converting to leaf springs

Larry Woodfin · Post by **Larry Woodfin** » Fri Jun 27, 2008 10:18 pm

This my seem like an usual question, but please humor me.

Has there been some instances where racers have converted a non-leaf spring car/chassis to leaf springs? Example, are you aware of anyone converting a General Motors "G" body [Malibu, Regal, Cutlass] to leaf springs and CalTracs? I realize this is consider usual, however it has my interest. I do have the equipment and knowledge to make such a conversion.

nosnerd · Post by **nosnerd** » Fri Jun 27, 2008 10:29 pm

would this be in a drag racing application?HP?TQ?tire size?

please elaborate

alan

Larry Woodfin · Post by **Larry Woodfin** » Fri Jun 27, 2008 11:06 pm

yes, drag race only, it is simply a thought I have considered for some time. I would first built a new frame/spring support structure about 5" - 5 1/2" inboard of the factory frame. [while the factory frame was till in place.] I would work with John Calvert {Calvert Racing, CalTracs owner} in ref to leaf spring dimensions, spring rate, and spring support points location. Would use an Afco roller rear spring eye like some Mopar applications. In addition, would work with Calvert to correctly position a set of CalTracs.

Once the new support structure was in place the factory frame would be removed, then wheel tubs added. Using a G body as an example, I would make room for about a 30 X 12 or 31 X 12 tire.

The proposed project would weigh about 2900 - 3000 with driver, be small block powered and run low 10's 1/4 mile.

hotrod · Post by **hotrod** » Fri Jun 27, 2008 11:32 pm

I have fabricated an entirely new leaf spring setup on a car that had a major engine transplant. It came with a weak 6 cylinder (Studebaker champion) and I dropped a built 58 Chrysler Hemi in it. The stock rear springs were totally inadequate so I built new perches with 3 holes in them to have adjustable front spring height adjustment and new rear spring hangers, and grafted them on the side of the OEM frame and welded gusset plates to allow an extra body mount at the front spring eye. It was very simple and straight forward to build and worked very well in my case.

The 1960's vintage Chryslers with their leaf springs which had a short stiff front section and longer more supple rear section handled the torque of my Chrysler hemi quite nicely. The Chrysler Imperials of that period also had a built in traction bar that operated in tension on the top of the axle housing from the factory. Carol Shelby used a similar setup on other cars a few years later. It made for a nice low profile traction bar that was very weight efficient.

Larry

Bubstr · Post by **Bubstr** » Sat Jun 28, 2008 10:58 am

I don't see any reason you couldn't put a leaf in any car. Especially if your redoing rear frame. I have heard that Cal tracts don't work the best with the Mopar SS type spring. I'm not sure why they do better on a mono leaf. Instant centers are instant centers and spring rate is spring rate. The leaf is harder to adjust these things but is probably the strongest side control you can get. Weight is a bit of a problem too.

I have tried a side by side leafs to 4 link, using the same engine different cars the same weight. One SS the class before pro stock, and B/Gas. Times was with in hundreds. Gasser had a little MPH advantage from frontal area. Both very competitive cars Mopar in 70 71. Of course they didn't have 60 ft times then. They would probably be slow by todays standard with so much better tires.

Larry Woodfin · Post by **Larry Woodfin** » Sat Jun 28, 2008 2:10 pm

I often consider if something can be done a different way. In seasons past, I have built fast cars with ladder bars and four links, all successful and consistent.

Then two years ago I built an F/SA Nova with CalTracs and his split-mono spring and shocks. As I began running the stocker I talked with John Calvert several times about fine tuning the suspension. I found John insightful and experienced. Plus, there was something special & smooth about the Nova's handling. The Nova lifted the wheels smoothly and drove dead straight. We are talking driving with one finger smooth. John explained how the side to side stiffness of the leaf spring [as mentioned above] greatly enhanced the straight line handling.

