Frame-mounted rear swaybar options

[crakarjax]

I'm looking to spend around $200 on a rear swaybar, and I want the bar to be mounted to the frame instead of the trailing arms or axle housing to reduce unsprung weight.

I found a pic on the forum of what looks to be a stock style bar but with no details -- has anyone used something similar?

There's also the option to piece something together with parts from Speedway but I don't yet know enough about my setup to be able to do this, and I think that realistically I would never change out the bar so this might be overkill. But, has anyone gone this route and have a parts list? http://1speedway.com/index.php?route...tegory&path=76

And here's someone's writeup of installing that style in a camaro:
http://www.rhoadescamaro.com/build/?p=876

TIA

[tinydb84]

I just bought this for my truck:

Its the RJ Racing kit: http://www.rjracecars.com/Anti*Roll-Bars-Prodlist.html

Welder series has one for a similar price too.

[crakarjax]

Wow man, right on budget too! Have you tried to install it yet? I'd love to see pics and get some tips from you when you do. I like that welder series has lots of pics and install information.

I don't like that there are no effective rate charts or anything on either site. I'm sure it could be calculated by the material/thickness/length though. I've got a size of standard sway bar (1.25" front, 1" rear) that I'm shooting for and I'd like to match the rate on those if I can. Any ideas about that?

[tinydb84]

Honestly no clue how I am going to fit it in...I have a four link with bag on bar, two links on the inside, two on the outside, and a watts link. I wasnt planning on even running one.

I remember one site has a chart with all the spring rates but I forgot which one. I would think you could email each place to see what they say.

Any reason you dont just run the stock one? I thought CCP offered a stock one. I am bagged with a lot of travel and didnt want to wear out the bushings.

I am going to probably run the same size front and rear. I did a lot of work and doubt my front/rear weight ratios are anywhere near stock.

[halfstep]

That first photo looks like the NO LIMIT, top mount rear sway bar.
$239.00
www.nolimit.net

[crakarjax]

Originally Posted by halfstep

That first photo looks like the NO LIMIT, top mount rear sway bar.
$239.00
www.nolimit.net

There's no pic on the No Limit site; I did check it out but passed because I couldn't see the bar. http://www.nolimitengineering.com/pr...tegory=6157532

Originally Posted by tinydb84

I remember one site has a chart with all the spring rates but I forgot which one. I would think you could email each place to see what they say.

Any reason you dont just run the stock one? I thought CCP offered a stock one. I am bagged with a lot of travel and didnt want to wear out the bushings.

I am going to probably run the same size front and rear. I did a lot of work and doubt my front/rear weight ratios are anywhere near stock.

I don't think there is a stock bar per se, but I do want to avoid a bar mounted to the trailing arms, and that seems to be 90% of all the bars out there made for our trucks.

[PGSigns]

The racecar anti roll bars are not the same as a sway bar. They are intended not to have any flex and no cornering loads. You will break stuff with that type of setup if you really need a sway bar for street use. If you are not just drag racing they are the wrong choice.
Jimmy

[crakarjax]

Originally Posted by PGSigns

The racecar anti roll bars are not the same as a sway bar. They are intended not to have any flex and no cornering loads. You will break stuff with that type of setup if you really need a sway bar for street use. If you are not just drag racing they are the wrong choice.
Jimmy

Thanks for the warning, I had no idea. I'll not be drag racing but will be autoX and street, I'll look into this and come back with what I find.

[crakarjax]

TL;DR the style of bar doesn't matter, it's the rate that matters, as both styles are just springs. Drag applications benefit from stiffer springs while street/strip of street benefit from softer springs. Stiffer springs will result in a harsher ride. At no point was breaking stuff mentioned in the below article so I can't attest to the veracity of that claim.

I found an amazing article on this subject, and I'm glad I did -- I know much much more about roll bars now!

From http://www.dragzine.com/project-cars...ti-roll-bars/:
The terminology for an anti-roll bar (ARB), sway bar, and stabilizer bar are typically interchangeable since the component is intended to perform a similar task of preventing excessive lean or roll during acceleration or launch. Most of the aftermarket racing community refers to the product as an anti-roll bar, whereas an auto manufacturer might refer to the component as a stabilizer bar or sway bar. Within this article, we will refer the drag race aftermarket products offerings as anti-roll bars or simply ARBs.

[tinydb84]

Originally Posted by PGSigns

The racecar anti roll bars are not the same as a sway bar. They are intended not to have any flex and no cornering loads. You will break stuff with that type of setup if you really need a sway bar for street use. If you are not just drag racing they are the wrong choice.
Jimmy

Thanks for the heads up. I just spent some time over on the Yellow Bullet forums. Looks like people are split on running them versus not. I know the new Roadster Shop C10 chassis runs splined style.

Of course I already opened mine up and started screwing with it. I think I will run it and if it breaks go with a more traditional sway bar.

I think I will modify it to take some of the strain off it. What are your thoughts on mounting the arms inboard of the frame and swapping out the end links to the more traditional sway bar bushing style? Do you think I will be able to get enough play out of it?

