Engine mounts, Transmission bushing/ support mount

[Slade]

Hey can I ask a few questions? I drive a 2014 BRZ A/T, only bolt on mods and a tune, nothing crazy. (Front pipe, EL catless header, Exhaust, drop in filter) nothing crazy. I need new motor mounts. I've done some research on these forums and it seems that:

-If you have some mods, you shouldn't replace your mounts with another set of OEM mounts, is that right?
-Cusco and Perrin add a lot of NVH which is something I do not want because this is my daily.
STI mounts add very little NVH, but they are still recommended for a car with some mods. They are almost like OEM+, so it seems like this is the route I should go with correct?

Now with the transmission mount. You don't actually need to replace the entire thing, just the rubber insert is that correct? Does it matter if I have an A/T? I'm considering getting the Whiteline insert. But will that add any NVH? I'm not clear on that for the transmission mount.

Thanks for your help, I just want to make sure I buy the best thing for my preference. Sorry if these are silly questions, I'm just not 100% clear.

[why?]

Originally Posted by GiannisK

OMG guys so many responses in such little time.
You guys are amazing.

From all the answers i've read the most common answer i see is go for STi mounts.

As for the mtec shifter spring i will definitely get that since it was also recommended from other forums and groups that i've read on.

I already have the perrin rear shifter bushing and whiteline transmission bushing installed on the car, oil was changed 2 weeks ago but i honestly cant remember the oil brand need to ask my mechanic.

As for the vibration i mostly get them on low rpms between 1k to 2.5k. Most of the vibrations are while i'm starting to accelerate from idle. Don't get me wrong the feel it gives that you are connected to the car is amazing but still the car has become quite harsh to drive for a daily. It also happens if lets say I brake while in 3rd to get past a bump and don't downshift to 2nd which drops the RPMs to around 2K so yet again those ranges of RPMs. If i'm cruising on the freeway at 3k rpms then its all fine.

As for the differential inserts am i looking at the right thing here?
There's mount bushing and outrigger bushing which one are you talking about @RayRay88

https://ukwhitelineperformance.com/p...23-bushing-kit
https://ukwhitelineperformance.com/p...25-bushing-kit

Thanks once again guys for the info, highly appreciated.

Don't let the car go below 2k unless it is in neutral. And in 5th and 6th keep it above 2.5k. Every one of these sounds like a farm tractor at those low revs.

Originally Posted by Slade

Hey can I ask a few questions? I drive a 2014 BRZ A/T, only bolt on mods and a tune, nothing crazy. (Front pipe, EL catless header, Exhaust, drop in filter) nothing crazy. I need new motor mounts. I've done some research on these forums and it seems that:

-If you have some mods, you shouldn't replace your mounts with another set of OEM mounts, is that right?
-Cusco and Perrin add a lot of NVH which is something I do not want because this is my daily.
STI mounts add very little NVH, but they are still recommended for a car with some mods. They are almost like OEM+, so it seems like this is the route I should go with correct?

Now with the transmission mount. You don't actually need to replace the entire thing, just the rubber insert is that correct? Does it matter if I have an A/T? I'm considering getting the Whiteline insert. But will that add any NVH? I'm not clear on that for the transmission mount.

Thanks for your help, I just want to make sure I buy the best thing for my preference. Sorry if these are silly questions, I'm just not 100% clear.

It really is personal preference. The best way is to find someone local to you with those motor mounts and get a ride. The firmer it is, the more NVH you will experience. There is no way around that.

[GiannisK]

Thanks everyone once again for your time and effort

Appreciated.

I found all the answers i was looking for.

[DocRecon]

Originally Posted by NoHaveMSG

Maybe a good carbon one, otherwise hell no. Even the DSS carbon has issues because of it's diameter to weight. My DSS aluminum one has terrible vibration even after being rebalanced. I am going to put a stocker in the car and cut this one up so it can't hurt anyone again.

I'm about ready to install the DSS Aluminum Driveshaft. Do you know if I should change the output carrier bearing on the tranny too so it'll probably get a better seal? I don't want gear oil leaking everywhere.

[NoHaveMSG]

Originally Posted by DocRecon

I'm about ready to install the DSS Aluminum Driveshaft. Do you know if I should change the output carrier bearing on the tranny too so it'll probably get a better seal? I don't want gear oil leaking everywhere.

I never did, just give it an inspection at least and replace as needed.

[DocRecon]

Originally Posted by NoHaveMSG

I never did, just give it an inspection at least and replace as needed.

Thank you!

[Spawn_Of_Creation]

I'm thinking about doing the Sti engine mounts, Whiteline Trans Insert Bushing, Perrin Support Mount, Perrin Shifter Mount Bushing, Whiteline Positive Traction kit, and Whiteline Support Outrigger Insert too as a daily. Let me know how the NVH is once you put in the STI mounts.

Ive heard the Perrin Trans Support Mount is the 2nd most NVH, and Whiteline Support Outrigger is 3rd out of what you have done. I've also heard that the STI Trans Mount does the same as the Perrin Support Mount, but doesn't increase NVH.

