Drivetrain Slop
 

Ok so I know we have all experienced the drivetrain slop in these cars. Lots of transmission and diff bouncing that make this car extremely difficult to drive smoothly at low speeds, especially during your clutch catch-point learning phase. Don't blame my driving style, I have not driven an automatic regularly in a decade.

So, I know there are bushings available to help alleviate this. I am looking at the rear shifter bushing, the transmission mount and the diff bushings. I'm thinking that stiffening all of these up will help with the earthquake of movement that the stock bushings allow. I'm ok with a but more NVH (because racecar) but I don't want to weld the tranny and diff to the body or anything.

Am I on the right track with my goal here? What have your experiences been with this slop and your solution for it?

Leave your "learn to drive n00b" comments at the door.

Diff and rear subframe bushings/inserts, and trans bushings are good places to start. You'll have more noise, but it shold reduce slop. The shifter bushing has no bearing on this.

Tightening up the rear suspension bushings would help too. But there's always going to be some slop.

I noticed a big reduction in slop after installing the Whiteline Rear Subframe Insert Bushings

They are especially noticeable at the track when exiting corners with lots of throttle or when launching the car.

[ame="http://www.youtube.com/watch?v=IDfJ_zYFPcs"]BRZ / FT86 / FR-S Whiteline Subframe Lock Out Kit - YouTube[/ame]

Thanks for that. I'm thinking the subframe bushings will wait, since the driveshaft and exhaust don't have to be lowered to get them in. So far the transmission insert and diff insert are the frontrunners (KDT925 and 926).

I didn't take my exhaust off or lower my driveshaft to do the subframe bushings!??

Right. That's my point. Since my exhaust is being replaced at the same time, why not upgrade the bushings that easy to upgrade without the exhaust in place. Rear subframe bushings can be done anytime, whether the exhaust is attached to the car or not, so those will wait.

After watching that vid for the third time, I can finally see just a teeny teeny bit of movement in the subframe bushings. Nothing like the full inch of deflection my BMW 135 had.

The diff however moves so much it's scary. No wonder it's impossible to drive this car smoothly.

I'll be getting either the inserts or diff bushings first.

I recently went through this. I installed the WL subframe bushings, excellent difference there in feel off the line, Perrin shifter bushing also excellent. I installed the Perrin trains mount that I'm not 100% with mainly cause I do a lot of hwy driving and at 3-4k the whine it produces when the T is loaded against the tranny framework support I find annoying even with music up. Going to try the Whiteline Positive shift bushing and put stock T in. For someone just racing it would've been perfect but that's not me I need to keep nvh to a minimum for my tastes. Another thing I installed for shifter feel that I'm really impressed with is the Mtec springs kit for tranny that's one of my favourite cheap mods yet. :clap:

I have the Torque Solution bushings installed in mine and they definitely helped a lot.

Torque Solution Parts

Does any of this stuff help the automatic shift/drive/behave a little smoother?

I just installed the Whiteline positive shift kit and it did help a little, but it alone is not enough. I'm modifying a mount stiffener to work with the whiteline bushing and am going to see how they do together. I've heard mixed reviews. If everything goes as planned I'll have it installed next Saturday, maybe sooner.

The WL or Kartboy saddle style tranny mount coupled with a Perrin or alt T type together is HELLA whiny, so either you can deal with it or not depends on if you like noises like that. I must be getting to be an old fart, I don't like high pitch whine noises on hwy not one bit.