Integrity Performance

Ok so it appears that there is a lot of confusion about how these are supposed to fit, and exactly what they are supposed to do or not do, and how exactly they work.


So I figured I would try to put together a sort of FAQ, where I will address the questions and concerns I have seen come up about this mod over the years. (its been around for subbies since at least early 02, I dont know if the GC body needed them or had them available)


I got a set, they dont fit in correctly

------THEY ARE NOT SUPPOSED TO FIT FLUSH!
For those of you who havent seen them, they have a "lip" at the top near the bolt head. This is NOT supposed to snug up to the subframe. They stop going in when they run out of thread, and that is how they are supposed to look. This is a VERY big issue of confusion, but the fact is that they are not supposed to fit flush.


Then how can they work???

------ They are there to prevent lateral movement of the subframe. Be it side to side, or front to back twisting. They are not designed to prevent up and down motions.



Then what good are they if they still allow some movement?

------- The handling problem that they are designed to resolve is that when you come into a turn and REALLY load the rear suspenion, the subframe can (and does) deflect a bit and shift to one side or even worse, twist. This causes several problems. It changes the toe on the back wheels, and it changes the wheelbase on both sides, making one longer and one shorter. Obviously once you are back going straight it goes back to normal, but it does make for a "loose" feeling in the rear suspension.

Why cant we just stick a bolt in there? Wont it do the same thing?

------ Unfortunately, its not that simple. The entire reason it works is that the subframe lock bolts fill up the entire gap. A bolt will not fill the whole gap, thus the subframe can still move around.

Ok, Im sold on a set. What can I expect?

------ This is subjective and hard to explain in perfect detail. The easiest way to put it would be this. You know how when you go into a hard turn it feels like the rear of the car is kind of "following" you around? When you do these bolts, it will feel like the rear wheels are actually part of the vehicle. It will all the sudden be apparent that they never really felt connected to the car, almost like the rear wheels were on the end of a rope getting a whip effect, and now, they are bolted solid to the car. Its a feeling of a LOT more control.
Suffice it to say, I have yet to hear of someone do it and not be please with the handling results

What about noise vibration and harshness?? Wont these make my car louder inside?

------ Not really. 99% of people say they dont notice any increase in NVH at all from them. This goes back to the first part of this FAQ. If they bolted it solid and fit flush, you would likely get a lot more NVH into the cabin.

But its so cheap! Does it REALLY work? Is it maybe just in your head?

----- Yes its very affordable. Yes it really works. No its definately not in our heads :)



*this is a work in progress* As I think of more info, or people ask questions, I will add to it :)

I need to read up on Kartboy's new subframe bolt setup to make sure to cover it as well. It looks very similar to the whitelines, so it SHOULD be the same. But I want to make sure first.

Attached Images

	bolt gap 1.jpg (59.1 KB, 507 views)
	side view gap.jpg (65.1 KB, 541 views)

 

CraigB

Awesome! Thanks for the info. This is the way I was thinking that it worked (limits horizontal movement, not vertical).

__________________
CraigB
04 FXT

Canonshooter

For anyone getting into suspension mods, these are a must-do.

One of the issues you will run into without these bolts is excessive cross-camber; different camber readings on each side. This is because the top mounting point of the struts are fixed - the unibody - while the bottom mounting point is on the subframe. Move the subframe and you move the bottom of the strut in relation to the unibody, and the camber and toe settings shift. By installing these bolts, you not only eliminate much of the movement, but they will center the subframe as well resulting in closer - if not exactly identical - camber on each side. And even if your camber readings come out close without them, that will change as soon as you hit the twisties and place lateral force on the subframe.

Bottom line - if you really want to "dial-in" your rear alignment, these bolts are a must!

Peaty

Hope you don't mind I added a couple of pics, to your post above, of the KB setup. Still working on the ScoobyMods page but I think those may help a little.

__________________
Peaty

2010 Legacy 3.6 R - Limited

2006 B9 Tribeca - Limited

1999 Miata - MX5

jerry 1 a b

Just to clarify, this is not true for all brands. I have the Perrin set, and they ARE supposed to fit flush, and they do. Perhaps the bolts they supply are shorter than the Whiteline and Kartboys.

Just out of curiosity, I'd be willing to remove one and measure it to compare.

Here's a picture.

wgb113

Just got my Kartboy Botox Bolts in the mail today and they'll be going in tomorrow.

Quick question on the install...on ramps or on jack stands (suspension under load or no load?)

Bill

__________________
04 Forester XT PSM
04 Forester XS JBP

jerry 1 a b

^^^ I did mine on ramps. Easy as pie!

pleiad7

I just got back from a track session with my car and I have to say, the bolts really DO work. I was quite amazed at how "together" the car felt in the turns. Seems to have been the "missing link" in my suspension setup.

__________________
-Silke
04 FXT PP PSM ~ "Subed"
98 Forester S ~ "Slynki"

Peaty

For the KB set it's not the bolt that determines if they sit flush or not, it's the insert. The kit is suppose to limit lateral movement not horizontal. I have a feeling if the bolt was flush it would just bend and distort the lower metal section of the subframe (part with the large hole) as the upper section is much thicker and less likely to distort and bend.

Ramps or jack stands, either way. If you use jack stands then you will just need a longer extension to get to the bolts is all. When the suspension droops it just just gets in the way more is all.

__________________
Peaty

2010 Legacy 3.6 R - Limited

2006 B9 Tribeca - Limited

1999 Miata - MX5

CraigB

Good to hear. I was wondering how noticeable it would be with the aluminum STi lateral links. I remember how different it felt after I installed those and that was even before I installed the STi sway bar & springs. Mine go on tomorrow!

__________________
CraigB
04 FXT

Canonshooter

Don't know anout the KB version, but the Whiteline bolts eliminate all movement of the subframe in relation to the unibody. To get the bolts inserted, both openings through the subframe must line up with the captured nuts welded on the unibody in order for the bolts to pass through the subframe. Once the bolts are tightened and the rubber subframe bushings squashed down, little if any movement will occur between the subframe and unibody in any direction.

rktwgn

I've got some "knocking" noises since installing the subframe bolts (Whiteline). I only hear these when doing slow direction changes like maneuvering through a parking lot, but they've been there from the first day I installed the bolts. They were not there prior to that day so are not the result of a sway bar upgrade. I love the improvements from having the bolts installed but I sure would like to clear this little "side effect" up. Any suggestions?

KeNd0

your lucky I tried that and destroyed my first set of sflb`s. I was no where near the 60ft lbs, and all four sf bolts were loose.

Mine were from Group A, second set went in smooth as silk, however they do not sit flush.
The only problem I had was the clunk I heard when I jacked up on the diff to take out the jackstands. Everything seems ok since, weight shift?

EricB

Is there down side to these? Put another way, why wouldn't you do this mod?

Integrity Performance

Mind?? Dude those pics add a LOT to that post in my opinion. Good call!