STi grp N tranny mount review

[Kartoffel]

Yesterday I installed an STi group N urethane transmission mount. Here's a quick review after 1 day with the new mount.

Installation: Requires a 14mm deep socket. a 3/8" to 1/2" adapter and a LONG handled ratchet would have been very helpful, too. I managed to break everything loose with an 8" long 3/8" ratchet, but it sucked. Get a breaker bar or airtools if you can. Hit all the nuts and bolts with liquid wrench or PB blaster and let them soak for a while. Check Scoobymods for full details.

Test Drive: The transmission does not lurch at all anymore. Before, there was a noticeable amount of bucking and heaving in 1st and 2nd if you get on and off the gas quickly. The tendency for the driveline to shake and shudder when bogging down and lugging in low gears is much less, too.

NVH: Yes, the new mount transfers more vibration to the frame of the car. There is no increased noise. The vibration is not bad. To me it feels like the vibration increased in the floor pan and the underbody frame members - not in the shifter. The vibration is most noticable in neutral at a dead stop, and when going down the highway above 3000 rpm. During medium speed driving and in traffic you really can't feel any difference. The shifter knob itself does not vibrate or feel different than before. As far as I can tell, any NVH you experience will be felt in the soles of your feet through the floor pan.

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[Ginseng]

I agree with your evaluation completely. The one thing you did not comment on was the ease of shifting. I found that the greatest benefit was that all the gears are exactly where you left them. The 2-3 shift now is rock solid even under full throttle, high RPM conditions. I did notice a bit more vibration on the shift knob and yes, the majority of the vibration is in the floor pan. This makes sense as the mount bolts to the subframe which bolts to the main frame rails.

BTW, I'm pretty sure the rubber is a high durometer vulcanized rubber and not urethane.

Wilkey

PS. Doesn't "kartoffel" mean "potato" in Austrian?

[Kartoffel]

Maybe it is rubber instead of urethane... I don't know. The STi tranny mount is WAY stiffer than the stock mount, and that's what counts.

Before installing this mount, I already had an STi shifter with Kartboy bushings. Over the whole life of the car, I have missed 2-3 shift maybe once or twice but only under HARD acelleration. Time will tell if the STi tranny mount prevents future missed shifts. I have a feeling it will be much easier to find the gears under acceleration.

Ja, bedeutet "potato" Kartoffel auf Deutsch.

[jlevy]

I just installed the tranny mount and some COBB hardened shifter bushings (with the stock shifter). The shifter doesn't feel isolated like it did before and I don't have to finesse (for lack of a better word) my shifts during high rpm shifting. NVH is increased a little, but no big deal. I mainly notice an increase in noise when accelerating through the gears. I probably won't even notice it in a couple of miles. This is the best mod since the front license plate removal mod

-my 0.02

[jaxscuby]

Did the motor & tranny mounts in just under an hour.

I noticed the more tranmitted vibration into the steering
wheel and more engine noise (the exhaust sounded louder?)

But it made the car feel more aggressive.
When i shift (rather quickly) from 1 to 2 the "thud" is not as
loud, same for the 2 to 3 shift the "thud" is reduces
just as in the 1 to 2. And for the remaining gear changes
the "thud" (rear diff stopping againts rubber snubber) is
also reduced.

going to do top mounts with SPT springs next...
more to write about in the near future..

[Peaty]

Install w/ pics here:

http://www.scoobymods.com/forums/sho...=&threadid=234

[kensington]

did the engine, tranny and pitch stop rod today. used the scoobymods.com instructions, worked great. Only recommendation would be when putting it all together put the crossmember you totally removed on part way then fit the bolts for the STi mount in the hole and get the bolts started, then tighten everything up. Definitely recommend an extension to get the bolts off, 3 ft. pipe extension was my most valuable tool today.

The results;
As stated above I did more than just the tranny mount, LOVE IT Car stays squatted and just goes and goes fast. Helped out on the lift during acceleration as much as the anti-lift kit did before I did the uppipe/turboback. NVH up the A$$. Emphasize the V. Especially in the seat and floorboards. Noise is up a bit, and harshness not really an issue. Definitely more noticeable than the Whiteline Anti-Lift Kit. Worth it though, car feels great. The exhaust does also sound louder.

[Kartoffel]

Yup. I installed STi motor mounts last week. There is now MUCH more vibration than with just the tranny mount.

[CTKAG]

Installed the STi transmission mount, engine mounts and pitch stop rod this weekend. I can't attribute the change to any one of the mods but there is a noticeable difference.

My primary reason for performing these changes was to improve shifter feel, and the shifting now feels much more precise. I had been thinking about Kartboy shifter bushings (I already have the STi shifter assy.), but may not need them now.

I was skeptical about claims of increased exhaust sound, but I do think I notice it - I really can't explain why though.

NVH doesn't appear much different, although my MRT exhaust, which was very close to the differential protector, now rattles, so I may have to try repositioning it or maybe some urethane hangers.

EDIT: OK, after some more driving:

I think the increased exhaust note must be do to resonance induced by vibration. And yes, there is increased vibration felt through the pedals and the 'seat of the pants'. Also notice significant vibration at start-up and shut-down - again, primarily in the exhaust. Will do some tweaking later. Still happy with the shifter feel.

[Siper2]

I had the trans./engine mount set installed by Exeter Subaru in NH when I was there for the big Subaru of New England car meet in late June of this year. I probably could've managed the trans. mount by myself, but not the engine ones, so... time short, I just had them do it.

To be perfectly honest, I don't notice much of a change with the trans mounts. Maybe a wee bit more vibration in the car, but the shift action feels about the same, to me. If I thought about it really hard I might notice a little more precision in the throw (meaning less of a chance of grinding), but....

I will say one thing though: when it comes to shifter movement, I've noticed that there's significantly less shifter/shift knob vibration at highway speed. With the OEM mount, it used to shake quite a bit on the highway, but now it barely moves.


I notice a bigger difference from the engine mounts. Way less nose dive and rise on engine braking and acceleration, and since the real purpose of them I think is to stop side-to-side engine movement, to me the car feels a little better in the corners. Less twist, I guess. For lack of a better term.

The best is the sound at idle. The only breathing mods I have are a K&N panel filter and the factory BroSpeed muffler, so the extra rumble the engine makes now is pretty cool.


Just FYI, I have a Kartboy shifter and bushings, FHI Ver.5 suspension, 20mm Whiteline rear swaybar, Whiteline front strut tower brace, and Kartboy exhaust hangars. A few of those might contribute to my results a bit.

-S2-

[feropont]

O/T Its a funny description Kartoffel: "1942 Sturmovik ace
za rodinu! " Any input in our victory in WWII?

[whtlegacy]

where did you guys get your tranny mounts? i'm in the market but I've heard of some vendors selling regular mounts as STI Grp N mounts. Who can I trust for a good price?

[cnk]

I got mine from MPJ Performance at www.mpjperformance.com $170 shipped for STi Group N engine and tranny mounts.

Calvin

[whtlegacy]

Can anyone confirm that MPJ Performance's mounts are actually Group N and not just STI?

[SINthetic]

Hoe can ya tell if there are Group N or STI?

[whtlegacy]

i think the short answer is that you really can't without being able to test the rubber compound for stiffness

[cnk]

They're Group N. I had confirmed it with them before ordering. Just drop them an email or IM them if you're worried about it.

Calvin

[0260B4U]

the parts numbers are different for the group N stuff. The CUSCO engine and tranny mounts are even stiffer than the Group N. if your worried you can always call Subaru of Jax 904-641-6455 and speak with the parts manager Bill Cook. He will get you the correct mounts. He's da man

Dont worry bout the little bit of NVH. The mounts will soften a bit over time.

[Mishmosh]

I concur about the added vibration with the tranny but especially the motor mounts. I don't mind it at all though.

[bemani]

Originally Posted by 0260B4U

Dont worry bout the little bit of NVH. The mounts will soften a bit over time.

That's when you have to replace them!

[forced4]

Great mod...I did the tranny along with the engine mounts. The engine went from ~3/4" side to side when revving to less than 1/8". Now at stop lights the car trembles with anticpation of the next green light Shifting was improved with the tranny mount for sure. I added a shortshifter and bushings later and the shifting is unbelievable!!! The tranny does not buck as much when lifting off the throttle.

NVH did increase but not to intolerable levels..you just know the engine is running moreso.

[Biaxin]

what is "NVH" ?

sorry.. =)

[0260B4U]

Noise Vibration Harshness

Before someone comes along being a dick, always best to read through the FAQ section. Some people on here are less than friendly.

[shogun90]

I had the STI Grp N Engine & transmission mounts installed along with the Kartboy front and rear shifter bushings. There is an increase in NVH, but I notice it more at idle as opposed to while driving. You can really hear the boxer engine, you would have thought something was done to the exhaust. Great product though.

The Kartboy shifter bushings make a difference to my STI short throw shifter. Nice a crisp. I am considering to also get the 97-01 short throw shifter to further reduce the shifter throw.

All in all I am very happy with all the installs. I paid 120 and they had it done in less than 2 hours.

[ej25power]

I just installed my Group N tranny mount and took it for a small round the block test spin. I love the NVH and I want more! When I shift, it feels way more solid than it did with the old flimsy mount. I also installed the Kartboy tranny xmember bushings while I was in there. They're slightly oversized, but a good amount of torquing the bolts took care of that. I can't wait to go WOT through a few gears now

I think I'm going to get a shop to do my engine mounts. I just don't feel up for that right now. Looks like it will piss me off a lot. That would be the first mod I've ever paid to have done...sad