Brace and Bars - Options and Opinions

Stanley

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1997 Thunderbird 4.6L V8
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I'm new to car mechanics so forgive me if this is obvious, and don't assume I know any basic thing in your replies because I'm at the "car go vroom" stage of automotive knowledge.

I have a 97 Tbird with the Sport package and want to have the suspension rebuilt. Towards that, I'm browsing the SCP website and he has a lot of different braces for sale:

Rear torsional load brace
Front subframe suspension support brace
Front subframe lower engine cradle brace
Pinion brace
Rear anti-sway bar
Front anti-sway bar

And I've seen pictures of braces running through the trunk

As I understand it, braces and bars both make your suspension stiffer, which is good for performance-oriented handling but comes at a cost to your cushy ride. As this is a daily driver and my wife loves what she calls the "living room on wheels" feel that the Thunderbird has, are any of these recommended? I'm wondering if any one or two would be considered such an improvement to handling or reducing strain on other components or some other factor I don't know about that people would say they're worth getting even for pleasure rides: I'm willing to give up a little bit of squish for a lot of handling or reliability. As I understand it, it's all trade-offs, but with no practical experience I can't really say how much and in what way. Thanks.
 
It is a bit of a balancing act - adding a brace adds mass to a car which many feel is already too heavy. Old, worn-out shocks and bushings can make it easy to confuse floaty suspension with chassis flex, so a full suspension rebuild (just say NO! to ebay kits, lol) is definitely a good place to start, though you're probably running into the same problem many of us are fighting: no great options for front shocks!

At any rate, some braces help stiffen up the chassis more than others. I seem to recall people saying the LECB is one of the more useful ones. I don't have any experience with them first hand - just what I've read over the years. The SC L-braces are known to firm up the rear of the car over the factory V-brace behind the rear seat. I didn't notice much difference though.

Changing the sway-bars is probably not something most people should consider unless they're tuning the suspension (springs, shock and sway-bars all need to work together) for a particular motorsport application. That's tough now because, again, not really anything out there for front shocks.
 
Starting with the braces the first thing to remember is braces do not make the suspension stiffer, they don’t magically reduce body roll, don’t bring peace to the middle east etc. You can brace a stock LX up to the nine’s but it isn’t going to change the handling in any measurable way the way stiffer springs stiffer shocks and bigger sway bars do.

Bracing is meant to stiffen the unibody, theoretically providing a stiffer foundation for the suspension to articulate from which is a good thing in itself, as the body is no longer acting like an extended “spring”. In application however color me a skeptic of most readily available “braces”. IMO the biggest issue these cars have is torsional flex and things like shock tower bars don’t really address it. The only ones mentioned that I think have ever been worth doing on this chassis is the lower engine cradle braces(assuming those are the ones that link the K member to the frame rails.

As for sway bars, yes the bigger you go the harsher the ride will be, you definitely wouldn’t want something like the Addco 1-3/8 option, and for some performance applications they’re even considered too big since the larger the sway bar the less independent the suspension behaves. I’d recommend sticking with the stock front bar and using either the 1-1/8 or maybe 1-1/4 Addco rear bar(but I wouldn’t do that by itself). Springs will make a bigger difference, progressive rate like eibachs or vogtlands keep a little ride quality but when you toss the car through a corner they load up and act more like stiffer springs. The sort of double edged sword with progressives though is while they retain ride quality for everyday driving they still want a stiffer shock for when they do load up…killing the ride quality.

I’d say for your needs the smallest Addco rear sway bar is the only thing I’d really do suspension/chassis wise and instead upgrade the brakes, eg 99-04 Mustang PBR calipers with good pads, and get a set of good performance tires, wider the better. Braking is one of the most overlooked pieces of a good handling car and grip is all that matters in the end.
 
