Running no rear sway bar on track?

[Whiskey11]

With springs in the stock location I did. Big springs, but still in the stock location.

I'm not saying your statement doesn't have basis in fact. But using broad blanket statements like "With OEM type springs you can't reasonably get enough wheel rate to run without a rear bar" is rarely a good idea when talking about suspension. There are LOTS of ways to tackle a overall setup.

I tend to agree. High rear RC (disadvantages of it's own), high rear spring rate (275lbs/in or "SPINECRUSHING (TM)" ride) and stock 09 GT rear bar where the keys to my car's handling. The T2R completed the package by allowing the car to be freer off throttle and corner while powering down. Drove brilliantly if I do say so myself. I think if I would have gone to your level of rear spring rate I could have, and would have, pulled the rear bar entirely.

 

[Roadracer350]

I have H&R race springs and Konis on my car with no rear sway bar. With the rear bar removed and soft shock settings, the car does lean/roll pretty good but there is more grip on corner exit. I get little more push but I don't mind it. I've run my fastest times with this setup.

Hey I know that tripod!!!!

 

[Department Of Boost]

How big of springs?

I have H&R RSS coilovers with 630/515# springs on the car now, and I ran the optional 570/460# springs for about a year. Rear springs are in the stock location. I've tried the FRPP 22mm, OEM 20mm, OEM 18mm, and no rear bar. All with an FRPP front bar, middle hole.

No rear bar is a handling mess, as described above, with understeer and rotation issues. When the rear tires do break loose in a corner, it's less predictable and harder to manage. The 18mm rear bar is a bit less of the same, with the 460# rear springs, but I haven't tried the 18mm with the 515# springs yet. For the past several months I've switched between the 20mm 22mm rear bars (with both the 460's and 515's), and I'm still deciding between these two bars.

With the 20mm rear bar, my current wheel rate (in roll) comes close to, but short of, the wheel rate with 350# shock mounted rear springs and no rear bar. With the 22mm rear bar, I'm just short of the rate of the 350# shock mounted springs and an 18mm rear bar. Each of these bars have pros and cons in different situations, so I'll probably continue switching between them.

I get the "blanket statement" thing, and that with chassis/suspension, "everything depends on everything else," as said by Neal Roberts. While I'm by no means an expert or even close, I've spent literally hundreds of hours researching specifically the S197 chassis and read a few books on suspension in general. When I figured out the FR cars were running that Watson bar ($400 btw), an 18mm, or no rear bar, I ran out to the garage and took mine off. Unfortunately, this was before I'd discovered wheel rate, in my research.

All of this to say that I feel pretty comfy with the statement I made. There are a few known exceptions to what I said (e.g. MM springs and Kenny Brown PHB), but none were mentioned here. The op mentioned H&R Race springs which have nowhere near enough rate to run with no bar, and be fast. Maybe with a watts and a really low roll-center, but even then I'd bet you'll want at least a small rear bar.

I apologize if I came of as "corrective" or chastising. I have a pet peeve about absolutes, especially on forums. Not really for the people speaking in the. But the secondary effects of other people, lots of people reading that absolute and taking it as stone cold fact. And then repeating it as such. I see a ton of bad information that I know had its origin in an absolute that was taken incorrectly or wasn't thought through by the reader.

I have a bad habit of coming down on both feet.

You are clearly well versed in S197's. Certainly more than me. My professional suspension days were long ago. And your statement is probably correct far more often than it is incorrect. Especially when factoring in most peoples driving styles. Which tend toward "tidy" or a little tight.

My personal style is completely "unhooked". The majority of my track time has been racing superbike. If whatever I'm on/in isn't moving all over the place and "talking" to me I can't go fast. The no rear bar, lots of traction and WAY too much HP thing works for me.

I tend to agree. High rear RC (disadvantages of it's own), high rear spring rate (275lbs/in or "SPINECRUSHING (TM)" ride) and stock 09 GT rear bar where the keys to my car's handling. The T2R completed the package by allowing the car to be freer off throttle and corner while powering down. Drove brilliantly if I do say so myself. I think if I would have gone to your level of rear spring rate I could have, and would have, pulled the rear bar entirely.

I forgot about the T2R as a factor. I have one too. Love that thing! I drive TrackLock (sp) cars and in my head I'm always like "WTF is wrong with this thing?!?!" before I realize it's a TrackLock.

And I have a Watts link with a roll center I have no idea where. Maybe in the center of the earth, maybe on the moon.

Two big factors that really effect the overall setup. Whatever that setup is, it works. I'm not racing anyone with it. I just drive it and have fun. My days of sweating tenths are behind me. Kinda takes the fun out of it when it gets too competitive.

