Watch this video and give me swaybar advice please

[MFE]

See my sig for the overall setup and car.

Here's the history: I installed all the MM components you see in my sig, with the A-arms in the lower position on the K-member and with the stock 5.0swaybars. I ran 2.8-3.0 degrees neg camber on track. The result was a far-improved car, but the dominant behavior in steady-state cornering was understeer. The outside edges of the front tires were being punished even with the negative camber.

Next step: I moved the A-arms up to the higher position, raising the roll center and improving the camber curve. Result: Steady-state understeer was even worse.

Next step: I installed a 4-cylinder front swaybar, the smallest available for the platform. Result: Much better, but a lot of body roll and still a little more understeer than I'd like. Tires throughout this process ranged from Kumho MX to Bridgestone RE-01R's to Dunlop Direzzas to NT01 R-comps. All of them in 245/45-17 on 17x8 wheels.

Latest step: I installed an EVM rear swaybar, set as stiff as a stock Cobra bar in its current setting. This is stiffer than the stock 5.0 bar I had on the rear. Result: Much improved balance, in fact a tendency to oversteer in the sharpest, flattest corner of Heartland Park (entry to turn 14, leading back onto the straight). Tire shoulders show some wear but not punishment. Right front tire still shows signs of scrubbing, although I'm careful to manage slip so the tires squeal, not scream and howl.

That's the setup you see in the video, starting at 1:25. I held up my buddy Dan in his 93 viper for a lap early in the session specifically so I could capture this

http://videos.streetfire.net/video/H...ays_644178.htm

So, after all that is said...here's what I'm thinking. That's still a #### ton of body roll. It may in fact be worse off than trading theoretical lateral grip due to load transfer and flattening the car to keep the tires planted better. So do I put my stock 5.0 front bar back on, stiffening the front, and putting the rear bar at full stiff, which is something like 15% stiffer than it is now?

Thanks for reading.

[LT1HAHA]

What about stepping up the spring rates?

[MFE]

Not interested in doing that.

[tigerdrvr]

I think you've kind of answered your own question. You feel the front roll is more than you'd like, you have a stiffer bar sitting on the shelf and the rear is adjustable...easy enough to do some testing at your next track session

What is your front alignment, btw? I'm thinking the adjustment range of the EVM bar may not be enough in the back to keep you out of understeer with the 5.0 front bar...just based on the other information you gave.

[BULLITT1992]

Panama!!!!


BTW, I like how he put in the disclaimer, "Track Prepared Mustang" instead of just "Mustang."

If you are getting more roll than you want and you like the springs the way they are, it looks like you will have to play with the sways to get what you want. Since you already have the 5.0 bar, it won't cost you anything except a little of your time to install. I would try that first and see where it gets you. If nothing else it might give you something for comparison to help you narrow down what you need/want.

[2k2GT]

Subscribing. I feel the same way towards body roll/spring rate as MFE does.

Also, I know this isn't swaybar/problem related, but do you think the 245 wide tires are holding you back(for the weight the car is)? I realize that sticky tires would only amplify body roll, but was just curious on reasoning for 245's. Are 275's a problem on the Fox cars?

[MFE]

I'd absolutely be faster with more tire, but 275's would mean 9-inch wheels. 9-inch wheels means SN95-length axles or new studs in my current axles because there isn't enough stud in my current axles to support 1/2 inch spacers, and I'm just not in the mood yet.

[2k2GT]

Originally Posted by MFE

I'd absolutely be faster with more tire, but 275's would mean 9-inch wheels. 9-inch wheels means SN95-length axles or new studs in my current axles because there isn't enough stud in my current axles to support 1/2 inch spacers, and I'm just not in the mood yet.

Completely understandable, thanks!

[DaveW]

More bar, both ends.

DaveW

[xmustangloverx]

That Viper makes your car look like a little toy. I don't know whether it's that Foxes are tiny or that Vipers are freakishly large. You can definitely tell how much the rearend moved in that video though.

[2k2GT]

Originally Posted by DaveW

More bar, both ends.

DaveW

MM advises against this. I sold off a 32mm Steeda front bar because it was too stiff according them/people on here.

[DaveW]

Originally Posted by 2k2GT

MM advises against this. I sold off a 32mm Steeda front bar because it was too stiff according them/people on here.

Not at all being a smart ass, but if MFE wanted MM's book recommendations, he could have PM'd Jack.

My theory, which Jack may shoot all to hell, is that the rear is relatively softly sprung, and until the addition of the EVM rear bar, had very little rear bar (stock bars = the suck). With the TA and relatively low RC, it has been overpowering the front, creating false positives in the under-steer department.

If it were my car, I would try the bigger front bar, crank some more into the rear and see what it did. Also, if there is any adjustment on rear RCH, raising it a bit might make a big difference if there is still push. In my experience, a little bit of PHB adjustment goes a looooooooooooooooooong way.

