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What does removing front swaybar do on this setup?

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What does removing front swaybar do on this setup?

Old 02-24-15, 09:51 PM
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What does removing front swaybar do on this setup?

FC chassis
Parts shop max extended track control arms
Roll center adjusted drop knuckles
Bearings
Stock rear bar
Racing beat front bar
17x9 wheels on r compounds
700 front 450 rear springs
Torsen differential
240whp 195tq
Triple adjustable shocks

Looking to eliminate understeer and dive corners at full tilt, carry speed, and increase mid corner handling.
I did the control arms and knuckles and saw two videos of pbm testing, one with sway and one without. I liked how the pbm without handles more, as I'd like the car to be fun driving. I have not driven the car since the arms and knuckles and swaybar removal. I'd like it to get lots of angle like a low power, slow motion drift that biases with the torsen, grip style instead of smoking the tires.

I took the front bar off as it is very heavy and I believe it induces understeer.
No swaybar
Swaybar but with 2jz motor. You can see the steering wheel is tighter and the car is taking inputs to the steering a little more firmly, but I swear the car seems to be doing a lot more averaging and isn't pulling off the same crazy transitions. Perhaps it drives more predictably and less like a bus, but it is translating to better small corrections and worse overall full board tilts.
guy talk about sway bars, particularly front sway on miata

I've ran No rear bar on many cars for years, but its kinda boring. Once that setup is dialed in, the stock rear bar makes the handling a little more spicy, and aftermarket rear bar goes straight into drifting oversteer. I'm hoping to reverse this process and limiting front roll with the shock tuning and springs, but allowing the front to actuate better to dive and bite to carry speed. Perhaps adding a stock front bar after its dialed in and a little boring.

Does anyone have experience in this? The front bar is heavy and I think the car may just handle better at fullt tilt if I tune the shocks and springs to do the job. I understand road feel and small inputs may be deminished. I'm looking for traction and maximum g forces.
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Old 02-25-15, 02:23 AM
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Removing the front sway bar and leaving the rear one on is going to create oversteer.
Generally from the factory, cars are set up to tend towards under steer. This is because it is consider easier to correct for by the average driver.

Of course, All the changes that have already been done to the car are going to alter that balance, but as far as the sway bars themselves, by putting a stiffer front bar on and leaving the stock rear one you are tending to make it have more under steer.

Now, I'm no drifter, but it would seem to me having no front bar and leaving a stock bar in back would be very loose and hard to drive, especially on entry to the turns. I can't imagine that you would be able to generate MORE Gs that way.
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Old 02-25-15, 11:12 AM
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Drop front spring rate in 100# increments until you are happy.
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Old 02-25-15, 12:30 PM
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stop watching videos and try it. in the 13 minutes that the fat cat guy takes to explain how he can sell you a sway bar for a car you don't own, you could have disconnected your bar and tried it.
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Old 02-25-15, 06:20 PM
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If my car ran. Maybe next month
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Old 02-25-15, 09:59 PM
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Note - Miata front suspension is dual A-arm. FC is McPherson struts. Different beast entirely.

Do a search. This has been covered ad nauseum. Short version - stiff front sway bar to avoid roll and associated camber loss under bump in McPherson strut suspensions. Since you have drop knuckles, your situation is slightly different than for a lowered stock setup.

Bottom line is that there are too many variables to allow for someone to "bench race" your setup. Especially someone on YouTube. Try it on the track and see what works for you.

Good luck,

-b
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Old 02-27-15, 11:36 PM
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most drifters remove the front sway bar for more steering angle...

I'm running no sway bars at all, but still tuning it, but so far so good.

Read Xhead's threads on it on MR2OC (multi-national autocross champion)
STS2 MK1 suspension setup w/host XHead - MR2 Owners Club Message Board
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Old 02-28-15, 10:27 AM
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I would not pull it off without trying it. I run similar spring rates to you with an RB front bar and my car needs the front bar. I have the stock front geometry though. I run no rear bar at all but I have 400 whp so understeer is not a problem. For you a stock rear bar is a good place to start, but I would not be surprised if you pull off the rear bar. This is turn 2 at Willow Springs... No understeer at all as you can see.


You'll need more front spring similar to eage8 if you want to run without the front bar. It's critical the car stays pretty flat during cornering to keep the tires planted. That will give you the most front grip and is why you gain more front grip when you stiffen the front end of Mac strut cars.
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Old 02-28-15, 11:53 AM
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If you remove the front swaybar, you're gonna swap ends. Drift guys usually either relocate the bar or put in a smaller one. Lose it and the car will be near impossible to control.

Get a larger rear one to take care of understeer. Either that or a more aggressive alignment.
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Old 02-28-15, 07:57 PM
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Science Behind sway bars is very simple .

And the science behind Using spring rates to replace sway bars is as well ..

