Swaybars, 101?
04-28-08, 08:47 PM
#31
Lexus Test Driver
carchitect,
Your explanation is helpful. Thanks! It makes sense to me.
Just want to confirm one more time. Stiffening the chassis by this brace will actually improve the ride since it let the suspension work better?
Besides, how do you compare Eibach Pro-kit and F-sport springs? I just want to have better cornering and less body roll without sacrificing the ride quality and the ability to cope with less than desired road condition. I don't plan to drive aggressively and is either option (Eibach or F-sport springs) an overkill?
Also is the total setup (F-springs+F-suspension+F-sways+F-rear brace) an overkill for my situation?
Thanks
Your explanation is helpful. Thanks! It makes sense to me.
Just want to confirm one more time. Stiffening the chassis by this brace will actually improve the ride since it let the suspension work better?
Besides, how do you compare Eibach Pro-kit and F-sport springs? I just want to have better cornering and less body roll without sacrificing the ride quality and the ability to cope with less than desired road condition. I don't plan to drive aggressively and is either option (Eibach or F-sport springs) an overkill?
Also is the total setup (F-springs+F-suspension+F-sways+F-rear brace) an overkill for my situation?
Thanks
04-28-08, 09:09 PM
#32
Intermediate
IMO, the F-sport brace does a lot of benefit for the vehicle. Every unibody vehicle has frame sections that hold the chassis together and help reduce the flexing to some point. The rear frame section rises up from the floor to head rearwards right after the rear of the floor pan. The frame then makes its way all the way to the rear of the vehicle. The F-sport brace helps triangulate this area and strengthen the rear frame so the suspension can do the work. If you still think these braces don't help, look under the rear of an Acura NSX and then make your decision if its important or not.
Anytime the chassis of the vehicle is stiffened the suspension does the job better which results in a predictable and consistent driver's feedback and control. It can help reduce the chances of snap oversteer followed after understeer.
The F-sport sway are designed for the F-sport suspension. While they will work out great for the stock suspension they are designed for the f-sport suspension. Some of the guys may need stiffer stuff and if thats the case they should look into the Hotchkis sways. The Hotchkis sways have a larger front and maybe desirable to those of you who are running a set of coilovers designed for roadrace.
For the Supra I'm planning on running 900 lbs/in front springs and 700 lbs/in rear springs along with shocks which have valves tailored for it. Its the Japan Ohlins road race setup. Needless to say the OEM swaybars ot even the aftermarket swaybars won't do much for a car running this stiff. So I had a set of custom swaybars made from MVP motorsports that were 36mm front and 26mm rear.
I also feel my sport pack IS350 has a tendency to understeer. Funny thing is that since I've lowered the front, (to make it look even) the vehicle drives like it was except the understeer tendency has been significantly reduced. I really thought 1/2" drop won't be that much of a difference.
Anytime the chassis of the vehicle is stiffened the suspension does the job better which results in a predictable and consistent driver's feedback and control. It can help reduce the chances of snap oversteer followed after understeer.
The F-sport sway are designed for the F-sport suspension. While they will work out great for the stock suspension they are designed for the f-sport suspension. Some of the guys may need stiffer stuff and if thats the case they should look into the Hotchkis sways. The Hotchkis sways have a larger front and maybe desirable to those of you who are running a set of coilovers designed for roadrace.
For the Supra I'm planning on running 900 lbs/in front springs and 700 lbs/in rear springs along with shocks which have valves tailored for it. Its the Japan Ohlins road race setup. Needless to say the OEM swaybars ot even the aftermarket swaybars won't do much for a car running this stiff. So I had a set of custom swaybars made from MVP motorsports that were 36mm front and 26mm rear.
I also feel my sport pack IS350 has a tendency to understeer. Funny thing is that since I've lowered the front, (to make it look even) the vehicle drives like it was except the understeer tendency has been significantly reduced. I really thought 1/2" drop won't be that much of a difference.
04-28-08, 09:25 PM
#33
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Besides, how do you compare Eibach Pro-kit and F-sport springs? I just want to have better cornering and less body roll without sacrificing the ride quality and the ability to cope with less than desired road condition. I don't plan to drive aggressively and is either option (Eibach or F-sport springs) an overkill?
Not knowing what your goals are with the vehicle, it would be hard to determine what to recommend to you. I'd have to drive a vehicle with the F-sport stuff for a few days to determine the ride quality. This I seriously doubt will be something happening in the near future since I'm not switching my suspension out anytime soon. I would imagine that the combo you've selected should help rather than hurt the way your vehicle performs with little drawbacks. The largest drawback I can see would be ground clearance. If you're careful, you would have little to be worried about.
04-28-08, 09:30 PM
#34
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Not necessarily. The sway bar should work out fine with the OEM suspension. The F-sport spring/shock would be a great pairing. If I were you I'd get the springs and shocks first. I think it would generate better results with the lowered center of G. and increased spring rates.
04-28-08, 09:37 PM
#35
Lexus Test Driver
By saying "improve" do you mean better road feedback and much more predictable handling then yes. Ride quality, well that may become stiffer and you may experience more NVH concerns. Once again, this is theory and since I have yet to drive a vehicle with this brace on or have yet to install one on my own car, I can't say how the vehicle will perform. At least not yet. Most races don't stiffen the chassis so much to make the vehicle unbareable to drive. Majority of time everyone enjoys the increased control of the vehicle
I've got the impression by the following web site that by using a rear member brace such as the F-sport brace, the chassis is stiffened and the suspension works better which will actually give a better ride when compared to stock.
http://www.flyinmiata.com/index.php?...0%20%201990-97
04-29-08, 07:30 AM
#36
Personally I'm not planning to do the F-sport shocks/springs because I like the ride just fine now... the sport suspension is right about where I'd want it for rough roads/bumps... and I don't really care either way about changing wheel gap. Maybe someday when I need to replace the shocks I'd use F-sports instead of stock sport.
