gt500 sway bars

[fastback2race]

what's the difference between gt sway bars and the gt500 sway bars in terms of measurement, driveability and handleing

 

[Bizzyb0nes]

getting ready to ask this very same question concerning how it would compare to a set of steeda/eibachs in stiffness/roll resistance

Also would be curious on input to how good the gt500 dampeners are compared to say, the frpp/tokico non adj/ ect

 

[Pony DNA]

getting ready to ask this very same question concerning how it would compare to a set of steeda/eibachs in stiffness/roll resistance

Also would be curious on input to how good the gt500 dampeners are compared to say, the frpp/tokico non adj/ ect

Hi Bizzyb,

Steeda anti-roll bars are excellent quality and have more than enough range of roll stiffness for most applications. FRPP's bars for the S197 are supplied by Eibach and these are also very good bars with very good alloy and stainless hardware. All of these front anti-roll bars are similarly sized at 35mm and offer similar roll stiffness and are all adjustable.

Steeda over the years has offered a wide range of rear bars for the S197's (20.6mm, 22.2mm and 25.4mm) designed to work with the front adjustable bar and has more than enough adjustment range for street or race use. The only way to change an S197's rear roll stiffness using these kits is to change bars and FRPP/Eibach do not offer matching larger rear bars. But you can easily change the handling balance using the front bar adjustments. You can also buy the larger GT500 rear bar (24mm) but it is a Ford GT500 production piece which is to say it is more coarsely made and does not match the FRPP/Eibach finish or hardware. Oh, BTW GT500's use the same 34mm front bar all GT's wear.

All of the factory dampers are reasonably good quality but poorly valved for some reason. If you are not going to buy an adjustable damper don't bother to spend the money on non-adjustable dampers they are mosly inadequate for real performance applications. Koni Sport or D-Spec are the only good choices for folks going with conventional struts and if this is too much money for you forget about coilovers.

HTH!

 

[Pony DNA]

what's the difference between gt sway bars and the gt500 sway bars in terms of measurement, driveability and handleing

Hi fastback,

This one is easy. All GT/GT500 have the same sized 34mm front bar and out back the GT has a 22mm bar and the GT500 has a 24mm bar. The two cars are sort of similarly balanced when throttle neutral because the larger rear bar of the GT500 balances out the extra 100lbs. over the front tires.

HTH!

Also wanted to say the GT500 35mm bar is a bit thicker and about 6% stiffer. This is not much of a difference but is noticable to most folks if you tell them you changed something. See my post below.

 

[ClassJ]

Actually that is incorrect. The GT500 does have a heavier front sway bar as well as a heavier rear bar. The rear bar is a larger diameter solid bar when compared to the GT.

The front tubular bar however is the identical 34mm OD but has an increased wall thickness. It carries a different part number, and if you weigh them there is a pretty significant difference, I don't recall what it was, but the GT500 bar is noticeably heavier.

On my car at least, the heavier bars made a nice difference. I already had the other suspension mods in my sig, and the sway bars really tied it all together, improved turn in, and flatness.

 

[Pony DNA]

Actually that is incorrect. The GT500 does have a heavier front sway bar as well as a heavier rear bar. The rear bar is a larger diameter solid bar when compared to the GT.

The front tubular bar however is the identical 34mm OD but has an increased wall thickness. It carries a different part number, and if you weigh them there is a pretty significant difference, I don't recall what it was, but the GT500 bar is noticeably heavier.

On my car at least, the heavier bars made a nice difference. I already had the other suspension mods in my sig, and the sway bars really tied it all together, improved turn in, and flatness.

Hi Class,

Oh, that might be right as I've only measured the outside diameters of all the bars on various S197 from 2005-2009 chassis. I'll have to borrow an ultrasonic tester and see what the wall thicknesses are now. I would not imagine the GT500 front bar is very much thicker or that the GT500 bar is significantly stiffer in roll.

