1971 Chevy Chevelle BMR Fabrication's Level 4 Brake And Suspension Package Upgrade - Turn & Run

Creating a Corner-Carving Chevelle With BMR's Level 4 Suspension Package

John Nelson Jan 1, 2009 0 Comment(s)
0901chp_01_z 1971_chevy_chevelle_bmr_fabrications_level_4_brake_and_suspension_package_upgrade Chevelle_driving 1/18

We all like a good dose of utility. The more uses we can put something to, the better. A street car is nice, and a strip car is cool, but a real street/strip machine, a muscle car that can both cruise the boulevard and throw down at the track, now that's really something to get excited about. That kind of dual-purpose utility is what BMR had in mind when it developed its Level 4 handling package for A-bodies, only with a twist. This setup is aimed at those who place a premium on handling, whether called Pro Touring or g-machine or some other turn-loving label. This is a serious setup, featuring strategically located spherical bearings as well as extensive tunability thanks to its Afco double-adjustable shocks. Can it be all things to all people? In this first installment we'll answer that question as it pertains to the street. In Part 2 we'll upgrade our subject '71 Chevelle's steering to match its enhanced suspension and put it to the test at the track.

First of all, this comprehensive package comes in two varieties: one for '64-67 A-bodies and another for '68-72s. In both cases the vehicle is lowered 2 inches at all four corners, thereby lowering the car's center of gravity. One of the most important features of this package is the use of tall spindles to improve the Chevelle's front camber curve, further increasing traction by allowing the front tires to remain squarer to the road as the suspension moves. BMR uses forged aluminum AFX spindles, which are light, very trick, and a direct bolt-in with BMR's upper and lower control arms. They also come with an extra benefit: the ability to bolt on a set of C5 Corvette front brake calipers for vastly improved braking.

The first big difference in this setup as opposed to BMR's other variations are the spherical bearings at the frame mount points on the upper and lower rear control arms. "It's a compromise between an all-out race setup and a street setup," says BMR's Allan Miller. "The bearings at the body locations articulate through their full range without binding." On the other hand, there's still some damping effect from the polyurethane bushings at the suspension-mount end of each rear control arm, though binding is greatly reduced here as well. While spherical bearings do tend to create a noisier, harsher ride, "This is less apparent in a full-frame car," according to Miller, assuring us that this setup is aggressive while remaining streetable.

The other big difference in the new Level 4 package is a set of four Afco double-adjustable shocks. In short, both compression and rebound damping are independently changeable, and with 40 settings at each location, their adaptability to various road and track conditions is extensive. Better yet, these adjustments can be made on the car in a matter of minutes. This versatility allows for soft settings to maintain comfort during a trip to the track, followed by harder settings for autocross, open track action, and even drag racing (though the straightline is not the strength of this kit). The shocks are performance-valved to match the higher spring rates found here.

So, what did all this reworking get us? Right off the bat the car's handling improved over a stock Chevelle's manners, at least as we've experienced these cars. Body roll was greatly reduced and turning ability considerably enhanced. On the other hand, when put to the test at the track, the car's steering took on a sluggish quality and didn't respond very quickly. This may or may not have been an issue with a less-aggressive package; even with this one, it probably wouldn't make a huge difference on the street. But in a setup aimed at autocross or open-track warriors, it's absolutely critical. So, before we lay all our cards on the table and tell you how this A-body performed, we're going to upgrade the stock steering box to something more performance-oriented, then head back to the track for more numbers. Until then, we bring you the highlights of this very comprehensive Chevelle suspension kit. Enjoy.

What we did:
Outfit a '71 Chevelle with a hardcore, multiadjustable suspension and brake setup

Bottom line:
We got good results-but there's more to be had

Price:
$5,400 for the complete package with C5 front brakes

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