Consensus regarding sway bars

I thought I ought to start a new thread as some might skip over the final update as something they've already read. I thought all of the information I received was great and I wanted to be sure that everyone was able to get the full benefit of all the information that was sent to me since some of it was sent in PM's and directly to my email:

OK - From the posts above and the PM's I've received,there seems to be a pretty good consensus:

The government mandates that brought about the increased ride height and the addition of the rubber bumpers changed the handling characteristics of MG's significantly. This was corrected by the addition of sway bars in the '77 - '80 model years.
The earlier RB model's handling is significantly improved by the addition of sway bars with or without making the CB conversion and is a desirable modification for all RB models not equipped with sway bars.
Although sway bars and kits are available for both the front and rear, those who have done both conversions have found that the addition of sway bars to the front provides better handling than the addition of sway bars to the rear. With the addition of only the rear sway bar, understeer became a problem. The best handling is achieved when both the front and rear conversion is made. HOWEVER, in cases where both conversions have been done, a sudden loss of traction in the rear without the usual ability to feel any change ("no gradual feedback") occurs when the vehicle is pushed to the limit and on slippery roads. Some who have done both conversions to their RB cars, have later removed the rear sway bar because of this characteristic.
Although the earlier RB cars did not have the mountings or holes for the front sway bars, the A-arms can be swapped out for earlier ones which did, or the existing A-arms can be modified by the addition of a gusset and hole. Kits are also available as aftermarket add-ons.
The earlier RB cars also did not have mountings for rear sway bars. There are aftermarket kits available online for this conversion as well. Although the sway bar assembly for the later RB cars can be added to the earlier cars with the welding of brackets, this is a less common conversion, but can be done.

I think that pretty well sums up all of the responses I received so I can make an enlightened decision regarding the addition of sway bars to my car. It only remains for one of this site's very knowledgeable individuals to go through the above, correct my errors, attach photos from those who have made the various conversions (which I know the members on this site will be more than happy to supply) and to add this topic to the library. I think it would make a very helpful and much needed addition.

Lloyd,
That is JUST the kind of additional input that is needed for the article. Why can't you be the one to correct my errors and write the needed article? As you can see, even with having asked for information, my knowledge is still deficient.

BTW, I did get a message from someone who had mounted the sway bar from a '77, I didn't realize until you posted what was involved in his doing that and now I know that it is something to avoid. Thanks!
Gary

Gary....this is a no win situation. You will get dozens of posts from guys who say a rear bar is bad.....avoid the hassle.

I've incorporated Lloyd's and Bill's additions and corrections and updated:

The government mandates that brought about the increased ride height and the addition of the rubber bumpers changed the handling characteristics of MG's significantly. This was corrected by the addition of sway bars in the '77 - '80 model years.
The earlier RB model's handling is significantly improved by the addition of sway bars with or without making the CB conversion and is a desirable modification for all RB models not equipped with sway bars.
Although sway bars and kits are available for both the front and rear, those who have done both conversions have found that the addition of sway bars to the front provides better handling than the addition of sway bars to the rear. With the addition of only the rear sway bar, Bill Boorse notes that this "will cause oversteer: the condition wherby the rear end breaks free and tends to travel toward the outside of the turn." The best handling is achieved when both the front and rear conversion is made. HOWEVER, in cases where both conversions have been done, a sudden loss of traction in the rear without the usual ability to feel any change ("no gradual feedback") occurs when the vehicle is pushed to the limit and on slippery roads. Some who have done both conversions to their RB cars, have later removed the rear sway bar because of this characteristic.
Although the earlier RB cars did not have the mountings or holes for the front sway bars, the A-arms can be swapped out for earlier ones which did, or the existing A-arms can be modified by the addition of a gusset and hole. Kits are also available as aftermarket add-ons.
The earlier RB cars also did not have mountings for rear sway bars. There are aftermarket kits available online for this conversion as well. Although the sway bar assembly from the later RB cars can be added to the earlier cars, as noted by Llyod Faust "...in order to mount the rear bar, the factory moved the fuel pump out of the way (into the trunk). The 77-80 bar will also not clear the battery boxes in the two battery cars. To mount a factory bar in a pre 77 car...is not worth the effort. "