Sway bars Control Lateral Roll ( SIDE TO SIDE ROLL ) ONLY . what does this mean . It means that when you brake You can have more weight transition forward . in order to get better braking grip

VS when you only run springs Because in order to have the same Latteral Roll resistance , The longitudual Weight transfer will also Suffer ( front to back )

Then braking in a straight line , Or accelerating . in a straight line puts no force onto the sway bar .

accelerating out of a corner or mid corner or trail braking you do put some strain on the sway bars . ( this is why some auto crossers remove the rear swaybar . more rear traction out of a corner . )

I tried this , Definitely rather have the rear sway bar .

Essentially that fat cat motorspots guy is an idiot . dont listen to him his explenation is half assed . I could of done a better job .

Your wheels are still independant ..

What a sway bar does is it borrows some of the spring / shock forces form the un loaded side and transfers it to the loaded side in order to increase roll resistance

Say you have 600 spring rates in the front , anda 50% sway bar . WHen you turn to the left ,

50% of the spring rate from the unloaded side ( being hte inside corner the left side of the car ) transfers to the outside ( loaded side where most of the load is and you essentially have a 900 spring rate .

but when you SMACK the brakes . The car returns to having 600 lbs . thats the basics
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Old 03-01-15, 09:51 AM
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Originally Posted by Tem120 View Post
Science Behind sway bars is very simple .
i agree, there are pretty much two things.

the science part is to look at the wheel rate as the car rolls. or take the spring rate and the bar rate together, this generates a curve. the ideal shape of the curve, or it straight line, is the important bit.

the second consideration is a structural one, some cars like the 1st gen Rx7 or the BMW E30 don't like rear bars because they interfere with suspension movement more than they help handling. or on an FC the front bar bends the chassis* so a HUGE bar might not work as well as a next size up from stock one. things like that.

*please see SAE paper 920244 "Development of lighter-weight, higher stiffness body for Rx7"
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Old 03-03-15, 08:42 PM
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Morning warmup sessions on the track. The very capable driver was on the track and kept spinning the car. The driver knew he could get control of the car, and he kept spinning in every turn. Crew was preparing to ask that he be black flagged to get him off the track before he wrecked the car.

Driver finally came in, complaining loudly...

Crew explained to the driver that the front sway bar link was missing on one side. We reconnected the front sway bar, and bought radios before the next race... Problem solved!
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Old 03-03-15, 08:46 PM
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Efinity, you didn't mention if you were racing or drifting this car. Setups are very different, along with driving style.
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Old 03-03-15, 09:22 PM
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Originally Posted by john mcnaughton View Post
Morning warmup sessions on the track. The very capable driver was on the track and kept spinning the car. The driver knew he could get control of the car, and he kept spinning in every turn. Crew was preparing to ask that he be black flagged to get him off the track before he wrecked the car.

Driver finally came in, complaining loudly...

Crew explained to the driver that the front sway bar link was missing on one side. We reconnected the front sway bar, and bought radios before the next race... Problem solved!
Of course he did, a finely tuned race car's setup got thrown out the window. If they added 50% more front spring it would have solved the issue too...

I'm really tired of people disconnecting the front sway bar without compensating with more spring and then complaining the car doesn't have enough front roll stiffness.... Of course it doesn't!
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Old 03-03-15, 09:25 PM
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Originally Posted by eage8 View Post
Of course he did, a finely tuned race car's setup got thrown out the window. If they added 50% more front spring it would have solved the issue too...

I'm really tired of people disconnecting the front sway bar without compensating with more spring and then complaining the car doesn't have enough front roll stiffness.... Of course it doesn't!
Word.
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Old 03-03-15, 09:40 PM
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Originally Posted by Chuck Baader View Post
Drop front spring rate in 100# increments until you are happy.
This

In our Trans am cars we have NEVER gone with spring rates as high as 700# and that is with a heavier car than an FC. Sounds like you need to take the car to a test day and work on your setup with a lap timer. do 5 laps and then a change. then another 5 laps etc
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Old 03-04-15, 06:41 PM
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"Crew explained to the driver that the front sway bar link was MISSING on one side."

Note: we did not intentionally disconnect the front bar and send the driver out uninformed! We don't like repairing the car after an accident.

This was the first use of radial tires on the track by the team and the driver. We had increased the camber and changed the springs to a slightly softer rate, prior to putting on the new radial tires. In the process of spring changing, the lower link is disconnected from the sway bar to allow the suspension to move enough to replace the spring. So unintentionally, we either did not tighten the lower link bolt enough or left it off. (The sway bar is connected by 2 heim joints on each side and secured with nyloc nuts.) You do not simply unplug a 1.250" front bar and not expect significant handling differences....

The driver was mistakenly under the impression he was coping with freaky radial tire handling. Didn't realize what was wrong, for a couple of exciting laps. Watching the car on track, the crew recognized the problem very quickly, but couldn't notify the driver without a radio. That's what led us to insure we were never again without radio contact to the driver.

Stuff happens, even to the good guys
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