All three upgraded front bars for GT500's I've seen and installed were still only 35mm yet all showed increased roll stiffness over the stock GT500 bars. The Steeda GT500 front bar is the same part number as their GT bars and still shows a noticable increase in stiffness, Eibach's front and rear bar kit has a 35mm bar and is the same part number a a GT and show the same level of roll stiffness increase. FRPP's GT500 bars are just relabled Eibach kits and have the same bars in the kits. These are the only ones I've seen in person and installed and driven on. But anything is possible I guess.

What did you feel the GT500 bars did to the handling balance? Did you change on the bars or did you make other changes at the same time?

Cheers!

 

[Blair]

http://www.mustangandfords.com/featuredvehicles/mdmp_090312_2010_ford_mustang_details/index.html

Here's a great article I found a while ago that compares the suspension changes over the 05-09 GT's, 08 Bullitt, and 2010 GT and track pack. According to this article the GT500 came with 34mm OD x 5.8mm ID hollow front bars and the GTs have 34mm OD x 5.1mm ID hollow bars. The GT500s have 24mm rear solid bars and the GTs have 20mm solid bars.

Blair

 

[ZmanM3]

Hmm, this is an interesting idea. A rear sway bar is really about the last piece I need to finish up my suspension. The car handles great now but I think that there may be some benefit to me.

 

[SoundGuyDave]

I think we ought to branch this discussion out into how the anti-roll bar plays into the overall suspension package...

For discussion:

The car in the pic (mine) has BMR bars front and rear, billet rear links, and BMR springs. The front bar is set to soft (3 points of adjustment) because with it any harder, the car pushes like a pig. I included the rear shot to show that it's not just the front bar that is letting the chassis dip... This is a classic case of the "hard bar, soft spring" side of the argument. Anybody care to chime in that's running soft bars and hard springs? I am now of the firm opinion that you need to make the coarse chassis setup with springs, and then tune with the bars. Dampers, naturally, are set to suit the spring.

 

[Pony DNA]

Hi Dave,

What was the suspension setup when those photos were taken? Springs, dampers, relocated front or rear pick-up points, camber devices, alignment settings etc.? Are you running a staggered wheel and tire setup? What size wheels and tires are you running? Also what make and model tires?

That looks like a moderately turn so I would expect that even with any sort of decent street performance tire you would have plenty of roll no matter how you set up your off the shelf bars.

The problem shown here with the soft spring/stiff bar model is not normally a problem for a street car with SLA front and rear suspension as are most better european cars. This can make for a very nice riding car that can still corner reasonbly flat and is very stable at speed usually setup with higher damping rates at slower damper speeds, think Big Merc or any standard/non M series BMW.

But the S197 has strut front suspension and struts cannot be easily and/or cheaply designed to gain camber. So when the body rolls your front tires' contact patch shrinks due to the tire rolling over and the load on the contact patch goes up and then you get the increased slipangles which may be the cause of your push with the bar setup stiffer. You can go to a stiffer front bar setting if you set your static camber up much more agressively. Then the combination of additonal roll stiffness limits roll giving you more contact patch and front grip which improves your handling balance reducing push. I know this may sound backwards given the usual rules we have all heard for changing handling balance over the years but for a strut suspension this works due to the limited camber gain of a strut suspension and the increase in front grip.

HTH!

I think we ought to branch this discussion out into how the anti-roll bar plays into the overall suspension package...

For discussion:

The car in the pic (mine) has BMR bars front and rear, billet rear links, and BMR springs. The front bar is set to soft (3 points of adjustment) because with it any harder, the car pushes like a pig. I included the rear shot to show that it's not just the front bar that is letting the chassis dip... This is a classic case of the "hard bar, soft spring" side of the argument. Anybody care to chime in that's running soft bars and hard springs? I am now of the firm opinion that you need to make the coarse chassis setup with springs, and then tune with the bars. Dampers, naturally, are set to suit the spring.

 

[Vapour Trails]

F1Fan you made it over here. I see the hallmarks of your posts.