Jim,
You're right, of course! lol! But if no one else benefited from this, I did. If I hadn't done the post, for example, I might have tried the conversion that Lloyd warned me against. As he said (paraphrasing his comments), even if something is possible, that doesn't mean that it isn't ridiculously difficult or something that I would want to do. I enjoy looking at (and even commenting on) some of the projects that some industrious individuals undertake, but that doesn't mean they are something I want to do or have the necessary skills to pull off. I have in mind the individual who widened his MG. Wow! What an undertaking! It would have been enough to send me to an undertaker,though (play on words intentional).
Gary

Gary, I think you also got some info on what lowering a RB car will do to necessitate or obviate sway bars. (thought I read someone saying to remove the rear sway bar on 77-80 if you lower it???)

Since lowering the RBB is a very common change, maybe you could add those tidbits to your article.

I have an '80 B, lowered (Moss kit) but have not added or removed any other suspension items except replacing bushings, shocks (with stock from Peter), swivels/kingpins. Very happy with it!

David

David,
I did receive a post or two that suggested removing the rear sway bar if the car is lowered. You are right that the increased ride height on the RB cars is what makes having sway bars a necessity for good handling. The first MGB I ever drove was in '69 (belonged to friend in college) and it would take a 90° corner @ 60 mph.
The posts I received regarding removing the rear sway bar were not because the road gripping ability was less, it was because they were indicating that you were unable to feel any indication that you were pushing the cornering ability of the car past it's limits until the wheels actually broke free from the pavement. One individual that races his B stated that he let off on the gas at that point and traction was always regained. He still has both sway bars. I'm afraid if it were me, though, I would probably end up in the ditch or worse.
Gary

Consensus? On most subjects I'm not sure you could get a consensus that there is no consensus. :D

The general consensus I believe is that the best handling and road holding is achieved with a tight front and a loose rear meaning a sway bar at the front but not at the rear.

Daniel,
Sounds like the Star Trek TOS episode with the Daniel Harcourt Fenton Mudd character where they told the robots I cannot tell a lie and then turned around and stated "I'm lying." LOL
I didn't mean to indicate unanimity when I said consensus. There are times when I don't agree with myself, as far as that goes. I hope, though, that I was able to even out all of the comments and arrive at some conclusions that are at least generally true.
Gary

Gary.

You did a good write up.

The answer to the rear sway bar question is that you should only add an after market rear bar if the front bar is upgraded in size.

The factory rear bar had long arms and so the rate is much lower than a comparable sized aftermarket bar.

Other issues with rear bars are the effectiveness of the mounting system. A number of the designs have problems with stress failure. I've heard good things about Dave Headley's rear bar, but havn't any hands on knowledge. Other bars I'm familiar with require installer modifications to be safe.


If I could add the comment that if a 1975-76 MGB is lowered using higher rate, shorter springs, there may not be a need to install a front roll bar. The higher rate spring and lowered height may be all the owner needs for confident driving.

Kelvin.

Kevin,
Sounds like we may have found the person to write and submit an article for the library! I deserve no kudos for the write up as I knew absolutely nothing about the topic beforehand except that it was a very desirable upgrade. As your post shows, I still haven't gathered enough information to write a totally correct, comprehensive article. It seems even clearer to me, though, that such an article would be a boon not only to me, but to many others.
Care to be the one to write the article? It's been my hope that someone like you would write an article. I suggested it to Lloyd, but I got the feeling since he didn't post back that it's not something he wants to do.
Gary

Maybe Lloyd and I can collaborate?



More likely it will end up with one of us using the line..... _____ you ignorant slut!


LOL.

I think the write up you have done so far is quite good. Getting too deep into a discussion will likely end up just getting more confusing.

It's pretty basic.

If you do a lot of high speed cornering in a B - upgrade to a 3/4" front bar.

If you really want to carve turns at high speed on the street - upgrade to a matched front and rear bar and increase damping appropriately.

Adding a front bar to a 1975-76 is an improvement.

If you increase spring rates, your car will be more uncomfortable to drive, but you won't need to increase bar stiffness.

Kelvin,
I sent you a PM, but I see you've posted again here. I like the collaboration idea. You and Lloyd would do a great job and could probably get to a point where you liked each other again sometime in the future.
I look forward to reading ya'lls article.
Gary

We can argue this all day....but I go with what Colin Chapman had to say on the subject:

"The springs are there to prevent suspension bottoming under severe braking, if they do this, they are stiff enough.......control body roll with bars".

I made a set of blade adjustable bars for a car I was working on (not an MGB).....very educating as to how suspension dynamics works in real life. I know a good many people on this forum think their car is just right (as Jim stated). But if you are sensitive to the various adjustments....you will soon learn that the back must be dealt with as well as the front.....don't expect it to 'dial itself in'.

Lloyd,
Wow! That bit of information about springs and bars alone was worth all the posting! That's another reason to have you and Kelvin write the article. You both know things like that about which the rest of us have no clue. I would love information like that prefacing the article so that the rest of us would know what we were actually trying to accomplish.
Gary

Gary....Kelvin's your guy.....:devil:

Lloyd,
Your posts are always appreciated. I hope you don't get tired of posting. I do understand why you don't want to do the article. I know you get tired of all the emails that are sent your way arguing against things you've posted, but some of us aren't too hard headed to listen and we do learn a lot from your posts.
Thanks!
Gary

Gary.....it is very frustrating. If I protest...then I'm a whinner...so I'd rather not do it. I have spent a good portion of my life involved with other people's race cars on a professional level. I've even had a few of my own. I don't know it all or claim to, but I'm also not just a guy who bought an MGB and a MOSS catalog and now has it covered.

If I try to offer up some info....it always results in arguments. Everyone here has a computor and an internet connection.....therefore they can post as much as anyone else...right or wrong...just type and click. If I let something go...then most people will not get the correct answer.....if I respond...there is no end to it....it is easier for me to walk away from not posting in the first place, then it is to walk away from a challange to something I have said.

I posted the info on speedo interchanges today (on another thread) and thought I'd be doing everyone a favor from my first hand experience....no theory or guessing...pictures even. Nope...always somebody has to disagree. They have never actually done it...but still they disagree. Oh well.

I hear you Lloyd.8-)

If you really want information on suspension tuning, a google search will provide enough info to make your head explode.

Another thing I have to wonder about this subject is how different people come to form these opinions. Have they tested the modifications on the track? Granted, you can probably sence a change in body roll on the street. But if someone is testing for understeer or oversteer at the limits, I hope it's on a closed course with runnoffs. The runoff area on the street could be a gaurdrail or oak tree. I suspect most do these mods and after a drive in the country, pronounce they have the best handling MGB around.

These threads are always the most interesting to me. I've started to do the modifacations I think will work best for my GT. Right now it has Peter's adjustable Armstrong lever shocks up front, red poly bushings throughout, 550lb one-inch lowering springs and the stock 9/16ths (5/8ths?)factory sway bar. It also has new pivots, B&G's castor reduction kit, a new steering rack, and new 15 X 7 wheels with 205 R55 15 tires.

The up-rated 3/4s bar is in the future. As are Headley's 1" drop spindles. I wanted to go with the stock factory spring load (480? 348? What is correct for a 67 GT?), but I couldn't find any in those poundages that would also give me a 1" drop. I did not feel comfortable cutting my old springs "about a coil" and heating the end and beating it and grinding it flat to properly fit the coil seat in the cross member. Nor did I particularly trust the yahoos around here to make what I wanted.