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You will be unlikely to feel any difference in adding bracing, unless you're autocrossing or doing Lemons racing.
If you're just starting out with these cars, There's a lot that you'll want to change, but the bracing isn't it. These cars are heavy, and adding 300lbs of steel isn't going to help. :)
That said, Lazarus probably has 300lbs of bracing in it, lol. :)
Instead of that, I would recommend three mods that you will feel:
Do the PBR brake Upgrade. This runs about $250, and you buy the 2004 Mustang GT PowerStop PBR calipers from RA; you can also get drilled/slotted rotors that look cool. You will really notice the difference. These work on 15" wheels, but barely.
Read the thread on upgrading the shocks: We are working on a better front shock solution, but there are some options.
For the rear shocks, the koni's are available for the Mustangs with IRS; they are adjustable, so you can match them to the front's.
Remove the intake silencer, and fix the vacuum leaks. If you haven't replaced any, there are serious problems with the evap circuit for sure. :) There are 8x 2" pieces of 1/4", and one piece of 3/8" "fuel rated vacuum hose" in that run, that starts at the Throttle body, and ends at the gas tank.
The charcoal cannister and solenoid are probably laying in the front cover, under the ail inlet. :) They were in my cars...

If it has new plugs and wires, you're probably good for a while.
If the car is new to you, there are some things you'll want to do.
Get a new set of motorcraft plug wires.
Get a new set of plugs
There is a sticky in the 4.6 section with how to do that replacement.
Get a set of NTK O2 sensors, and install them in the front position, and move the ones currently in front to the rear position, unless they're wet with oil. If they have been covered with oil or coolant, replace all 4.
Clean the maf. Advanced sells maf cleaner, and the t-20 security bit to remove it.
Change the oil. Walmart or RA has the FL-820S filters for ~$350, and castrol Syntec full synthetic 5W20 or 30 oil is about $25.
Get a gallon of coolant.
Inspect the radiator lines, soft places means replace them.Gates, Motorcraft, or dayton make good hoses. Don't forget to check the heater hoses carefully.
Unless you have a tune for your car that includes a 180 degree thermostat, buy a stock thermostat. It won't run cooler by only changing the thermostat.
Don't use a K&n filter; they are hard on the maf. :)
Get 6 quarts of Mercon V trans fluid and a filter. Change the fluid, drop the pan, change the filter. Dorman sells a pan with a drain plug for $20, it's worth it. :)
You need to drop the pan the first time. The thing you are looking for is the "Secret Toy", the plug ford originally had in the dipstick plughole to keep fluid inside it on the assy line. Finding it in the pan, means the pan has never been dropped. Post up a pic of the stuff stuck to the magnet. If it's more than a thin coating of black slime, you should start looking for a 2002 gran marquis transmission, lol.
Also look for a 1993 Mark 8 driveshaft. that year only is a one piece aluminum driveshaft; ours suck, and aftermarket starts at $450.

Inspect everything under the car. Look for blown seals, bad bushings, etc.
Replace the coolant. I drain the old, and put the hose in the thermostat housing with the thermostat out, lower hose off, and let the hose run for a while.

Make sure the spark plug wells don't get filled with water, a shopvac and air blowoff tool will empty out any water.

After doing all this, your car is in a known state. When you first get one, you never know what's been done when. Now you do.
I keep a logbook for each car; that way I know the Tbird needs Mustang brake pads, as does Lazarus, but the red Cougar is stock. :)
You can get PBR calipers at the jy, but rebuilt, powdercoated ones are almost as cheap. Stainless brake lines are a nice improvement to brake feel, if you do the pbr's.

If you find a 93 mark DS, get the rear lower control arms. They're aluminum, and accept the Energy suspension poly bushings, which are stiff as fuck. :) Check the balljoints in the front suspension; if the bushings are blown, you'll want to replace the UCA's and LCA's.If you replace those, do the endlinks, and the tie rod ends. I could feel a 0.1mm play in an inner tie rod...
After doing the control arms, get a 4 wheel alignment. These cars are easliy adjustable, and the settings in the article work very well.
If an alignment shop tells you they're hard to set up, get a different alignment place. Do everything on the suspension at once, so you don't have to have it aligned more than once.
Be sure to check the rear control arm bushings, esp the inner upper one; it's an alignment point for caster, and they lose the rubber as a powder when they're bad, and will have 1/4" of play, or more.