 

[Pony DNA]

F1Fan you made it over here. I see the hallmarks of your posts.

Hi Vapour,

Is that good or bad?

Cheers!

 

[Pony DNA]

Hi ClassJ,

I went and thought about it and the stiffness difference between the GT500 and GT 34mm bars is pretty small given the published 0.7mm difference in wall thickness of these bars. I calculated the difference to be a little more than 6% for the front bars and about 207% for the 20mm and 24mm bars all things being equal, bushing and link stiffness. You added more weight to the nose for a 6% stiffer front bar so the difference you are likely to feel are even smaller. The big difference in handling you felt was probably due to the huge difference in rear roll stiffness. The 35mm bars from Steeda add 10% on top of the GT500 bars when set to the middle adjustment and I think Eibach/FRPP are about the same when set the same. You can add more front stiffness using your GT500 front bar by drilling another hole closer to the front of the car. Steeda, Eibach/FRPP have holes about 2" apart for adjusting the effective rate of the bar.

HTH!

Actually that is incorrect. The GT500 does have a heavier front sway bar as well as a heavier rear bar. The rear bar is a larger diameter solid bar when compared to the GT.

The front tubular bar however is the identical 34mm OD but has an increased wall thickness. It carries a different part number, and if you weigh them there is a pretty significant difference, I don't recall what it was, but the GT500 bar is noticeably heavier.

On my car at least, the heavier bars made a nice difference. I already had the other suspension mods in my sig, and the sway bars really tied it all together, improved turn in, and flatness.

 

[SoundGuyDave]

Double post, sorry...

 

[SoundGuyDave]

Hi Dave,

What was the suspension setup when those photos were taken? Springs, dampers, relocated front or rear pick-up points, camber devices, alignment settings etc.? Are you running a staggered wheel and tire setup? What size wheels and tires are you running? Also what make and model tires?

BMR variable-rate springs, Tokico D-Spec rear shocks (medium-soft) OEM Struts (Broke a D-Spec!), no pickup relocation, MM c-c plates PLUS crash bolts... I don't recall the caster settings, but they were even, at stock +.5*, camber is set to -2.5*(geometrically maxed out), toe to 1/16" out. Wheels are all 18x9.5, +50mm offset, tires ARE staggered (255/45-18, and 285/40-18) on thrashed 300 treadwear summer tires (Nitto NT555's with about 30 lapping days on them).

That looks like a moderately turn so I would expect that even with any sort of decent street performance tire you would have plenty of roll no matter how you set up your off the shelf bars.

Which was a good portion of the point I was making!

The problem shown here with the soft spring/stiff bar model is not normally a problem for a street car with SLA front and rear suspension as are most better european cars. This can make for a very nice riding car that can still corner reasonbly flat and is very stable at speed usually setup with higher damping rates at slower damper speeds, think Big Merc or any standard/non M series BMW.

But the S197 has strut front suspension and struts cannot be easily and/or cheaply designed to gain camber. So when the body rolls your front tires' contact patch shrinks due to the tire rolling over and the load on the contact patch goes up and then you get the increased slipangles which may be the cause of your push with the bar setup stiffer. You can go to a stiffer front bar setting if you set your static camber up much more agressively. Then the combination of additonal roll stiffness limits roll giving you more contact patch and front grip which improves your handling balance reducing push. I know this may sound backwards given the usual rules we have all heard for changing handling balance over the years but for a strut suspension this works due to the limited camber gain of a strut suspension and the increase in front grip.

HTH!

You've actually made my point right there! ARB's are NOT a panacea of handling, but only a component that functions within a system. It's the system itself that helps to control the contact patch, which is, after all, the only think keeping us glued to the road for acceleration, braking and turning. The ARB only serves to modify the wheel rate under side-load, without significantly affecting longitudinal jounce or rebound. I will respectfully disagree with you on being able to stiffen the front bar, though. It seems the stiffer I go, the more understeer I wind up with. I suspect that the reason for that is with a softer bar, there is less tendency for the inside tire to unload, meaning it still is making a contribution to the net tractive force. Even with the stiffer bar, the car is still going to pivot around the roll center, which is admittedly too low right now, and all that does is increase the load to the outside tire up to 100%, and start decreasing the load on the inside tire, to the point where the net tractive force is lower than with a softer bar.

