Springs VS Sway Bars for Handling Gains?
11-11-2009, 03:08 PM
#1
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Springs VS Sway Bars for Handling Gains?
Assume an S197 Mustang, GT or Pony Package, and the desire to improve autocross performance. Vogtland springs (1.3/1.3 drop) caused too much drop for worry-free street driving (scraping issues) although did improve the handling in autocross events. Hmmm.......
Since most springs out there are "lowering springs", and most drop the car at least 1" in the front, my question would be to objectively compare any gains from a good set of adjustable sway bars (yes, like Sam's latest
) to gains from a typical set of aftermarket springs.
*I* found that the drop from the springs added to the drop from 255/40/17 Dunlops simply made the car too low for the street, yet still am looking for cornering gains.
Comments, experiences and opinions please.... thanks!
Since most springs out there are "lowering springs", and most drop the car at least 1" in the front, my question would be to objectively compare any gains from a good set of adjustable sway bars (yes, like Sam's latest
) to gains from a typical set of aftermarket springs.*I* found that the drop from the springs added to the drop from 255/40/17 Dunlops simply made the car too low for the street, yet still am looking for cornering gains.
Comments, experiences and opinions please.... thanks!
11-11-2009, 03:56 PM
#2
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Swaybars are in fact springs too. They are torsion bars and so they do everything in terms of body roll that springs do (and more).
In fact I don't think I have them anymore, but I used to have pics of two F-bodies in the same corner, on the same line, on the same tires (even the size and wheels were the same). One car I setup with 500 (at the time) pound springs and a 1-3/8" front bar, the other car had 1000 pound springs and a 1-1/4" front bar---they looked identical (FWIW, they even ran similar times with their respective drivers). 3mm worth of bar was worth--on that car, the same roll stiffness gain as doubling, in this case an extra 500 pounds, the spring rate.
Adjustable bars allow you to fine tune the balance of the car, springs can't do that. I've always been one to run relatively softer springs and a good big of front bar on most RWD cars.
In fact I don't think I have them anymore, but I used to have pics of two F-bodies in the same corner, on the same line, on the same tires (even the size and wheels were the same). One car I setup with 500 (at the time) pound springs and a 1-3/8" front bar, the other car had 1000 pound springs and a 1-1/4" front bar---they looked identical (FWIW, they even ran similar times with their respective drivers). 3mm worth of bar was worth--on that car, the same roll stiffness gain as doubling, in this case an extra 500 pounds, the spring rate.
Adjustable bars allow you to fine tune the balance of the car, springs can't do that. I've always been one to run relatively softer springs and a good big of front bar on most RWD cars.
11-19-2009, 01:18 PM
#3
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How does changing the front bar to a larger one (and leaving the rear stock) compare to changine the rear bar to a larger one (and leaving the front stock) in terms of handling/balance. I've read some conflicting info on this.
11-19-2009, 01:39 PM
#4
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I would never put a bigger front bar on an S197 GT and leave the rear one stock. It's already setup in such a way that a stock bar setup causes the inside front tire to come off the ground. The rear roll stiffness needs to be increased relative to the front. Not saying more roll stiffness in the front is useless, but it can't overwhelm the rear which is what happens stock.
Were you maybe asking what if you change the front bar to a smaller one with a stock vs. a stock front and a bigger rear?
Were you maybe asking what if you change the front bar to a smaller one with a stock vs. a stock front and a bigger rear?
11-19-2009, 02:27 PM
#5
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I was just asking because a guy I met who ran F-stock with an S197 (and was a very accomplished driver who went to national competitions) upgraded the front bar while leaving the rear stock. He said it really reduced understeer, which had me confused. The only other mod was D-spec shocks/struts.
This is a message I received from him a couple years ago when I was considering buying his car.
