Z06’s LT6 Has Magnetorheological Engine Mounts: Part I

[John]

Skank was right in his predicting this a long, long time ago even before the Z06’s reveal. As Harlan just said a few hours ago at the Sebring Corvette Corral…

The Z06 has magnetorheological engine mounts. saying, ‘that flat plan crank needed help with vibration.’

Thanks to “Itomn” for being at that presentation and sharing that important piece with us. With him was also “Skank.” For those not familiar with that word, per Wiki with thanks:

A magnetorheological fluid is a type of smart fluid in a carrier fluid, usually a type of oil. When subjected to a magnetic field, the fluid greatly increases its apparent viscosity, to the point of becoming a viscoelastic solid. Importantly, the yield stress of the fluid when in its active ("on") state can be controlled very accurately by varying the magnetic field intensity. The upshot is that the fluid's ability to transmit force can be controlled with an electromagnet, which gives rise to its many possible control-based applications.

https://en.wikipedia.org/wiki/Magnetorheological_fluid

As in the Corvette “mag ride” shocks…; whose full name is either “magnetic selective ride control (“MSRC”) or even more full-length is based on its magnetorheological shocks..

[John]

Picture of Chief Corvette Engineer Josh Holder, Harlan, and Ed Moss, Chassis Engineer at the Sebring presentation.



Picture credit to CorvetteBlogger there at Sebring this race weekend.

[ltomn]

Make no mistake! Knowing the conversation he politely responded to questions and said the engine needed some help with the inherent vibration that comes in a flat crank. This is not a bad thing but a technical advancement. Three cheers to GM!!

[Trans Damm]

Any chance they will be adjustable by user to give more of a visceral feel when your in the mood and a softer one in tour? Made tied into the modes? Or always the same setting to absorb the vibrations

[Milliwatt Rob]

I am thinking, that may address vibration transmitted to the chassis, but would not address any issues of vibration transmitted to engine components. Or things bolted firmly to the engine, such as the DCT.

[JB]

Gm traditionally has one of the longest most arduous validation processes. Somehow Id imagine engine accessories will be designed to operate as long as they do with the LT2 .

valid concern yet my moneys on Corvette engineering

[Skank]

Since I had the chance to discuss these Magnetorheological powertrain mounts with Harlan today, I noticed that BWI just opened up a new plant North of Bowling Green in Indiana. Here's the article on it and explanations on the powertrain mount functions.

https://magneticsmag.com/magneride-m...tion-facility/

https://www.bwigroup.com/powertrain-mounts/magneto-rheological-powertrain-mounts/

www.BWIgroup.com

[John]

Any chance they will be adjustable by user to give more of a visceral feel when your in the mood and a softer one in tour? Made tied into the modes? Or always the same setting to absorb the vibrations

Great links Skank, and super job of your asking this question and our all learning from your doing it.

After reading the links in Skank’s post two above, with these mounts also having different dampening capabilities based on the amount of electrical input, I do believe that this is how the Z07 as one example is able to be both a much more capable track vehicle than the C7 Z07 was, yet have in touring mode a softer ride, Sure there were other factors such as inherent gains in the ME base architecture, but these MagneRide magnetorheological engine mounts are another overriding, major reason imo.

I believe as Trans Damm’s question asks, that the changes in mode assisted greatly by different amount of current in the engine mounts, is how come Vehicle Performance Manager Alex MacDonald was able to accurate state in this video as he changed the mode from first track, then sport, but the biggest difference in ride/comfort came when he went into touring mode, e.g., his characterizing it after that change to tour as it “now being cross country comfort.” Of course the difference in electrical current to the shocks was the “biggie” in that ride change, but I believe that it also was a simultaneous calibration change to the engine mounts in that same mode change.

This will be a GREAT Bash question and I know the Z06 Engineer who lead the MSRC calibration process over the past few years will be at the Bash. I am going to ask it there.

Here’s the EddieX video with Alex describing (go to 17:00):

[dcbingaman]

Exactly how these mounts work would be interesting to see. They likely respond to the 2nd harmonic vibration of the engine much like the suspension shocks respond to the ripples in the road. User inputs may not be required - rpm will be the independent variable. Differential mount stiffness and damping will be the dependent variables.

WRT to impact on the engine, DCT, etc. if the mounts actively damp the second harmonic vibration, it will help both chassis AND powertrain component life. Very trick and very cool. I always thought that something like this would be required to tame a FPC V-8 of this displacement.

[John]

Thanks Binger for your teaching us more.

[Abouttime]

Also thinking these motor mounts may be tuned to respond to resonant frequencies inherent in all engines, rotational assemblies, etc.. Perhaps using engine speed data to alter mount fluid viscosity (damping) at those engine speeds that produce resonance. Cool stuff!

[Skank]

Yesterday was very gratifying for not only the Corvette team but for us fans. Being able to discuss and ask questions to Harlan and the engineers at these presentations will always expose thought provoking info about our Corvette. Last year at Laguna Seca I talked with Josh Holder and verified that the C8 Stingray used conventional powertrain mounts. I asked him if Magnetorheological mounts were being used on the Stingray and he said no. Yesterday when talking to Harlan I mentioned that, and after viewing the cutaway Z06 on display I said that since BWI already has had the MR mounts for over a year that it made sense to use them on the Z06. Using progressively baited questions seems to be the least offensive way to get this info. Harlan did acknowledge that they were MR mounts and that it helped with vibration control as well as other performance issues. I mentioned that these mounts maintain driveline stability from the Transaxle DCT to the half shafts then finally the contact patch of the tires during track driving and he and I agreed especially after I watched the Nurburgring videos. I also discussed the potential split rear window configuration that I posted on MECF as well as CF. Mentioning to him that I discussed this with Vlad Capitinov a few years ago at Laguna Seca then a few weeks ago at the Daytona 24hr with Phil Zak was enough to get his attention on this. I told him about the Split Rear Window thread on MECF and he said he would take a look at it. I do believe he and Phil Zak already have seen that thread by Phil Zaks reaction at Daytona, but who knows for sure! Finally I asked him if Corvette Marketing observes other Sportscar forums. I told him of a few threads on MECF of FerrariChat, Porsche Rennlist, Lamborghini, Lotus and McLaren forums that had owner responses and views on the new Z06. Those threads were eye opening to me and he agreed. Overall a very enlightening conversation with Harlan who is clearly very polished at keeping info well controlled and managed. My final comment to him was why haven't they officially mentioned the MR mounts before and he said because there was so much other info to show. ????

[John]

Always wonderful to learn more. Great job Skank.

[John]

MR engine mounts =another benefit. We remember Skank suggesting even before the Stingray was revealed, that he believed that the Z06 would have magnetorheological mounts for exactly the following reason. Was he ever correct!

Harlan did acknowledge that they were MR mounts and that it helped with vibration control as well as other performance issues. I mentioned that these mounts maintain driveline stability from the Transaxle DCT to the half shafts then finally the contact patch of the tires during track driving and he and I agreed.

[netsinah]

MR engine mounts =another benefit. We remember Skank suggesting even before the Stingray was revealed, that he believed that the Z06 would have magnetorheological mounts for exactly the following reason. Was he ever correct!

Reason #1,989 to buy the new Z06!