Simplest Bestest Mods to tighten up steering, turn in and body flex

[7 skulls]

TRD door stabilizers made a difference in initial turn in for me. https://www.trdparts.jp/english/part...tabilizer.html

[RToyo86]

I actually just ordered a set of those stabilizers from japanparts. Hoping to stiffen the doors to help with creaks and rattles. Some added chassis rigidity is a nice bonus.


I did my handling mods in stages. It gave me a much better practical understanding of what every part does.

[Racecomp Engineering]

Originally Posted by Racecomp Engineering

I like the Perrin Steering Rack Lockdown a lot for the money and ease of install.

How many miles on your car?

- Andrew

Also to clarify what I said here...those are nice but not "best mod you can do" type of thing. Just relatively cheap and easy to install and I like the change.

- Andrew

[NLSP]

Originally Posted by Broz

...The steering input/response and oversteer/tail happiness are what I love most about the car.

I’d like to make it even better.
Any suggestions for the first mods to tighten up the steering feel and turn in alittle more.
With moderate expectations
Avoiding any additional jarring or bouncing around. A little more NVH is understandable.
Keeping in mind I'm now switching from stock 215/17s to 245/18s (either Yokohama Advan Sport A/S+or Michelin Pilot Sport A/S 3+ Tire)...

Hello fellow Vancouverite

If you enjoy steering response and oversteer, then going to a wider wheel & tire can negatively impact those factors.

A wider footprint can make the car feel less agile during quick low-speed transitions (e.g. slalom) and harder to kick the tail out, but a nice confidence booster with high-speed corners (e.g. Sea to Sky highway), so you'll have to weigh the pros and cons for your preference. (I used to run 17x9 with 245's, now changed to 16x8 with 225's).

And generally, all-season tires will have squishier sidewalls than summer tires (the stock Michelin Primacy HP are summers), so that may reduce some steering response. Would definitely recommend dedicated summer/winter setups if you're serious about performance vs. having a tire that's a jack of all trades, master of none.

Otherwise, some simple things you can consider to tighten things up are:
- first, check that your suspension/sway bar bushings aren't dry-rotted from age/sitting a while
- OEM crash bolts (to give you around -1 front camber)
- steering rack bushings
- front strut bar (from a reputable brand)

[StraightOuttaCanadaEh]

Originally Posted by RToyo86

I actually just ordered a set of those stabilizers from japanparts. Hoping to stiffen the doors to help with creaks and rattles. Some added chassis rigidity is a nice bonus.


I did my handling mods in stages. It gave me a much better practical understanding of what every part does.

It will definitely help with the rattles and creaks. Got rid of all of my door-related noises.

[Westen86]

I will try to update everyone on how a complete set of SuperPro bushings feel. I mean complete. 80k "street" duro diff bushing, swaybars, subframe inserts and every control arm.

[Plumbus]

Originally Posted by Capt Spaulding

On the bushing/insert front, I suggest the steering rack, front and rear sway bars, and differential. FWIW mine are all Whitelines. I also have a set of rear subframe bushing inserts, a shifter bushing and a rear trans mount bushing sitting in my parts box. The shifter and trans mount I'm putting off until I need to pull the transmission. The subframe, I'm on the fence about. I'm trying to balance NVH and handling precision and think I may have found my personal sweet spot where I am. Not sure yet. It feels substantially more crisp (if that makes sense) without the jarring you seem to have experienced with your WRX.

The shifter and trans mount were extremely easy to install without needing to drop the transmission, you just need to support the trans with a jack while you remove the trans support bracket. The diff bushings which I assume you have installed also were super easy to install and brought little to no NVH. The subframe inserts are the ones you have to think about, they are intermediate difficulty because of fragile bolt threads but also they increase rear stiffness substantially. in exchange, you get reduced or no wheel hop and a significantly more responsive and feeling rear end.

Originally Posted by RToyo86

I actually just ordered a set of those stabilizers from japanparts. Hoping to stiffen the doors to help with creaks and rattles. Some added chassis rigidity is a nice bonus.


I did my handling mods in stages. It gave me a much better practical understanding of what every part does.

Can you do a review once you get them? I have heard mixed things about them and they are extremely expensive for what they are, but if they offer some improvement they could be a last mod to burn money on for those of us obsessed with handling and feel.

[RToyo86]

Originally Posted by Plumbus

Can you do a review once you get them? I have heard mixed things about them and they are extremely expensive for what they are, but if they offer some improvement they could be a last mod to burn money on for those of us obsessed with handling and feel.

Sure. I'll need some time too see if I can make out any difference. I paid $227cad shipped. If you are in the states they should be 30% cheaper
I notice door flex/movement Just driving around hitting bumps.

[Capt Spaulding]

Originally Posted by Plumbus

The shifter and trans mount were extremely easy to install without needing to drop the transmission, you just need to support the trans with a jack while you remove the trans support bracket. The diff bushings which I assume you have installed also were super easy to install and brought little to no NVH. The subframe inserts are the ones you have to think about, they are intermediate difficulty because of fragile bolt threads but also they increase rear stiffness substantially. in exchange, you get reduced or no wheel hop and a significantly more responsive and feeling rear end.

