Mega Motor Mount Mashup

[lucky phil]

I'm always intrigued as to why people want to replace engine mounts on a road car. There is a ton of R&D time and money that goes into motor and gearbox mount technology at the factory test facilities not only with regards to NVH but there is also the impact engine harmonics has on the chassis from a structural perspective. The fact the engine has movement is neither here nor there for a road car and even if you like or can tolerate NVH then that's fine but no one is considering the impact on the chassis structure. Engine vibration frequency can be a killer on chassis structure and cause cracking over time.
Aftermarket mount manufacturers will do zero testing on the complex stuff I can guarantee you that. Stiffer isn't always better, well not with regards to motor mounts anyway.
Dedicated track cars, it doesn't matter as mileage is low, tracks are smooth, NVH doesn't matter and chassis cracking etc is an accepted compromise.
Why do people think race car practices translate perfectly onto road cars and manufacturers who spend lots of money and research on things like suspension bushings and engine, diff and gearbox mounts are simplistic enough to only be interested in driver and passenger comfort.
Has anyone ever looked at a commercial jet engine dancing around on it's wing strut in flight? It's not doing that for the passenger comfort it's doing that to protect the structure. If it was rigidly mounted without controlled flex you'd be losing engines due to structural cracking all the time.
Motorcycles with rigidly mounted engines are the same, some vibey engine configurations used to be frame structure killers. Now those engines configurations are generally made with balance shaft/s which helps negates the issue.
Something to consider when thinking about aftermarket engine mounts.
Phil

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[Funkjaw]

I'm always intrigued as to why people want to replace engine mounts on a road car. There is a ton of R&D time and money that goes into motor and gearbox mount technology at the factory test facilities not only with regards to NVH but there is also the impact engine harmonics has on the chassis from a structural perspective. The fact the engine has movement is neither here nor there for a road car and even if you like or can tolerate NVH then that's fine but no one is considering the impact on the chassis structure. Engine vibration frequency can be a killer on chassis structure and cause cracking over time.
Aftermarket mount manufacturers will do zero testing on the complex stuff I can guarantee you that. Stiffer isn't always better, well not with regards to motor mounts anyway.
Dedicated track cars, it doesn't matter as mileage is low, tracks are smooth, NVH doesn't matter and chassis cracking etc is an accepted compromise.
Why do people think race car practices translate perfectly onto road cars and manufacturers who spend lots of money and research on things like suspension bushings and engine, diff and gearbox mounts are simplistic enough to only be interested in driver and passenger comfort.
Has anyone ever looked at a commercial jet engine dancing around on it's wing strut in flight? It's not doing that for the passenger comfort it's doing that to protect the structure. If it was rigidly mounted without controlled flex you'd be losing engines due to structural cracking all the time.
Motorcycles with rigidly mounted engines are the same, some vibey engine configurations used to be frame structure killers. Now those engines configurations are generally made with balance shaft/s which helps negates the issue.
Something to consider when thinking about aftermarket engine mounts.
Phil

For most vehicles I am inclined to agree!

Here's my issue with the Supra: I've owned ~25 RWD manual sports cars in my life and driven hundreds more, and this chassis is by far the one of most problematic when it comes to rear-end stability in factory form. So for me, I'm just exploring ways to make it a little more capable on the road, without sacrificing much, if any, of the original characteristics as defined by Toyota/BMW.

Again, I do agree for the most part, and there are probably a ton of owners out there just slapping on parts for problems that don't even exist - but as you can see in the following video, the engine has way too much slop than what a high performance 400hp engine should have. It's actually mind boggling. (Watch the first 13 seconds)

 

[lucky phil]

For most vehicles I am inclined to agree!

Here's my issue with the Supra: I've owned ~25 RWD manual sports cars in my life and driven hundreds more, and this chassis is by far the one of most problematic when it comes to rear-end stability in factory form. So for me, I'm just exploring ways to make it a little more capable on the road, without sacrificing much, if any, of the original characteristics as defined by Toyota/BMW.

