Sti Flexible Draw Stiffener- Differences

[Clutch Dog]

So after buying two sets of "Sti Flexible Draw stiffeners"
And being possibly the only guy to have both in hand at the same time.

The first set, you will see is Part Number: ST20118AS000
This is the part you will see on the STI.jp website: (Link:https://www.sti.jp/en/parts/subarubr.../ST20118AS000/)
and this is the part that is a direct bolt-in to my subframe as you will see below

The second set, you will see with the red tape came from a USDM 2018 BRZ tS
Requires: Part Number: 20101CA010 Subframe (2018 Brz tS, with premanufactured bolt holes)
This is not a bolt-in to my 13-16 FRS ( the mounting holes are not there)
Based on another set of photos from Elliot's tS, it looks like the tS has the mounting holes for it.
Unconfirmed, But I am wanting a 17+ twin subframe photo to confirm or deny that this will bolt in to those chassis, no modifications needed
Now this Draw Stiffener could work with any ZC/ZN chassis if you do not mind drilling holes.

Both function the same, both fit under the rear fiberglass under body panel, and both are adjusted the same as a standard adjustable Endlink

The First one-bolts into the car using hardware already installed on the car. it will use the left and right chassis bolt from the swaybar subframe assembly
and the front aluminum skid pan mounting bolts will attach it to. These bolts are standard M8x1.5.
I torqued them down to 32 ft lbs. the chassis bolts are torqued down to 44 ft-lbs
the second set of bolts that hold the feet to the sides of the car i used as alignment holes, and did not torque more than hand tight ( for me about 20 ft lbs)

(Click on the pictures for a bigger view)


13-16 Part is on the Left, Right is 2018 tS: Notice the Bolt spacing




Notice on the tS bolt on the right side is slotted



The dampers are parallel on the TS stiffener
They are opposite on the STi unit


Mounting Pad for the 13-16 STi Stiffener

13-16 STi Stiffener Bolts up through the bottom of the subframe, the bolt holes are from the skid pan, no drilling necessary

Another photo, sorry for the lame phone pictures. I wish I had a lift.



The following is from a 2018 BRZ tS and the OE stiffeners on that unit.

Notice on the '18 Stiffener it bolts in from behind the brace going forward. Up from under the car



This is the better of the side foot mounting, it only uses one bolt ( chassis bolt) and theres a lock out tab that goes up under the sway bar subframe.
This matches with the 13-16 as well, as the sway bar subframe is the same.



Check the postings here on the BRZ tS parts page for more information or photos, not discussed here: http://www.ft86club.com/forums/showthread.php?p=3093771
If any of you guys, have any more information, or want to correct me or add, please do so. I want to shed the most light on these parts as possible.

[norcalpb]

You need the 2018 Ts front crossmember, a 2017 front crossmember is the same as 13-16

[Clutch Dog]

So the Draw stiffener specifically from the tS, needs the tS subframe? well phooey,didnt think Subaru would do that to us.

That said Im pretty sure a drill and some lock nuts could fix that issue.

[norcalpb]

Originally Posted by Clutch Dog

So the Draw stiffener specifically from the tS, needs the tS subframe? well phooey,didnt think Subaru would do that to us.

That said Im pretty sure a drill and some lock nuts could fix that issue.

20101CA010 - $215

I would strongly recommend against drilling, I would personally want the orientation of the bars to be 100% oem with no permanent holes.

[JIM THEO]

Without intention to hijack your thread may I ask, if I fit the STI flexible draw stiffener and STI flexible tower bar do I have the same result as with the stiffener and flexible V-bar?
I just bought the draw stiffener and the cost of the flexible tower bar is much lower than that of the V-bar while car is already equipped with V-bar (not flexible though).
I know STI suggests draw stiffener with the V-bar while it CAN be used with flexible bar but doesn't mention what the difference, if any, is between those two combinations.

