12:05 Garage- ’70 Duster build
Totally, it's definitely a balance. But I know that even in my street driving I'm bottoming my suspension still with a 300 lb/in wheel rate and the Hellwig sway bars, and I've maintained about the same amount of travel as stock so I'm at a spot where I know I need increase my wheel rate some. The 1.18's with a 370 lb/in rate may be a bit high, I'll have see once I get them into the car. But I don't think a 350 lb/in rate is going to be too much.
Yep, that's basically the same design as the Kit Cars used. It used a tube with bushings at the ends and a splined shaft sway bar running through the bushings. These are pictures from the spring car catalog, and some of the ones used on the kit cars. I split up the catalog page so it would be large enough to read here, check out those torsion bar diameter and wheel rates on the second page. 1.38" and 654 lb/in !
Yep, definitely a balance. You have to evaluate the suspension travel and how often the bottoming out is happening. If it's just during cornering while autoX'ing then the larger sway bar would be the way to go and should take care of it. But if the bottoming is also happening through bumps then you may need to increase the wheel rate. Obviously too high of a wheel rate will upset the car over bumps, but, so does bottoming the suspension. You want the lowest wheel rate that allows you to use your entire suspension travel without bottoming out the suspension frequently.
For me at 300 lb/in and in the neighborhood of ~5.5" of suspension travel I still probably bottom the suspension a little too much, even just on the street and that's leaving a pretty wide margin for tire grip in the corners, I'd obviously push harder on an autoX course. I'm beginning to come around to the idea that 350 lb/in is a lot closer to where the car needs to be for just the wheel rate off the springs.
Totally, it's definitely a balance. But I know that even in my street driving I'm bottoming my suspension still with a 300 lb/in wheel rate and the Hellwig sway bars, and I've maintained about the same amount of travel as stock so I'm at a spot where I know I need increase my wheel rate some. The 1.18's with a 370 lb/in rate may be a bit high, I'll have see once I get them into the car. But I don't think a 350 lb/in rate is going to be too much.
Yep, that's basically the same design as the Kit Cars used. It used a tube with bushings at the ends and a splined shaft sway bar running through the bushings. These are pictures from the spring car catalog, and some of the ones used on the kit cars. I split up the catalog page so it would be large enough to read here, check out those torsion bar diameter and wheel rates on the second page. 1.38" and 654 lb/in !
Yep, definitely a balance. You have to evaluate the suspension travel and how often the bottoming out is happening. If it's just during cornering while autoX'ing then the larger sway bar would be the way to go and should take care of it. But if the bottoming is also happening through bumps then you may need to increase the wheel rate. Obviously too high of a wheel rate will upset the car over bumps, but, so does bottoming the suspension. You want the lowest wheel rate that allows you to use your entire suspension travel without bottoming out the suspension frequently.
For me at 300 lb/in and in the neighborhood of ~5.5" of suspension travel I still probably bottom the suspension a little too much, even just on the street and that's leaving a pretty wide margin for tire grip in the corners, I'd obviously push harder on an autoX course. I'm beginning to come around to the idea that 350 lb/in is a lot closer to where the car needs to be for just the wheel rate off the springs.