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

[Plumbus]

Originally Posted by Capt Spaulding

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

Maybe I didn't explain myself well but you are correct, you want to loosen all 4 bolts enough for the inserts to be inserted and for the subframe to be level. but there should always be 3 bolts partially threaded since you are only holding the subframe with a single jack in the middle. There should be more than enough thread in the bolts to squeeze the inserts without "cocking" the subframe alignment or needing to force it.

As far as the feeling, it could very well be tolerable for you. It took me a bit to get used to it but now I don't even notice, it's like a racecar for the street. I also have the damping set to the middle so it could be even softer. I would urge you to find someone nearby with inserts in their car and ride shotgun to see how you like them.

[Capt Spaulding]

Originally Posted by Plumbus

Maybe I didn't explain myself well but you are correct, you want to loosen all 4 bolts enough for the inserts to be inserted and for the subframe to be level. but there should always be 3 bolts partially threaded since you are only holding the subframe with a single jack in the middle. There should be more than enough thread in the bolts to squeeze the inserts without "cocking" the subframe alignment or needing to force it.

As far as the feeling, it could very well be tolerable for you. It took me a bit to get used to it but now I don't even notice, it's like a racecar for the street. I also have the damping set to the middle so it could be even softer. I would urge you to find someone nearby with inserts in their car and ride shotgun to see how you like them.

Actually, I think you explained your procedure very well. I had read the cross threading horror stories and wondered why so many had that problem. I looked at the inserts and the subframe and concluded that if you loosen only one set of bolts (front or rear) and lower the jack to install the inserts the added thickness of the insert will position the subframe at an angle compared to it's original position. As a result, the bolts will be lined up at a slight angle with their holes and cross threading becomes really easy.

I concluded the way to avoid that is to loosen all 4 bolts (just as you advised). That makes it much easier to get the bolts properly aligned with the holes and hand tightened. I was just trying to explain my thought process and congratulate you on reaching the same conclusion. Apparently, I didn't do such a great job.

[7 skulls]

Originally Posted by grumpysnapper

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

Yup. . Could definitely feel it but then again I've always been a sensitive sort. To paraphase Niki Lauda, I've got an OK brain, but a great ass.

[RToyo86]

I can see how there may be a difference with the stabilizers. Toyota shows a graph where they show less chassis deflection when turning sharply/hard.

Probably nothing huge. 5%? 10%? 15% better feel?
You'd need to be quite comfortable with the current setup of the car to potentially notice anything.


For me when I crack the windows and hit bumps the window rattles as the door shakes. Stuff like that bugs me and is the main reason for the mod. Plus seeing how much the door moves around normally and in autocross I figure it's an easy two bird one stone mod with no NVH downside.

Based on feedback on bushing inserts I'll probably be doing diff, sway bars, trans, then steering lockdown.
Everything else seems like it'll add too much NVH for me on a daily.

[NoHaveMSG]

Originally Posted by Capt Spaulding

Actually, I think you explained your procedure very well. I had read the cross threading horror stories and wondered why so many had that problem. I looked at the inserts and the subframe and concluded that if you loosen only one set of bolts (front or rear) and lower the jack to install the inserts the added thickness of the insert will position the subframe at an angle compared to it's original position. As a result, the bolts will be lined up at a slight angle with their holes and cross threading becomes really easy.

I concluded the way to avoid that is to loosen all 4 bolts (just as you advised). That makes it much easier to get the bolts properly aligned with the holes and hand tightened. I was just trying to explain my thought process and congratulate you on reaching the same conclusion. Apparently, I didn't do such a great job.

I just cheated and used a forklift to position the subframe. Of course I replaced bushings, didn't do inserts. I think your explanation of why these get cross threaded is right on. It is a long bushing so if the subframe is not parallel to the car it is easy to flatten a thread or not get it in their straight.

[NLSP]

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.

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.

I've had the TRD door stabilizers installed for a while now; I also have the TRD front strut bar installed for even longer (they were installed at separate times).

It's similar/adds to the effects of installing a front strut bar in terms of making the car feel a little more sharp, solid and planted when driving spiritedly/hard. Would definitely recommend if you're a "feel" chaser; would not necessarily recommend if you're a lap time chaser.

As a bonus, they both help with uneven pavement feel less crashy (more refined).

[Capt Spaulding]

Originally Posted by NLSP

I've had the TRD door stabilizers installed for a while now; I also have the TRD front strut bar installed for even longer (they were installed at separate times).

It's similar/adds to the effects of installing a front strut bar in terms of making the car feel a little more sharp, solid and planted when driving spiritedly/hard. Would definitely recommend if you're a "feel" chaser; would not necessarily recommend if you're a lap time chaser.

As a bonus, they both help with uneven pavement feel less crashy (more refined).

Well, impulse got the better of me and I spent money to fix something that was probably not broken. When the door stabilizers arrive I'll add another data point,

[grumpysnapper]

Originally Posted by 7 skulls

Yup. . Could definitely feel it but then again I've always been a sensitive sort. To paraphase Niki Lauda, I've got an OK brain, but a great ass.