The rear has new poly bushings and spring pads and new 93 pound 1 inch lowering springs. At least that's what the Made in UK lables tell me. I think the car is still high in the rear, but that may only be due to the fact that they are not broken in. The distributor told me "give them five hundred miles." It also has refurbished Armstrong levers. The whole set up seems stiffer than hell to my butt-based up and down test. Despite the softer 93 lb springs (stock is 110lbs)it's far stiffer than the up-rated 550lb springs up front. Of course I have not adjusted the shocks up front yet. I think they are set on 58 Buick right now.

In the future I plan to exchange the rear shocks for a pair of Peter's adjustable Armstrongs, add Headley's axle locator to keep it centered from side to side, and his lowering plates to level the car front to rear.

So now it comes down to "Sway Bars." If I have stiffer springs up front, and the ability to stiffen the shocks to ox cart levels, (I'm thinking around stock levels for most driving situations) would I benefit from an up sized sway bar up front? If so, would I also benefit from an appropriate one in the rear?

The GT has more weight in the rear than the roadster and that weight, since it is glass raises the center of gravity as well. Now in racing GTs all the glass is light weight Lexan, the hatch is light weight fiberglass and I doubt there is ten pounds difference between a roadster and a GT in the sheet metal. So what the factory did on the GTS, or what racers are doing today might not work well in a fully streetable GT that's only going to be on challenging roads occassionally.

Any suggestions?

I'd like to pass along my thanks to all of you who have been discussing this topic in this and the previous thread, especially Simon for getting the ball rolling. I'd been thinking about putting a front sway bar on my '76 B this year, and as somebody with pretty limited automotive skills and knowledge -- especially around suspension -- I'm finding the discussion helpful in terms of improving my understanding of how sway bars work, what an installation would actually involve, and whether it's a good idea in the first place.

If an article does result, you can count on at least one avid reader!

Dave....two different things here...ride height and spring rate. The springs sold by all the vendors combine the two...

For a street driven MGB, the springs are already stiff enough...in fact too stiff in the rear as stock, they skitter around on bumps in stock setting. On a smooth race track..different story, usually. That is what is so nice about coil over shocks....not that they work so much better (once adjusted) but that you can set the ride height without changing the SPRING RATE. One has little choice if they want to buy a set of springs to lower their car....you have to go with the spring rate that is sold over the counter....not a good choice if you can't make your own.

For a car that is driven on an uneven road surface (street driven MGB) softer springs and bigger bars will yield superior results (not to mention a better ride). Now lowering the car is all about visual mostly and that is where yu run into trouble...making it lower with stiff springs usually isn't making it better, despite what you have told yourself on that first test drive. Lower stiffer springs will give better numbers on a smooth skidpad...but hit a ripple or bump...you'll be all over the place. Hope you have quick reflexes.

If you drive around at 8/10s....you'll usually never experience what I'm talking about.

EDIT: The castor reduction kit is used too make the car steer easier, not handle better. Poly bushings take the 'play' out of the suspension pivots...not that much really. If using adjustable rear shocks...they MIGHT make a difference on a race track by delaying weight transfer on tight twisting stuff...but probably not much in real numbers on the street. File under same catagory as springs that are too stiff.

One further thing....the front shocks on an MGB are already marginal...they even allow quite a bit of movement before "damping" begins. Adding more unsprung weight to the equation (bigger wheels and tires) just compounds the problem.

Gary, I think the message is the article is yours and you should write it and let Kelvin and Lloyd be your consultants. Go for it, man. You don't have to be THE expert and you can offer a mild disclaimer that this is what you've learned and to each his own. As they say in the advertising world, "Your results may vary." :)o

Thanks Lloyd for the intel. I'm aware that the larger wheels and tires do add to the unsprung weight. But the increase is unlikely to be all that much more on a car equipped with wire wheels in the first place. The knock off alone is heavy, as is the hub, spindle, brake calipers & brake discs and original wire wheel. At least the Daytons are tubeless rims, so that tiny bit weight is gone too, along with the dust shields off the back side of the disk brakes.