[ptc]

Originally Posted by crakarjax

TL;DR the style of bar doesn't matter, it's the rate that matters, as both styles are just springs. Drag applications benefit from stiffer springs while street/strip of street benefit from softer springs. Stiffer springs will result in a harsher ride. At no point was breaking stuff mentioned in the below article so I can't attest to the veracity of that claim.

I found an amazing article on this subject, and I'm glad I did -- I know much much more about roll bars now!

I think you missed a little something in the interpretation between a "street/strip - Drag race" anti-roll bar and a typical higher rate aftermarket "anti-SWAY bar".....

"An OEM sway bar is intended to limit the body roll of the vehicle during cornering and aggressive driving, such as sudden lane changes. An OEM sway bar consists of a solid or hollow forged steel bar, rubber mounting bushing and connection links with sandwiched rubber isolators. Since this bar is designed to meet the needs of the average consumer and not the performance enthusiast, the tolerances and overall feedback of the sway bar is typically loose."

Aftermarket (larger) ANTI-SWAY bars are for 'street' or ROAD RACING type tracks and designed for cornering on twisty roads, etc and they reduce BODY ROLL to the suspension systems (F&R).

STREET-STRIP/DRAG race type anti-ROLL bars are designed to reduce chassis to suspension roll in LAUNCH modes of operation ONLY. This design of connection to the chassis and rear axle housing reduces chassis twist and trys to put the forces of the traction to the tires, which is required to win races. ------ Totally different than trying to make it around hard corners at high speeds with less body roll.....

For a street car anti-sway bar you want the front bar connected to the frame rails and the ends connected to the lower control arms. The rear bar should be connected to the frame rails and either the trailing arms or the shock mounting points of the leaf or spring system. if it is an IRS system then connect it to the frame and the lower control arm also.

[crakarjax]

Please do correct me if I'm misinterpreting but...

Originally Posted by ptc

I think you missed a little something in the interpretation between a "street/strip - Drag race" anti-roll bar and a typical higher rate aftermarket "anti-SWAY bar".....

"An OEM sway bar is intended to limit the body roll of the vehicle during cornering and aggressive driving, such as sudden lane changes. An OEM sway bar consists of a solid or hollow forged steel bar, rubber mounting bushing and connection links with sandwiched rubber isolators. Since this bar is designed to meet the needs of the average consumer and not the performance enthusiast, the tolerances and overall feedback of the sway bar is typically loose."

They also stated
"The terminology for an anti-roll bar (ARB), sway bar, and stabilizer bar are typically interchangeable since the component is intended to perform a similar task of preventing excessive lean or roll during acceleration or launch."
Please don't cherry-pick your information just to make a point.

Originally Posted by ptc

Aftermarket (larger) ANTI-SWAY bars are for 'street' or ROAD RACING type tracks and designed for cornering on twisty roads, etc and they reduce BODY ROLL to the suspension systems (F&R).

STREET-STRIP/DRAG race type anti-ROLL bars are designed to reduce chassis to suspension roll in LAUNCH modes of operation ONLY. This design of connection to the chassis and rear axle housing reduces chassis twist and trys to put the forces of the traction to the tires, which is required to win races. ------ Totally different than trying to make it around hard corners at high speeds with less body roll.....

Please explain the difference between body roll and chassis to suspension roll?

Since the body is directly and firmly attached to the chassis, and the only real movement is between the chassis and suspension, these sound like exactly the same thing. Sure, the forces are coming from two different places (inertia vs driveline torque) but the required force to equalize the movement seems to be exactly the same in both cases.

Originally Posted by ptc

For a street car anti-sway bar you want the front bar connected to the frame rails and the ends connected to the lower control arms. The rear bar should be connected to the frame rails and either the trailing arms or the shock mounting points of the leaf or spring system. if it is an IRS system then connect it to the frame and the lower control arm also.

Your description of desired street car sway bar mounting points does not conflict with the anti-roll bar mounting points, so I'm not sure what you're getting at? The only difference I see is the stiffness mounting points of the bars, and as tinydb84 pointed out, it doesn't seem unreasonable to just use different mounting hardware.

From the article,
"Any flex in the anti-roll bar system can result in inconsistencies in the launch, which is why the construction of the anti-roll bar is very important."

I'm pretty confident that this is the only difference between the two styles, other than the desired spring rate which depends on the application. Although I don't agree with everything you've said, I think this is a vital piece of information that I wouldn't have discovered otherwise -- so thanks!

[crakarjax]

A thought just occurred -- the arm and bar style sway bars can be found with arms having multiple holes in them. This allows you to tune the stiffness pretty easily and would make it simple to switch from track tuning to street tuning! I might go this route but can't remember where I've seen that style of arms.

Also found this other excellent source of detail: http://iracing.wikidot.com/component...l-bar-sway-bar

[smbrouss70]

Originally Posted by crakarjax

There's no pic on the No Limit site; I did check it out but passed because I couldn't see the bar.

The picture in your first post is INDEED the bar from No Limit. LINK

He also has their rear shock and panhard bar kit.

