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PowerFlex Street Inserts Review (both)

HBEcoBeaST

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#1
Had these in for a few weeks but due to a calf injury, I couldn't really give them an honest review until now.

Currently running a Cobb RMM. PSMM was on it's way out, I thought the bolt was gone but it seems the rubber failed. Decided to buy new OEM mounts to go in with the PowerFlex units. Even with new OEM mounts and the inserts, cost was less than half a set of complete motor mount upgrades. I was considering several options, but I didn't like how certain brands re-used the top mount of the psmm, or the cost and NVH of other brands. New OEM mounts + inserts fit within my needs and budgets.

First Impressions: Is this thing on? Upon starting my car I was expecting some type of increased vibration but felt almost nothing. Very surprised since my Cobb added more NVH than this. Very pleased.

Shifting now feels AWESOME. Really improved shifting feel, engagement and limiting unnecessary movement. I thought it felt good before, but now it's 'solid' feeling in the best way possible.

Torque steer is just about eliminated. With my TB bracing and these mounts I can now put the power down much better. While the TB traction bar eliminated wheel hop and greatly helped torque steer, it didn't eliminate it. My stratified e30 tune has a torque bomb down low and sometimes my car would lunge to the left or right upon acceleration. With the mounts my wheels are now much more planted. Although the car is faster down the road, it almost feels slower since it's much more controlled. I'm not battling the wheel when I punch it in 2nd or 3rd. I am assuming much of my torque steer was coming from the failing PSMM. Glad I replaced it.

Overall 10/10: Super easy and affordable mod. Really glad I replaced the OEM mounts too. I used the lube supplied with the mounts and greased them good. I can't believe how much difference a few pieces of poly can make. The car is so much more enjoyable with the TB bracing and these mounts, it also feels like it could handle a lot more power.

Besides my e30 tune, my handling upgrades have been my favorite on this platform. Crossing my fingers I get these regular Fiesta Bilstein Coilovers form the UK so I can make my car handle even better without much of a drop. Then I'll start chasing more power.
 


Spork1569

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#2
Great review. I have these same ones and can speak volumes on how good they make the car feel.

I think they should be recommended as much as the RMM in the amount of difference they make to the car. There's a little extra vibes when the ac is on but otherwise very little nvh
 


OP
HBEcoBeaST

HBEcoBeaST

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Thread Starter #3
Great review. I have these same ones and can speak volumes on how good they make the car feel.

I think they should be recommended as much as the RMM in the amount of difference they make to the car. There's a little extra vibes when the ac is on but otherwise very little nvh
I couldn't believe how little vibration they added. I was nervous I'd have to raise my idle and get a strut tower brace to quell the vibes. Luckily my fears didn't materialize.

I also didn't know how much play was in my shifter until I got these mounts. The lever only moves into and out of gear like a gated shifter now. No excess play. So nice!

For around $200 you could get these inserts with a RMM and call it a day. Definitely the best bang for the buck.

With my TB traction and torsion bars handling is epic. Almost done with my suspension/chasis mods!
 


Ford ST

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#4
Cool sounds like you really enjoy it.
The mount that you have to reuse the top piece is the one I plan on giving a try in the future. I figure if I end up not liking it I will use the original mount with a insert.
Thanks for the review I wish more people would post their impressions of the modifications that they do.

Sent from my LG-LS997 using Tapatalk
 


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#5
I installed mine on friday with the APR bolt. I agree with everyone about how connected the car feels but so far I have to say that the noise is terrible! I have a little bit of added vibrations but that's not my issue, now I can feel the engine through the whole car. Best way I can describe it would be to say it is like a humming sound through all gears and speeds that does not diminish. I though it was cool for about 10 minutes then not so much. I know low frequencies travel and since the engine is more firmly mounted to the frame, those frequencies will reverberate through the whole car.....I just hope it gets a little better because a long trip might make me go insane.
 


