Running no rear sway bar on track?

Folks,
in my 2000 GT, fully suspended by Maximum Motorsports, coil overs, etc., I ran no rear sway bar for years, the car handled fantastic.

A few weeks ago, at Sebring, in the 07, the rear was getting a little loose, broke free a couple times, nothing dramatic, but I'm looking for more rear grip.

Anyone lose the rear sway bar to soften up the rear a bit??

The car has MM Street/Track box.
Koni Yellows
H&R Race Springs
36mm (i believe) front sway bar
MM CC Plates
Adj PH bar, of course
Lower control arms
3.73's
I was running NT05's, since I'm getting to old and lazy to change tires at the track....

thats about it

Any other thoughts?

A friend suggested to turn the Konis to full soft, but, by that time, the day was about over.

TIA,

I've always thought the same thing, but I think it is just the nature of these cars. I would think no rear bar would just add more slop and make the problem worse though.

You would think, but thats not the case.
Sway bars are more for "fine tuning". With the right springs/shocks, you can run no rear sway bar. There are several threads on C-C about it. Just wondering anyones experience with the S197 chassis

I ran with no rear sway bar for about 6mo and liked it but there were a few occasions and drivng situations where I felt having a bar would have helped.

Long story short, my journey took me from a 24mm RSB, then no RSB, then to a 20mm RSB and then ending at an 18mm RSB from what I believe used to be a V6 convertible stang. This in combination with all others mods I already had was a good compromise.

My next move was going to be picking up the baby 302S RSB from Watson Racing if the 18 mm didn't work out but so far I'm happy with it. I am still very curious if the Watson unit would be better yet

The Ford Racing cars only have a rear bar because it is mandated by the rules. They tell me they would run no bar and do the tuning out back solely with springs.

The Ford Racing cars come with an little itty bitty bar that they had made up so they can meet the rules but have very little swaybar back there.

I run no swaybar on my 2007. I have a lot of spring out back though.

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.

Department Of Boost said:

The Ford Racing cars only have a rear bar because it is mandated by the rules. They tell me they would run no bar and do the tuning out back solely with springs.

The Ford Racing cars come with an little itty bitty bar that they had made up so they can meet the rules but have very little swaybar back there.

Click to expand...

Out of curiosity - is sta-bar bushing material unrestricted? Six foam rubber bushings . . .


Norm

Department Of Boost said:

The Ford Racing cars only have a rear bar because it is mandated by the rules. They tell me they would run no bar and do the tuning out back solely with springs.

The Ford Racing cars come with an little itty bitty bar that they had made up so they can meet the rules but have very little swaybar back there.

I run no swaybar on my 2007. I have a lot of spring out back though.

Click to expand...

I think that is ideal for a pure race car, but many of us daily drive our cars. The soft spring stiff bar setup is a compromise so that on date night we can adjust the bars back to full soft for near-stock comfort

Dept. of Boost, Roadhouse,
Thanks for the replys.

Roadhouse, I have the same shocks and springs. Will definitely run no rear bar my next time out.
Thanks.

Havent run a rear bar on my car for 3 years. Dont regret it at all. Tracked it last night and didnt miss it.

I don't know how y'all do this....I tried it once without a rear bar and the car was just push push push all over the place.

Setup is a very personal thing... I like a nice, loose car, where the tail will step out, one of my enduro co-drivers wants the car totally neutral, like it's on rails, and the other co-driver will drive anything we give him, but likes it a wee bit tighter than I do. I think driving style has a lot to do with it. My buddy Joe and I tend to run very similar lap times, but do it in completely different ways. He attacks the apex, sometimes braking all the way in, I float the car in and get on the gas earlier and harder. He wants rotational control on the brakes (in other words, tight, and he'll trail brake to rotate), and for my driving style, I want it loose, to get the rotational control with the gas pedal. We're within tenths of each other on any given day...