[slotard]

The basic concept of stock vs roadrace vs street/strip vs drag race bars are certainly the same, although different ones mount somewhat differently.

Are the drag race ones significantly higher spring rate or something like that? I'm curious as to how they'd likely break things if run on the street.

I can understand an excessively stiff bar causing poor ride quality. A perfectly rigid bar turns the rear suspension into a swingarm, with no ability to flex back and forth (only up and down). If one tire hit a bump, rather than that side rising and the other staying (roughly) stationary, you'd end up lifting the other side off the ground a hair (given an adequate bump).

[PGSigns]

Here is the deal that you are missing. All sway bars or anti roll bars are made of spring steel and the rate of the spring determines its resistance to flex or its rate. A bar made of a steel tube made from mild steel has almost no ability to twist under load and is designed not to. In a drag race application you are trying to resist a small force and you do not want to have any twist. On a street car you need to be able to let the suspension articulate as you drive. So as the suspension moves the bar will need to be able to flex just like the bar does on the front of your truck. If the bar has no flex something will have to give. What will happen is the mild steel will be pushed to its yield strength. Most of us knows what happens when you bend mild steel back and forth. You can get narrow bars with splined ends in several rates. Most folks use a rear bar with about 1/2 the spring rate as the front.
Jimmy

[crakarjax]

Originally Posted by PGSigns

Here is the deal that you are missing. All sway bars or anti roll bars are made of spring steel and the rate of the spring determines its resistance to flex or its rate. A bar made of a steel tube made from mild steel has almost no ability to twist under load and is designed not to. In a drag race application you are trying to resist a small force and you do not want to have any twist. On a street car you need to be able to let the suspension articulate as you drive. So as the suspension moves the bar will need to be able to flex just like the bar does on the front of your truck. If the bar has no flex something will have to give. What will happen is the mild steel will be pushed to its yield strength. Most of us knows what happens when you bend mild steel back and forth. You can get narrow bars with splined ends in several rates. Most folks use a rear bar with about 1/2 the spring rate as the front.
Jimmy

4130 and spring steel alloys like 5160, 1065 have pretty darn near the same modulus of elasticity so the material shouldn't be a factor. Now, the arm length has a very large effect on spring rate and the kits appear to have really short arms, but the lack of detailed info is pretty concerning.

Feel free to copy this spreadsheet and you can play with the values yourself!
https://docs.google.com/spreadsheets...it?usp=sharing

[BR3W CITY]

Ok so one of you explain to me please, since I only have a front sway bar; as a road-used truck with drag tendencies, where does one draw the line on "too stiff for the street" or "Too soft for the track"? Can you run a stiff bar, and have something like a disconnect? I've seen guys disconnect their front sways to run at the track (aiming for the exact opposite effect).

I just have a normal trailing arm rear, and I'm setting up coil overs this season hopefully fwiw. I enjoy street driving 2-3x a week in summer, but the truck is built with straight line speed in mine.

[PGSigns]

Well we use anti roll bars on drag cars very seldom. Mostly on high HP cars with very good chassis under them. As I said before they see little load. Some folks use it as a bandaid for poor suspension setup. On a drag race application Tuning the instant center, spring rates and the shock speeds all gets done first with the bar disconnected. Once the car is happy with the setup the anti roll bar can be used to reduce the torque roll in the car and ad small amounts of preload into the setup. It all has to work together. The chassis has to be stiff, the spring rates need to be right and always buy the best shocks you can. A good double adjustable shock is a wonderful thing for getting one to leave and drive well. A rear bar is the last thing on the shopping list if at all. Here is a car I built with a arms and a 4 link. This is a street car that has all the glass and on DOT tires. Got greedy on the setup and had to calm it down. There is not an anti roll in this car.
Jimmy

[crakarjax]

Ok so this is off-topic now but your mention of not needing a bar at all got me thinking some more... I'm wondering for my application (street/autox/pro-touring?) how I should calculate what size bars would be optimal for my setup. I know that I've seen people mention trying different spring rates and observing the effect and tuning from there, but I'd rather just get it right the first time, or at least as close as I can without wanting to re-tune. I know front/rear bias is important but not sure how to figure what the bias should be, and then what the overall rate should be! I'm going to see if I can find some answers at pro-touring.com and I'll come back with whatever I learn.

[kamikazekyle05]

As mentioned before, that is a no limit kit. I have the same one on my 67

[crakarjax]

Did the kit come with instructions? The pic I posted shows that some pads had to be trimmed and also has the mounting brackets mounted outward instead of sitting on the frame...

[PGSigns]

Look at the Nolimit thread just below this on on there new trailing arms. Rob has a good explanation of the rear geometry on these trucks and the setup is right up your ally with the design. As far as picking the best bar to start with a lot of factors come into play and the entire setup you pict to run will drive the bar choice.
Jimmy

[kamikazekyle05]

If I remember right they came with instructions. I didn't have to trim the pads. I may have the brackets mounted wrong. http://nolimitengineering.com/news/p...t-3-suspension This one shows it mounted to the frame also