Anti-sway bars pro's and con's? • The Dodge Challenger Message Board

by **Goldenblack440** » 16 Oct 2007 14:48

HI, i have just bought a 71 Chal (318 auto) that has no front sway bar. And it goes without saying, no rear one either. I'm definitely putting one on, but am wondering how big a difference to body roll do they make? My 73 Rallye Chal has both front and rear, so i will be swapping them both into the 71. Has anyone had first hand experience with driving Challengers with and without any sway bars, and only front, and also both front and rear?

Being from Australia, our Aust Chargers, which were designed for the racetrack (short wheelbase and wide track) actually handle better without a rear anti-sway bar. And i have been in a Charger with no front sway bar either, but with Koni shocks, and that handled like it was on rails- very flat and firm around corners. SO as the Challenger is a similar style- low and wide track, wondering how much difference they make. I suppose a BB car would definitely benefit.

by **Eddie** » 16 Oct 2007 19:19

I haven't driven a Challenger without one so I can't comment on what that experience would be like. My 440 powered, but aluminum top ended heads on up, has both front and rear frame hung sway bars, fat torsion bars, fat strut rods, fat end links, poly graphite bushings eddies I.A.S. shocks, 15"ralleys handles very 'flat' there is no body roll and it handles very responsive, I am pretty sure the Firm Feel sway bars have something to do with that. Plus they dont cost that much for the benefit gained. Unless it's dedicated drag car, I say use one even if it's small block car. The benefit in great handling far outwieghs any cost to me! :biggrin:

by **dave-r** » 16 Oct 2007 19:33

I would never drive a car without some sort of front sway bar at least.

Sure you can get away without one. But the suspension would have to be VERY stiff (almost solid) to make up for it.

You will find the Challenger is probably a half ton heavier than the Oz Charger which is based on the A-body chassis. I have owned both and believe me the Challenger feels a lot heavier to drive.

E-body and B-body cars lean heavily on the bends. It is normal to fit a 1-1/8th" front sway bar and a 3/4" rear to get control as well as heavier suspension (I use 1" bars on the front of mine and uprated rears) and gas shocks.

by **Eddie** » 16 Oct 2007 19:49

I need to upgrade my front sway bar someday. It's the stock bar/setup. My Rear is a 7/8" Firm Feel unit. I think I will go with the Firm Feel Front 1 1/8 unit someday. :mrgreen:

Dave is right. E-Body cars are a bit heavy.

by **ianandjess** » 17 Oct 2007 8:59

gday goldenblack mine has only the std front bar & we have some pretty tight corners down this way & ive pushed it pretty hard through the turns & it hardly leans at all i was very impressed but it will still get heavier suspension as i can afford it
cheers ian

by **Goldenblack440** » 19 Oct 2007 15:22

dave-r wrote:You will find the Challenger is probably a half ton heavier than the Oz Charger which is based on the A-body chassis. I have owned both and believe me the Challenger feels a lot heavier to drive.

E-body and B-body cars lean heavily on the bends. It is normal to fit a 1-1/8th" front sway bar and a 3/4" rear to get control as well as heavier suspension (I use 1" bars on the front of mine and uprated rears) and gas shocks.

Thanks for the feedback- re the weights comparison- not 100% accurate but i think the Challenger with a SB V8 weighed around 3600lb, whereas the Oz Charger RT was under 3000. The SB Chargers were around 3250, so half a ton, yes, its a lot.

Interesting to see the dimensions of the torsion bars and anti-sway bars you guys are using- i'll have to look out for the Firm Feel ones. That setup of Airfuel Eddie's sounds awsome.

Speaking of rear setups- my 71 having the little 7 and a bit diff only has the worn out light duty suspension as well. If i'm putting in the 8 3/4 posi behind the 440, should i get an extra leaf added each side? i will try and get a Valiant Hardtop (same as Dart) leaf to fit, bearing in mind that Ebody heavy duty suspensions in Australia arn't on every street corner, and their weight makes shipping difficult. There's also the uneven-leaf Hemi setup to consider. I also am thinking of getting the rear suspension reset about 1" lower, but perhaps half inch would be better as they are already quite a squat car.

Lastly, Ian and Jess, what part of Oz are you in? your Chal sounds like it handles very well- is it a SB (318)?

by **dave-r** » 19 Oct 2007 15:28

I would argue that in the real world a small block Challenger is probably a lot heavier than 3600lbs.

My 440 big block has had a LOT of weight removed to make it much lighter then even a stock small block version and it still weighs over 3800lbs.

by **Goldenblack440** » 19 Oct 2007 15:49

Wow-ee that is heavy! And they put 198 cube sixes in these cars!! That's sacrilage. How did they ever get into top gear? Then again, our new cars here (Fords and GM products with the fuel injected sixes) are over 1800KG dry!! (3950lb) so in 35 years they havn't learnt much in the way of weight saving for performance.

by **drewcrane** » 19 Oct 2007 22:57

my experience with my car came with a front sway bar as it is an r/t,however i installed an origonal "t/a rear sway bar, and the car was too stiff in the rear, i spun the car a couple of times before i removed the rear bar, also by buddie is running a 70 trans am cuda, he has no rear sway bar, when wt speed is when the car get squirrly, and tends to over steer , really bad, btw, my car weighs 3625, the trans a car 2500 lbs, we too have done alot to make our cars as light as possible , his car is a race car ie, stripped interior , fiber glass panels where ever possible , these cars weigh alot go check your true weight of your car ,and then have the front , and the back , to find the balance , the back of my car weighs only 1500 lbs , so obviously alot of weight is on the front, so get a front bar and you will notoce a huge difference.drew

by **ianandjess** » 20 Oct 2007 1:14

gday goldenblack im just 400 km south of you down in denmark yep its a 318 car for now but im going to look into how much stuffing around it will be to put a new gen hemi in it im still looking at my options as far as engines go with our dollar getting so strong it makes it more affordable
cheers ian

by **dave-r** » 20 Oct 2007 9:52

drewcrane wrote:my experience with my car came with a front sway bar as it is an r/t,however i installed an origonal "t/a rear sway bar, and the car was too stiff in the rear, i spun the car a couple of times before i removed the rear bar, also by buddie is running a 70 trans am cuda, he has no rear sway bar, when wt speed is when the car get squirrly, and tends to over steer , really bad,

The problem here is wrong suspension rates. Not the sway bar.

Sway bars add a little to the spring rates. So if a car has a tendancy to oversteer at the rear adding a sway bar will make it worse.
Same at the front if it understeers and you uprate the sway bar.

The front and rear suspension rates MUST reflect the front/rear weight of the car. So depending on the weight ballance of your car your idea suspension may be completely different to someone elses.
These rates must also include the sway bar rates.

I spent a lot of time working out the correct rates for my car. In the end I have ended up with a car that corners as flat as a pancake with just a slight amount of understeer at a constant throttle position, ballanced by the power at the rear wheels trying to push it into oversteer.

So if you fitted a rear sway bar and it oversteered it means either the front bar was not big enough to match or your front suspension is too weak.

I cannot stress enough the need for sway bars. If you think you can corner fast without one fitted at each end you are dreaming. Unless the suspension is almost solid.
But you need to put some thought and understanding into the effective suspension spring rates.

by **Goldenblack440** » 20 Oct 2007 10:28

First, Drew, thanks for info- your experience with rear sway bar and spinning is exactly the same as our Aussie Chargers- they do not not like rear bars, that is, do not like a stiff rear end and handle much better (more forgiving) without them. By the Way, that icon pic of your black Chal on the track is fantastic. Can i ask how much you lowered the rear to get that look? i can see its under power in that shot, so the arse is squatting down, but it has still been lowered some- correct? i want that sort of stance. How many leaves in the rear springs?

Also DAVE- i wish i could "pop over" to Britain with my Chal and pay you to sort out mine as well ! It is a science, and not for the weak or people with no research or knowledge. Along your line of thinking, what about stiffening up the body with torque boxes (mine is a SB car) and frame connectors? I am putting BB torsion bars in and Koni Adjustable Shocks (the best for the dollar here), but what should i do with the rear springs? Add another leaf to make 5 leaves and get them reset 1" lower? That's my thinking at the moment.

Ian and Jess- if you are thinking about a new Hemi, have you tried calling Dodge City Conversions in Vic (they are on Ebay as well) They are, or were, selling new crate 6.2 Hemis for under $9000 ! They might be out of stock now though. And i've just been told they had a 70 Chal, factory 383, factory 4 speed, 8.75 etc, running and driving for under $20k. And i just spent $25k on a 71 318 auto. Oh well.

by **dave-r** » 20 Oct 2007 10:51

The stiffer the body the better. :thumbsup:

The simple trial and error approch to suspension is to increase the spring rates to the front if it oversteers.
If it understeers increase the rates at the rear.

Trying to expain it in more detail than that is VERY involved and i suggest you get a book on it like the old Super Street Mopar book.

Otherwise I would have to explain things like "front roll couple". :s008:

by **dave-r** » 20 Oct 2007 11:00

Goldenblack440 wrote:I am putting BB torsion bars in and Koni Adjustable Shocks (the best for the dollar here), but what should i do with the rear springs? Add another leaf to make 5 leaves and get them reset 1" lower? That's my thinking at the moment.

Again. You are just guessing with the spring rates. Chances are it will be wrong.

If you fit hemi spec front suspension try fitting hemi spec rear springs too. At least then it will be ballpark. http://espo.com/ are your best source for springs.

Measuring rear spring rates is easy. You just put the spring on the ground arch up and measure its height at the center. Then stand on it and measure its new height.
Then weigh yourself. From that it is easy to work out how many pounds per inch the spring rate is.

If you want the front wheel rate you can use my math spreadsheet http://www.challenger440.pwp.blueyonder.co.uk/maths.xls which has a little form to work that out for you from torsion bar diameter.

by **drewcrane** » 20 Oct 2007 15:32

dave is so right , i have played around with my leaf springs to achieve the look , but i have sacrificed the handeling of the car , cause the springs have a higher spring rate, they are too stiff, at the time i did this there were not to many aftermarket companies making springs now there are several companies that offer springs, that is why i weighed my car so i can fine tune my suspension better and dave that chart is a great place to start, thanks,dave have you tried your car on a road course?

by **dave-r** » 20 Oct 2007 16:38

drewcrane wrote:dave have you tried your car on a road course?

