Sway or not to Sway

[Ted G]

Hey all.....

I'm trying to finalize my build with FFR. I was wondering if anyone had any positives (or negatives) on the sway bars (both front and rear). I am going with IRS and the standard Koni shocks with 18" wheels.

Also, anyone have a great set up for Power Steering pump and brackets? This will be a DART 427 motor.

Thanks !!

[Dave Tabor]

My car is a Coupe with IRS and Nitto NT01 tires.

I'd say drive it without the rear sway bar and see if you can get the car to understeer- on a track.
Then you can think about the rear bar.

I'd order both bar setups so you have them- but go slow on using the rear bar.

Are you going to track the car?
If not, I doubt you'd ever get to the limits of wanting a rear bar - and you should not unless you're on a track/autocross.

Here's my car with too much rear bar:

https://youtu.be/qDhbn54QU5w

And forget OEM power-steering pumps- go straight to a KRC setup.

Dave
Gen III Coupe #17
FRPP x302b
TKO600/IRS

[GoDadGo]

My car is a Coupe with IRS and Nitto NT01 tires.

Here's my car with too much rear bar:

https://youtu.be/qDhbn54QU5w



Dave,

Thanks For Sharing Your Opinion & Video.

> My car (The Redbone MK-4 Roadster) sports a 3-Link rear that I added a .75" front sway bar.
> The car doesn't push, nor is it tale happy unless I force the issue with too much throttle.
> I was considering adding a rear bar, but after seeing your video, I'll save my money.

Thanks Again For Sharing Your Opinion & Video!

Steve

[BEAR-AvHistory]

Bars are funny things. You will always here a lot of chatter hey I'm getting bars. People like that get them because they are cool race kit. I approach bars as a fix for handling issues. Depending on how the car performs you might need Front and Rear, one end or the other or none at all.

I don't work mine that hard, some fun autocross (not competitive without power steering) , Charity type track days & almost daily street duty. Car works well as its set up so no bars yet.

[Fman]

FWIW I have no sway bars with IRS and base Koni shocks, I have one track day of mild newbie driving and it was fine. Definitely never an issue driving around town or some spirited driving on some decently twisty roads. Not saying to not get them you gotta do what works best for your build.

For Power steering I went with Jones Racing. I picked it up along with all brackets and pulleys from Gordon Levy which has been great so far. It is calibrated for the steering rack with correct pressure. Gordon will send you what you need, one stop. This is just one option, there are others out there as well. I also picked up my Champ 7" deep oil pan and alternator bracket from Gordon.

[JohnK]

If you're on the fence about sway bars, I would suggest that you talk to FFR and see if you can at least buy the rear sway bar mounts at the time you purchase the kit. The front sway bars would be pretty easy to retrofit later on should you decide you want them but the rear sway bar mounts look like they would require a fair bit of disassembly of the rear suspension to retrofit later on.

[frankeeski]

If you're thinking about ordering it with swaybars, just do it. You can remove them if you decide you don't like or need them. But adding them later, shipping from F5R can be a killer.

To the PS the question becomes who are you getting the engine from? Most engine builders are going to give you the option of a PS pump and serpentine belt system. I like the Ford pump and plenty of companies have a belt systems for a Ford small block. My advise is to make sure all the components for the front engine dress all match.

[magicmarto]

I have a MKIV with a front sway bar and a 3 link rear end, with no bar.
The handling is awesome. have not pushed hard on a track yet, but aggressive back road driving seems to be the right balance.
Plus you can "soften" or "harden" the front bar by the different holes at the end of the bar.
M

[mikeinatlanta]

I'm a fan of higher roll center, no bar setups. That said, bars allow quick and easy adapting for differing track conditions. For street I'd much rather spend some time and money getting the springs right without a bar.

[CraigS]

I like bars but I am an avid autocrosser. I agree w/ JohnK that getting just the rear bracketry would be a good idea if possible. This is an inexpensive OEM pump that works well after trimming the pressure relief spring a little. This version is for a remote reservoir. It fits a 99 Explorer. I think there may also be versions w/ the attached reservoir like the label shows but never used one.
https://live.staticflickr.com/65535/50583217846_a90e5d48a5_z.jpg (https://flic.kr/p/2k4SdnC)20200216_074516 (https://flic.kr/p/2k4SdnC) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
I used a mount from Breeze. BTW Breeze also has pumps etc and is another good source for parts. I agree w/ frankeeski about getting everything on the front to match. At one point I had a two groove crank pulley and ran a separate belt for the PS pump. It is a lot nicer to have just one belt but the combination of brackets and spacers to make that happen isn't always easy to come up with. Getting your engine supplier to put that together so you don't end up experimenting and buying several parts that you never use is a good idea.