The car has a few mods for competition in autocross "stock" class (value around $2000):
- Tokico D-Spec adjustable struts/shocks
- Steeda Front Sway Bar
- Ford Racing catback exhaust (made by Borla)
- Custom race alignment
- Scroth harness
The car has been a top contender at national level autocross events:
- 1st place F-Stock 2006 SCCA Milwaukee National Tour
- 2nd place F-Stock 2006 SCCA US Nationals Topeka
- 2006 WSCC Club Autocross Champion
11-19-2009, 03:05 PM
#6
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Suffice to say, I don't agree with Noel, for there very reasons:
1. With a stock front bar the car would carry a front tire. When the inside front is off the ground, more roll stiffness doens't do anything to help you.
2. The cars are tight in stock form, even with -2 camber that's because they lack adequate wheel rate in the rear vs. the front. Adding more front bar doens't make that better, it makes it worse.
3. He had some good results to be sure. We never ran head to head, the only thing I can tell you is that @ Nationals that year I setup the car that won (Jason Burns' Mach 1), and having run an FS S197 that I setup (not a Shelby, the one I drove a few times in 2006) back to back against Jason's car, I know which one is faster--and it wasn't the Mach 1.
I don't know why he feels the way he does. But those are some of the reasons I feel as I do. And in fact I experiemented with a V-6 31.7mm bar made adjustable on my car in FS trim to get better balance. It worked on sweeper courses, made it not as good on slalom courses. Overall, not being a primary autox car I didn't like it on the street and just slapped my GT front bar back on. Note this is before the car was on the way to ESP as it is now.
In the end, I hate to be blunt... but he was running a better car than the rest of FS was (and so was @ at the Tour I dominated in an '05 in 2006, which is what got me on the S197 bandwagon). The results were good, but I've been running the cars a lot more in various trims, and feel that a big front bar added with a stock rear bar is a mistake on any car that has a normal type spring split. Put a car on big time stiff rear springs, and soft fronts, things would change--but there is no reason to do that.
1. With a stock front bar the car would carry a front tire. When the inside front is off the ground, more roll stiffness doens't do anything to help you.
2. The cars are tight in stock form, even with -2 camber that's because they lack adequate wheel rate in the rear vs. the front. Adding more front bar doens't make that better, it makes it worse.
3. He had some good results to be sure. We never ran head to head, the only thing I can tell you is that @ Nationals that year I setup the car that won (Jason Burns' Mach 1), and having run an FS S197 that I setup (not a Shelby, the one I drove a few times in 2006) back to back against Jason's car, I know which one is faster--and it wasn't the Mach 1.
I don't know why he feels the way he does. But those are some of the reasons I feel as I do. And in fact I experiemented with a V-6 31.7mm bar made adjustable on my car in FS trim to get better balance. It worked on sweeper courses, made it not as good on slalom courses. Overall, not being a primary autox car I didn't like it on the street and just slapped my GT front bar back on. Note this is before the car was on the way to ESP as it is now.
In the end, I hate to be blunt... but he was running a better car than the rest of FS was (and so was @ at the Tour I dominated in an '05 in 2006, which is what got me on the S197 bandwagon). The results were good, but I've been running the cars a lot more in various trims, and feel that a big front bar added with a stock rear bar is a mistake on any car that has a normal type spring split. Put a car on big time stiff rear springs, and soft fronts, things would change--but there is no reason to do that.
11-19-2009, 07:39 PM
#7
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More on Sway Bars and Springs
OK, I've had a Steeda adjustable 35mm front bar on my 2007 Pony Pkg for most of it's autox life. I'm putting back on the factory Pony Bar (34mm) this weekend to try out what Sam had shared with me before....that the stock bar would be faster. I did find, through his advice, that the Steeda bar on full soft was plenty, and faster than the stiffer settings on most courses. Looking forward to the experiment.....hoping it turns in better.
Sam, if you would, ponder this for me. On a lark I picked up a used set of GT 500 stock springs. The front springs have thicker wire diameter, and are about one full coil less than my Pony/GT setup. That translates to a much stiffer front spring.
My question......what can I put on the back (purchased from you, of course) to get those front springs to work, if anything? (NOTE: The GT500 rear springs measure the same exactly (!) as my Pony Pkg. rears, which are the same as the GT rears!).
I'm trying to find a way to stiffen the car without lowering it more than the 275/40/17 tires already do.
Thanks for your thoughts.........
