Whiteline differential insert bushings review

[DarkSunrise]

Had the diff cradle and outrigger inserts (KDT925) put in today. First impressions:

- Reduces, but does not eliminate, drivetrain lash. Before when I would let off the gas, especially going downhill at lower speeds, I could feel moderate drivetrain shock. Almost a double jerk, as if the drivetrain was bouncing off the stock bushings on decel. Now it is a single jerk.

- There is a more immediate reaction from the rear end to throttle input. This is particularly noticeable when applying gas mid-corner. Before, the soft bushings seemed to absorb some of the initial application of throttle. Now the rear end will step out more immediately because of the stiffer inserts.

- There is some gear noise when letting off the gas, especially under 2000 rpm. Sounds like a faint, medium-pitched whir.

- There is also a faint, hollow noise when letting out the clutch in 1st and 2nd.

Overall, I'm really happy with this upgrade, particularly the way it stiffens up the drivetrain lash. The car feels more connected. I don't notice any additional vibration, just some new mechanical noises, which aren't annoying at all.

Next track day is this weekend. I'll update if I notice any differences with these inserts.

[Mikepage]

Thanks for the input @DarkSunrise

[Mikepage]

I just remover the set of bushings insert in the front (the outrigger) of the diff and every clunk and gear wine at any speed are gone...

Am thinking keeping the car like this because it's just perfect

I think it's the perfect compromise if your car is a DD. Anyway, with the rear bushings insert, just that maybe remove 80 % of the movement of the diff... What do you think?

[Fizz]

Originally Posted by Mikepage

I just remover the set of bushings insert in the front of the diff and every clunk and gear wine at any speed are gone.

Do you mean you removed the "outrigger" bushing inserts? I'm about to install this weekend and contemplating if I should skip on the outrigger bushings.

[Mikepage]

Originally Posted by Fizz

Do you mean you removed the "outrigger" bushing inserts? I'm about to install this weekend and contemplating if I should skip on the outrigger bushings.

Yes the 2 on the left first post first picture...

See my previous post I added a picture

[DarkSunrise]

Just a quick update after the track days. The diff inserts make the rear end react slightly more abruptly to changes in throttle position. You have to be more careful when initially applying throttle at apex - as I later found out when it rained!

Also wife-approved. The other day, as we were riding in the car, I asked whether she could tell that I had done something to the car. She had no idea. I only have the rear diff inserts though. Probably would be a lot worse with transmission inserts and/or engine mounts.

[Mikepage]

Originally Posted by DarkSunrise

Just a quick update after the track days. The diff inserts make the rear end react slightly more abruptly to changes in throttle position. You have to be more careful when initially applying throttle at apex - as I later found out when it rained!

Also wife-approved. The other day, as we were riding in the car, I asked whether she could tell that I had done something to the car. She had no idea. I only have the rear diff inserts though. Probably would be a lot worse with transmission inserts and/or engine mounts.

You have the Whiteline set also right?

Did you give a try to the outrigger before making this choice?

I think it's the best without the outrigger... For you wife and for the comfort of course...and do not say me "because race car" lol i was loving the feeling with, but, too loud for me during long trip like my last 1600km.

Thanks!

[DarkSunrise]

Originally Posted by Mikepage

You have the Whiteline set also right?

Did you give a try to the outrigger before making this choice?

I think it's the best without the outrigger... For you wife and for the comfort of course...and do not say me "because race car" lol i was loving the feeling with, but, too loud for me during long trip like my last 1600km.

Thanks!

Ah sorry should have been clearer. This was with the full Whiteline KDT925 package (mount in cradle & support outrigger insert bushing).

http://www.whiteline.com.au/product_..._number=KDT925

I'm not sure if I got lucky or what, but there's barely any increased NVH. My wife couldn't even tell. I don't have any other inserts or bushings though.

[Mikepage]

Originally Posted by DarkSunrise

Ah sorry should have been clearer. This was with the full Whiteline KDT925 package (mount in cradle & support outrigger insert bushing).

http://www.whiteline.com.au/product_..._number=KDT925

I'm not sure if I got lucky or what, but there's barely any increased NVH. My wife couldn't even tell. I don't have any other inserts or bushings though.

Ok then it's probably very different when you have the subframe inserts

[DarkSunrise]

Originally Posted by Mikepage

Ok then it's probably very different when you have the subframe inserts

Haha yeah I would imagine so. I am wondering whether I should try adding the Perrin transmission mount insert. Seems like the next logical step.

[Grateful Dave]

Originally Posted by Mikepage

I will say Whiteline is just perfect.

I have this Whiteline Setup for over 2 months and I love it! My canyon carving is so much better and way more fun!
KCA416 Camber adjusting bolt
KSR210 Steering- rack & pinion,
KDT926 Gearbox- positive shift kit
KDT925 Differential- mount in cradle & support outrigger insert bushings
KDT922 Rear Crossmember- mount insert bushings

All these bushings & the camber bolts make a difference. The car accelerates better, the turning and cornering are better and the traction is way better.

Yes, I do have some new clunks, whines and vibrations, but this car has so many other NVHs', so it doesn't bother me. I have the "Crickets", "water bottle clicking popping sounds" and other stock noises. I haven't heard much luck with replacing the fuel pump, so I didn't replace it. I tried lubing inside the trunk per Subaru but it didn't work. I'm not going to remove the back seat ledge with brake light to fix it as recommended by Subaru unless It drives me completely crazy.

If you want the FR-S/BRZ to accelerate better, corner & turn better and have way better traction, I highly recommend this Whiteline package

[Ubersuber]

There is a ton of driveline movement on these cars under wheelspin. It seems like the transmission support could also use stiffer bushings in addition to the ones holding up the diff. Are both types available?

Anyone supercharging this car should fit stiffer driveline bushings first or at the same time, it is brutal.

[Mikepage]

I will add, just a little detail, after removing the outrigger, it's more difficult to engage the first gear during moving when the car is not completely stopped...

[Mikepage]

Originally Posted by Ubersuber

There is a ton of driveline movement on these cars under wheelspin. It seems like the transmission support could also use stiffer bushings in addition to the ones holding up the diff. Are both types available?

Anyone supercharging this car should fit stiffer driveline bushings first or at the same time, it is brutal.

You probably talking about wheel hop...but wheel up is impossible to resolve at 100%...