[RoadRacer]

My 2c.. why wouldnt you have sway bars?

Apart from the obvious (they control roll, and hence camber change), they allow you to easily tune your car. You can start with safe understeer and tune oversteer when/if you want to as you gain experience with the car. Or even easily disconnect them.

But they're such a crazy simple way of tuning..

[J R Jones]

Ted, I suggest a broader perspective on anti-sway bars involving ride quality, not prioritizing aggressive driving leading to oversteer/understeer.

Anti-sway bars provide an additional spring rate for each wheel.
Driving across a speed bump lofts each axle-wheels simultaneously, each wheel compressing it's coil-over as much as the spring rate and shock damping allow.
If you avoid the speed bump with one wheel, the response is similar for the deflected wheel.

In the second example if you had an anti-sway bar, the non bumped wheel holds one end of the anti-sway bar while the bumped wheel tries to twist it. (torsion bar)
At that moment the anti-sway bar adds spring rate to the coil-over spring and damping.

The anti-sway bar spring rate is progressive and reactionary.
If the car is in a turn and the body is rolling, a bump will have two effects:
The outside wheel spring rate is higher (coil/shock + bar) and the inside spring rate is less (coil/shock - bar).

Potentially you can spring your car for worse case deflection (turn + brake + bump) with the coil-over alone.
Potentially you can spring your car for worse case deflection (turn + brake + bump) with the coil-over and plus-minus the anti-roll bar.

Bottom line you may find more ride comfort with lighter coil-overs supplemented with anti-roll bar(s).
The caution made previously is appropriate, too much A/R bar has consequences.
jim

[Ted G]

Wow,

What great responses. Now I am really confused but I like the idea of going with the sway bars and fine tuning them or removing them altogether if needed.

I will not track my car competitively, but maybe for those charity events, etc. I will drive it fairly hard though. My builder is Elliot Franklin and I'll work with him on the PS pump and front end assembly. I love the look of the KRC pump and heard good things.

Learning a lot from you all.... Thanks again!

[mikeinatlanta]

Why not bars? Weight. Trying to bring my car in as close to 2,000lb complete as possible.

[RoadRacer]

Why not bars? Weight. Trying to bring my car in as close to 2,000lb complete as possible.

Ha, I get that. I weighed at 2280 with a full tank (no people) and I was a little disappointed ;) My car has zero frills, but to be fair it is an all-iron SBC.

[CraigS]

To ad to JRs thoughts that bars can allow a softer ride look under any current street car. I am betting it will take a lot of looking before you find one w/o at least a front bar. Also consider that manufacturers don't put anything on a car that they can skip because $5 per car is millions of lost profit at the end of a year. So if they stuck a bar on it, they felt it was worth it.

[Tooth]

To ad to JRs thoughts that bars can allow a softer ride look under any current street car. I am betting it will take a lot of looking before you find one w/o at least a front bar. Also consider that manufacturers don't put anything on a car that they can skip because $5 per car is millions of lost profit at the end of a year. So if they stuck a bar on it, they felt it was worth it.

That's definitely why I'm confused on this one.

[rich grsc]

That's definitely why I'm confused on this one.
There is no cut and dry answer. It almost always different for every car, driving it will tell you what you need.

[Jim1855]

I'm planning on bars but not sure which ones. Most likely build my own with allowances for a lot of adjustability. Each end has it's own challenges, big surprise there.
Jim

[J R Jones]

rich is correct. Evaluating handling is not easy. Sensing the differences is tough, and after investing time and labor, objectivity is tough.
The scientific method (A-B-A) and instrumentation is ideal, but requires investment and skills. (Maybe CraigS could go into the business of measuring and setting-up cars Per-diem VA to CA is brutal)

Assessing ride quality? Maybe your wife can help.
Assessing performance? Data Acquisition. a closed course and a stopwatch.

More realistic would be to have the mounts and bar(s) and an autocross event. After familiarization run back to back with the ARB link connected and disconnected.
jim

[GTBradley]

Why not bars? Weight. Trying to bring my car in as close to 2,000lb complete as possible.
I had weight/performance vs comfort on my mind throughout my build. You can't have it all and in my case I wanted as much comfort for longer drives while still keeping as much performance for autocross as possible. Throughout the build I asked myself, do I really need this and is there a lighter way of doing it? Lightness is part of the reason I bought the Coyote as the power to weight ratio is excellent, but I also splurged on things like cockpit sound/heat mat, heater, foot box blowers, windscreen washer, etc. I felt happy that my roadster came out at 2272 pounds. Point being, you will need to forgo all extras and some comfort to get to 2000 pounds.

I'll add too that it rides very well and autocross performance seems very good without anti-sway bars. Next season I plan to try the front bar and possibly the sticky tires.

[GTBradley]

To ad to JRs thoughts that bars can allow a softer ride look under any current street car. I am betting it will take a lot of looking before you find one w/o at least a front bar. Also consider that manufacturers don't put anything on a car that they can skip because $5 per car is millions of lost profit at the end of a year. So if they stuck a bar on it, they felt it was worth it.
If I'm correct in saying the anti-sway/anti-roll bars are to help with the weight of the body transitioning from side to side, then I would assume that car manufactures are just being realistic about how chunky and high profile there vehicles have become.

[Hoooper]

You wont find very many production performance cars made in the last 30 years or more that dont have a front sway control at a minimum, and 99% have rear control as well. I dont think that necessarily means you "need" sway bars though, there is more to your choice than just the best performance or ride quality

[Hoooper]

If I'm correct in saying the anti-sway/anti-roll bars are to help with the weight of the body transitioning from side to side, then I would assume that car manufactures are just being realistic about how chunky and high profile there vehicles have become.

Sway bars have been standard on performance cars since before cars started getting really big. Even the 2100lb miata in 1990 had front and rear sway bars.

[J R Jones]

I had weight vs performance vs comfort on my mind throughout my build. You can't have it all and in my case I wanted as much comfort for longer drives while still keeping as much performance for autocross as possible. Throughout the build I asked myself, do I really need this and is there a lighter way of doing it? Lightness is part of the reason I bought the Coyote as the power to weight ratio is excellent, but I also splurged on things like cockpit sound/heat mat, heater, foot box blowers, windscreen washer, etc. I felt happy that my roadster came out at 2272 pounds. Point being, you will need to forgo all extras and some comfort to get to 2000 pounds.

I'll add too that it rides very well and autocross performance seems very good without anti-sway bars. Next season I plan to try the front bar and possibly the sticky tires.

GTBrad, mikeinatlanta,
The Corvette and Lexus sport sedan chassis I have worked with have hollow ARB, and the weight difference is significant.
All the load is controlled by the material close to OD.
BTW how much do non-functional quick jacks weigh?
jim

[GTBradley]

Sway bars have been standard on performance cars since before cars started getting really big. Even the 2100lb miata in 1990 had front and rear sway bars.
Agreed, but I'm speaking of the majority of cars on the road - SUVs and Trucks. But even sports cars have gotten much heavier over the years. The Mustang GT 500 is almost 4300 pounds! In addition, I can't imagine a buyer of a brand new sports car these days would be okay with the manufacturer cheating them out of sway bars, even if they don't know what they do. I really don't know whether the FFR roadster needs them or not, but there seems to be a divide on this, some automatically put front and rear bars on their roadsters, others none at all.

It would be interesting to see a comparison of track times for that Miata with and without those bars.

[Hoooper]

Agreed, but I'm speaking of the majority of cars on the road - SUVs and Trucks. But even sports cars have gotten much heavier over the years. The Mustang GT 500 is almost 4300 pounds! In addition, I can't imagine a buyer of a brand new sports car these days would be okay with the manufacturer cheating them out of sway bars, even if the don't know what they do. I really don't know whether the FFR roadster needs them or not, but there seems to be a divide on this, some automatically put front and rear bars on their roadsters, others none at all.

It would be interesting to see a comparison of track times for that Miata with and without those bars.