OP
HBEcoBeaST

HBEcoBeaST

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Thread Starter #7
I installed mine on friday with the APR bolt. I agree with everyone about how connected the car feels but so far I have to say that the noise is terrible! I have a little bit of added vibrations but that's not my issue, now I can feel the engine through the whole car. Best way I can describe it would be to say it is like a humming sound through all gears and speeds that does not diminish. I though it was cool for about 10 minutes then not so much. I know low frequencies travel and since the engine is more firmly mounted to the frame, those frequencies will reverberate through the whole car.....I just hope it gets a little better because a long trip might make me go insane.
You're running the street inserts? Do you have an aftermarket rmm? Did you lube the mounts. I barely noticed my mounts as far as vibrations go.
Wheres the DIY with pictures?


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Lol I figure there's enough installs on them. It's pretty easy just taking some minor things off to get to the mounts.
 


TyphoonFiST

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#8
You're running the street inserts? Do you have an aftermarket rmm? Did you lube the mounts. I barely noticed my mounts as far as vibrations go.


Lol I figure there's enough installs on them. It's pretty easy just taking some minor things off to get to the mounts.
There isn't any Videos that's for sure....[emoji848]

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#9
You're running the street inserts? Do you have an aftermarket rmm? Did you lube the mounts. I barely noticed my mounts as far as vibrations go.


Lol I figure there's enough installs on them. It's pretty easy just taking some minor things off to get to the mounts.
Street insert and AWR rmm. I lubed er up pretty good. It slipped in place really easy honestly.
 


Spork1569

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#10
Street insert and AWR rmm. I lubed er up pretty good. It slipped in place really easy honestly.
What durometer AWR RMM? I used to run the 70A and that alone caused more NVH than running all 3 inserts I have now. I could see it being a bit much if you're running all 3 in that case.
 


TyphoonFiST

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#11
Where is Dave at on this? I know he was in talks with power flex and they know the O-ring that holds the mount in is poopy and they were coming out with a Viton ring that's more resistant to heat and chemicals.

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OP
HBEcoBeaST

HBEcoBeaST

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Thread Starter #12
Where is Dave at on this? I know he was in talks with power flex and they know the O-ring that holds the mount in is poopy and they were coming out with a Viton ring that's more resistant to heat and chemicals.

Sent from my SM-N950U1 using Tapatalk
Yup I'm running just the supplied ring ATM. Didn't have any decent zip ties. I will keep an eye on it.

It's sad how long I've been sitting on these inserts so even if it was updated mine would be the old style.
 


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Denver
#13
Had these in for a few weeks but due to a calf injury, I couldn't really give them an honest review until now.

Currently running a Cobb RMM. PSMM was on it's way out, I thought the bolt was gone but it seems the rubber failed. Decided to buy new OEM mounts to go in with the PowerFlex units. Even with new OEM mounts and the inserts, cost was less than half a set of complete motor mount upgrades. I was considering several options, but I didn't like how certain brands re-used the top mount of the psmm, or the cost and NVH of other brands. New OEM mounts + inserts fit within my needs and budgets.

First Impressions: Is this thing on? Upon starting my car I was expecting some type of increased vibration but felt almost nothing. Very surprised since my Cobb added more NVH than this. Very pleased.

Shifting now feels AWESOME. Really improved shifting feel, engagement and limiting unnecessary movement. I thought it felt good before, but now it's 'solid' feeling in the best way possible.

Torque steer is just about eliminated. With my TB bracing and these mounts I can now put the power down much better. While the TB traction bar eliminated wheel hop and greatly helped torque steer, it didn't eliminate it. My stratified e30 tune has a torque bomb down low and sometimes my car would lunge to the left or right upon acceleration. With the mounts my wheels are now much more planted. Although the car is faster down the road, it almost feels slower since it's much more controlled. I'm not battling the wheel when I punch it in 2nd or 3rd. I am assuming much of my torque steer was coming from the failing PSMM. Glad I replaced it.

Overall 10/10: Super easy and affordable mod. Really glad I replaced the OEM mounts too. I used the lube supplied with the mounts and greased them good. I can't believe how much difference a few pieces of poly can make. The car is so much more enjoyable with the TB bracing and these mounts, it also feels like it could handle a lot more power.

Besides my e30 tune, my handling upgrades have been my favorite on this platform. Crossing my fingers I get these regular Fiesta Bilstein Coilovers form the UK so I can make my car handle even better without much of a drop. Then I'll start chasing more power.

