 |
|
|
|
|
 |
|
|
 |
|
|
 |
|
|
|
|
|
|
 |
|||||
|
VINTAGE IFS |
|||||
 |
|||||
|
|
|
We built our ’32 and ’34 Ford Tudors to join in the fun at the same shows you see us working. We faced the same dilemma many of you do — how can we keep a classic look without giving up the ride and handling qualities we’ve come to enjoy in our hot rods? The axle tramp on rough roads and constant bumps over simple highway tar strips just isn’t acceptable today. Over 15 years ago, we started doing customer’s cars with our Vintage IFS. It separates the suspension of each front wheel so that they can react to the road surface without affecting the other wheel. Which is just what any IFS (Independent Front Suspension) does. We did 7 cars before releasing this kit, having tried coilovers and rack & pinion but found that Vega cross steering with a cross spring did the best job while retaining the vintage look. The cool part is that you begin with a conventional dropped axle setup and then split the tie rod and axle in a matched method that absolutely prevents any bumpsteer English sports racers and the Allard cars used this same concept of splitting the axle, but did not split the tie rods to match (other than on the latest Allard road cars.) With the skinny tires of the day, the bumpsteer that resulted was not a criplling problem. Ford’s Twin I-beam setup on the 64-89 trucks were a similar attempt, but used a long axle to eliminate bumpsteer, so Ford let that problem go and was willing to accept the bumpsteer that gave these fine trucks a reputation of wearing front tires. Today’s wider and stickier tires demand more, so we took the next step of splitting the tie rod with a very stable central idler arm. Common axle bearings are used for exceptional stability. This kit works so well that it received a “Best New Product Award” at the 200 NSRA Street Rod Nationals! Other manufacturers have followed our path with a split axle IFS using coilovers and racks, but we respectfully disagree. The coilovers simply look too modern on a nostalgia themed car. Our thinking is: If a car is high tech enough to look right with coilovers, then why not just use a regular control arm IFS? When a design uses longer axles like the Ford Twin I-beam, they have the same problem with tie rods as Ford did. A rack has to be designed with overlapping tie rods, and we feel that design is simply too complex and bulky. Our shorter axle design makes the matched tie rods simple, but will have more camber change than a long axle. In the real world of hot rods, you generally see about 6 inches of total suspension travel, so the camber change is not our enemy as much as the bumpsteer would have been. In fact, geometry analysis indicates that our Vintage IFS changes camber only 24% faster than the proven Mustang II IFS. Many rodders have examined the front tires of both our cars and noted no abnormal tire wear. If tire wear is correct and even, good handling will surely result. When you cut the axle for the split, you can narrow it some extra for additional tire clearance on a fendered car. The axle spuds that provide the pivot are machined round for use in 2" OD × .250 wall tube axles. They can also be used in FORGED I-beam axles but cutting a notch in the axle, we made them round to protect those who cannot tell a forging from a casting. This design will only work on the ’28-’34 cars. Rack and pinion conversions don't work due to rotations between components not seen in the ’28-’34 cars. Rack and pinion conversions don’t work since they are longer with respect to the centerline of the car and would not allow connection to the central idler arm so critical to this design. The most difficult part of the entire project is getting the spring right. Since this design has leverage present in a way the spring is loaded (as on any IFS system,) we supply additional leaves to stiffen the spring rate. We are trying to achieve the same axle shape, or “smile” that existed before the axle was cut. Doing so preserves the desired ½ to 1 degree positive camber setting of the wheels. You may have to experiment a time or two before you get that spring pack just right. The easiest way to do this is to drop the entire axle pivot center section down out of the crossmember, along with the spring. Clamp the leaves on each side of the center bolt to prevent their flying loose and then replace the center bolt with at temporary longer pin. Release the clamps and open the spring slack so that the extra leaves can be installed. LEave the main leaf on the shackles at all times. It is very difficult to “stretch” the spring enough to allow the shackles to assemble to the spring unless you are handling only the main leaf alone. Then the stack can be completed and the center bolt replaced. If you insist on doing it the hard way, you can place a scrap piece of 2 × 4 wood on top of the axle and jack up the car’s weight. The spring eye will slide along the wood yet ramin at the proper height as it flattens and gets longer. The spring perches that rotate the shackle’s eyes and bolt in make the job easier as well. You can release their mount bolt enough to make the shackle distance shorter, and then retighten after the spring is installed. |
|
|
|
|
|
|
 |
|||||
 |
|||||
|
For info on these Chasis products go to |
|||||
|
|||||
|
|