Get the suspension right, add some good brakes, and you can think about performance mods. :)

I have Hooned Lazarus for 500k miles. It has a bunch of mods, and feels great to me. It has PBR's, Konis, sport springs,Bracing,a PI intake, 2002 GTmaf 2004 mustang water pump, Headers, true dualMandrel bent 2.5", exhaust,Mark lca's, aluminum driveshaft, 2002 GM trans that I built, a locking diff, poly and delrin rear bushings, 255lph fuel pump, 24lb injectors, and a tune I wrote.
I got him in 1999, inherited from my dad with 28k miles on it. It's over 500k now. :)
 
If you look at the sticker in the driver's doorjamb, and the core tag, they tell you what is on your car. If you're really lucky, there's a paper build sheet under the carpet, under the rear seat/trunk area.
 
Thanks gents: this is really helpful.

If you look at the sticker in the driver's doorjamb, and the core tag, they tell you what is on your car. If you're really lucky, there's a paper build sheet under the carpet, under the rear seat/trunk area.

Yep: that's how I knew I had the Sport package (and an open diff, unfortunately; what a strange combination). I've had her for about a year: the proverbial little farmer's car I got from a village in the middle of nowhere. A mechanic had it and tarted it up a bit with 19x9" Mustang GT wheels, which while nice-looking give a rough ride, bottom out easily (though that could be other suspension things as well), are prone to rubbing, and have the ponies on the centre caps which make me feel like a bit of an idiot: I'm thinking of replacing them with 18x8s, but that's another thread. But he and the owner prior kept up the basic maintenance: transmission is in great shape, body is solid, sure enough the MAF needed cleaning but that's been done, etc. The mechanics I've had work on it (three different shops) have all commented on what great shape it's in for its age, which makes me willing to sink some money into it. I just want to start with the suspension (which will eventually include Mustang hubs and brakes) for safety and because I figure there's no point in going for power if the car isn't in a shape to handle it.

Thanks a ton for the comprehensive run-down of work to do: it's great to have that all in one place. Hopefully some rando doesn't total this one like they did my poor '95.

IMG_20220507_172102.jpg
 
If those are gt wheels, the hubswap has been done. With 19" wheels, I'd skip the PBR brakes, and do the Cobra brakes.
I've found by long experience, and lots of driving that the BFG Sport tires make the best summer sticky tires. They do not work well in cold temperatures, as you'd expect from a summer tire. I really like the handling on my cars, but I have a stiffer suspension than most people find comfortable. :) When I did the poly upgrade, I thought I'd have to buy a kidney belt, lol. But I'm used to it now.
You can get various centers for the wheels, just verify the diameter before you order them. My Mark 8 wheels needed new ones, and I looked at snakes, horses, and just chrome, which I went with. It sounds like it's been well maintained, so you will likely have a long, trouble-free life out of it.
 
I applied some custom vinyl T-bird logo center cap decals on the cobra center caps I have on my wheels, made by an acquaintance of @MadMikeyL - ClintD. I don't know if he's a member here but the last I heard, he was still able to run them off. Maybe Mike can get you in touch!

20170324_184006s.jpg
 
If those are gt wheels, the hubswap has been done. With 19" wheels, I'd skip the PBR brakes, and do the Cobra brakes.
I've found by long experience, and lots of driving that the BFG Sport tires make the best summer sticky tires. They do not work well in cold temperatures, as you'd expect from a summer tire. I really like the handling on my cars, but I have a stiffer suspension than most people find comfortable. :) When I did the poly upgrade, I thought I'd have to buy a kidney belt, lol. But I'm used to it now.
You can get various centers for the wheels, just verify the diameter before you order them. My Mark 8 wheels needed new ones, and I looked at snakes, horses, and just chrome, which I went with. It sounds like it's been well maintained, so you will likely have a long, trouble-free life out of it.
More likely they are on bolt circle adapters. Those wheels are 42mm offset, they should tuck in with a hub swap not stick out and rub. I know as I had them. They don’t take universal center caps either.

IMG_2981.jpeg
 
What SCP sells as the FSSB and LECB, which I believe are based on the original Kenny Brown designs, was revised to a one-piece design by both Johnny Langton and Rod that connects the front framerail to the K-member. It noticeably reduces chassis flex in the front end.

Bracing the back seat with the L or X or the rear shock towers doesn't do much in terms of feel. Theoretically, it eases the forces on the Thunderbird's rear window if that's even a thing to be concerned about, which I've never even considered.

