rear sway bars

Does anyone make a good rear sway bar for the CGT?

Dave Headley makes an adjustable rear race bar. the difference between a street bar and this application in it will require additional trunk reinforcement, and may want to move the bar up vertically to increase ground clearance. Think the MGOC also wake a rear street bar. Also think Ron Hopkins make a bar- think that's what I have on my MGC

ADDCO makes a good rear bar (3/4"), but it is intended to be used with their matched 7/8" front bar. This does make a good combination, however I would not use a rear bar if the front was not also upgraded either with stiffer torsion bars or a stiffer anti-roll bar.
You can get from Kirk's, Victoria British or Moss.
The ADDCO bars are good, but in my experience the enclosed mounts for the rear end links are poor. I can supply a drawing of a better end mount. And the frame of the MG could use some reinforcing to prevent fatigue cracks as well.
I have used the ADDCO bars on two MGC GTs since 1978 and both were improved a lot, but both had cracks.

Drawings would be appreciated. Where does the frame need reinforcement after the bars are added?

Couldn't find my drawings, so I dug the parts out of the old parts bin and took a picture. To use these I removed the upper spring pad and fitted these instead. They are about 0.200" thick, have a center hole about 1.045" with a UHMW bushing in the center to locate the spring bolt to the axle perch. The 4 holes are 7/16" for the U-bolts and the forward inside hole for the end link bushing is 5/8". The left one still has the old adjustable end link in place.
I have replaced these with new bottom shock mounts with the anti-roll bar endlink mount and anti-tramp bar mounts integrated into one piece. The new setup was modeled after a set a friend bought for his '74 B many years ago. I think he got his from Ron Hopkinson and it had a swaybar end link mount in a very similar place, so I think the rear bar design that ADDCO has is probably just like everyone elses.
The ADDCO rear bar mounts to the top of the rear wall of the trunk (boot) just above the front of the fuel tank. On MGBs that have used this bar this is where they crack. We did make a few larger reinforcing plates for Bs on both sides of the sheet metal to spread the load out and this seemed to do the trick. I had extra plates between the bar mounts and the sheet metal to space the bar away from my trailer hitch and never had a problem.
On the C, however the 7/8" front bar puts quite a bit of stress on the original mounts and I tore the frame on both the '68 and the '69. It took a few years of hard driving, but I would recommend adding a layer of sheet metal to this area and welding it around the edges to prevent this from happening. Use about 18ga sheet and make it 5 or 6" long and bend it up the outside a couple of inches as well.
Hope this helps.

Timely info, Mark! My CGT has that exact arrangement - Addco 3/4" rear and 7/8" front. I didn't really like the looks of the Addco rear links, but I'm still a ways from being back on the road, so user's feedback can be applied now before screwing up things. I will take a look at my setup again and get back to everybody.

Paul Briggs
CGT #7560

How essential is a rear sway bar? The list of things to do on this car keeps growing. I'm beginning to think I may need a complete teardown.

I think you need to determine how important it is to YOU. How do you drive the car? If you toodle around and never plan to push the car’s performance envelope, it’s not required. If you plan on wringing the car out in autocross, track day, or other performance venue, you will probably find a rear bar and a larger front bar a worthwhile change.

You need to remember that tire technology is light years ahead of where it was when these cars were designed. Junk tires today are better than good tires then, and good tires today have as much grip as race tires than. The cornering loads the car can attain are significantly higher. But remember it’s the guy turning the wheel and right footing the throttle that determines the actual cornering loads.

There are two areas you want to consider- balance and grip. Regardless of ultimate grip, you want the car balanced. Select your tires based on what grip you want, then tune for balance. Balance can be achieved with changes to camber, tire pressure, sway bars, spring rates, roll center heights, and a pile of other stuff.

I’ll be bold enough to suggest that if you’re asking this question, you probably want to read a couple of the primers on performance handling. I’d suggest books by Herb Adams or the guy that designed the Quasar sports racer, whose name escapes me right now. I’ll probably remember right after I post..

So the answer to the question is……

It depends……

Fred Puhn.

Told you.

Mark's comment is very important. If you think the "C" has understeer now, try it with a performance rear sway bar without upgrading the front end bar hardware. Extremely dangerous.

Another route to try is a late model (1975+rubber bumper car) sway bar if you can get the rear mounts from a scrap yard or donor car. It will ride a bit softer, be easy to weld and will require less upgrade to the front end, urethane bushings, links, hardware and such.... JB