 

[DevGittinJr]

I've been taken wrong/ misunderstood on these forums plenty of times, so no judging here. I doubt I know more than you, or too many others for that matter. And I've learned a bunch from this site.

A blower is definitely one of the exceptions to what I was saying. Definitely would be a different suspension setup (actually front and rear) than the same car n/a. Although, I am interested in how well that works in slow corners, with no rear bar.

I've read on here that Whiskey11 was running a raised roll-center. IIRC the GC coilovers are shock mounted out back. But assuming there in the stock location, my question there is, aren't you adding body-roll while loosening up the rear? And when the rear does break loose, what's that like? One thing I like about the bigger rear bar is that while "loose," it seems more predictable.

 

[Department Of Boost]

I've been taken wrong/ misunderstood on these forums plenty of times, so no judging here. I doubt I know more than you, or too many others for that matter. And I've learned a bunch from this site.

That's the thing about suspension. There is never any limit to the learning. I know a lot about motorcycles, snomobiles, ATV's and specifically a lot about damper design/setup. My car knowledge is much more limited. Of course I can apply what I do know and come up with some pretty good stuff. But I would be far more effective if I had your specific S197 knowledge. Together we would be pretty dangerous.

A blower is definitely one of the exceptions to what I was saying. Definitely would be a different suspension setup (actually front and rear) than the same car n/a. Although, I am interested in how well that works in slow corners, with no rear bar.

Lots of extra weight with how I'm set up. A 3.4L Whipple, all of the associated hardware and about 100 cu ft of coolers certainly are a big factor. So is 650ft lb of tq at 4000rpm!

I've never run the car hard trough a AutoX speed course. I would guess the slowest I have run the car through a corner hard is 45-50mph. And I tend to not run my entry speeds as high as you would with something lighter and less power. That is in part because I get that style from motorcycles (slow in, fast out) and because the car works better like that. I wouldn't say it pushes going in, or at least not to the point where your turning the wheel and the car won't turn anymore. I wouldn't call it stuck like glue though, that's for sure. It's "not bad".

I've read on here that Whiskey11 was running a raised roll-center. IIRC the GC coilovers are shock mounted out back. But assuming there in the stock location, my question there is, aren't you adding body-roll while loosening up the rear? And when the rear does break loose, what's that like? One thing I like about the bigger rear bar is that while "loose," it seems more predictable.

It really doesn't roll that much. I don't spend much time in real race cars though.

As far as breaking loose that is pretty much all the time. It's never really hooked up. It's a lot like a superbike. Touch the throttle, get the tire/tires "turning" (not spinning) and just ride the slide. So it doesn't unhook and all of a sudden release all of that energy. It's never really hooked up in the first place.

IDK if this analogy will mean much to most people. But a 300-400hp car with good tires/traction is like riding a 600cc sportbike. It will break loose sometimes and toss you around. My stupid/useless 2007 is like a superbike. You're always sliding a little.

As odd as this sounds I can't ride 600's for shit, they scare the crap out of me. I'm much better on a superbike (1000). At least with the superbike you know it's trying to kill you all the time.

 

[Whiskey11]

I've been taken wrong/ misunderstood on these forums plenty of times, so no judging here. I doubt I know more than you, or too many others for that matter. And I've learned a bunch from this site.

A blower is definitely one of the exceptions to what I was saying. Definitely would be a different suspension setup (actually front and rear) than the same car n/a. Although, I am interested in how well that works in slow corners, with no rear bar.

I've read on here that Whiskey11 was running a raised roll-center. IIRC the GC coilovers are shock mounted out back. But assuming there in the stock location, my question there is, aren't you adding body-roll while loosening up the rear? And when the rear does break loose, what's that like? One thing I like about the bigger rear bar is that while "loose," it seems more predictable.

The GC coilovers use the stock location for spring location. The higher rear roll center is closer to the center of gravity of the car = less body roll. This means less grip at that end and is basically like stiffening a swaybar without the negative of lifting the inside tire and overloading the outside tire.

The high RC does create some interesting turn in response with the Torsen. The rear of the car is so free the car almost, and I do mean ALMOST, oversteers going into a corner. It turns in very well. Power down isn't effected because of the suspension geometry on my car (Torque Arm + 65% antisquat) and the car actually tightens up some on the power (wants to push). Everyone I've had in my car since I made the big changes has been absolutely in love with the way the car handles and grips the course. The biggest complaint is lack of power followed by brake bite.

 

[Norm Peterson]

As far as breaking loose that is pretty much all the time. It's never really hooked up. It's a lot like a superbike. Touch the throttle, get the tire/tires "turning" (not spinning) and just ride the slide. So it doesn't unhook and all of a sudden release all of that energy. It's never really hooked up in the first place.

IDK if this analogy will mean much to most people. But a 300-400hp car with good tires/traction is like riding a 600cc sportbike. It will break loose sometimes and toss you around. My stupid/useless 2007 is like a superbike. You're always sliding a little.

Sounds like that beast of yours drives on the track in 3rd/4th up above 100 like its stockish cousin might feel like in an autocross in 2nd at 45-ish . . . almost never "stuck down".


Norm

 

[Department Of Boost]

Sounds like that beast of yours drives on the track in 3rd/4th up above 100 like its stockish cousin might feel like in an autocross in 2nd at 45-ish . . . almost never "stuck down".


Norm

Yeah, pretty much. It really is silly. It's fun to drive in short bursts. But it really wears you out mentally. I really would rather have a 3200# S197 with a stock Yote in it for bombing around the track. And with the price tanking on S197 stuff I may have one in my future. The 2007 will get parked and only come out for the occasional "cruise night", big smokey rolling burnout and a mile event here or there.

I'll never sell/part out the 2007. But it is pretty much useless.

 

[roadhouse]

Hey I know that tripod!!!!

Oh heeyyyyyy

 

[DevGittinJr]

That's the thing about suspension. There is never any limit to the learning.

I think it goes something like "a smart guy's always learning, but a dumbass knows everything."

IDK if this analogy will mean much to most people. But a 300-400hp car with good tires/traction is like riding a 600cc sportbike. It will break loose sometimes and toss you around. My stupid/useless 2007 is like a superbike. You're always sliding a little.

Great analogy. I'm not into motorcycles at all, but I rode road bikes ("10-speed" bicycles) with Ben Spies, back when he was racing AMA sport and super bike. Your explanation between the two isn't far off what he described.

The high RC does create some interesting turn in response with the Torsen. The rear of the car is so free the car almost, and I do mean ALMOST, oversteers going into a corner. It turns in very well. Power down isn't effected because of the suspension geometry on my car (Torque Arm + 65% antisquat) and the car actually tightens up some on the power (wants to push). Everyone I've had in my car since I made the big changes has been absolutely in love with the way the car handles and grips the course. The biggest complaint is lack of power followed by brake bite.

It sounds like your car handles a lot like mine does with the 22mm rear bar. With the Torsen (T2R), it rotates so quickly that on-throttle, it seems a bit "loose," on entry. But on exit, it seems to "tighten" up. I'm thinking this might work for autox, and probably the 20mm rear bar for track days. Learning to trail-brake may also call for less rear bar. I hadn't thought about it in a while, but the Torsen makes the car drive so much better. It applies power better in, pretty much, all situations, and it seems to almost propel the car around corners.

 

[SlowJim]

You enter corners on throttle?

 

[DevGittinJr]

You enter corners on throttle?

Not as a rule, but it's something I've been trying a lot lately. Mostly because I've been braking early while learning to heel-toe downshift. I don't think I prefer on-throttle entry at all (as opposed to late braking and/or, trail-braking), but I've read/am reading a lot about driving techniques and I've been trying out different things just to see what I'm able to notice about how the car responds.

 

[Whiskey11]

I think it goes something like "a smart guy's always learning, but a dumbass knows everything."



Great analogy. I'm not into motorcycles at all, but I rode road bikes ("10-speed" bicycles) with Ben Spies, back when he was racing AMA sport and super bike. Your explanation between the two isn't far off what he described.



It sounds like your car handles a lot like mine does with the 22mm rear bar. With the Torsen (T2R), it rotates so quickly that on-throttle, it seems a bit "loose," on entry. But on exit, it seems to "tighten" up. I'm thinking this might work for autox, and probably the 20mm rear bar for track days. Learning to trail-brake may also call for less rear bar. I hadn't thought about it in a while, but the Torsen makes the car drive so much better. It applies power better in, pretty much, all situations, and it seems to almost propel the car around corners.

My car was loose on entry (off throttle) due to the unloading of the Torsen differential. Basically it becomes open and allows free rotation of the axles at the speeds they need. When you apply power it starts to force the outer wheel to spin faster. This combination was extremely important in autocross as the car could put power down earlier and earlier and earlier in a corner without ever really effecting the balance too much. It was to the point that once the car was basically starting to turn to the apex you could get on power and carry the rotation from the T2R powering the outside wheel to well onto the next straight. The ability to put power down while also turning was a substantial advantage and being looser at entry meant the car turned in great too.

 

[Department Of Boost]

Great analogy. I'm not into motorcycles at all, but I rode road bikes ("10-speed" bicycles) with Ben Spies, back when he was racing AMA sport and super bike. Your explanation between the two isn't far off what he described.

Ben is the mother F'n man. I've had the pleasure of going bar to bar with him (the little bit I could keep up). Wow, that kid has some major talent, focus and aggression. Too bad Yamaha GP treated him as a second class citizen. Otherwise he would he could have been a MotoGP champ.

My all time favorite pic of him. Sliding that sucker waaaayyyyy sideways into the corner. And that is a FAST corner!!

 

[Vorshlag-Fair]

I don't know how you'd get an S197 setup to where it could handle "better" with no rear swaybar, unless it was really screwed up to begin with....

Swaybars or anti-roll bars are very useful things, and removing them completely is usually a desperation move to fix other issues. Most racers I've seen running without a swaybar are usually REALLY BAD at chassis setup.

Even Formula1 cars use anti-roll bars (the "T" bar above) at both ends, and they have a 3rd one called a "FRIC", or "Front to Rear Interlink" (read more here). Where an anti-roll bar limits "roll" side-to-side, the FRIC system limits dive/heave front to back. F1 does not "make" the teams run anti-roll bar setups. They do it because IT IS FASTER. Do you think some Mustang internet expert has this stuff figured out better than these teams??

But hey, I'm willing to test anything. And yet when we have tested swaybar stiffness on our S197 car at more than one dedicated test day, and let the clocks decide, swybars always ended up being necessary for the fastest times. At the event above I had the Vorshlag crew adjust the bars and then I'd make laps on an easy-to-drive course. Come in, check the times, make more adjustments, drive more. After hours of this testing, the swaybars ended up at full stiff on BOTH the front and rear, which was the fastest setup. And we had 450F, 175R #/in coilover springs and monotube adjustables. We obviously needed more spring rate... (ended up at 800/350)

Most of the folks discussing swaybars for Mustangs on the internet are running around on craptastic lowering springs, bottoming out their OEM length struts, and have worn out tires that were no good to begin with. Their test conditions, data measurements, and setup is very probably "less than optimal". Take your advice.... carefully. Be skeptical!

What I'm saying is - don't take anyone's advice as "solid" that you don't know personally, that tests scientifically, and that is fast. Of course every spring/shock combo on a given chassis might take a unique swaybar stiffness to be ideal. But running "no rear bar" is almost always a bad idea. I've tested this on numerous chassis and usually end up with larger than stock, adjustable bars at both ends.

Swaybars are a big, dumb piece of steel. There's not a lot of "Technology" in the design, and I usually don't care about brand-to-brand differences. I'm not saying there is any perfect swaybar, but I do like the Whiteline stuff for their large range of adjustment plus the added inboard wheel room in the rear. Sure, its solid so it isn't as light as some bars out, but on a 3600 pound car like the S197, the miniscule weight differences in swaybars becomes pretty moot.

If you cannot afford to do a dedicated and timed test, with a course simple enough to take out the "Driving variable", then trust someone who has done this for nearly 3 decades. Get adjustable bars at both ends, bigger than stock. DON'T use a big swaybar as a crutch for lack of spring rate, though, just for tuning and roll control. Have someone take pictures of your car loaded up in corners and look at the relative lean you have. It should be under 3 degrees or so, otherwise you are putting too much load on the outside tires and giving up mechanical grip.

Good luck, and stay skeptical!

 

[Department Of Boost]

I don't know how you'd get an S197 setup to where it could handle "better" with no rear swaybar, unless it was really screwed up to begin with....

Yet the Ford Racing guys would run no bar if the rules allowed.

 

[Vorshlag-Fair]

Yet the Ford Racing guys would run no bar if the rules allowed.

Well the suspension parts they put on the 302-S includes some of the low end junk from the Ford Racing catalog, too.

Don't confuse politics with good engineering.

 

[Department Of Boost]

Don't confuse politics with good engineering.

Can you explain the political advantage to wanting to run no rear swaybar?

 

[csamsh]

Can you explain the political advantage to wanting to run no rear swaybar?

Not what he meant......

Perhaps explore the possibility that the boss 302S/R does not have the best parts, isn't optimized, and is being run a certain way because the rules dictate it and because Ford Racing is politically connected to one entity or another?

When looking at a racecar for design/setup input, always keep in mind that many things may be the way they are because they have to do that for the rules. Perfect example- DTM aero. Looks awesome? Yes. Is there a better way to do it that the rules prohibit? Probably.

 

[2013DIBGT]