No. To far to find one and too expensive. But I think I will next time it is running.

But UK roads are are lot more tricky to negotiate than a circuit anyway. Very narrow and lots of tight bends.

by **Eddie** » 20 Oct 2007 22:25

Dave, what size sway bar would you put on mine, it has the factory setup, the only thing done was new poly bushings? I have a 7/8 Rear bar T/A frame hung from Firm Feel already in place. I think I need a fatter bar, but how big? Should it be matched to the 1.14 T-Bars as a matched spring rate set? Someday I will use different wheels and rubber possibly a tad wider,(being aware of the offset and fender lip). Is it poosible to increase the diameter of the front sway bar and re-use my end links and brackets? Or should I just leave it alone? Thanks

by **dave-r** » 21 Oct 2007 11:42

I would never go fatter than a 7/8ths bar on the rear. 3/4" is usually fine for most applications.

Why do you feel you need to change anything?

It took me months to to come up with the spec I felt I needed for my car. It is based on front/rear weight, center of gravity height, front and rear roll center, roll axis, and finally roll couple distribution.

After that I needed to work out what the existing spring rates (wheel rates) were and what I actually needed. From that I was able to calculate what size bars I needed and the spec for my rear springs including camber to get the height right. But that involved something not in the books because I needed to work out what length and thickness each leaf in the spring would have to be. I had to buy Physics books to work that out.

The only bit I got wrong enough to matter was the leaf spring camber. I was out an inch or so. I had to have the leaf springs re-bent to get the height where I wanted it.

In your case Eddie if it understeers or oversteers you should increase or decrease the spring rates at the front or back. So if it does one or the other let me know and I will offer some suggestions. But if it is driving fine as it is don't bother.

by **Eddie** » 21 Oct 2007 12:01

I see, Thanks for the tips Dave. I thought that with the components I chose I 'needed' to go bigger on the front bar.

by **drewcrane** » 21 Oct 2007 13:01

i will refer back to this dave and i might need to pick your brain some more , what are the current spring rates for a stock r/t car such as mine , or how do i find out? is there a number on the torsion bar?

by **dave-r** » 21 Oct 2007 14:01

airfuelEddie wrote:I see, Thanks for the tips Dave. I thought that with the components I chose I 'needed' to go bigger on the front bar.

Everything is different from car to car Eddie. Find a place where you can safely drive around in large circle faster and faster without moving the steering. See which end of the car starts to slide first. Front (understeer)or back (oversteer).
THEN I can make suggestions for you. :wink2:

by **dave-r** » 21 Oct 2007 14:06

drewcrane wrote:i will refer back to this dave and i might need to pick your brain some more , what are the current spring rates for a stock r/t car such as mine , or how do i find out? is there a number on the torsion bar?

Already covered this further up the thread.

Get the diameter of your torsion bar and use the neat thing I put on my maths spreadsheet to see what your front spring rate is. I have also already described the method of measuring rear spring rate.

What I have not covered is how sway bars add to this. Well I am reluctant to do so as it is complicated and probably better described and understood from a book on the subject.

by **dave-r** » 21 Oct 2007 14:24

OK I did some common torsion bars for you.

0.86 diameter bar = 110lbs/in

0.90 bar = 132lbs/in

0.92 bar = 144lbs/in

These ratings are correct for B and E body cars. Not others.

by **Eddie** » 21 Oct 2007 16:49

Thanks a lot Dave. I never knew how to do that. I want to find this out before I put the car up for the Winter and there is a large parking lot I know where to do it, after 5:00 pm and on weekends its vacant. Cool :thumbsup:

by **dave-r** » 21 Oct 2007 17:58

If you want to be really cool Eddie. Bang a stick in the ground with a 50ft length of string attacted to it. Orget someone to stand on one end of the string instead.
Use the string to draw a 100ft diameter circle on the ground with a bag of flour or something.

Now drive around that circle. Increase your speed gradually lap after lap until one end of the car starts sliding and you have to adjust the steering to compensate.

More steering lock to keep on the line means understeer. Less steering lock means oversteer.

Now make a note of what speed this happens at!

From that I can work out what lateral G-force you were able to achieve. :wink2:

by **Eddie** » 21 Oct 2007 18:14

Will do Dave. I have the perfect lot to do this in. I want to be as accurate as I can so Thanks for the tips. If I'm going to get a parts recommendation I want the Data as accurate as possible. I'll post some details as usual. :thumbsup:

by **drewcrane** » 21 Oct 2007 19:08

sorry dave i fell behind in the info but this will help alot, hope you can find a track somewhere there and open your car up with out the fear of cops!!!!!!!!!!! :lol:

by **Eddie** » 21 Oct 2007 19:36

I'll be sure and wear a 'turbine" around my head when I do this. protects my eyes from the sun. :biggrin: