Engine mounts, Transmission bushing/ support mount
 

Hello everyone and greeting from Cyprus!

I'm new to this forum, and I'm quite glad to be here.

I tried searching for some answers to my issue but there are so many topics that i got lost over and over.

If this topic already exists, by all means you can close this one and maybe guide me to the where i need to be.

Basically we all know how harsh 2nd and 3rd gearing can be on these cars when stock. At least on pre-facelift models.

In my case I own a 2015 GT86 for almost 2 years and really wanted to smoothen out the shifting of those 2 gears.

I found various solutions online such as change to motul oil, mtec spring, rear shifter bushing, engine mounts, transmission bushing, transmission support mount etc. etc.

The ones that I've done so far are the motul oil and the perrin rear shifter bushing which does help but not that much. So i decided to buy the Cusco engine mounts, the perrin transmission support mount and the whiteline transmission bushing. I did get warned that there would be some vibrations in the cabin of the car but upon finishing installation yesterday, much to my surprise those vibrations are not "some", it feels like I'm driving a truck and since this is my daily driver i cannot tolerate all this noise and vibrations.

I would be really glad to know if i remove any of these 3 components if the vibrations will be gone. Should i remove the mounts and keep the support mount and bushing? should i remove the bushing only? or take everything out and put stock ones back on?

I would highly appreciate any input here.

Thanks in advance guys.

Regards
Giannis K.

those Engine mounts create a ton of NVH. Trans will add some too.
Harder mounts for a daily is not ideal. I ran some on my integra and learned that lesson.

Go back to stock mounts or go STi for OEM plus . They're stiffer without being harsh.

The engine mounts are causing all the NVH, the increase in NVH from the other two is almost negligible. I would recommend STI mounts. I have the Perrin mounts and they still produce a significant amount of NVH compared to stock, especially at idle.

Having said that, in regards to smooth shifting, I've done all of the mods you've done which never helped, however fitting a one piece (aluminium) driveshaft made shifting smooth. It no longer grinds or catches, just shifts smoothly and precisely.

Ditto on the mounts, at this point I would goto STi mounts, no point in going to OEM when you have everything else.

Mtec shifter springs, Shifter bushing, Whiteline transmission insert, and most importantly, whiteline diff inserts. I put all of these in and the shifter feel is absolutely night and day difference. Even in the cold brutal cold (-15C) the shifter is smooth after one or two shifts. I noticed the biggest difference in the diff inserts, trans mount insert and the Mtec shifter springs.

What are you running for transmission oil? Last time it was changed?

Also recommend the one piece drive shaft

Sent from my ONEPLUS A5010 using Tapatalk

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.

which point(s) in the rpm range are you getting vibrations at? Mine starts at 140km/h (87 mph)

At first it was around that same speed, around 90mph. I used some weighted tape about a third of the way from the transmission output and it went up to around 100mph before it would start vibrating. Rebalancing got it up to around 105mph. It is speed related(or more the RPM of the driveshaft). There is a thread on here somewhere discussing wall thickness, and critical speed attributing to it.

Weighted tape, interesting! Never heard of it before. Which kind is it specifically and how much of it did you use? May try it myself. Thanks in advance.

I used this.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Clean the driveshaft very well and make sure you wrap it in the proper direction. Warm it up a bit and roll some out ahead of time, the foil is very thick and if you are not careful you can cause a crease in it. Then it will not lay down evenly. It is quite a bit easier to do with the driveshaft out of the car. Run it in bands about a 1/3 away from one end of the shaft, I don't believe which end matters too much. I can't remember how many wraps I did, it was a while ago. This was suggested to me by a gentleman who I met at a track day that was an engineer for Boeing, specifically in harmonics and vibration damping. With some experimenting I am sure you could get better results then I did. I just got tired of messing with it.

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.

Oil makes a good bit of difference in shifting, especially cold. I like Redline MT-90, some others are running a variety of oils with good results, Pennzoil Synchromesh, Motul Gear 300.

KD 925, Inserts. :thumbup: