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Discussion Starter #1
I'm looking at my options

Current Swaybar on car is 0.94" or 23.876mm
Current Poly bushing on car is 24mm => Energy Suspension 9.5160 (or 95160G)
Therefore, gap is 0.124mm oversized

If we go with the 0.91" (or 23.114mm) swaybar to see if that will help handling, we have three options:
1) Run with the stock rubber bushings. Probably 100K mi on them.
2) Use the current 24mm Poly bushing (0.886mm too large)
3) Buy a 23nmm Poly bushing and sand it out a bit (.114mm too small) => Energy Suspension 9.5159 (or 95159G)

I'm guessing the right answer is #3 but i'd like your opinions here.
Regards,
-g
 

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Discussion Starter #2
I just pulled the old swaybar off the car and tried the 24mm bushings on the 23.114mm bar (0.91"). The 0.886mm gap allows for too much lateral movement (rocking) compared to even the worn OEM Cleavite bushing that was on the 0.91" bar to begin with (well used).

Option #3 -- buy a set of Energy Suspension 95159G bushings is the way to go.
-g
 

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Seems like some bars are hollow while others are not. Not sure about this case though. You know for sure when you pick them up lol
 

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.94 to .91 to help with handling? Why? Isn't that how it DOESN'T work lol?

Im confuzzled.
Depends on the help you want.

Let's say you have a neutrallying handling car, but it rolls more than you like.

So you put a front anti-sway bar on it to help hold the front down.

That, by itself, will create understeer. That is, S4Gunn goes into a corner, and it wants to go straight instead.

So you beef up the rear anti-sway bar.

Oops. You went too far, now it OVERSTEERS - S4Gunn goes into the corner, turns the wheel to turn 90*, the car goes through 115* as the tail end swings out.

What S4Gunn is probably wanting is to tune for a small bit of understeer; or it's currently oversteering.

Sometimes, more is not better.

Sometimes, less is better. Depends on what you're doing and how you're driving.

Also, the stiffness of the shocks will affect the ideal sway bar stiffness (which is, all else the same, related to the size).

Edit: A quick note on what does what - http://www.motoiq.com/MagazineArticles/ID/1595/PageID/2101/The-Ultimate-Guide-to-Suspension-and-Handling-Part-3-Balance-the-chassis.aspx

RwP
 

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Discussion Starter #6
Depends on the help you want.

Let's say you have a neutrallying handling car, but it rolls more than you like.

So you put a front anti-sway bar on it to help hold the front down.

That, by itself, will create understeer. That is, S4Gunn goes into a corner, and it wants to go straight instead.

So you beef up the rear anti-sway bar.

Oops. You went too far, now it OVERSTEERS - S4Gunn goes into the corner, turns the wheel to turn 90*, the car goes through 115* as the tail end swings out.

What S4Gunn is probably wanting is to tune for a small bit of understeer; or it's currently oversteering.

Sometimes, more is not better.

Sometimes, less is better. Depends on what you're doing and how you're driving.

Also, the stiffness of the shocks will affect the ideal sway bar stiffness (which is, all else the same, related to the size).

Edit: A quick note on what does what - The Ultimate Guide to Suspension and Handling Part 3: Balance the chassis

RwP
RalphP's hit it exactly. We had a very neutral driving car after upgrading from stock to a combination of slightly beefier sway bars + cut SC springs + Eibachs in the rear.
We messed it up a little by changing the F/R weight ratio with a V8.
We then really messed it up by upgrading to Bilsteins. While the car can now pull a good deal more lateral Gs than before but the car is not forgiving at all and the "snap" when it transitions from grip to oversteer is a good deal more abrupt. Before, we could toss the car into a corner (inducing oversteer) knowing we could easily catch the car at the end of the turn (well before the car would be aimed in the wrong direction). That's not true anymore.

http://www.tccoa.com/forums/26-racing/180730-results-experiences-our-7th-24-hours-lemons-race-tbird.html

The goal with going with a smaller swaybar is to induce a little understeer or make the car more neutral again -- giving us more time under traction before the point where the backend breaks free.

We could also move weight back (fuel cell in trunk) or raise the ride height of the front 1/4". All of this is under consideration.

Bottom Line: "Moar" is not always better.
 

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You could also soften up the shocks some, S4Gunn; that would make the transition into understeer smoother and more forgiving.

RwP
 

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Discussion Starter #8
One more thing:
Rear sway bars essentially defeat IRS because force being applied to compress the outside suspension is being applied to compress the insides mention. When the rear bar is too big the inside wheel can actually lift up. While some vehicles like shifter karts are designed with this in mind (they actually corner best with three wheels on the ground and it's quite a blast when you first experience this firsthand), the Thunderbird is no shifter kart. We need all the traction we can get for those rear wheels which means keeping both of them planted for as long as possible.
 

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Discussion Starter #9
You could also soften up the shocks some, S4Gunn; that would make the transition into understeer smoother and more forgiving.

RwP
I thought about that but there aren't that many options between Monroe Sensatrac and these bilsteins.. maybe the Tokicos.

FWIW, If there was an option to change the Bilstein fluid, I would have gone with a lighter weight oil. The only way to do so would be as part of a revalve job. I'll consider that in the future.

.
-g
 

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Well, there's also the KYB GR-2 and the Sachs units; not sure how they'd rank, but it'd be worth some test runs on a track to see.

They're easy enough to swap; the problem is the $$$$s to test them.

RwP

Addendum: RockAuto also lists Gabriel. For an XR7, they're listed as "Original Ride Quality"; not economy.

Addendum 2: Most expensive is about $23 each; cheapest of those are $11 each. Not that much money IMO; but then again, it's not my money *grins*

RwP
 
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Discussion Starter #12
Well, there's also the KYB GR-2 and the Sachs units; not sure how they'd rank, but it'd be worth some test runs on a track to see.

They're easy enough to swap; the problem is the $$$$s to test them.

RwP

Addendum: RockAuto also lists Gabriel. For an XR7, they're listed as "Original Ride Quality"; not economy.

Addendum 2: Most expensive is about $23 each; cheapest of those are $11 each. Not that much money IMO; but then again, it's not my money *grins*

RwP
From what I read, kybs are soft. Dunno about the sachs. The other popular stiff dampener are SC shocks but finding those 20+ yr old dampeners in any decent condition isnt very likely.

If I had access to a shock Dyno and i was to do this over again, I might experiment with adding Schrader valves to my original Monroe shocks. That would be cheap but considering how quickly i blew them out, i suspect you need better valving and not just heavier oil.

As it stands today, im gonna keep the bilsteins and look for other ways to Balance things out.
 
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