I HAD relocation brackets in the rear, but had to pull them to keep in-class, and the amount of brake dive and nose lift under accel I get now is staggering in comparison. The only solution that I can see for this is to increase the spring rate dramatically. Now that the car's a track-toy, I'm no longer unwilling to sacrifice ride quality and street manners, so next year it'll be coilovers with much higher rate springs, and I get to start tuning all over again. There is a possibility that I'll be able to fit some adjustment to the front roll center (hiked upwards) if there are sufficient points available after the coil-overs, which is unknown right now due to a pending revision in the damper classing.

 

[Blair]

Hi Vapour,

Is that good or bad?

Cheers!

HA! I knew it... I am a long time lurker on "the other site" and I picked up on that too. Why did you stop posting there?

 

[Pony DNA]

BMR variable-rate springs, Tokico D-Spec rear shocks (medium-soft) OEM Struts (Broke a D-Spec!), no pickup relocation, MM c-c plates PLUS crash bolts... I don't recall the caster settings, but they were even, at stock +.5*, camber is set to -2.5*(geometrically maxed out), toe to 1/16" out. Wheels are all 18x9.5, +50mm offset, tires ARE staggered (255/45-18, and 285/40-18) on thrashed 300 treadwear summer tires (Nitto NT555's with about 30 lapping days on them).

Which was a good portion of the point I was making!

You've actually made my point right there! ARB's are NOT a panacea of handling, but only a component that functions within a system. It's the system itself that helps to control the contact patch, which is, after all, the only think keeping us glued to the road for acceleration, braking and turning. The ARB only serves to modify the wheel rate under side-load, without significantly affecting longitudinal jounce or rebound. I will respectfully disagree with you on being able to stiffen the front bar, though. It seems the stiffer I go, the more understeer I wind up with. I suspect that the reason for that is with a softer bar, there is less tendency for the inside tire to unload, meaning it still is making a contribution to the net tractive force. Even with the stiffer bar, the car is still going to pivot around the roll center, which is admittedly too low right now, and all that does is increase the load to the outside tire up to 100%, and start decreasing the load on the inside tire, to the point where the net tractive force is lower than with a softer bar.

I HAD relocation brackets in the rear, but had to pull them to keep in-class, and the amount of brake dive and nose lift under accel I get now is staggering in comparison. The only solution that I can see for this is to increase the spring rate dramatically. Now that the car's a track-toy, I'm no longer unwilling to sacrifice ride quality and street manners, so next year it'll be coilovers with much higher rate springs, and I get to start tuning all over again. There is a possibility that I'll be able to fit some adjustment to the front roll center (hiked upwards) if there are sufficient points available after the coil-overs, which is unknown right now due to a pending revision in the damper classing.

Hi Dave,

So you have to deal with some sort of class rules? Can you get away with installing longer front lower control arm ball joints? Can you relocate your front control arms or do both changes and still be within the local rules you are using? This actually works pretty well with lowered cars and raises the front roll center quite a bit. It's like installing a ginormous front anti-rolll bar and makes the front end of the car highly resistant to roll. But if the car has not been lowered too much you can over do it when you combin these mods and the car gets a sort of weird unnatural motion that is hard to describe.

Do you have the MM plates with caster adjustment? How much additional Caster can you crank into the struts? The Steeda HD strut mounts are limited in how much camber you can crank in and there is no caster adjustment available. Adding caster can help slightly with dynamic camber angle when the wheel is being turned.

What is a crash bolt? Camber bolts at the top of the strut ears?

