55, C32
Yes, timing is everything. These transmissions just don't react fast to manual inputs. The other day I was driving a relative's 2013 TL with paddle shifters and it made me realize how antique our transmissions are.
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Joined: Jun 2012
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From: SF Bay Area
C55 AMG, 300D-T & Karmann Ghia
haha! You're right about that! I tried it my last couple drives to/from work. It went surprisingly well- far better than I expected!!
Only issue say when I tried it from 3rd to 2nd while giving hard left foot braking before a corner. Nothing like a mid-corner power lurch to break the rear end loose!
Only issue say when I tried it from 3rd to 2nd while giving hard left foot braking before a corner. Nothing like a mid-corner power lurch to break the rear end loose!
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'07 CLS 63, '91 E34 M5 Dinan Stroker
Nice to hear others trying this too. It is fun when you get it right. Coming from a 335i I miss the rev-matching blips but wish It had the authoritative bark of the C63! Have you seen the video of the formula 1 C63 medical car? Just sick.
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From: USA
Kleemann C55, C32
I'll have to check that out. I have seen clips of other cars with modified or aftermarket exhausts and they all sound sick when the throttle is blipped. I just recently removed my secondary cats only (resonator still in place) and it sounds pretty nice for what it is.
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From: New Hampshire
C 32 AMG & FG2 Civic Si
I've got the Eurocharged TCU tune and I always drive in manual mode, and when I think the oil is warm enough (after 20 minutes of driving or so) I usually rev match. Most of my trips though are less than 20 minutes so I don't get to do it much. But it is very rewarding when you get it right, it just takes practice.
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From: SF Bay Area
C55 AMG, 300D-T & Karmann Ghia
I'm getting better with rev matching in M, probably 4/5 are really natural. That fifth is basically whenever I try to bring in left foot braking- anybody have luck with the throttle blip while diving deep into a curve?
Happy 4th!!
Happy 4th!!
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Joined: Nov 2012
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From: San Diego, CA
2005 C55 black on black aka DVS C55, 2007 C230 sport silver on black for the boss
What is your review and thoughts on the TCU tune, please?
In M mode does the shift take less time than stock? or just firmer?
In S mode I assume it is faster and firmer shift?
Chirp any gears?
Overall pros and cons?
Thanks...
When I first inquired on this thread I thought it was the throttle match while braking. I've tried but without success, requires two feet and left foot braking and its very hard to find a safe place to work on the technique....
Rev matching while going down the road is easy... I do it all the time
Member
Joined: Feb 2014
Posts: 134
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From: New Hampshire
C 32 AMG & FG2 Civic Si
In M mode, shifting is definitely faster than stock. I almost never drive in S or C mode though, so I can't really give an answer on that. No chirping either, except I suspect that in the rain, losing traction is probably very possible during aggressive shifting, but I haven't done it. The manual mode is very good if you think you'll use it a lot. A lot of members have reported that the auto modes (S and C) feel worse after the Eurocharged TCU tune though. They say the car feels lazier and shifts too early. Again, I almost never drive in those modes except for in traffic so i don't really know. Hope that helps!
Thread Starter
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Joined: Mar 2014
Posts: 173
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From: USA
Kleemann C55, C32
I'm going to have to look into the TCU tune as I think the current upshifts and downshifts are way too slow. Any improvements in time would be great.
On another note, I started giving sharp/quick jolts to the gas peddle, raising the RPM by only 250-300 RPMs, immediately after downshifting and noticed that I have improved greatly my chance of hitting rev matches. I no longer downshift and count to 1.5 seconds before hitting the gas peddle.
On another note, I started giving sharp/quick jolts to the gas peddle, raising the RPM by only 250-300 RPMs, immediately after downshifting and noticed that I have improved greatly my chance of hitting rev matches. I no longer downshift and count to 1.5 seconds before hitting the gas peddle.