Mitch: When you say the car "got loose" on you, was it consistent, like at turn-in, or corner entry? Or was it a balance thing that you were feeling, down around apex? Or was it under throttle-up at exit? Or was it only in one specific section of track? Trying to reduce the variables here. If it was a gross handling issue, then yeah, the rear bar may be the answer. If it was just getting twitchy on you here and there, but it wasn't predictably so, you might want to go small, like tire pressures or damper settings.

Department Of Boost said:

The Ford Racing cars only have a rear bar because it is mandated by the rules. They tell me they would run no bar and do the tuning out back solely with springs.

The Ford Racing cars come with an little itty bitty bar that they had made up so they can meet the rules but have very little swaybar back there.

Click to expand...

Those cars have much higher rear wheel rates as the rear springs are on the shocks, instead of the axle. With OEM type springs you can't reasonably get enough wheel rate to run without a rear bar.

I really like these threads. (sway bar, spring rate, etc preferences)

FWIW, I am having more and more shops and racers call to order our front 38mm 5-Way bar. I always ask them about their combos, and the common scenario tends to be something along the lines of a massive front bar (now that we have one) and little to no (18mm) rear bar, with a pretty serious spring out back.

It is odd, because it tends to be all the West coast racers. Massive front bar and decent spring up front, small or no bar out back with a very stiff rear spring.

This is common with both the PHR and Watts set-ups.

We have been tracking one of our S197's alot lately on square 295 Hoosiers, and I am liking the combo on that car with the following.

Front Koni's: 40~%
Front Spring: 240lb/in (have used 260 and did not notice much difference)
Front Bar: 1000lb/in

Rear Koni's: 0-10~%
Rear Spring: 220lb/in (stock location)
Rear Bar: 260lb/in
Watts Link: RC Position set to 2" below axle CL



This is on a small tight track. Car makes about 550hp detuned and weighs in at 3720 in "race trim".

I have tested just about every combination on this thing, and the above is where I like it on a tight track on the 295's. We will be running the car at Sebring testing various set-ups too.

We have some BFG Rivals coming in soon, and I am also going to try and get some testing in on various UCA / LCA Angles (mounting points) with the Slicks and Rivals.

On that note, the majority of customers I speak with rarely ditch the rear bar with a stock location rear spring, and I would say the ones who (ditch rear bar with stock location rear springs) most commonly have Watts systems.

Glad you posted this Mitch, as I'm going through the same thing. Yanked my rear sway bar (20mm) off to attempt a little paint project with it that took longer than expected so I put the car back together with it off. At the time I had Steeda Pro-Actions, H&R Race springs, adjustable LCA's in middle hole of BMR bracket, 34mm front bar with poly bushings, and a BMR adjustable PHR.

Car had silly amounts of grip on sweeping freeway on/off ramps. Didn't notice much on medium sized corners (terrible description, I know. It's late). However on smaller and more technical corners, I felt the car pushed too much.

Fast forward a couple weeks and I put my Watts Link back on, still no rear sway bar. Car took the medium and tight corners much better, but felt that the long sweepers weren't as good. I had more control over the entire car, but the rear end grip just wasn't there in my opinion.

About a week after I tossed my rear sway back on and holy shit, perfect. Handles like it's on rails with much less body roll, yet the same feeling of massive grip out back from the Panhard/no rear sway setup on sweepers. Rotated perfectly through small corners and slightly understeers on mediums depending on road conditions but more the most part, it's near neutral.

I'm in love with this setup, crazy thing is it's on skinny 235 all seasons right now. Can't wait to try it out with the Rivals and R1's. I was not able to get any track time while swapping parts, but I have a track day next week and I'll report back with results, but I'll be ready to yank the rear sway off I'll be running the Rivals

I posted my impressions of running with no rear bar on another forum about a year ago.