But I would like less body roll and less understeer... Originally I'd planned to get the hotchkis swaybar set... but now seeing they use the same size rear bar as the F-sport, but the Hotchkis uses a -larger- front bar, I'm leaning toward the F-sport bars instead... I'd be unlikely to play with the adjustability of the Hotchkis rear much anyway, and unless I hear something significant about materials or geometry differences I'd suspect the F-sport bars to be closer to neutral handling than the Hotckis combo... which is the opposite of what I expected honestly.
But I would like less body roll and less understeer... Originally I'd planned to get the hotchkis swaybar set... but now seeing they use the same size rear bar as the F-sport, but the Hotchkis uses a -larger- front bar, I'm leaning toward the F-sport bars instead... I'd be unlikely to play with the adjustability of the Hotchkis rear much anyway, and unless I hear something significant about materials or geometry differences I'd suspect the F-sport bars to be closer to neutral handling than the Hotckis combo... which is the opposite of what I expected honestly.
04-29-08, 10:18 AM
#37
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The easiest way to look at sway bars is to compare them to an elastic band. The bigger the bar (stronger elastic), the more energy/sway will be absorbed (harder to pull that stronger elastic), and the harder it will release (snapping the elastic) when traction is overwhelmed.
Note that this process occurs during weight transfers (ie: swerving). In the end, weight will always transfer during transitional maneovers, it's just the rate at which it moves that is trying to be controlled through sway bars.
Hotchkis kits are typically extremely well engineered for OEM setups. Having said that, I found their stiffest setting on my 350z to be too stiff and bump steer and loss of suspension independance began to show. At that point stiffer springs with better dampers to offset the harshness would be the next upgrade - albeit a costly one.
As for the understeer, the biggest issue is the stagger setup on the OEM is350. I've recently installed Azenis 245/40/18 up front and 255/40/18 rear and that has helped the balance quite a bit. I do plan to purchase the Hotchkis sways once I sell the 350Z.
Note that this process occurs during weight transfers (ie: swerving). In the end, weight will always transfer during transitional maneovers, it's just the rate at which it moves that is trying to be controlled through sway bars.
Hotchkis kits are typically extremely well engineered for OEM setups. Having said that, I found their stiffest setting on my 350z to be too stiff and bump steer and loss of suspension independance began to show. At that point stiffer springs with better dampers to offset the harshness would be the next upgrade - albeit a costly one.
As for the understeer, the biggest issue is the stagger setup on the OEM is350. I've recently installed Azenis 245/40/18 up front and 255/40/18 rear and that has helped the balance quite a bit. I do plan to purchase the Hotchkis sways once I sell the 350Z.
Last edited by fritZman; 04-29-08 at 10:37 AM.
04-29-08, 11:02 AM
#38
Tech Info Resource
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So what's your point here? There are factory installed braces underneath the car. From the New Car Features:
This aftermarket piece adds weight in the hope that it will improve chassis stiffness noticeably. Without a watch and a timed course, it's a pretty tough call to say the car will handle better or not. The weight penalty is real, this can't be questioned. More dead weight to accelerate, corner, and stop. Does the added stiffness offset the increased pork? That's the real question.
IME, I've never seen a brace that aided a street car except under the most extreme circumstances - R compound tires, aftermarket suspension, and driven at/near the limits of adhesion. Something few, if any, experience on a regular basis. So, in my estimation, this mod is much like a lot of other suspension mods - something to lighten the owner's wallet more than anything else. I see no way it will improve "ride" quality if your primary measure of ride quality is smoothness.
04-29-08, 02:24 PM
#42
Lexus Test Driver
So what's your point here? There are factory installed braces underneath the car. From the New Car Features:
This aftermarket piece adds weight in the hope that it will improve chassis stiffness noticeably. Without a watch and a timed course, it's a pretty tough call to say the car will handle better or not. The weight penalty is real, this can't be questioned. More dead weight to accelerate, corner, and stop. Does the added stiffness offset the increased pork? That's the real question.
I
This aftermarket piece adds weight in the hope that it will improve chassis stiffness noticeably. Without a watch and a timed course, it's a pretty tough call to say the car will handle better or not. The weight penalty is real, this can't be questioned. More dead weight to accelerate, corner, and stop. Does the added stiffness offset the increased pork? That's the real question.
I
I also have had this doubt in my mind b/c this aftermarket brace would definitely add some extra weight to it. Sometimes when you have a few aftermarket parts being added at the same time, it's hard to tell which gets the most credit or contribution to the overall improvements.
How about just upgrading the OEM swaybar to F-sport swaybar without changing brace or touching the suspension? Does it make any sense to someone who only wants to reduce body roll and is already satisfied with the OEM ride setup?
04-29-08, 03:38 PM
#43
Tech Info Resource
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Hi lobuxracer,
I also have had this doubt in my mind b/c this aftermarket brace would definitely add some extra weight to it. Sometimes when you have a few aftermarket parts being added at the same time, it's hard to tell which gets the most credit or contribution to the overall improvements.
How about just upgrading the OEM swaybar to F-sport swaybar without changing brace or touching the suspension? Does it make any sense to someone who only wants to reduce body roll and is already satisfied with the OEM ride setup?
I also have had this doubt in my mind b/c this aftermarket brace would definitely add some extra weight to it. Sometimes when you have a few aftermarket parts being added at the same time, it's hard to tell which gets the most credit or contribution to the overall improvements.
How about just upgrading the OEM swaybar to F-sport swaybar without changing brace or touching the suspension? Does it make any sense to someone who only wants to reduce body roll and is already satisfied with the OEM ride setup?