My overarching thing here (besides being a big spring, big bar type of guy ) is that with a lot of body roll, the front camber is all gone and with it, grip. The MM K member is good, but not that good. Heck, if I plug 5 degrees of body roll into SuspensionAnalyzer for my new car, the camber sucks and that is with an SLA with 19" long control arms.

Just thinking out loud, not arguing.

DaveW

[Han Solo]

You guys take all the bind out of the ass end then you don't want it to roll and understeer.

[MFE]

Because now, when it slides, it's predictable and easy to recover. The curve of traction to no traction is very flat, compared to the uneven spike it was before.

[DaveW]

Originally Posted by MFE

Because now, when it slides, it's predictable and easy to recover. The curve of traction to no traction is very flat, compared to the uneven spike it was before.

Are you comparing the 4 link to the TA or small bar to big bar?

DaveW

[BULLITT1992]

I would definitely try what you have now and then tune from there if it isn't enough.

[2k2GT]

Originally Posted by DaveW

Are you comparing the 4 link to the TA or small bar to big bar?

DaveW

Not at all being a smartass, but i'm pretty sure he's comparing the 4 link to a TA. Otherwise he would've EMAILED Jack H. about the differences instead of making a thread about swaybars.

[tigerdrvr]

Needs more cowbell...definitely more cowbell...

[MFE]

Originally Posted by DaveW

Are you comparing the 4 link to the TA or small bar to big bar?

DaveW

What I have now to the 4-link. Yeah, it still slides, but it's so much more progressive. Less lateral acceleration and speed of the rear end when it gets loose, if you know what I mean. Less histrionics required to save it, and an infinitely improved probability of success.

Stock 5.0 bar is back on the front and the rear will be adjusted tomorrow. I have an event on the 14th, should be the same configuration so I'll actually be able to loosely compare times.

FWIW, the only video I have of this configuration dates back to 2007, at the last point I was on the old suspension before doing all the MM stuff. As it sat with the soft bar on the front, as of the event in the video, my good lap times were 5 seconds better, at 1:40, compared to 1:45 with the old suspension. When I get up to MAM I might be able to make a similar comparison.

[MFE]

What is your front alignment, btw? I'm thinking the adjustment range of the EVM bar may not be enough in the back to keep you out of understeer with the 5.0 front bar...just based on the other information you gave.[/QUOTE]

On the track I'm running 3.0 degrees neg camber, whatever minimal toe-out I get from putting it there compared to my 1.25 street setting, and IIRC about 7 degrees of positive caster. I have to look up my records from when I set it all up. I never change the caster. I run minimal toe-in on the street, around 0 to 1/32 toe-in. My toe gauge isn't any more precise than that. It doesn't toe out much with the camber change.

[Cellos88gt]

Is it possible to drastically reduce roll without messing with spring rates?

[tigerdrvr]

So, you should have enough static camber to still have a decent outside front footprint at full roll, but the tire wear says you are working the outside of the tires fairly hard. I would think more front bar would be indicated or more spring, as you also have thought.

When you say "steady state" understeer, I'm hearing you saying it doesn't push on turn in, but only after you pick up the throttle?

[MFE]

Originally Posted by tigerdrvr

So, you should have enough static camber to still have a decent outside front footprint at full roll, but the tire wear says you are working the outside of the tires fairly hard. I would think more front bar would be indicated or more spring, as you also have thought.

When you say "steady state" understeer, I'm hearing you saying it doesn't push on turn in, but only after you pick up the throttle?

Mostly when I'm neutral on the throttle, mid-corner. Which of course limits how soon I can get on the throttle without pushing wide. Corner entry is nice. Crisp and responsive but not overly twitchy.

The kind of corner I notice it on the most is at 2:07 - 2:13 on that video, or :25- :30 and 1:28-1:32 in this video, which is from my car starting where the other video leaves off. http://www.youtube.com/watch?v=_Gt9mqp_V4M That corner and the next left after it onto the main straight are really indicative of the kind of patience required to maintain front grip, while other cars are still typically gaining ground on me. I've tried different approaches and that's about as fast as I can make it in those places.

[tigerdrvr]

Have you experimented a bit with the shock settings? Is it possible that it is jacking down on the front ? Maybe a little less rebound on the fronts is worth trying.

Still, the 5.0 front bar sounds like a good thing to test, in any case, with the rear bar set to full stiff.

[2k2GT]

Originally Posted by d90212

why not have the boys @ corner-carvers critique it since their all suspension engineers...

[Marlin]

Originally Posted by MFE

I'd absolutely be faster with more tire, but 275's would mean 9-inch wheels. 9-inch wheels means SN95-length axles or new studs in my current axles because there isn't enough stud in my current axles to support 1/2 inch spacers, and I'm just not in the mood yet.

I saw you post about this the other day. I was under the impression you can run a 9" 275 in the back. I am running a 275/40/17 with a stock length axle. The fender lip was already rolled but it appears I could get away without doing that. I think I could get away with a 285 or 295. I used a 6.125 wheel so the quads had to go, which I am not happy about, but so far so good.

