Leaf spring suspension

[NHRA1926]

Daily Driver Sst. I run a 3700 lb 67 Camaro with a 496 pump gas John Lingenfelter engine. It runs 10.50's @ 127 mph. It's still a street driven car with full interior and working lights and such. It has Caltrac bars, Afco shocks, (which are a must with the bars). I installed Caltrac split mono leaf springs and did see a big difference. But, the biggest gain in 60 ft. times was when I installed a set of Mickey Thompson Pro Drag Radials. 60 ft times went from high 1.40s - low 1.50s, all the way down to mid to high 1.30s. The Calvert springs and bars put a HUGE down force on the tires this is why the Afco shocks are so important. I used to run Competition Engineering shocks, but there is no way they can overcome the body separation of the down force caused by the Caltrac bars. Coming of the trans-brake @ 3,000 RPM, the car used to flatten the tire to the point that it was wearing off the side wall writing of the tires, then obviously it would spin, then hook hard again, folding the tire, spin, then hook and take off. the only way I found this out, was by video taping the launch, and playing it back frame by frame in slow motion. The tires completely stopped all that from happening. Best thing I've ever done to the car. Now the cars carries the front wheels about 2 feet high till just passed the tree. I am very satisfied with John Calverts products. I did notice in the picture that you tie the car down using the frame. In theory, this is the correct way the not wear out the suspension during transport. But, keep in mind that you have a very heavy 4500 lb car. you may want to try tying it down at the rear axle instead, and stiffen the shocks during transport mode. It may be putting too much pressure on the springs during transport tying it down from the frame. Just my 2 cents. Hope this helps.
Lugnut

[DailyDriverSst]

Originally Posted by NHRA1926

Daily Driver Sst. I run a 3700 lb 67 Camaro with a 496 pump gas John Lingenfelter engine. It runs 10.50's @ 127 mph. It's still a street driven car with full interior and working lights and such. It has Caltrac bars, Afco shocks, (which are a must with the bars). I installed Caltrac split mono leaf springs and did see a big difference. But, the biggest gain in 60 ft. times was when I installed a set of Mickey Thompson Pro Drag Radials. 60 ft times went from high 1.40s - low 1.50s, all the way down to mid to high 1.30s. The Calvert springs and bars put a HUGE down force on the tires this is why the Afco shocks are so important. I used to run Competition Engineering shocks, but there is no way they can overcome the body separation of the down force caused by the Caltrac bars. Coming of the trans-brake @ 3,000 RPM, the car used to flatten the tire to the point that it was wearing off the side wall writing of the tires, then obviously it would spin, then hook hard again, folding the tire, spin, then hook and take off. the only way I found this out, was by video taping the launch, and playing it back frame by frame in slow motion. The tires completely stopped all that from happening. Best thing I've ever done to the car. Now the cars carries the front wheels about 2 feet high till just passed the tree. I am very satisfied with John Calverts products. I did notice in the picture that you tie the car down using the frame. In theory, this is the correct way the not wear out the suspension during transport. But, keep in mind that you have a very heavy 4500 lb car. you may want to try tying it down at the rear axle instead, and stiffen the shocks during transport mode. It may be putting too much pressure on the springs during transport tying it down from the frame. Just my 2 cents. Hope this helps.
Lugnut

Hi Lugnut,

Thanks for the info! That's not my photo, that's from Steve Dziony (same platform I have). Definitely going with double adjustables on each end, the front are stock mount so my only limitation is dimensionally correct shocks for the front. I'm adding a crossmember for the ARB and rear shocks, so I'll have regular mounts and a decent set of options for the back.

So you are finding that in your application, there is enough vertical separation available in the spring to give full droop to fully plant the tires? This was my main concern when talking to the tech at Calvert - they have a split mono profile for my application, but since they use spring arch to set ride height independent of spring rate, this is where my knowledge runs out. I'm use to using spring rate as a component of ride height in coil applications, and thought that it would at least factor in for my application given the obesity of the truck.

The problem I'm running into is that most of the setups on the platform I'm using are N/A, regular cab, and completely stripped out of all HVAC and anything else not required by stock/Sstk interior rules. I'm working with a power adder, extended cab, and fully functional interior. I'm 5-600 pounds heavier than most, and about 400 pounds over the next closest combination I can leach notes form.

This is exactly what I needed to know - I was planning to run the MT 3062S (29.5 x true 10.5 x 15) but given my weight, I wasn't sure even a stiff wall and 12 PSI would be enough to hold up. I've read some people have issues with the PBR tires on lackluster prep tracks, but every situation is different.