[Plumbus]

Originally Posted by Spawn_Of_Creation

I'm thinking about doing the Sti engine mounts, Whiteline Trans Insert Bushing, Perrin Support Mount, Perrin Shifter Mount Bushing, Whiteline Positive Traction kit, and Whiteline Support Outrigger Insert too as a daily. Let me know how the NVH is once you put in the STI mounts.

Ive heard the Perrin Trans Support Mount is the 2nd most NVH, and Whiteline Support Outrigger is 3rd out of what you have done. I've also heard that the STI Trans Mount does the same as the Perrin Support Mount, but doesn't increase NVH.

I have the sti engine mounts, sti trans mount, perrin shifter bushing, whiteline front + rear diff bushing inserts (outrigger) kit (kdt925), and the whiteline positive traction kit (rear subframe bushing inserts, kdt922). Of these, the most severe was the rear subframe bushing inserts, surprisingly. nvh increased moderately, but worse of all it made the rear of the car substantially stiffer. I installed HKS SP coilovers before the inserts (8k square), and the inserts made the rear stiffer than the coilovers themselves. everything else increased the NVH just slightly, and cumulatively, and absolutely transformed the car. It is the PERFECT balance, not too harsh but also you get enough feeling and feedback like a racecar. Could not be happier.

Also STI trans mount is better than perrin support mount + whiteline bushing for transmission. does a better job and is less harsh.

[Spawn_Of_Creation]

Originally Posted by Plumbus

I have the sti engine mounts, sti trans mount, perrin shifter bushing, whiteline front + rear diff bushing inserts (outrigger) kit (kdt925), and the whiteline positive traction kit (rear subframe bushing inserts, kdt922). Of these, the most severe was the rear subframe bushing inserts, surprisingly. nvh increased moderately, but worse of all it made the rear of the car substantially stiffer. I installed HKS SP coilovers before the inserts (8k square), and the inserts made the rear stiffer than the coilovers themselves. everything else increased the NVH just slightly, and cumulatively, and absolutely transformed the car. It is the PERFECT balance, not too harsh but also you get enough feeling and feedback like a racecar. Could not be happier.

Also STI trans mount is better than perrin support mount + whiteline bushing for transmission. does a better job and is less harsh.

Do you recommend both diff bushing sets 925 and 922? or just the 925 if the 922 makes the rear end too stiff?

[NoHaveMSG]

Originally Posted by Spawn_Of_Creation

Do you recommend both diff bushing sets 925 and 922? or just the 925 if the 922 makes the rear end too stiff?

I honestly don't think the 925's do that much. They take up some windup in the drivetrain, but moneywise, not the biggest bang for the buck in the amount of work you need to do to install them. The factory bushings are pretty stiff and if you look at the distance between the outrigger mounts, and the amount of deflection in the stock bushings, I don't really feel you are gaining that much.

I have had my car with solid subframe mounts and the 925's, then traded diffs and am back on stock bushings, can't tell that much of a difference.

[Breezio]

I don't recommend the Perrin transmission mount 'bushing' bolt thing.
It adds a stupid amount of NVH for probably very little benefit. I'm going to remove mine when I get a chance and just leave the Whiteline bushing insert.

[scion fr-s]

Originally Posted by Breezio

I don't recommend the Perrin transmission mount 'bushing' bolt thing.
It adds a stupid amount of NVH for probably very little benefit. I'm going to remove mine when I get a chance and just leave the Whiteline bushing insert.

Yup, I took out my Perrin tranny mount. Awful amount of NVH. I run their shifter bushing with Whiteline trans mount.

[Capt Spaulding]

Originally Posted by Spawn_Of_Creation

Do you recommend both diff bushing sets 925 and 922? or just the 925 if the 922 makes the rear end too stiff?

I have both. At present, only the 925s are installed. I'm a little leery of increasing NVH to an intolerable level and decided to take it in stages. The 925s reduce drive train wind-up and seem to make shifts a lit more responsive. It's a hard call on the degree to which they add to NHV. At roughly the same time I installed them I did a pretty thorough sound deadening project in the trunk and the car is substantially quieter from that. All in all, if given the choice, I'd do the 925s again.

[Plumbus]

Originally Posted by Spawn_Of_Creation

Do you recommend both diff bushing sets 925 and 922? or just the 925 if the 922 makes the rear end too stiff?

The 925 and 922 do very different things. The 925 removes slack from the drivetrain, making power delivery more immediate/responsive. The 922 makes the rear feel more connected to the ground, helps with problems like wheel hop, but it also makes it substantially stiffer. It is impressive how much slack the stock rubber subframe bushings absorb, they were really well designed to make the car street friendly. I don't regret it, but I do wonder how much more stress I'm adding to the chassis by removing that slack, especially in the unforgiving city roads. Control of the rear is even easier now due to better feel and no wheel hop.

The 925 is much, much easier to install than the 922, and I would still install it again. 922 is much trickier because you want to make sure the subframe doesn't drop on your head or that you don't strip the subframe bolts. It took me awhile to get the guts to install it to be honest. I would probably still do it again, but think about what you want your car to feel like after everything is said and done.