I pretty much have the same setup and it’s a good way to go. I don’t notice any NVH with street inserts and Cobb RMM. The only difference is I’m running a Whoosh Traction Bar. What RPM are you launching at?

I have no wheel hop launching @ 2400rpm, but I do have hop when launching around 2600-2800 RPM.
 


OP
HBEcoBeaST

HBEcoBeaST

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Thread Starter #14
I pretty much have the same setup and it’s a good way to go. I don’t notice any NVH with street inserts and Cobb RMM. The only difference is I’m running a Whoosh Traction Bar. What RPM are you launching at?

I have no wheel hop launching @ 2400rpm, but I do have hop when launching around 2600-2800 RPM.
Honestly I'm comparing the upgrade to a failed PSMM so I was getting mad torque steer every time I gave it the beans. Usually while rolling in the mid 2000s RPM. Once I installed the TB traction bar wheel hop was eliminated but it made the torque steer even worse since I now had traction and the broken mount made it hard to keep straight.

Short of bad pavement I get zero wheel hop now, I'll just do a burnout. With my stratified e30 tune and it's torque delivery down low I'm very impressed. I'd have to add a bit more power before I need anything else.
 


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#15
What durometer AWR RMM? I used to run the 70A and that alone caused more NVH than running all 3 inserts I have now. I could see it being a bit much if you're running all 3 in that case.
70A, was fine just a little vibration by itself but since I added the powerflex.....I'll give it some time and maybe it will settle in. I like the way the car responds though!!!
 


Dpro

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#17
I also installed the Powerflex pasenger side mount. Yes initially there is a little vibration at idle its very mild. It starts to go away after a few hundred miles. The elimination of TQ steer from my tune was instantly noticeable though. It was a night and day difference. Also the car no longer tram lines on grooves in the freeways.
 


Last edited:

maestromaestro

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#18
I have both sides installed. I honestly don’t notice a lot of difference, but I’m sure having stiffer mounts helps minimize parasitic power losses.

I’m not sure to what extent these can moderate torque steer. What would be the mechanism? TS is there because it’s a big ask of the front wheels to drive AND to steer, what with the weight transfer rearward. MMs fix the engine in place, so to speak - but it’s not that the engine’s movement is what causes the TS in the first place, I’d think. To that end, now that I have the Sprint Booster installed, Powerflex mounts or not, the car torque steers like a motherfucker.
 


OP
HBEcoBeaST

HBEcoBeaST

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Thread Starter #19
I have both sides installed. I honestly don’t notice a lot of difference, but I’m sure having stiffer mounts helps minimize parasitic power losses.

I’m not sure to what extent these can moderate torque steer. What would be the mechanism? TS is there because it’s a big ask of the front wheels to drive AND to steer, what with the weight transfer rearward. MMs fix the engine in place, so to speak - but it’s not that the engine’s movement is what causes the TS in the first place, I’d think. To that end, now that I have the Sprint Booster installed, Powerflex mounts or not, the car torque steers like a motherfucker.

In a fwd car the engine/trans movement does have a lot of effect on torque steer since the motor's movement directly effects the power being put to the ground. The more the motor moves the more it will deliver power unevenly between the wheels, increasing torque steer. Less motor movement=less torque steer.

If you don't have an upgraded rear motor mount the difference won't be as noticeable. Also front chasis bracing makes a huge difference on how much power you can put down while keeping traction.
 


maestromaestro

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#20
In a fwd car the engine/trans movement does have a lot of effect on torque steer since the motor's movement directly effects the power being put to the ground. The more the motor moves the more it will deliver power unevenly between the wheels, increasing torque steer. Less motor movement=less torque steer.

If you don't have an upgraded rear motor mount the difference won't be as noticeable. Also front chasis bracing makes a huge difference on how much power you can put down while keeping traction.
I have all of those bits. Maybe because the side mounts were the last of these modifications I didn’t notice the difference. I hear you on the movement contribution to TS, but I’d think it’s secondary to the inherent issue with the FWD cars. I’d expect the side mounts to be more of a factor in weight transference in the turns, reducing inertia and power loss in track outs.
 




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