I dont know that I would call the GT500 a sports car but yeah it and nearly all other cars have gotten heavier. Trucks and SUVs certainly drive WAY better with sway control due to their high COG, replicating that kind of control with spring rates would result in a covered wagon ride quality so sway bars are definitely needed. Lower COG cars can use other tricks to get away without them but still they are used. I will say, even in formula 1 where the cars are the lightest and stiffest they have sway bars, they just do things for you on track and on the road that cant be replicated with spring and shock adjustment. Again, that doesnt mean they are "needed" on an FFR, its all about understanding the options. If you drive a lot on rough roads or roads with bumps on one side and not the other a sway bar may not be the right choice.

[J R Jones]

GTBradley, Hooper, TedG, Anti roll bars are not trunk mounted script like automakers are fond of, at least the Marketing department is, engineering and styling, not so much. They are function based hardware intended to have ROI.

The Miata would make for an interesting ARB survey as Mazda spends more on SCCA racing that any other manufacturer and the field of "Spec Miata" can be 60 or more cars.

Some companies do not have ARB. Saabs did not, but they had Lotus develop a (prototype) active AR system that was amazing.
Citroen has Hydropneumatic suspension with no ARB. Recently the Citroen Activa version of the Xantia has roll-free suspension, with the Citroen’s hydrolastic anti-roll bars causing the car to remain totally neutral and flat through bends, meaning every corner can be taken flat-out, with the emphasis on flat, and the rubber on all four tyres giving optimum contact with the road surface. Somewhat more expensive than an ARB.
The GM/Delco magnetic particle computer controlled suspension had (some) anti roll control.

If an ARB is a band aid on a car, it is a tourniquet on a SUV or truck. Same hardware.

Side notes, the often disparaged leaf spring system on a live axle has a natural 10% anti roll characteristic.
Racing in the rain benefits from weight transfer and ARBs are disconnected. Go figure.
jim

[mikeinatlanta]

GTBrad, mikeinatlanta,
The Corvette and Lexus sport sedan chassis I have worked with have hollow ARB, and the weight difference is significant.
All the load is controlled by the material close to OD.
BTW how much do non-functional quick jacks weigh?
jim

Don't know, but they made for some fine paper towel roll holders. I do know that they weigh significantly more than my custom built, hollow, 20ga bumpers and aluminum bolts.

I'm not knocking bars. They are perfect for quickly changing setup, keeping your sports car marshmellow soft, and for those who can't get their springs right to start with. :)

[mikeinatlanta]

Agreed, but I'm speaking of the majority of cars on the road - SUVs and Trucks. But even sports cars have gotten much heavier over the years. The Mustang GT 500 is almost 4300 pounds! In addition, I can't imagine a buyer of a brand new sports car these days would be okay with the manufacturer cheating them out of sway bars, even if the don't know what they do. I really don't know whether the FFR roadster needs them or not, but there seems to be a divide on this, some automatically put front and rear bars on their roadsters, others none at all.

It would be interesting to see a comparison of track times for that Miata with and without those bars.

Bars being needed (or better) is a subject hotly debated by true experts, so us debating here with less knowledge than the experts is kind of silly. That debate aside, the undisputable fact is that bars are a far easier and more convenient means to an end and will always be very popular on both street and track. Even with my high roll center and 750lb springs I kept provision for a bar during the build.

[Hoooper]

I'm not knocking bars. They are perfect for quickly changing setup, keeping your sports car marshmellow soft, and for those who can't get their springs right to start with. :)

Imagine a racing series having combined budgets of around $3-4 billion per year and being told that you all run sway bars because you can get your springs right haha ;)

[RoadRacer]

I love how we can have these religious debates here without anyone getting all snippy or butthurt :D

Even though everyone should have sway bars. <drops mic>

[NAZ]

Anti-Roll Bar (ARB) or no ARB – choose wisely. And don’t get too wrapped around the axle on if you “need” an ARB or not – there is no one answer that works for every application. Testing and systematic experimentation will reveal what works best.


The primary role of a race car suspension is to control weight transfer and maximize traction by maintaining tire contact over an irregular racing surface. The suspension is a complex interrelated system that each aspect of must work in concert to maximize performance. Making one adjustment here can affect one or more other areas there. Most handling issues can be influenced by more than one adjustment and each adjustment is a compromise of delicate balances.


Adding components like ARBs can increase the adjustability options for tuning a suspension system but at the same time adds another layer of complexity. I suspect most street performance car enthusiasts will simply purchase an ARB “kit” that may or may not be adjustable. After all, how do you select the correct rate bar for the application when dealing with a home-built car?

