Rear Sway Bar - 70 Javelin

hffej wrote: What kind of improvement with just the bigger front bar and no rear bar?

A bigger front bar, without doing anything to the rear, will tend to make it understeer more. Adding a rear bar with a bigger front bar helps to maintain balance.

I added a late Concord 1 1/16" front bar and 3/4" rear bar to my '74 Javelin, with some slight mods to mount the front bar (bar is shorter, so not a direct fit). Combined with new bushings, KYB shocks, wider wheels and tires and a 12:1 steering box it made a noticeable improvement ... but still not to the level of a modern econobox let alone a performance car.

Hope this helps,RD.

Later centre links may be slightly larger diameter which may reduce deflection to help steering response ... but not sure you'd notice in regular driving?

I wouldn't recommend shortening a stock sway bar ... tough to join it back together reliably.

The 1 1/16" front bar from the Concord was not as wide as the Javelin bar and had shorter arms, so coupled with the larger diameter was noticeably stiffer ... guessing it would be close to the 1 1/8" Addco bar for a Javelin. To fit the Javelin needed some modified Energy Suspension frame mounts, trimmed lower control arm bump stops and slight changes to the links.

The factory Concord 3/4" rear bar mounted under the axle to brackets sandwiched between spring and shock mounts, so needed holes slotted/redrilled in the brackets to match up to the narrower u-bolt spacing on the Javelin (Concord had the spring iso-clamps, so wider spacing). The links mounted to brackets bolted to the frame, so drilled holes in the frame and reinforced it to suit.

I also added a Concord 1 1/16" front bar to a '73 Hornet with no rear bar. Less roll than stock as it had no front bar ... but handling balance was much better after adding extra leafs to the rear to increase rear spring rate. The front bar was a direct bolt in to the Hornet using the Concord parts.

If wanting to optimize handling keeping mostly stock parts, I'd suggest replace all bushings and any worn joints, get custom higher rate front and rear springs with lowered ride height (coil-overs on front and Flexform leafs on rear ... if in the budget), adjustable shocks (to tune for handling/ride comfort), later Spirt/Concord bars or the Addco bars and a rear panhard ... and most importantly, fit better tires. If wanting bigger bars than stock or to tune the bars, best to custom mount stock-car style bars like on the TA car.

Depends how big your budget and tolerance for a rougher riding car how far you go.

Hope this helps, RD.