Stiffening mounts for DD

[FR-Slide]

I know that there are a few options out there for upgrading the OEM motor and trans mounts, and wanted to see what would be the best option for a DD/canyon carver.

Whiteline keeps coming up in searches for the trans bushing, but I saw that there are also trans MOUNTS (solid mounts), as well as other PU/rubber bushings offered by vendors like FT86SF. Is the whiteline bushing the best/preferred for a mostly street car?

Assuming (since I don't see much offered) that most folks are still on the OEM motor and diff mounts. Coming from VAG-world, these were common upgrades, so just covering bases here.

There's not a ton of slop in the drivetrain, but there is a bit of play that is noticed when engine braking or hard shifting that I'd like to cure. Thanks for any tips.

[gramicci101]

New engine mounts, transmission bushing, and rear diff outrigger/subframe braces or inserts will lock things down dramatically, at the cost of increased NVH. Perrin, Cusco, and STI make engine mounts, a lot of companies make transmission bushings, and a few different companies make braces or insert bushings for the rear diff.

Check www.ft86speedfactory.com under drivetrain>diff/trans mounts, under engine>motor mounts, and under suspension>bushings for ideas.

[FR-Slide]

Thanks. NVH isn't nearly as bothersome to me as a sloppy drivetrain or the trans kicking around under hard accel/decel, but I don't need solid motor mounts or anything crazy.

What led me here to begin with was the page you linked I was trying to decide if the Whiteline bushing would be sufficient, or if it would be wise/useful/worthwhile to also put in one of the "packages" they have (like the Perrin mount with the Whiteline bushing). Or, would that be overkill for a street machine?

[gramicci101]

I'm looking at doing Perrin engine mounts, the Whiteline/Perrin shift combo, and Whiteline diff outrigger inserts.

The issue I have with only doing a transmission bushing is that the engine can still move, and now since the transmission can't move with the engine, it might put undo stress on where the engine and transmission mate. People with more experience than I have with this vehicle might disagree with that statement, but that's my opinion.

[SirBrass]

Then get yourself the rear shifter bushing, transmission mount bushing, mtec springs, and rear diff mount bushings. That'll lock down the drivetrain in the areas where (on this car) it is prone to more movement.

Motor mounts won't really help out much until you start seriously upping the torque from the engine.

As far as the transmission mount goes, it's only a single collar back near the driveshaft interface, with a black mount between the mount collar and the transmission. It's the void IN the transmission mount that is filled by the transmission mount bushing, thus stiffening up the transmission's mounting under hard accel/decel.

Rear shifter bushing will help with your hard accel/decel shifts, as will MTec springs, and help decrease the feel of the shifter moving around on you, too.

[FR-Slide]

Perfect, thats exactly what I was looking for, thanks! I figured MM's at this stage weren't required, was going to focus mainly on the trans and maybe rear diff.

Will pick up the shifter and trans bushing, and start looking into rear diff as well.

I must admit I'm a bit lost on the MTEC springs though; I thought that was part of a shift kit? Or are those what are responsible for returning the shifter to N? (sorry, never messed with that stuff before)

[SirBrass]

The springs are separate from a shifter bushing kit.

On phone I am. Therefore, if mistakes I make, Frank Oz blame you should.

[OrbitalEllipses]

Originally Posted by FR-Slide

Perfect, thats exactly what I was looking for, thanks! I figured MM's at this stage weren't required, was going to focus mainly on the trans and maybe rear diff.

Will pick up the shifter and trans bushing, and start looking into rear diff as well.

I must admit I'm a bit lost on the MTEC springs though; I thought that was part of a shift kit? Or are those what are responsible for returning the shifter to N? (sorry, never messed with that stuff before)

MTEC springs are what return the shifter to N - the largest improvement from what people have said is 2nd-3rd and 4th-5th (IIRC). Honestly the stock shifter is pretty good, though I've noticed pretty significant variance between cars. I've got the trans mount insert and rear shifter bushing which really improved precision and movement in the both trans and lever.

I'm going to disagree with @SirBrass on engine mounts. The engine has super soft mounts from the factory and if you watch any dyno you can see how dramatically the engine rocks inside the crade during on/off throttle. It already makes more than enough torque to rock in the cradle, so I don't think upping power is a requirement to do these. When you tip in the throttle do you ever notice how the revs bounce a bit THEN climb? There's a few places that comes from - most notably the engine, trans mount, and rear diff carrier. Of these, which moves the most? The engine. I'd argue it's among the best changes you can make to the car and I'd do it before the diff carrier (I've had a pro tell me the diff carrier bushings are responsible for the most NVH, especially when combined with certain other modifications). I think engine mounts are where you can make up the most slop in the driveline. Just my two cents on that, though. Regardless, improving any driveline slack will improve how the car feels.

[SirBrass]

I'll have to look into possible engine mounts, then.

[fazm]

Check out powerflex, they make excellent bushings for the vast majority of the car.

[reeves]

Originally Posted by FR-Slide

NVH isn't nearly as bothersome to me as a sloppy drivetrain or the trans kicking around under hard accel/decel, but I don't need solid motor mounts or anything crazy.

What led me here to begin with was the page you linked I was trying to decide if the Whiteline bushing would be sufficient, or if it would be wise/useful/worthwhile to also put in one of the "packages" they have (like the Perrin mount with the Whiteline bushing). Or, would that be overkill for a street machine?

Subaru STI mounts should be stiff enough for your DD/street needs, without the NVH of solid aftermarket mounts.. http://www.ft86club.com/forums/showthread.php?t=33512

[tbertran]

Originally Posted by fazm

Check out powerflex, they make excellent bushings for the vast majority of the car.

I'm looking at their page right now (http://powerflexusa.com/brz.aspx) and I apologize if it's a stupid question but I'm not seeing any engine mounts on there... Are they called something else?

[ducks]

I have perrin motor mounts, forced fab trans mount (same as the perrin), whiteline subframe inserts, and whiteline diff inserts.

I had the motor mounts and trans mount installed first. It helped with the slop, but at the same time, accentuated the remaining slop at the rear end. Once the whiteline bushings were in, power delivery felt much more direct.

As for NVH-

N: The motor/trans mount combo made engine startup louder, but it mellowed out as they broke in. There's some transmission whine/resonance at low speeds and certain gears and rpms (~35 mph in 4th for instance). There's also a humming resonance from the diff at 70mph in 6th which can get annoying on long drives. From a DD standpoint, I think the worst of it comes from the trans mount and I'm planning on swapping to the whiteline insert when I get a chance. It's been in for 6 months though, so it's definitely tolerable.

V: I think the worst of it was during the first couple days/weeks with the motor mounts. Having an idle of 750rpm helps. Now that everythings broken in, I only notice increased vibration during startup and when lugging the engine or about to stall :/

H: Not exactly sure what this measures, so minimal imo.

[skuts?]

N = Noise
V = Vibration
H = Harshness

-Taylor