Again, I do agree for the most part, and there are probably a ton of owners out there just slapping on parts for problems that don't even exist - but as you can see in the following video, the engine has way too much slop than what a high performance 400hp engine should have. It's actually mind boggling. (Watch the first 13 seconds)

Thats certainly a dramatic video with regards to engine movement BUT does it actually mean anything? Things aren't as simple as they might appear. Because the movement demonstrated doesn't necessarily mean and extrapolate that the movement under full torque load will be proportional. The std mount looks like a fairly sophisticate piece and If I were wearing my engineering hat I would presume that what has been demonstrated is the mounts high frequency absorption capability not it's ability at peak torque loads. So you can move it as demonstrated but that doesn't mean that it's going to move some proportionally massive amount under peak load. The mount I can almost assure you has the ability to deal with a wide range of loads and frequencies. So what you are seeing in the video is almost certainly only a small zone of what the mount can deal with. Lets be honest if the movement of the mount was proportional to what the video showed then the engine would be smacking the hood all the time or hitting a mount stop which would defeat the purpose.
It makes a good marketing tool though. Bit like those guys at car shows with their little contraption to show the benefit of their oil additive.
Phil

 

[Funkjaw]

Thats certainly a dramatic video with regards to engine movement BUT does it actually mean anything? Things aren't as simple as they might appear. Because the movement demonstrated doesn't necessarily mean and extrapolate that the movement under full torque load will be proportional. The std mount looks like a fairly sophisticate piece and If I were wearing my engineering hat I would presume that what has been demonstrated is the mounts high frequency absorption capability not it's ability at peak torque loads. So you can move it as demonstrated but that doesn't mean that it's going to move some proportionally massive amount under peak load. The mount I can almost assure you has the ability to deal with a wide range of loads and frequencies. So what you are seeing in the video is almost certainly only a small zone of what the mount can deal with. Lets be honest if the movement of the mount was proportional to what the video showed then the engine would be smacking the hood all the time or hitting a mount stop which would defeat the purpose.
It makes a good marketing tool though. Bit like those guys at car shows with their little contraption to show the benefit of their oil additive.
Phil

I hear your points and I would normally be on your side here - but again, my experience with racing and cars begs to differ. This car is too soft for it's own good. You can literally feel the car twist and wag and hop every chance it gets as you drive it 8 tenths and beyond - ESPECIALLY with all the assists off. So yes I believe the engine flex absolutely means something, if not a lot of something. Just my 2 cents

 

[razorlab]

I hear your points and I would normally be on your side here - but again, my experience with racing and cars begs to differ. This car is too soft for it's own good. You can literally feel the car twist and wag and hop every chance it gets as you drive it 8 tenths and beyond - ESPECIALLY with all the assists off. So yes I believe the engine flex absolutely means something, if not a lot of something. Just my 2 cents

I don't feel any of that on track and I have all OEM mounts on everything drivetrain related. Suspension is a different story.

 

[Funkjaw]

I don't feel any of that on track and I have all OEM mounts on everything drivetrain related. Suspension is a different story.

Good to know... Wonder if there is a difference there between the autos and the manuals.?.. but maybe not, because wheel hop is very prevalent in the automatics in factory form and the largest contributor to wheel hop is bushing deflection in the drivetrain. Could just be the tracks you run have tamer conditions and better coefficient of friction surfaces than the back roads I drive, not 100% sure TBH. I'm also on bone stock suspension, could be a multitude of things really.

That's what I love about this hobby tho; lots of feedback, opinions, data, and experiences from other owners that gives my ADHD stuff to feed on as I nerd out

 

[Funkjaw]

Everyone - I got around to installing the red PowerFlex Engine Mount Inserts on my 2023 manual. *I ONLY INSTALLED THE LOWER HALF OF THE INSERTS*

All in all it was surprisingly easier than I thought and took me about 2 hours, while having covid of all things. Strat-Supra - I was in fact able to just jack the engine up from underneath and wiggle the mounts out. I did not have to remove the brackets. I did remove the downpipe. So now I am genuinely curious why you had issues doing this method ?. Where did you jack the engine from?

You can see my jacking point on the transmission here, I jacked the engine up until it wouldn't go any more. It was kinda sketch with the blocks of wood, but it worked!

Here is the driver's side mount. With just raising the engine I was able to get enough clearance to to wiggle the driver's side mount out without removing the bracket.

Here is the passenger side - plenty of room to wiggle the mount out without removing the bracket (downpipe was removed, unsure if I needed to remove it but I did it anyways).

As mentioned at the beginning I only installed the lower half of the inserts, because I felt this would offer the most amount of stiffness with the least amount of increase to NVH. Also, the kit didn't come with any grease, but I am a big believer in putting grease wherever poly contacts metal, so I greased the outside of the insert with poly bushing specific grease before encapsulating it with the top of the mount.