FFR doesn’t provide builders with a design that has near as much adjustment as a purpose-built race car but there is still enough that you could unintentionally adjust in some pretty undesirable handling characteristics. And adding another component like an ARB will provide an opportunity to make more mistakes if the bar rate is all wrong for your particular application. And how can an ARB kit builder know exactly what your car needs? OEMs spend a lot of engineering and testing hours developing their suspension systems. As car builders, we are on our own and how well our car handles is usually based on our knowledge of the system.


If you like to tinker and experiment, and do your homework – adding an ARB can be rewarding whether it’s an improvement or not. Everything you learn while doing is rewarding. But plan to do a lot of testing and be open to changing other aspects of your suspension so your system components all complement each other. Don’t just bolt one on and call it a day.



Have fun with your build. Don’t be afraid to experiment but do your research.

[sread]

Since this thread seems to have run its course - maybe even jumped the tracks, I don't feel too bad about going off topic a bit more. A question for Mr Jones: You seem to have quite a pedigree dealing with many aspects of car design, racing and development of numerous types of sports cars stretching back quite a few years - are you related to the famous Jones racing family? Curious minds want to know.

[mikeinatlanta]

Imagine a racing series having combined budgets of around $3-4 billion per year and being told that you all run sway bars because you can get your springs right haha ;)

If they can't pick the right driver then something as complex as springs is next level difficult.

[J R Jones]

Since this thread seems to have run its course - maybe even jumped the tracks, I don't feel too bad about going off topic a bit more. A question for Mr Jones: You seem to have quite a pedigree dealing with many aspects of car design, racing and development of numerous types of sports cars stretching back quite a few years - are you related to the famous Jones racing family? Curious minds want to know.

sread, Thank you, that is entertaining speculation but no, there is no racing heritage in my ancestry.
In later years we raced a GT40 MKIV in vintage that attracted groupies that suggested I looked like Geo W. Bush. I grew a beard and wondered if Laura would see me that way.

Parnelli is an accomplished driver but not my favorite. I enjoyed seeing him matched against my heros, Mark Donohue and Dan Gurney in Trans Am. Jones had a brutal style that consumed equipment.
Donohue, Gurney, Jim Hall, Niki Lauda, Fangio, Ken Miles, Schumacher (to some extent) had engineering backgrounds and an ability to read the machine and the tires. That leads to control without consumption that looked like, and was, smooth. The guy I currently see in that way is Repsol Honda's Marc Marquez in Moto GP.

Also later in life we raced a 1954 Corvette (Blue Flame Six) in La Carrera Pan America, a seven day race/rally across Mexico. Certainly a race requiring conservation of assets. We were 3rd day one and 1st for three days when the "hard charger" lost the rear end crossing the paint stripe on a downhill going into a hairpin. The guardrail ended our race.
jim

155674

155675

[J R Jones]

GTBradley, Hooper, TedG, Anti roll bars are not trunk mounted script like automakers are fond of, at least the Marketing department is, engineering and styling, not so much. They are function based hardware intended to have ROI.

The Miata would make for an interesting ARB survey as Mazda spends more on SCCA racing that any other manufacturer and the field of "Spec Miata" can be 60 or more cars.

Some companies do not have ARB. Saabs did not, but they had Lotus develop a (prototype) active AR system that was amazing.
Citroen has Hydropneumatic suspension with no ARB. Recently the Citroen Activa version of the Xantia has roll-free suspension, with the Citroen’s hydrolastic anti-roll bars causing the car to remain totally neutral and flat through bends, meaning every corner can be taken flat-out, with the emphasis on flat, and the rubber on all four tyres giving optimum contact with the road surface. Somewhat more expensive than an ARB.
The GM/Delco magnetic particle computer controlled suspension had (some) anti roll control.

If an ARB is a band aid on a car, it is a tourniquet on a SUV or truck. Same hardware.

Side notes, the often disparaged leaf spring system on a live axle has a natural 10% anti roll characteristic.
Racing in the rain benefits from weight transfer and ARBs are disconnected. Go figure.
jim

How much roll os too much roll? Try running the Moose Test:

Why New Cars Keep FAILING the Moose Test

https://www.youtube.com/watch?v=qIN8CyhYREM

Note the winner with active suspension.
jim

https://www.youtube.com/watch?v=qIN8CyhYREM

[RoadRacer]

Makes me want to autox a Citroen Xantia!