For a track only car you have it about right, get your springs and dampers working first then tune front rear balance with bars. For a street car the manufacturers seem to generally use the softest possible springs and cover them up with higher valving in compression for a faux "sporty" ride that when pushed are actually pretty terrible handling. The coilover rates that seem to be working well for road course cars are 8"-10" race springs with helpers in the 500-600lb. range up front and 200-300lb. at the rear using the stock spring locations trending higher for outboard axle mounted race style coilovers. Most of the strut coilover cars are using the stock location pattern front and rear bars from Steeda and FRPP/Eibach which seem to be enough to trim the front/rear balance.

That said my DD street car is on Steeda Adjustable Suspension with 325lb. springs in front and 250lb. springs at the rear. Keep in mind this car also has Steeda HD adjustable strut mounts, Steeda billet camber plates, relocated front and rear control arms X5 ball joints, bumpsteer kit, 35mm front bar and 20.6mm rear bar, modified bushing Steeda adjustable LCA's with poly/spherical ends, Steeda Adjustable comp/street UCA w/HD LCA mount and Saleen PJ Watt's link and a few items I forgot to mention. Oh the car is on a set of 9"x19" and 10"x19" SAleen PJ wheels with Goodyear Eagle F1 A/S tires in 245/45x19 and 275/40x19.

The ride is firm as you can imagine but still useable but I don't have to worry about a rule book. I adjust the Steeda adjustable strut mounts to max positive and then use the billet camber plates to set the camber to -2 degrees. Then I marked adjust the strut mounts to the maximum negative setting that both left and right mounts can get to and mark the strut towers and mounts. This only adds about 1/2-3/4 degree additoinal negative camber but it's enough to make a very noticable difference. With the D-Specs cranked up and 38psi in the front tires and 34psi out back the car's steering is sharp and the car sets in a turn very quickly with very little push even in slow 1st or 2nd gear turns. The front grip is very good because the control arms are relocated and the roll center is raised leaving the tires in full contact with the surface. I have the Steeda adjustable Comp/Street UCA adjsted to the long setting which moves the IC rearward and the LCA's level to very slightly uphill towrds the axle to promote stability in high speed turns andwith roll oversteer. I still get decent bite out of corners due to the UCA adjustment unlike most lowered cars without LCA brackets and Steeda adjustable Comp/Street UCA kit installed.

Cheers!

 

[Bizzyb0nes]

Since LCA's relocation brackets were brought up...I noticed after lowering my car...from back of the lca's to front is angled down, which I know is not good...but I was under the impression that it was mainly an issue concerning drag racers....do the cars being setup for the twisties still need the rear lca's angled down to up (from rear to front)

 

[SoundGuyDave]

Hi Dave,

So you have to deal with some sort of class rules? Can you get away with installing longer front lower control arm ball joints? Can you relocate your front control arms or do both changes and still be within the local rules you are using? This actually works pretty well with lowered cars and raises the front roll center quite a bit. It's like installing a ginormous front anti-rolll bar and makes the front end of the car highly resistant to roll. But if the car has not been lowered too much you can over do it when you combin these mods and the car gets a sort of weird unnatural motion that is hard to describe.

Do you have the MM plates with caster adjustment? How much additional Caster can you crank into the struts? The Steeda HD strut mounts are limited in how much camber you can crank in and there is no caster adjustment available. Adding caster can help slightly with dynamic camber angle when the wheel is being turned.

What is a crash bolt? Camber bolts at the top of the strut ears?

For a track only car you have it about right, get your springs and dampers working first then tune front rear balance with bars. For a street car the manufacturers seem to generally use the softest possible springs and cover them up with higher valving in compression for a faux "sporty" ride that when pushed are actually pretty terrible handling. The coilover rates that seem to be working well for road course cars are 8"-10" race springs with helpers in the 500-600lb. range up front and 200-300lb. at the rear using the stock spring locations trending higher for outboard axle mounted race style coilovers. Most of the strut coilover cars are using the stock location pattern front and rear bars from Steeda and FRPP/Eibach which seem to be enough to trim the front/rear balance.