THOUGTS AND IMPRESSIONS

Here is a video of me demonstrating the amount of engine flex after I installed the (lower half) inserts. As you can see, it takes a lot of effort to produce any movement now. If I had to put a number on it I would say just the lower half of the inserts increased mount stiffness by ~75%. Before I could rock the engine back and forth with just one hand (like the Verus engineering video) now using two hands and putting as much effort as I can it barely moves!




So how does it drive?
AMAZING. No more mother f!%$!ng wheel hop (and I tested it on cold tires)! Crisper gear changes. Slightly improved throttle response. Less hectic power slides (you can think of these as minimally counter steered power over drifts).
UPDATE: When I tested this the weather was rather warm (75f-85f yes Texas has some weird winters). We have since had an extreme cold front with freezing weather and after doing some further testing on 30f roads wheel hop is still in fact there, just not as much. Traction links have been ordered

What about NVH increase?
There is a slight rumble on initial cold start that goes away almost immediately. That same rumble is there during a warm start but to a lesser extent. And that's it. No increase to idle acoustics, no vibrations added while driving, nothing. I couldn't be happier with just how little it added any NVH.

I am going to keep the top halfs around in case I start throwing some power modifications at the car, at which point the top halfs would likely be helpful to account for the extra torque that just the bottom halfs might not be able to handle.

 

[garudathree]

Yup, everyone who had NVH issues with the power flex inserts generally made the mistake of using the top mounts unmodified.
By only stiffening the bottom, the oem fluidlastic damper is still able to trim high frequency vibrations. Just ignore the other guy. Treat these as bump stops

 

[swrdply400mrelay]

Did you re install the transmission mounts?

I know it’s winter but wondering if the NVH increases with the AC on.

 

[Funkjaw]

Did you re install the transmission mounts?

I know it’s winter but wondering if the NVH increases with the AC on.

I did not, I am on the OEM trans mounts. I might revisit the trans mounts in the future, but I am going to drive this around for a bit as is.

As for AC, I will test this and report back

 

[Strat-Supra]

That's interesting, I jacked at the same point. The only difference I can think of is that I swapped the transmission mounts before doing the inserts. I might take the transmission mounts out to see if I can feel any difference vs stock, as I did both transmission and engine at the same time.

Good to know about only using the bottom inserts and cutting the top ones short to reduce NVH. Since a Femto unlock and tuning software is required to slightly increase idle rpm to offset the resonance from the mounts at idle. I will probably pull the mounts and either remove the top insert or cut them down a little. I'll swap to the stock transmission mounts prior and see if ljacking the engine works.

Appreciate the insight.

 

[Funkjaw]

That's interesting, I jacked at the same point. The only difference I can think of is that I swapped the transmission mounts before doing the inserts. I might take the transmission mounts out to see if I can feel any difference vs stock, as I did both transmission and engine at the same time.

Good to know about only using the bottom inserts and cutting the top ones short to reduce NVH. Since a Femto unlock and tuning software is required to slightly increase idle rpm to offset the resonance from the mounts at idle. I will probably pull the mounts and either remove the top insert or cut them down a little. I'll swap to the stock transmission mounts prior and see if ljacking the engine works.

Appreciate the insight.

Let us know how it goes! I do wonder if your increased power levels would warrant keeping the top half of the inserts - maybe as you mentioned just cutting them down might be the ticket.

On the topic of trans mounts - I was thinking of encasing the stock mounts with something like Windo-Weld (has a cured durometer of 50). So it's stiffer than OEM, but not as stiff as full poly because it will still be mostly OEM rubber. Crazy idea or genius? ?

 

[i3igpete]

Also, wheel hop was still very much there with the powerflex mounts

I assume you already tried traction arms and toe links to fix this? if not, you should do that before anything else.

 

[Funkjaw]

I assume you already tried traction arms and toe links to fix this? if not, you should do that before anything else.

I have not - I like to start closest to the engine and work backwards

Also, ???

 

[Strat-Supra]

Swapped the transmission mounts, idle is tolerable. Not seeing a need to remove the engine mounts to cut or remove the top piece. If I decide to go Femto and all, I'll most likely swap back to the Powerflex transmission mounts and raise the idle a little bit.

I do like it better with both the engine and transmission mounts swapped, it's the NVH at idle that makes it a no go for me.

The Windo-Weld idea is interesting, seems people have been using it for engine and transmission mounts for years. Not sure how well it would work as ours aren't encased, you'd have to figure out a way to encase them while curing. From what I've read it takes 3+ days for the Windo-Weld to cure.

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