Thanks! The steering rack, sway bar, and diff bushings were cake. It wasn't that the transmission needed to come out for the tranny bushings, looking at the install convinced me to put the two trans bushings, along with my MTEC shifter springs off until I needed to pull the trans. I may rethink that now.

WRT to subframe bushings, I think I've figured out why the bolts get cross threaded and how to avoid doing that. What's your experience with NVH?

[Mike_ZN6]

- Perrin Steering Rack Lockdowns
- Whiteline Rear Subframe Mount Bushing (KDT922)
- Whiteline Rear Differential Mount Bushing (KDT925)
- Quality Coilovers


This recipe really tightened up the chassis on my car without much increase in NVH at all. No tramlining, wheel hop, or unnecessary stiffness with this setup.

[Plumbus]

Originally Posted by Capt Spaulding

Thanks! The steering rack, sway bar, and diff bushings were cake. It wasn't that the transmission needed to come out for the tranny bushings, looking at the install convinced me to put the two trans bushings, along with my MTEC shifter springs off until I needed to pull the trans. I may rethink that now.

WRT to subframe bushings, I think I've figured out why the bolts get cross threaded and how to avoid doing that. What's your experience with NVH?

I did a few things to prevent the bolts from cross threading:

1. Lift the car level front to back,
2. Use a wire brush to clean the threads, and
3. Support the subframe by the diff, unscrew all 4 bolts around 20-30 turns each (to give clearance for the inserts), then carefully lower the jack. 3 bolts should always be partially threaded at any given time, and the 4th bolt is off to insert the inserts. After placing an insert, thread the bolt BY HAND (to same height as the other bolts), then do the next bolt.
4. After doing all 4, raise the subframe with the jack and thread all bolts by hand again. At this point you can remove one bolt at a time and add threadlocker, and/or just tighten the bolts with your torque wrench.

The idea is to keep the bolts as straight as possible as they are threaded into the hole without impacting against the subframe. If they don't go in by hand, stop, and try to straighten the subframe with a mallet so it does. If you can do that, the install is actually not difficult at all, it's just a matter of preparation. I also removed the wheels btw.

The NVH is not really bad in terms of noise or vibration, but the harshness does increase noticeably. Between changing to HKS SPs from '17 sachs dampers, and from the SPs to the inserts, the inserts made a bigger difference in harshness. Dips and potholes became significantly harsher after inserts. BUT, the car feels like a racecar. very responsive, and the feedback is substantial. I think they're the perfect in between before going to solid bushings which I would probably never do even in an actual racecar.

Overall I love it, but only because it's exactly what I was wanting the car to feel like.

[grumpysnapper]

Originally Posted by 7 skulls

TRD door stabilizers made a difference in initial turn in for me. https://www.trdparts.jp/english/part...tabilizer.html

Just want to double check if you are being serious or not?

[LancePower]

STi Steering Rack Bushing

They weight up nicely on turn-in.

[Capt Spaulding]

Originally Posted by Plumbus

I did three things to prevent the bolts from cross threading. 1. lift car level front to back, 2. Used a wire brush to clean the threads, and 3. Support the subframe by the diff, unscrew all 4 bolts around 20-25 turns each (maybe more, maybe less, can't remember), then carefully lower the jack. 3 bolts should always be threaded at any given time, and the 4th bolt is off to insert the inserts. After placing an insert, thread the bolt BY HAND, then do the next bolt. After doing all 4, raise the subframe with the jack and thread all bolts by hand again. At this point you can remove one bolt at a time and add threadlocker, and/or just tighten the bolts with your torque wrench.

The idea is to keep the bolts as straight as possible as they are threaded into the hole without impacting against the subframe. If they don't go in by hand, stop, and try to straighten the subframe so it does. If you can do that the install is actually not difficult at all, it's just a matter of preparation really. I also removed the wheels btw.

The NVH is not really bad in terms of noise or vibration, but the harshness does increase noticeably. Between changing to HKS SPs from '17 sachs dampers, and from the SPs to the inserts, the inserts made a bigger difference in harshness. Dips and potholes became significantly harsher after inserts. BUT, the car feels like a racecar. very responsive, and the feedback is substantial. I think they're the perfect in between before going to solid bushings which I would probably never do even in an actual racecar.

Overall I love it, but only because it's exactly what I was wanting the car to feel like.

Thanks. I had concluded the "loosening all 4 bolts" was the key to getting them correctly realigned. Otherwise the additional thickness of the insert cocks the subframe slightly creating a misalignment that leads to the cross threading.

I'm still on the fence about the subframe. My goal is to create a tight GT car. The added harshness you report leads me to reconsider installing the subframe inserts. At present it's smoother over expansion joints and pavement seams than my wife's Camry. I don't want to screw that up. With its current mods (camber bolts; 17x8 40et Konig wheels w/ 225 Conti ECS tires; steering rack, f&r sway bar, and diff bushings) plus a substantial amount of sound damping in the trunk it's pretty close to where I want it.

I'm thinking now that the shifter bushing/trans mount insert, the Mtek springs, and a set of Bilstein B6s will finish out my drivetrain/ suspension mods