That said my DD street car is on Steeda Adjustable Suspension with 325lb. springs in front and 250lb. springs at the rear. Keep in mind this car also has Steeda HD adjustable strut mounts, Steeda billet camber plates, relocated front and rear control arms X5 ball joints, bumpsteer kit, 35mm front bar and 20.6mm rear bar, modified bushing Steeda adjustable LCA's with poly/spherical ends, Steeda Adjustable comp/street UCA w/HD LCA mount and Saleen PJ Watt's link and a few items I forgot to mention. Oh the car is on a set of 9"x19" and 10"x19" SAleen PJ wheels with Goodyear Eagle F1 A/S tires in 245/45x19 and 275/40x19.

The ride is firm as you can imagine but still useable but I don't have to worry about a rule book. I adjust the Steeda adjustable strut mounts to max positive and then use the billet camber plates to set the camber to -2 degrees. Then I marked adjust the strut mounts to the maximum negative setting that both left and right mounts can get to and mark the strut towers and mounts. This only adds about 1/2-3/4 degree additoinal negative camber but it's enough to make a very noticable difference. With the D-Specs cranked up and 38psi in the front tires and 34psi out back the car's steering is sharp and the car sets in a turn very quickly with very little push even in slow 1st or 2nd gear turns. The front grip is very good because the control arms are relocated and the roll center is raised leaving the tires in full contact with the surface. I have the Steeda adjustable Comp/Street UCA adjsted to the long setting which moves the IC rearward and the LCA's level to very slightly uphill towrds the axle to promote stability in high speed turns andwith roll oversteer. I still get decent bite out of corners due to the UCA adjustment unlike most lowered cars without LCA brackets and Steeda adjustable Comp/Street UCA kit installed.

Cheers!

100% bang on, brother! You're going to be a valuable asset to this community!

I'm building to suit the NASA Time Trials rules, and they are DEATH on suspension mounting or pickup point relocation. Every 20 points is a class, and the Mustang starts as a TTD with a 14 point handicap. TTA is the land of modded C6ZO6 and Vipers, so I want to stay away from that, since I just won't have the horses (or pocketbook!) to compete.

Relocating the suspension mounting points is a 6 point mod, which is pretty heavy, considering that cams or modded OE heads are also 6 point mods... I had rear LCA brackets on the car before, with the bars set roughly flat to the road, and it was VERY nice. Not so nice without them, but still drivable aggressively. "Alteration of ball joints/dive angles" is a 2 point mod, and I have already budgeted for that. MY interpretation of the rules (not official!) is that something like the Whiteline ADK would fall under that heading as well, for no additional points cost, which will give me another 0.5* of caster, less compliance, and improved anti-dive characteristics, so I may do that as well. After all is said and done, I have a 2-point buffer available to stay in TTB, which I'm holding in reserve against an impending rule change on dampers.

Speaking of dampers, specifically coil-overs, do you have any thoughts on the merits or issues with the Ground-Control kit versus the Griggs kit? I think Griggs offers a better shock out back, but I'm concerned with how much stress the stock shock mounting bracket on the axle will take if it's used as a spring perch... Nowhere near enough budget to go SLA, but coil-overs are on the list for winter...

 

[SD07GT]

Griggs has a brace that is used between the LCA brackets and the rear shock location to strengthen that location , since basically you are using that as your spring perch.

From what I understand Ground control also valves Griggs rear shocks also as with the front coil over struts which are Ground control units that are painted yellow .

I'm using the G/C Track/School kit now with a front spring of 370 (i do have a blower on the car) and the rear of 225 . I'm also using the Steeda front Sway bar on the Softest setting with the 22mm..7/8 rear bar. Alignment settings are -1.75 camber + 7 caster 0 toe

I will say adding the x-5 ball joints and relocation brackets for the LCA in the rear finished off everything nicely. I really don't know if adding a adjustable UCA will do that much , so I could dial in some more negative pinion angle ?