[Clutch Dog]

Originally Posted by JIM THEO

Without intention to hijack your thread may I ask, if I fit the STI flexible draw stiffener and STI flexible tower bar do I have the same result as with the stiffener and flexible V-bar?
I just bought the draw stiffener and the cost of the flexible tower bar is much lower than that of the V-bar while car is already equipped with V-bar (not flexible though).
I know STI suggests draw stiffener with the V-bar while it CAN be used with flexible bar but doesn't mention what the difference, if any, is between those two combinations.

I do not know, I am not a subaru engineer. I have the flexible tower bar and the drawer stiffener now and it just feels more darty, The V-brace I am sure would have similar effect, but OE we are given a hard mounted bar vs a dampened bar. So I am sure it is for NVH and feel.

My current set up is STI Drawer Stiffener, STI Flexible Tower Bar "F", and OE FRS V-Bar (hard mount)

And I will probably run this till the day I die. Feels so good now

[JIM THEO]

Originally Posted by Clutch Dog

I do not know, I am not a subaru engineer. I have the flexible tower bar and the drawer stiffener now and it just feels more darty, The V-brace I am sure would have similar effect, but OE we are given a hard mounted bar vs a dampened bar. So I am sure it is for NVH and feel.

My current set up is STI Drawer Stiffener, STI Flexible Tower Bar "F", and OE FRS V-Bar (hard mount)

And I will probably run this till the day I die. Feels so good now

This is the setup I have in mind as I don't want to buy the more expensive flexible V bars while I already have from the factory bars there and just bought the draw stiffeners.
Guess no difference in NVH from the whole bars, am I wrong?

[nikitopo]

The flexible tower bar comes from earlier experience on AWD cars. It is good and can be used with the draw stiffeners, but it is not that good like the flexible v-bars. The flexible v-bars work better on a RWD car, but at the beginning they were not available and STI waited for the development. So, they used initially the stock v-bars which are not that solid and as an addition the tower bar. I remember reading this from the manufacturer, but I don't have the link now. Personally, I have the tower bar because at that time the other was not available. I don't know if the difference is that much to be noticeable, but the tower bar sounds a good cost trade off.

[JIM THEO]

Originally Posted by nikitopo

The flexible tower bar comes from earlier experience on AWD cars. It is good and can be used with the draw stiffeners, but it is not that good like the flexible v-bars. The flexible v-bars work better on a RWD car, but at the beginning they were not available and STI waited for the development. So, they used initially the stock v-bars which are not that solid and as an addition the tower bar. I remember reading this from the manufacturer, but I don't have the link now. Personally, I have the tower bar because at that time the other was not available. I don't know if the difference is that much to be noticeable, but the tower bar sounds a good cost trade off.

That's what I read in the forum too just asked experiences if someone has tried both bars w/draw stiffeners, as I understand it flexible V-bars increase torsional rigidity that a RWD needs more as the back pushes the front creating diagonal forces while flexible strut tower bar helps on 4WD more where forces are more evenly distributed.

[Clutch Dog]

Originally Posted by JIM THEO

That's what I read in the forum too just asked experiences if someone has tried both bars w/draw stiffeners, as I understand it flexible V-bars increase torsional rigidity that a RWD needs more as the back pushes the front creating diagonal forces while flexible strut tower bar helps on 4WD more where forces are more evenly distributed.

Well put

as far the general consensus.. I wish I had the extra funding for swanky STI V-bars.

For lateral flexing though, I will look at a trunk cross brace. Probably in house job, and painted sti red/pink

[JIM THEO]

My car is MY18 that is slightly reinforced in the rear end compared with MY13-17 cars so I may be stop there, actually I try to bring it to tS levels with as much parts as possible of it regarding suspension/chassis.

[norcalpb]

The sti V bars may be lighter than the standard v bars. I think the sti bars are hollow.

I’ll weigh both when I get home from work tonight.

[norcalpb]

So turns out the standard V-bars are 2lbs, and the TS V-bars are 2.8lbs

[86MLR]

Originally Posted by JIM THEO

My car is MY18 that is slightly reinforced in the rear end compared with MY13-17 cars so I may be stop there, actually I try to bring it to tS levels with as much parts as possible of it regarding suspension/chassis.

Where is this "slightly reinforced" rear end compared to 2017?

You got any official drawings or P/N's?

Cheers