Blair Harber’s 100 Targa Car AHX12
Page 2

Well it is 31 May 31, 2003 and the Targa Newfoundland starts 15 weeks from today.

Since my last report lots of progress has been made. I completed all the design and prototyping of the suspension components.The drawings for each part were e mailed to Blair who producer the cut out shapes in steel then shipped them to me. The miracles of modern CAD systems!!
We welded and ground and cut and welded and ground and welded and filed and cut and ground etc etc until after a many hours of work all the suspension parts were ready to go.
My ever willing helper Jim Keith and I spent several hours testing the mock up front suspension to determine the ideal position and length of the MGB steering rack that we are going to use. We were determined to eliminate any bump steer problems. The coffee cans just happen to be the right size to set the car at normal ride height when it is on the alignment pads.

With all this completed the frame of AHX 12 went back to Blair for assembly of the inner body, welding up the various brackets and bits that we had tacked on, and for painting. While this was happening I was building up the BN1 diff with its Studebaker limited slip unit and disc brakes. In the midst of all this Blair came down with a monster of a cold, but he has soldiered on and got the assembled frame and inner body assembly back to me on schedule three days ago. A day of work and we had all the rear suspension components installed and looking great. The new BN1 springs may present a bit of a problem. Their spring rate seems to be close to the original 147 lb / in at 160 lb / in but the free camber of neatly 5” is substantially more than the 3 ? of the originals. With the rear anti roll bar adding somewhat to this rate, I suspect that we may have to make some adjustments there. Fortunately spring leaves can be removed and substituted without having to completely remove the springs from the car.

BTW if you are installing the currently available rear springs in a BN1 which uses the tapered spacer plates you will need to modify the spring center pins to ensure that they engage in the holes in the spring mount plates on the diff. The ones supplied in the springs are too short.
This is what the finished product looks like for the left side. If you look closely you will see that AHX 12 now has a rear anti roll bar, tube shocks and Heim jointed radius arms and Panhard rod.

This is the right side before the anti roll bar was fitted the Panhard rod to frame mount is just visible on the right.
The 4 piston aluminium calipers are working on modified 3000 Mk I / II discs. The installation of these calipers presented a bit of a dilemma as we were left without any handbrake.

This I solved by installing a small mechanical caliper on a bracket on the front of the diff and fitting a go cart aluminium brake disc on the drive shaft flange.

The whole thing weighs very little, and being at the center of the car does not contribute significantly to the unsprung weight at an individual rear wheel.

 The front suspension was somewhat moreof a challenge. When the time came to install all the bits and pieces we discovered that as soon as one interference problem was resolved another reared its ugly head. Here is Dick Paterson, my last year’s co-driver for the Targa Newfoundland, modifying the steering lock stops. Man can that guy lay down a neat weld!!

Here is the finished front suspension with its shortened MGB rack, coil over front springs and 4 piston calipers. The camber and caster is adjustable and we have substantially improved lock over the original Healey setup. This is an exercise for the severely demented only… DO NOT ATTEMPT THIS AT HOME!!

And a detail of the right side.

Tomorrow it is on to the brake and clutch pedals, and steering column.

Michael Salter

www.precisionsportscar.com

Page 3