I got the castor reduction kit because of the wider tires. It was a nod to keeping the steering feel as light and close as possible to that of the original width tires.

I think 8/10s on public roads is about the upper limit of sanity. Too many variables to quickly otherwise. I might see 9/10ths if I get to cross the Targa Newfoundland off my bucket list. But I'd like to finish that event in one piece. Still, preparing a car capable of surviving the Tara Newfoundland provides a nicely balanced set of specifications to build to.

I replaced a Monroe tube shock set-up in the front and rear installed by a PO, who also put the 15 X 4.5 Dunlop 60 spoke wires on the car. The adjustable Armstrongs went on the front now because I don't want to have to get that far into the suspension again this year (getting on the road is my focus). Since I had to replace both front Armstrong shocks and upper A-arms with rebuilts (due to the tube shock arrangement) going for the adjustables wasn't that much more than the rebuilts with stiffer valving. Now I can tailor the ride for the kind of driving I'll be doing most of the time, and stiffen it up as appropriate to special events like autocross, a track day, or a challenging road (I've found none where I live). The adjustable rears while not strictly necessary would 'finish' the system nicely and can be put on in 15 minutes. As can the 3/4 inch sway bar up front.

But I still don't have a clue as to the adviseablity of a rear sway bar on my GT.

In 67 street GT, no matter how hard I pushed thru mountain rod corners, it did what I wanted it to do, with that being said, the minute I the track with it, it rolled in the ass end so bad it was terrible, now I thought long and hard about putting a rear sway bar on the car, but if the track which I only went to once a year for our LBC street car outing was the only place it needed a rear sway bar, it seemed sort a waste of money.

It was mentioned that rear sway bar would induce a loose condition and this could in fact happen, my rear sway bar is a David Headley's adjustable unit on the race car, it would be the primary way I tune the car for loose and push on given day, at a given track. This could also be a good set of tstreet driven car, several treet use this sway bat, you only have to drill a few hole in the truck, floot it mouns via special bolt on bracket at the rear housing, and should mount in street car without the issue of the stock type bar going into the early cars. Bottom line by going with adjsutable unit, you can tune the car for the condition whether it be normal street driving, or track day, or autocross, the adjustable unit would give you multi-puropose and tun-able set up.

I had a 1" bar in front and a 5/8" bar in the rear of my 72B. It's curve taking abilities were fantastic! Was not a good long distance driver, though. It handles like a MGB should, neutral most of the time but still able to induce oversteer when I wanted to.

Dave Headley is really clever at this and recommend the article on his website as a starter. I have done a hodge-podge of the things over the years. Panhard bar, fiberglass rear springs, 195 section tires, etc. The parhard bar was great for controling the movement of the rear end, but the car did not feel right to me. I know some have different perferences. Without the bar the tires would rub, even though the in lip was dressed.

I went with 3/4 bar up front with Dave Headley's rear bar. Car is a lot of fun. The only (and we are talking knit-picking here) trouble is jacking by the pumpkin (differential) is hard because the bar sits lower. But in use, Dave Headley's bar is really nice.

Thanks

As Kelvin noted, I think much of the disappointment with rear sway bars comes from using a rear bar thats not properly matched with the front. As stock type rear sway bars are somewhat hard to find and are difficult to install on early cars, many people will go with an Addco or other aftermarket bar that is too big in comparison to a factory sized front bar; and the car becomes unbalanced, tending toward oversteer.
Also, understeer is a much easier characteristic for the average driver to handle than oversteer. Most modern cars are designed with a chassis that tends toward understeer as this makes the car more "user friendly".
My B is a 74.5, lowered to CB height; moss 264-395 springs up front and stock rear springs with lowering blocks; adjustable tube shocks front and rear; 7/8" front bar and a 5/8" rear bar. It handles beautifully. I can kick the rear end out when I want, but I don't get the "snap oversteer" that others mention.
Suspension tuning is a complex process. Rarely can you make a mod to one part of the suspension with having to make a corresponding mod elsewhere.