"I searched around on here and didn't find any posts about first-hand experience running with no rear sway bar. I know KB and MM don't run rear bars on some of their setups but they are usually using a full system with coilovers and other fun stuff, so I wasn't sure how my basic setup would react to removing it. I had my car out at Hallett this past weekend and decided to pull the rear sway bar after driving Centri5.0's car (no rear sway, watts link) a few weeks prior. My car setup is H&R race springs, Koni adjustable shocks/struts, adjustable UCA, adjustable LCAs and relo brackets, MM adjustable PHB, -3 degrees of camber, square 305/645/18 Pirelli slicks, and stock GT front sway bar.

Overall I was very pleased with how the car performed with no rear bar. The car did have a tendency to push more than it did with the rear bar installed but the understeer could easily be combated with some throttle application. Once I got on the throttle (I could do so much earlier now) coming out of a corner the rear just stuck and pulled the car right through the corner with very little/no push. I was nervous that the car would understeer really bad once once I was on the throttle but that was absolutely not the case and I went faster than I've been at this track. This might not be the best setup for everyone but it worked for me and I thought I would share my experience in case others were considering doing the same thing. I know Mark (Centri5.0) and I will be leaving ours off for good."


"I just completed my second track day with no rear sway bar and I wanted to recap my experience to all of you.

Now that I was used to the characteristics of the car with no bar, I was really able to hammer down on the throttle on corner exit and have faith that it would stick. I'm amazed at how well this car can power out a corner. I was even starting to feel the car left up the front inside tire when coming out of certain corners, which was a wild feeling the first few times. It never upset the handling/balance of the car but it leans and you can feel it lift then drop again. "

Norm Peterson said:

Out of curiosity - is sta-bar bushing material unrestricted? Six foam rubber bushings . . .


Norm

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IDK, I never asked. They bushings don't look like foam.

Good thinkin though!!! That kind of thinking would take you far in the world of NASCAR where bending the rules is an art (which I completely appreciate).

SlowJim said:

I think that is ideal for a pure race car, but many of us daily drive our cars. The soft spring stiff bar setup is a compromise so that on date night we can adjust the bars back to full soft for near-stock comfort

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I hear this all the time. But I'll bet if you rode/drove my 07' you would think that it rides better than yours does.......with 375# rear springs.

DevGittinJr said:

Those cars have much higher rear wheel rates as the rear springs are on the shocks, instead of the axle. With OEM type springs you can't reasonably get enough wheel rate to run without a rear bar.

Click to expand...

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.

Department Of Boost said:

IDK, I never asked. They bushings don't look like foam.

Good thinkin though!!! That kind of thinking would take you far in the world of NASCAR where bending the rules is an art (which I completely appreciate).

Click to expand...

Could be instead of foam there are a few DIY'ed voids in the OE rubber that you might not see even if you were looking for them.


The matter of springs in the stock location is how it affects the amount of roll stiffness vs the amount of ride stiffness. It should be easier to get a good compromise between those without a rear sta-bar if the springs sit closer to the axle ends. It occurs to me that this may be behind Ford's choice of rear spring rates, being quite a bit higher than the front spring rates. Crutching the roll stiffness issue rather than resorting to bigger rear bars.


Norm

Norm Peterson said:

Could be instead of foam there are a few DIY'ed voids in the OE rubber that you might not see even if you were looking for them.

Click to expand...

Very true. They could effectively be hollow and just collapse.

The matter of springs in the stock location is how it affects the amount of roll stiffness vs the amount of ride stiffness. It should be easier to get a good compromise between those without a rear sta-bar if the springs sit closer to the axle ends. It occurs to me that this may be behind Ford's choice of rear spring rates, being quite a bit higher than the front spring rates. Crutching the roll stiffness issue rather than resorting to bigger rear bars.


Norm

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I'm sure you are right about the approach of outboard springs/roll stiffness/etc with how they are set up.

I myself am running a LOT more tire than the FR500/BOSS 302S/R and a LOT more power (more than double) so the car gets driven a lot differently. What I have works but I'm "backing up" most corners and not leaning on mid corner speed quite as much. I drive it like you ride a superbike. Something with way more power than traction/tire.

Department Of Boost said:

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.

Click to expand...

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 and motion ratio, 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.