Sam, if you would, ponder this for me. On a lark I picked up a used set of GT 500 stock springs. The front springs have thicker wire diameter, and are about one full coil less than my Pony/GT setup. That translates to a much stiffer front spring.
My question......what can I put on the back (purchased from you, of course) to get those front springs to work, if anything? (NOTE: The GT500 rear springs measure the same exactly (!) as my Pony Pkg. rears, which are the same as the GT rears!).
I'm trying to find a way to stiffen the car without lowering it more than the 275/40/17 tires already do.
Thanks for your thoughts.........
11-20-2009, 11:27 AM
#8
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An adjustable rear bar could be used to balance the car for the corners, but I wouldn't be surprised if you end up wanting slightly stiffer rear springs to minimize front:rear head-toss in normal driving. Good shocks can sort of cover this up without solving the root cause (mis-match of front vs rear ride frequencies). Until they wear out, that is.
Norm
11-20-2009, 12:11 PM
#9
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I don't think you're going to like the GT500's on your car, because it's going to sit a lot higher than it does now.... Look at a stock GT500, not exactly low, and you don't have that engine which means your car will sit higher....
What you need/want is more rear bar--like the Adjustable one I make (for this very reason). Any stiffer rear bar will add wheel rate, like springs do, but do it without a travel or ride penalty. Having an adjustable rear bar is giving you 3 bars in 1... Remember that I also use hollow tubing to minimize weight, and the bar is 100% bolt on (and works with Watts links too if you have or were ever to run one).
I know you have a front bar, but for those that don't: http://www.stranoparts.com/partdetai...D=80&ModelID=5
Rear bar (what you need): http://www.stranoparts.com/partdetai...D=80&ModelID=5
Or folks can do them as a set, and get a bit of a discount: http://www.stranoparts.com/partdetai...D=80&ModelID=5
Rear bar:
They are due for delivery today or Monday.
What you need/want is more rear bar--like the Adjustable one I make (for this very reason). Any stiffer rear bar will add wheel rate, like springs do, but do it without a travel or ride penalty. Having an adjustable rear bar is giving you 3 bars in 1... Remember that I also use hollow tubing to minimize weight, and the bar is 100% bolt on (and works with Watts links too if you have or were ever to run one).
I know you have a front bar, but for those that don't: http://www.stranoparts.com/partdetai...D=80&ModelID=5
Rear bar (what you need): http://www.stranoparts.com/partdetai...D=80&ModelID=5
Or folks can do them as a set, and get a bit of a discount: http://www.stranoparts.com/partdetai...D=80&ModelID=5
Rear bar:
They are due for delivery today or Monday.
11-23-2009, 04:16 PM
#10
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Since we are on the topic of sway bars, I'm wondering if that is what I now need.
This past summer I added a whipple supercharger & in the process about 120 pounds to the front of the car. This is a difference I can definately feel. I went from a 53/47 balance to 55/45. The car wants to keep going straight more than ever; and the front end of the car feels like it rolls more relative to the rear. I stiffened the front struts a bit, but I also need to maintain reasonable ride quality (I drive on terrible roads).
I never planned to touch the sway bars, but I don't like how the car handles at the moment, it's starting to remind me of how my 94 Probe GT handles.
Is a rear bar the answer? Or maybe both?
Edit: My weight balance is probably worse than 55/45. I reduced the weight in the rear by chaning the stock axle back out and I don't keep the spare in the trunk.
This past summer I added a whipple supercharger & in the process about 120 pounds to the front of the car. This is a difference I can definately feel. I went from a 53/47 balance to 55/45. The car wants to keep going straight more than ever; and the front end of the car feels like it rolls more relative to the rear. I stiffened the front struts a bit, but I also need to maintain reasonable ride quality (I drive on terrible roads).
I never planned to touch the sway bars, but I don't like how the car handles at the moment, it's starting to remind me of how my 94 Probe GT handles.
Is a rear bar the answer? Or maybe both?
Edit: My weight balance is probably worse than 55/45. I reduced the weight in the rear by chaning the stock axle back out and I don't keep the spare in the trunk.
Last edited by Vapour Trails; 11-23-2009 at 04:22 PM.