And speaking of weight, I have not weighed the individual components of each system, however, I do not think the weight penalty is that great. Besides, at least any additional weight is on the correct end of the car.

nosnerd · Post by **nosnerd** » Sun Jun 29, 2008 1:03 am

the afco roller set up is the way to go....

looks like ya got the whole thing scienced out

keep us posted...

alan

Alan Roehrich · Post by **Alan Roehrich** » Sun Jun 29, 2008 7:11 pm

I suppose it could be done, but the GM 4 link is far superior to any leaf spring setup. What you need in that application is an Alf Weibe set up, or you could use one of the other aftermarket setups (Metco makes some nice stuff). I narrowed my 84 Cutlass enough to use a 12" tire with plenty of clearance, I could probably get a 14" tire in it if I tried. The car ran in the 11 second zone, on street tires. All that car had was a 12 bolt, coil over shocks, and no hop bars. I used 4" square tubing (1/4' wall) to narrow the frame, because it was there. Ideally, you should probably use 1/8" 2x3 tubing and 1/8 plate gussets. We were in a hurry and used what we had, I had to drive the car in 48 hours.

You need only see cars like Kevin Borgstrom's B/SA 69 Chevelle carry the front wheels 3' high past the 60' clocks on the way to easy 10.50 ET's to know the GM setup can deliver, with the proper modifications.

I'll be using Alf's stuff on my new car when we find the right body to start on. And I find the time.

nhrastocker · Post by **nhrastocker** » Mon Jun 30, 2008 7:55 pm

Alan Roehrich wrote:I suppose it could be done, but the GM 4 link is far superior to any leaf spring setup. What you need in that application is an Alf Weibe set up, or you could use one of the other aftermarket setups (Metco makes some nice stuff). I narrowed my 84 Cutlass enough to use a 12" tire with plenty of clearance, I could probably get a 14" tire in it if I tried. The car ran in the 11 second zone, on street tires. All that car had was a 12 bolt, coil over shocks, and no hop bars. I used 4" square tubing (1/4' wall) to narrow the frame, because it was there. Ideally, you should probably use 1/8" 2x3 tubing and 1/8 plate gussets. We were in a hurry and used what we had, I had to drive the car in 48 hours.

You need only see cars like Kevin Borgstrom's B/SA 69 Chevelle carry the front wheels 3' high past the 60' clocks on the way to easy 10.50 ET's to know the GM setup can deliver, with the proper modifications.

I'll be using Alf's stuff on my new car when we find the right body to start on. And I find the time.

I agree with Alan... the Alf Weibe, 2nd generation traction system for GM, A and G bodied cars is the best. The system makes the car consistent and will hook in a car wash.

Larry Woodfin · Post by **Larry Woodfin** » Mon Jun 30, 2008 9:40 pm

I mentioned to Alan in a private message that the last time I talked with Alf he was not building parts and did not build any parts for a G body. However, that was about four years ago. Sounds like things may have changed. Do we have a current contact for Alf? If he is indeed building a G body system I want one.

nhrastocker · Post by **nhrastocker** » Mon Jun 30, 2008 11:49 pm

I think he is back in business since there are some cars that are running his new stuff.

bigjoe1 · Post by **bigjoe1** » Sat Jul 05, 2008 8:25 pm

I am NO IMPRESSED with the Cal tracks at all.Years ago we had a Nove leaf spring car that was pretty cast ( 9.40 at 142) calvert gave me some caltracks to try. It looked fast and better, but it NEVER ran quite as fast as before.

JOE SHERMAN RACING ENGINES

Larry Woodfin · Post by **Larry Woodfin** » Sat Jul 05, 2008 9:20 pm

Joe,

what did you take off that Nova when installing the Cal-Tracs?

bigjoe1 · Post by **bigjoe1** » Sat Jul 05, 2008 9:59 pm

I believe they were the Competition Engineering( Moroso) J bars. They were just the simple kind that bolt up to the spring pads( slapper bars)I always found what made the chassis work better was MORE HORSEPOWER

JOE SHERMAN RACING ENGINES

Larry Woodfin · Post by **Larry Woodfin** » Sat Jul 05, 2008 10:32 pm

When Gary Harwood began building his 27 Roadsters We were talking about rear suspension when he said "the harder it leaves, the harder it can leave"

It's the same thing Joe is saying, more power always helps!

Don Terrill’s Speed-Talk

converting to leaf springs

converting to leaf springs

question?

the afco roller set up...

cal tracks

leaf springs