Fast Cars IFS

[lal Naja]

Originally Posted by Donunder

Well I bit the bullet today and ordered my IFS from Ted at Fast Cars. Now I'll be like a kid a month out from Christmas waiting for it to arrive.

I thought that the AU Government took all bullets away? LOL

In preparation for your install, you should start measuring and and do your layout work.

Establish theoretical center line of the car. Take a few measurements across the frame and once you've established the center line, make permanent marks on the frame. I cut a slight groove (0.010" deep with a 1/32" cut-off wheel) in the front frame right under the nose of the car. Another in the frame right behind the IFS, one under the Differential pinion flange and a fourth at the very rear of the car. I use two welding magnets, one at the front & one at the rear and stretch the string between them. You can tap the magnets left or right and use a small Try-Square to center the string to the grooves in the frame.

Check the IRS and see if it's at 90 degrees to the center line and if it's centered on the centerline. Mine was not centered, nor was it at 90 degrees to the center line. (9/32" off center and right side was 3/8" too far to the back) measured at the center of the grease nipples in the bottom of the jag hub and run a string between them to check the 90 degrees to center line. Measure your rear hubs to determine if the grease nipple holes are equally spaced. I found these to be accurately spaced and the easiest points where I could attach a tape measure & strings.

Just in case you find your IRS is not centered or at 90 degrees, you can use the IRS as your datum and move the center line accordingly. Your car will be crabbing a little off center and may not be noticeable. It is a hand-made Cobra after all, LOL. Your choice. I choose to move the IRS and center it.

As I work alone I had to find a way to hook a tape measure to these grease nipple points. It is a PITA to try to measure by yourself. So I machined four custom screws from 1/4" x 28 tpi Machine Screws. Two are used in the JAG hubs and two in the FastCars bottom wishbone grease nipple points.

The the bottom half of the hex heads of the screws are machined to a sharp point to accurately point to the tape measure markings and the upper half to a small saucer shape where the tape measure hooks to. What a breeze to now take accurate front to back measurements and diagonal measurements.

Set your car level, at the correct ride height, pointing forward and measure rear camber. Adjust accordingly. I removed shocks front & back and used turnbuckles to hold the car in fixed ride height stance. If you don't do this getting in and out of the car, or compressing the suspension can change camber. Yes guys???

When you get your FastCars IFS. Mark the centerline on the K member. If you don't want to cut a groove, use masking tape and a fine indelible marker on the tape. My IFS was 1/8" off center and a little askew too.

Either drill out Ted's dead-on accurate four bolting holes from 1/2" to 5/8", may need to go as big as 3/4" like the MGB. Or make templates with tracing paper, cardboard, plywood and elongate the holes. I went through the trouble of elongating the holes with great painstaking accuracy. Then I had to enlarge them to make the IFS centered and at 90 degrees. Talk to Ted ask what he did for Russ.

After locating the IFS in its permanent location I welded locating six blocks to the chassis mounting plates, three on the left side, three on the right. Use 1/4" square key stock or bar x 3/4" long to make the stops. Now I can remove the IFS and re-fit the IFS with dead on accuracy every time. The Jag IRS will also have a positive alignment system.

Perhaps you don't need to do any of this if you have access to an alignment machine.? I've never used such a machine, so I had to be creative and make my own surveyor tools. I guess it's in my DNA, My forefathers worked for Sir George Everest and created the first maps of India. Their work is celebrated to this day for accuracy when compared to GPS mapping, but I digress......

Good luck,

Arthur