Am I right in thinking that raising or lowering the front end with the torsion-bar adjustment screws has no effect on torsion-bar pre-load? My front end feels softly sprung--even after installing the next largest diameter bars. The Monroe Gas Shocks don't seem to help. What say you?

Hi Steve,

Here are the wheel rates for various A-body T-bar sizes and general usage recommendations:

OD Wheel Rate Application(s)
========== ========== ==================================
0.810" 82 Lb/In SLANT 6/DRAG RACING
0.870" 109 Lb/In SMALL BLOCK V8/STREET/DRAG RACING
0.890" 120 Lb/In BIG BLOCK/STREET/DRAG RACING
0.920" 137 Lb/In PERFORMANCE STREET
0.990" 184 Lb/In PERFORMANCE STREET/SOLO/TRACK DAY
1.040" 224 Lb/In PERFORMANCE STREET/SOLO/TRACK DAY/ROAD RACING
1.090" 270 Lb/In SOLO/TRACK DAY/ROAD RACING/OVAL TRACK
1.120" 305 Lb/In SOLO/TRACK DAY/ROAD RACING/OVAL TRACK
1.140" 323 Lb/In SOLO/HD-ROAD RACING/OVAL TRACK
1.180" 380 Lb/In SOLO/HD-ROAD RACING/OVAL TRACK
1.200" 396 Lb/In HD-SOLO/HD-ROAD RACING/HD-OVAL TRACK
1.240" 452 Lb/In HD-SOLO/HD-ROAD RACING/HD-OVAL TRACK

Yep the smaller bars are akk pretty soft up to 0.990". As you get beyond 1" though, the rates start climbing rapidly. This is because a T-bar's stiffness is directly proportional to the 4th power of its diameter. Yep you can't pre load these puppies you just end up increasing the ride height, which is bad for handling. The Monrows will probably handle up to the 0.920" T-bar, but much more than that will require a better shock (Afco, QA1, Koni, Spax, Edlebrock, Bilstein, Penske, Ohlins, Sachs, Dynamic Suspension). Don't bother with KYB, they are valved to damp stock T-bars and provide a "Performance Ride" with excessive compression damping; VERY HARSH.

Some of the shocks listed above are VERY EXPENSIVE and may not be worth it for 99.98% of drivers. The Spax, when they are available, are just about perfect for Early A-bodys (JRP Inc. handled a group buy a while back. Menko?), and will handle at least up to the 1.180" T-bars (that's the combination I'm currently running on my '66 Dodge Dart (http://users.erols.com/dmapes/RKCP009.JPG) Afco and QA1 have the advantage of being reasonably priced, but they have to be custom configured; QA1 does have a fitment, but it'll likely have to be revalved for the bigger T-bars, same goes for Koni.

Somebody posted this link : http://farnorthracing.com/autocross_secrets6.html in a discussion about Miata shocks on Corner-Carvers (http://www.corner-carvers.com/forums/showthread.php?t=40837). The CC thread is pretty specific to the Mazda, but the farnorthracing link is part of a series of pages with some good engineering info.

Depending on your handling goals, you may be happy just adding a thicker front sway bar and/or moving the battery behind the right rear wheel (worthwhile even if you go for more T-bar and shocks).