What makes a more noticeable difference in the feel of the rear is swapping out the stock subframe bushings for UHMW. Also, changing the rear lower control arms to Mark VIII ones and using UHMW or Delrin LCA and knuckle bushings will do a number on wheel hop.



I have noticed more road noise and vibration with these upgrades and I don't recommend them if you want to preserve the stock feel of the car. However, the back of my car feels very cohesive and composed now, more than any bracing would do.
 
I thought they were the same dia as the Mark caps. my bad. :)
 
I applied some custom vinyl T-bird logo center cap decals on the cobra center caps I have on my wheels, made by an acquaintance of @MadMikeyL - ClintD. I don't know if he's a member here but the last I heard, he was still able to run them off. Maybe Mike can get you in touch!

That could be excellent. I tracked down some 1980s 2.75" Thunderbird caps, but I think all the Mustang wheels are going to have slightly smaller caps and won't take them. I'll keep this sticker option in mind.

More likely they are on bolt circle adapters. Those wheels are 42mm offset, they should tuck in with a hub swap not stick out and rub. I know as I had them. They don’t take universal center caps either.

Sorry, to be clear: are you saying that the caps on these GT wheels are not removable/alterable?

What SCP sells as the FSSB and LECB, which I believe are based on the original Kenny Brown designs, was revised to a one-piece design by both Johnny Langton and Rod that connects the front framerail to the K-member. It noticeably reduces chassis flex in the front end.

Bracing the back seat with the L or X or the rear shock towers doesn't do much in terms of feel. Theoretically, it eases the forces on the Thunderbird's rear window if that's even a thing to be concerned about, which I've never even considered.

What makes a more noticeable difference in the feel of the rear is swapping out the stock subframe bushings for UHMW. Also, changing the rear lower control arms to Mark VIII ones and using UHMW or Delrin LCA and knuckle bushings will do a number on wheel hop.

I have noticed more road noise and vibration with these upgrades and I don't recommend them if you want to preserve the stock feel of the car. However, the back of my car feels very cohesive and composed now, more than any bracing would do.

Thank you. A couple of questions here: is this single-piece brace that you mention still available anywhere, and (ignoring the rest of the rear stuff you mentioned for the moment) what's the benefit of switching to the Mark VIII arms in the rear vs. stock?
 
Thank you. A couple of questions here: is this single-piece brace that you mention still available anywhere, and (ignoring the rest of the rear stuff you mentioned for the moment) what's the benefit of switching to the Mark VIII arms in the rear vs. stock?
For the one-piece brace, not that I know of. Rod isn't making them anymore and JL passed away some time ago.

The Mark VIII rear LCAs are aluminum so they're considerably lighter than the steel MN12 rear LCAs. I forgot what the difference was because it's been several years since I last weighed them, but it was significant. You will need additional parts to make the Mark VIII rear LCA swap though including spring perches and LCA-to-spindle bushings and bolts.
 
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Also, this is a great guide that Rod put together on bushings:

 
Sorry, to be clear: are you saying that the caps on these GT wheels are not removable/alterable?

They’re removable of course but they don’t have the same diameter as the common center caps and are much shallower, so if you were to say put SVT center caps on that fit most other Mustang wheels they’d clip on okish but they don’t sit flush. But rather almost a 1/2” above the surface.

They can be physically modified though, but you essentially have to mill down the pony which is molded in peel off the black tin piece and flatten the area to accept a decal like Brandon has. @OxmanWI may be able to share details as he did that to those wheels himself, I never got around to it and got new wheels instead
 
With 19" wheels, I'd skip the PBR brakes, and do the Cobra brakes.

What year(s) of front Cobra rotors am I able to use if I do that? 99-04 rotors only, like the rears? There's lots of guides to the brake and hub changes, but while the rear portion is quite detailed they seem to gloss over the front part somewhat, perhaps because of all the possible options there.
 
Rotors are 94-04

Cobra rears aren’t worth changing from stock unless you actually did go the hub swap route
 
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I made my own cheapy x brace using the mark 8 lower brackets. Before this I had a combination of the stock V plus L plus X brace from the mark. I’d say this is very slept on. Made a big difference in how it soaks up bumps.






