Removal of Front M030 Anti Roll Bar
03-28-2019, 08:13 AM
#2
Rennlist Member
Seriously? If you don't understand what a sway/anti-roll bar does or how/why it works, you shouldn't be messing around with it. Put it back on and go lose three pounds if you're really worried that much about weight savings...
03-28-2019, 08:36 AM
#3
of course I know why a sway bar is... this comes from the CLR Guy at 911UK thread
03-28-2019, 08:50 AM
#4
https://en.wikipedia.org/wiki/Anti-roll_bar
My 1993 Mustang GT does not currently run a rear sway bar (solid axle). It rotates fine and its a common mod for guys running a similar suspension setup but thats a completely different car. I'm happy with how the Mustang rotates and handles as it sits and i've messed with different rear bars to come to this conclusion.
Unless youre in an off road application and need suspension articulation, I would not remove the front sway bar on any street car.
My 1993 Mustang GT does not currently run a rear sway bar (solid axle). It rotates fine and its a common mod for guys running a similar suspension setup but thats a completely different car. I'm happy with how the Mustang rotates and handles as it sits and i've messed with different rear bars to come to this conclusion.
Unless youre in an off road application and need suspension articulation, I would not remove the front sway bar on any street car.
03-28-2019, 08:54 AM
#5
Rennlist Member
Less front roll bar usually results in more oversteer on a 911. I guess if you wanted to drift everywhere it might be the thing to do but I would guess it would make unpredictable handling. Curious why you are asking?
03-28-2019, 10:24 AM
#7
Drifting
Entire books are written on the subject. I’m no expert, but I have lots of books on suspension tuning.
As I understand it (and of course, a true expert will come along and correct me) when the wheel on one side of the vehicle is compressed upward, the anti-roll bar pulls the wheel on the opposite side of the car upward too. Depending upon how stiff the bar is, it changes how direct the relationship is between the sides. The stiffer the roll bar, the more force is transmitted. It keeps that end if the vehicle “flat”, with less body roll.
If you take it out, you change the suspension dynamics - that end of the vehicle doesn’t have the wheels working together anymore, so you will probably have more body roll, and all of the complicated things that dynamic does to the rest of the vehicle’s handling (as mentioned above, oversteer is one good example).
Lots of people who race mess around with sway bars for suspension fine tuning. Smaller, larger, solid, hollow, etc. In my opinion, they have to be considered as a part of a complex system, not just by themselves.
You could potentially tune behavior out with other modifications (stiffer springs, for example), if you are knowledgable and motivated. I’m neither, so I stick with formulas that have proven to work on other 996 cars and leave the swaybars intact.
On the other hand, it depends on what you are trying to do... maybe removing it is exactly what you are looking for?
As someone else mentioned, for hardcore off-road some people detach or even remove the anti-sway bars. The independent motion and increased articulation is desirable in some terrain.
Side note: my land cruiser has sway bars that change (motor journalists and marketers call it detaching, but not really, it just decouples the sides temporarily) depending on settings.
As I understand it (and of course, a true expert will come along and correct me) when the wheel on one side of the vehicle is compressed upward, the anti-roll bar pulls the wheel on the opposite side of the car upward too. Depending upon how stiff the bar is, it changes how direct the relationship is between the sides. The stiffer the roll bar, the more force is transmitted. It keeps that end if the vehicle “flat”, with less body roll.
If you take it out, you change the suspension dynamics - that end of the vehicle doesn’t have the wheels working together anymore, so you will probably have more body roll, and all of the complicated things that dynamic does to the rest of the vehicle’s handling (as mentioned above, oversteer is one good example).
Lots of people who race mess around with sway bars for suspension fine tuning. Smaller, larger, solid, hollow, etc. In my opinion, they have to be considered as a part of a complex system, not just by themselves.
You could potentially tune behavior out with other modifications (stiffer springs, for example), if you are knowledgable and motivated. I’m neither, so I stick with formulas that have proven to work on other 996 cars and leave the swaybars intact.
On the other hand, it depends on what you are trying to do... maybe removing it is exactly what you are looking for?
As someone else mentioned, for hardcore off-road some people detach or even remove the anti-sway bars. The independent motion and increased articulation is desirable in some terrain.
Side note: my land cruiser has sway bars that change (motor journalists and marketers call it detaching, but not really, it just decouples the sides temporarily) depending on settings.
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03-28-2019, 12:00 PM
#8
Entire books are written on the subject. I’m no expert, but I have lots of books on suspension tuning.
As I understand it (and of course, a true expert will come along and correct me) when the wheel on one side of the vehicle is compressed upward, the anti-roll bar pulls the wheel on the opposite side of the car upward too. Depending upon how stiff the bar is, it changes how direct the relationship is between the sides. The stiffer the roll bar, the more force is transmitted. It keeps that end if the vehicle “flat”, with less body roll.