[MFE]

Originally Posted by tigerdrvr

Have you experimented a bit with the shock settings? Is it possible that it is jacking down on the front ? Maybe a little less rebound on the fronts is worth trying.

I haven't much, lately. I've settled on quite a stiff front rebound setting because that's what seems to give it the best overall behavior on track, but that may be an illusion.

[MFE]

OK, so the EVM bar can't be put on the full stiff position because it won't clear the TA that way Oh well. We'll see how it goes on the 2nd stiffest position.

[MFE]

Originally Posted by d90212

you make it sound like no companies have faults...yes i did say they have good customer service... but lets ask this a question...are you an engineer? because by gosh...im no engineer to know or see what would be fail or what wouldnt...yet everyone on CC is an engineer but me.
..I only used their part because no one had a kmember for a modular motor swap...back in what...9 years ago...and when something did happen...you know the rest...though if you were smart enough...you probably would be able to look @ their website and notice that their kmembers were made for 1/4 miles by just all the pics http://www.ajeracing.com/

then you get banned because shh...you mention griggs once had problems as well...

http://forums.mustangworks.com/f18/g...failure-15080/
and heres their customer service for ....oh my a bad weld .....but we'll take care of it with additional costs....NICE! who knows what would happen if it was a critical weld that went bad and you had no upper control arms in a exiting corner...you can send that to your widow as well...

since were so widow scared...dont DRIVE...because your already driving a ticking time bomb with gas...did i also mention your stock alternator wire for fox bodies is prone to catch fire! ROFL...oh yah...thats stock...what ford fool engineered that?! must of been a duma**

If you want to start a thread bitching about corner-carvers, have at it. If you #### up this thread or any other one with your mustangworld mentality one more time, it'll be the last time you have the opportunity here. Understood? Let's see it.

[tigerdrvr]

Originally Posted by MFE

OK, so the EVM bar can't be put on the full stiff position because it won't clear the TA that way Oh well. We'll see how it goes on the 2nd stiffest position.

Where are you on the rear shock setting? Sounds like you might have to take some of that rebound out of the front, go stiffer in the rear and maybe play with tire pressures, running the bigger front bar...but, you never know until you have a chance to run it and see what it does. Everything is a guess, at this point, you know?

[MFE]

I didn't have quite enough rebound dialed into the rear, as it was occasionally brake-hopping under really hard braking. Usually it only does that if I screw up my rev-matching.

[Toys]

My thoughts...

1) I think you're a little undersprung in the front compared to the rear beyond what you'll make up for with increasing bar size. I see you're running iron heads. The car looks as if it's twisting in the middle with everything falling on the front outside corner rather than rolling about the center of the car if you can picture what I'm trying to say. Are you adverse to 350lb, or better yet 375lb springs because you drive it daily or is that beyond what the Koni's will take? I was really surprised how well my car with 400lb springs rides on the street, but I don't drive it daily. I run a 1-1/8 bar with the 400lb springs which might be a good bar for you to have in your tuning stash.

2) Tires, although not going to fix your roll issues worth mentioning. You do enough track stuff I'm surprised you don't run an R-compound dedicated track tire. R58 17x9's fit nicely on the fox without axle changes. Especially if you select your tires carefully, 275/40/17 Kuhmo Ecsta V700's are about an inch narrower than say a Kuhmo V710. So likewise if you don't want to invest in new wheels find the widest tire in say a 255 series and maximize your contact patch.

[Goodson]

I'll ask this question. Aren't you theoretically increasing the spring rate by adding a bigger sway bar? Your car has a ton of body roll in that video. More than I would care to have.

I know it isn't an option but stiffer springs would be my next option if it were mine. I'm with Mike (Toys) on this one. 375's or 400's would be on the list with the 1 1/8" swaybar. I'm currently running 350# springs and the 1 1/8" swaybar. The ride quality is excellent on the street but is VERY soft for the track.

[MFE]

I do have R-comps, NT01's in 245/45-17's on stock SN95 GT 17x8 wheels, I just wasn't running them for this event. It was on the cool side and I was afraid it was going to be even cooler, so I didn't saddle them up. Meanwhile, I have a set of NT05's in 255/40-17 waiting for me at the tire store but they got here a day late and a dollar short, and I mounted my pair of RE-01R's I got on the Tire Rack blowout sale to keep as spares. Well...I needed them sooner than I thought I would, because I was getting close to cords on last year's Direzza's I had on the rear of the car and the NT05's hadn't shipped yet.

Anyway, I'm considering higher-rate springs for the future but I sure like the way they are on the street, and I do put 7000-8000 street miles on the car every year, in addition to 700-1000 track miles a year. And I don't trailer it, I drive it to events and home, every time so far

But wheel rate is wheel rate, right? What really would be the difference between running stiffer springs in the front, and the thicker swaybar?

[BULLITT1992]

Some of the pluses to getting your "wheel rate" with sways would be that it's only there when you need it (kinda) and you don't have to get "better" struts to handle the increase in rate. You have Koni DA's so you should have some overhead for springs I think.