I'm not trying to offend and I know people feel very strongly about some of these mods, (and I'm not questioning their ability to tighten the door in its aperture) but in the context of the original OP's question, are expensive and highly contentious door stabilisers a good route to pursue... given all the other options available?

It worries me that claims are made by these mod manufacturers that are completely unsupported with any actual measured data being supplied.
These claims are very easily measured and published, especially if it's your business to make and sell these things. But they don't do they?

I know part of the argument is about "feel", but if you can feel a change in something, you can measure it. (Particularly if your paying through the nose for it claiming to physically change something). If a racing driver has great feel in the wet, they are faster in the wet.

If the thought about the extra "feel" of these mods is because some drivers have an extra sublime ability to "feel" the difference, while the rest us us don't, is being more than a little presumptuous.

Originally Posted by RToyo86

I can see how there may be a difference with the stabilizers. Toyota shows a graph where they show less chassis deflection when turning sharply/hard.
Probably nothing huge. 5%? 10%? 15% better feel?
You'd need to be quite comfortable with the current setup of the car to potentially notice anything.

The graph (on the TRD website door jam page) doesn't relate to chassis deflection, but is a strange "steering angle" graph... that doesn't really say anything at all without a lot of (un-supplied) clarification.
A graph showing a change in "chassis deflection" could actually prove or disprove their potential usefulness.
5%, 10% or 15% better "feel" is an enormous improvement in a car... any car manufacturer would kill for an easy increase like that. So you have to wonder why they haven't all rushed to build tighter door jams into their own cars.... or even into the updated twins?

[WC-BRZ]

Hey gang, why do most wheel/tire setups go with an equal tire size on all four corners? Is it just for lateral stability?

Wouldn't a thinner front/wider rear tire be better as you'd still have some of the responsiveness and quick turn in from the front?

The McLaren Senna still runs a 245 front tire and if I'm not mistaken the 600LT and 720S also run fairly thinner fronts. In fact, I believe most supercars do this.

I'd imagine that a good quality tire compound would take care of added grip and you could stay with a 225-section front and feel free to go to 245 rear if needed.

Any handling/steering feel downsides by going with a non-staggered setup on our platform?

[marco_mc22]

I think staggered is the ideal recipe for some additional understeer on these cars

[RToyo86]

Originally Posted by grumpysnapper

I'm not trying to offend and I know people feel very strongly about some of these mods, (and I'm not questioning their ability to tighten the door in its aperture) but in the context of the original OP's question, are expensive and highly contentious door stabilisers a good route to pursue... given all the other options available?

It worries me that claims are made by these mod manufacturers that are completely unsupported with any actual measured data being supplied.
These claims are very easily measured and published, especially if it's your business to make and sell these things. But they don't do they?

I know part of the argument is about "feel", but if you can feel a change in something, you can measure it. (Particularly if your paying through the nose for it claiming to physically change something). If a racing driver has great feel in the wet, they are faster in the wet.

If the thought about the extra "feel" of these mods is because some drivers have an extra sublime ability to "feel" the difference, while the rest us us don't, is being more than a little presumptuous.



The graph (on the TRD website door jam page) doesn't relate to chassis deflection, but is a strange "steering angle" graph... that doesn't really say anything at all without a lot of (un-supplied) clarification.
A graph showing a change in "chassis deflection" could actually prove or disprove their potential usefulness.
5%, 10% or 15% better "feel" is an enormous improvement in a car... any car manufacturer would kill for an easy increase like that. So you have to wonder why they haven't all rushed to build tighter door jams into their own cars.... or even into the updated twins?

All valid points. I don't expect any improvements in handling but I do hope it takes care of the other stuff I mentioned regarding creaks and rattles. Seems like it has definitely done some good there according to a few others on here.

[Transport3r]

Originally Posted by grumpysnapper

So you have to wonder why they haven't all rushed to build tighter door jams into their own cars.... or even into the updated twins?

Tightening build tolerances is VERY expensive. These shims are a much cheaper way to achieve the tighter clearance. Pair that with the fact that 90% of drivers won’t notice, and I’m not surprised they don’t bother.

[nikitopo]

Originally Posted by grumpysnapper

The graph (on the TRD website door jam page) doesn't relate to chassis deflection, but is a strange "steering angle" graph... that doesn't really say anything at all without a lot of (un-supplied) clarification.
A graph showing a change in "chassis deflection" could actually prove or disprove their potential usefulness.
5%, 10% or 15% better "feel" is an enormous improvement in a car... any car manufacturer would kill for an easy increase like that. So you have to wonder why they haven't all rushed to build tighter door jams into their own cars.... or even into the updated twins?

I believe that these TRD door stabilizers are available for different models and they are not specifically designed for our cars. I would bet that these ones don't have of much usage on the particular chassis which is already stiff enough. If I recall correctly, STI didn't approve this kind of modification.

[7 skulls]

Way back when I was researching these, I came across a video of an frs doing auto cross. The POV, from a gopro suction cupped to the car, focused on the door/body seam and the amount of gap variation was a little scary. After these were installed, the door gap was stable. Sold me.