2018 Rev Matching

[Rocketman]

Rev-matching confirmed for all 2019 Mustang GT's.

https://www.autoblog.com/2018/03/12/2019-ford-mustang-california-special-rev-matching/

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[TexasRebel]

It probably reduces syncho wear, but to a degree that is negligible. The point of rev-matching, in the sense we are speaking to with "auto rev-matching" here, is to speed match two gearsets to or as-close-to as possible for a more seamless and less shocking load on the powertrain on a downshift... Rev-matching happens as you are shifting. The synchros are in play.

Rev-matching happens after you're in gear to bring the engine up to the same speed of the input side of the transmission. It saves clutch, and ride harshness. The synchros are still exclusively used to match the input side to the output side of the transmission. ...unless you're rev-matching during a double clutch...

There are articles all over the place today about rev-matching in the 2019 GTCS. I'll be curious to see how Ford implements the "current gear" data for rev-matching. It'll either be sensors on the gates, or, more likely, just a speed sensor on the input shaft.

 

[Rebellion]

Rev-matching happens after you're in gear to bring the engine up to the same speed of the input side of the transmission. It saves clutch, and ride harshness. The synchros are still exclusively used to match the input side to the output side of the transmission. ...unless you're rev-matching during a double clutch...

There are articles all over the place today about rev-matching in the 2019 GTCS. I'll be curious to see how Ford implements the "current gear" data for rev-matching. It'll either be sensors on the gates, or, more likely, just a speed sensor on the input shaft.

They must put both sensors in, at least in theory...need the current gear data to see how much additional RPM it needs, not the same RPM increases needed to downshift one and two gears.

 

[TexasRebel]

All it needs to know for Rev matching is the input shaft speed.

Once you get into gear the input shaft will be spinning proportionally to the output shaft, but you don't really care what that ratio is as long as the engine RPM can match the friction plate RPM and the clutch doesn't have to take that impact.

 

[ODucksFan]

Interesting... This appeared in Printing 2. It was not in the original.

It's in the third printing as well, which is dated March 2018.

 

[DukeGaGa]

Rev matching systems shouldn't be that hard to make, the only reason I can think of that they didn't put that in the 2018 is because of the cost, 2018 already has a price bump compared to the 2017, and the rev match system will kick it up a bit more. Though it would be nice if they offer it as an option, but it's Ford we're talking about, their options never really made sense to me, why in the world can't the black accent package be combined with other packages? And why the performance package wheels can't be replaced with something else?

 

[TomcatDriver]

All it needs to know for Rev matching is the input shaft speed.

Once you get into gear the input shaft will be spinning proportionally to the output shaft, but you don't really care what that ratio is as long as the engine RPM can match the friction plate RPM and the clutch doesn't have to take that impact.

But it would have to wait for it to be in gear and you could pretty easily "beat" it if you were fast particularly on vertical shifts. That's why (as I understand) Camaro and other cars use sensors in the shifter/shifter linkage, so it knows where you are going before you get there. Yea, we're only talking 1/10ths of a second. I have no idea how Ford decided to do it.

 

[TexasRebel]

But it would have to wait for it to be in gear and you could pretty easily "beat" it if you were fast particularly on vertical shifts. That's why (as I understand) Camaro and other cars use sensors in the shifter/shifter linkage, so it knows where you are going before you get there. Yea, we're only talking 1/10ths of a second. I have no idea how Ford decided to do it.

If matching engine speed to friction plate speed, the only lag is the time it takes to wind up the rotating mass of the engine. That can be done regardless if the transmission is in gear or not. Obviously there would have to be a floor, but past that if the ECM just mirrors the speed of the friction plate with the engine the speeds on both sides of the clutch are always matched.

 

[TomcatDriver]

If matching engine speed to friction plate speed, the only lag is the time it takes to wind up the rotating mass of the engine. That can be done regardless if the transmission is in gear or not. Obviously there would have to be a floor, but past that if the ECM just mirrors the speed of the friction plate with the engine the speeds on both sides of the clutch are always matched.

I think perhaps I was not using the term "in gear" correctly. The speed is not going to match until the syncro's and the gear is locked up, which doesn't occur until toward the end of the shiftier travel. Ideally the ECU would get started matching engine RPM as you fist began to travel through the gate into the new gear.

In an extreme application (that will probably become reality some day) a university built a transmission with no clutch and no syncros by precisely controlling the input (they used electric motors) so the teeth perfectly lined up for the shift. It was not a traditional "manual", more like a SMG.

 

[Rebellion]

If matching engine speed to friction plate speed, the only lag is the time it takes to wind up the rotating mass of the engine. That can be done regardless if the transmission is in gear or not. Obviously there would have to be a floor, but past that if the ECM just mirrors the speed of the friction plate with the engine the speeds on both sides of the clutch are always matched.

Makes a ton of sense, I stand corrected :cheers:

 

[Rebellion]

I think perhaps I was not using the term "in gear" correctly. The speed is not going to match until the syncro's and the gear is locked up, which doesn't occur until toward the end of the shiftier travel. Ideally the ECU would get started matching engine RPM as you fist began to travel through the gate into the new gear.

In an extreme application (that will probably become reality some day) a university built a transmission with no clutch and no syncros by precisely controlling the input (they used electric motors) so the teeth perfectly lined up for the shift. It was not a traditional "manual", more like a SMG.

Would still hypothetically need some sort of clutch for the "launch". Your concept sounds very similar to a DSG, more like a dog DSG...I like this idea.

 

[draph]

If the ECU is already monitoring engine speed and gear selection, and it's already "throttle by wire" (ie computer controlled air/fuel), adding rev match is entirely a software endeavor. Given the "misprints" of 2018 manuals, I suspect the software implementation was delayed to work out the bugs. I look forward to the first 2018 buyer who attempts to flash his firmware in attempt to get rev match on a 2018. Heck, someone might play dumb and try it with a warranty complaint, if that person has one of those misprinted manuals that says you are supposed to have the feature on a 2018...but wait until the 2019s have been on the market awhile...

 

[l'Ingegnere]

If the ECU is already monitoring engine speed and gear selection, and it's already "throttle by wire" (ie computer controlled air/fuel), adding rev match is entirely a software endeavor. Given the "misprints" of 2018 manuals, I suspect the software implementation was delayed to work out the bugs. I look forward to the first 2018 buyer who attempts to flash his firmware in attempt to get rev match on a 2018. Heck, someone might play dumb and try it with a warranty complaint, if that person has one of those misprinted manuals that says you are supposed to have the feature on a 2018...but wait until the 2019s have been on the market awhile...

'18's don't have the right hardware, the ECU doesn't know gear position.

 

[TexasRebel]

'18's don't have the right hardware, the ECU doesn't know gear position.

Or input shaft speed.

 

[l'Ingegnere]

In an extreme application (that will probably become reality some day) a university built a transmission with no clutch and no syncros by precisely controlling the input (they used electric motors) so the teeth perfectly lined up for the shift. It was not a traditional "manual", more like a SMG.

In a similar vein but slightly more crude and limited in capability, Koenigsegg has been using a Cima gearbox in their Agera series cars that use an additional clutch pack to accelerate synchronization times on upshifts.

[ame]

http://www.cimaingranaggi.it/en/home/Capabilities/Capabi_Gearboxes/Race_1100

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