IMG_2554.jpeg
 
I'd also recommend at least the Cobra front brakes. Jump to the Brembo calipers with either the 13" or 14" rotors if you want to go a bit further.

The Cobra rear rotors with the relocation brackets are a solid improvement.

Bracing the K-member to the front frame rails makes an immediately noticeable difference. As does full length subframe connectors. The videos that Irv posted above show how much the rear subframe moves around with stock bushings. Tying it to the frame rails via SFC's accomplishes much the same as the UHMW bushings, with the upside of stiffening up the middle of the chassis as well.

That little bit of tubing doesn't add anywhere close to 300 lbs to the car. In fact, it's just over a tenth of that.

finished 4.JPG16422323_10100127293630553_2938588760195510282_o.jpg183008265_10100674156892193_5574918794106101731_n.jpg183143045_10100674157151673_7032288239037952543_n.jpg
 
Thanks for posting this up again, Rod. Lost a few bookmarks like this over at the other place when I was....banned
 
I'd also recommend at least the Cobra front brakes. Jump to the Brembo calipers with either the 13" or 14" rotors if you want to go a bit further.

The Cobra rear rotors with the relocation brackets are a solid improvement.

I'm definitely planning on the Cobra rears. The fronts I'm a little more ambivalent about, if only because I'm having a hard time parsing all the varied bits of information on the front end part of the upgrade: there seems more variance there. My lack of automotive background makes some threads pretty much unintelligible at times. I'll probably just start a new thread when I get to that stage rather than trying to hash it out here in one not designed for it: I've got a lot of other suspension stuff I'd like to get to that's more straightforward.

Bracing the K-member to the front frame rails makes an immediately noticeable difference. As does full length subframe connectors. The videos that Irv posted above show how much the rear subframe moves around with stock bushings. Tying it to the frame rails via SFC's accomplishes much the same as the UHMW bushings, with the upside of stiffening up the middle of the chassis as well.

That little bit of tubing doesn't add anywhere close to 300 lbs to the car. In fact, it's just over a tenth of that.

Thanks for the personal experience there. I assume those are the Mark VIII arms showing? And a LPW diff cap. Hey, some of these things are starting to finally become familiar...
 
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I wouldn't increase the rear disc diameter if you're not going to increase the front. The Cobra parts are a bolt on, other than drilling the 5x4.25" bolt pattern into the rotors.

Yes, those are Mark VIII rear LCA's and a LPW Racing diff cover.
 
I didn't find much of a difference in stopping power going from the stock rear rotors to the 11.65" Cobra rear rotors, but that's truly all things being equal since the front was already converted to 13" Cobras and I reused the rear pads which were still fresh. It would look goofy since you'd have a 1" bigger rear rotor than the front but with PBR calipers on stock 10.5" rotors I don't think they'd be a bad match as far as brake balance goes. But having said that with 18-19" wheels go big and go Cobra or Brembo

Middle ground solution to the IRS bushings if the pricetag is too high or the prospect of ride degradation is a turnoff is you can partially lower the IRS and shorten the bushing sleeves by about 1/4". This adds extra preload to the rubber once retightened and definitely has a positive effect on damping cradle movement as I can attest to with a wheel hop prone 5-speed, and NVH didn't seem to change. It's not something I'd attempt if the car has any rust though. You'll likely have issues removing them to install UHMW ones too but you don't have to worry about the bolts being rusted into the stock sleeves, you just cut them out and use new (or good used) hardware
 
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You need caliper relocation brackets, to use the larger rear disks. The cobra rears don't have our style e-brake hookup, so relocation brackets. Dave Dalke was making these a couple of years ago.
 
Bill still has the relocation brackets at supercoupe performance as well.
 
I was playing in the garage today, and I found another rear stb that is for the red Cougar. Since I also have a set of koni's for the red car, I'll do those while I'm there. I need to swap wheels, so it will be a fun day. I have a set of sport shocks for the front. I'm saving the other set for you, B. :)
My niece that recently fucked me over for 20k is going to lose her winter parking spot; I'm putting Lazarus there until I get the rod knock fixed. :) I think I'll put the engine on the back porch, so her door won't open, lol.
 

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