If you take it out, you change the suspension dynamics - that end of the vehicle doesn’t have the wheels working together anymore, so you will probably have more body roll, and all of the complicated things that dynamic does to the rest of the vehicle’s handling (as mentioned above, oversteer is one good example).
Lots of people who race mess around with sway bars for suspension fine tuning. Smaller, larger, solid, hollow, etc. In my opinion, they have to be considered as a part of a complex system, not just by themselves.
You could potentially tune behavior out with other modifications (stiffer springs, for example), if you are knowledgable and motivated. I’m neither, so I stick with formulas that have proven to work on other 996 cars and leave the swaybars intact.
On the other hand, it depends on what you are trying to do... maybe removing it is exactly what you are looking for?
As someone else mentioned, for hardcore off-road some people detach or even remove the anti-sway bars. The independent motion and increased articulation is desirable in some terrain.
Side note: my land cruiser has sway bars that change (motor journalists and marketers call it detaching, but not really, it just decouples the sides temporarily) depending on settings.
As I understand it (and of course, a true expert will come along and correct me) when the wheel on one side of the vehicle is compressed upward, the anti-roll bar pulls the wheel on the opposite side of the car upward too. Depending upon how stiff the bar is, it changes how direct the relationship is between the sides. The stiffer the roll bar, the more force is transmitted. It keeps that end if the vehicle “flat”, with less body roll.
If you take it out, you change the suspension dynamics - that end of the vehicle doesn’t have the wheels working together anymore, so you will probably have more body roll, and all of the complicated things that dynamic does to the rest of the vehicle’s handling (as mentioned above, oversteer is one good example).
Lots of people who race mess around with sway bars for suspension fine tuning. Smaller, larger, solid, hollow, etc. In my opinion, they have to be considered as a part of a complex system, not just by themselves.
You could potentially tune behavior out with other modifications (stiffer springs, for example), if you are knowledgable and motivated. I’m neither, so I stick with formulas that have proven to work on other 996 cars and leave the swaybars intact.
On the other hand, it depends on what you are trying to do... maybe removing it is exactly what you are looking for?
As someone else mentioned, for hardcore off-road some people detach or even remove the anti-sway bars. The independent motion and increased articulation is desirable in some terrain.
Side note: my land cruiser has sway bars that change (motor journalists and marketers call it detaching, but not really, it just decouples the sides temporarily) depending on settings.
03-28-2019, 03:07 PM
#9
Rennlist Member
I stand by my original reply - 1 less hamburger with fries a week and you'll be ahead of the game... 
03-28-2019, 10:46 PM
#10
2.8lbs, so about a gallon of fuel fuel less at the next fill for the weight savings, as for handling I'd say the effect would be negative. Forgot to reconnect the swaybars on the 4Runner once, it was like driving on 4 flat tires.
If your feeling brave and have access to a skidpad or something of the sorts it would make for an interesting experiment in a controlled environment.
If your feeling brave and have access to a skidpad or something of the sorts it would make for an interesting experiment in a controlled environment.
03-29-2019, 02:52 AM
#11
03-29-2019, 12:23 PM
#12
Instructor
If I remember correctly, the CLR guy removed the power steering system. Removing the front sway bar would make it easier for him to steer without the help of P/S.
03-29-2019, 12:29 PM
#13
That car also has WAY less weight, and relatively stiffer springs, so it doesn't need a swaybar to control body roll. On a street car, swaybars are essentially a way to keep the car flat in the corners while still having soft enough springs that the ride is comfortable over bumps. If you're willing to have an uncomfortable ride, they aren't as necessary.
10-07-2019, 09:05 AM
#14
AutoX
That car also has WAY less weight, and relatively stiffer springs, so it doesn't need a swaybar to control body roll. On a street car, swaybars are essentially a way to keep the car flat in the corners while still having soft enough springs that the ride is comfortable over bumps. If you're willing to have an uncomfortable ride, they aren't as necessary.
Changes include the following:
LCA's which effectively push the front hubs out 26mm
Modified (extended) Tie rods
Custom Top mounts
Custom Spring caps (to suit Ohlins)
Ohlins suspension
CLR castor arms
Besides these, the pinch bolts were customised (where the ARB droplink is connected to the hub) and the complete chassis geometry altered to suit. My reason for ARB removal was primarily to reduce the steering force needed to overcome the ARB torsional loads (PAS deleted). As pointed out by the two posts above, much lighter weight plus stiffer suspension were factors which enabled this path.
Last edited by CLR; 10-07-2019 at 10:29 AM.
10-07-2019, 09:55 PM
#15
Rennlist Member
CLR, you may have just saved someone's life!