I wanted to make a separate post to address the no swaybar ride issues of my racecars. My DSP X1/9 weighed about 1930 lbs, on grid, ready to run. Weight bias was in the 44/56 F/R range. The front springs were 750 lbs/in and the rears 500ish lbs/in. When I first tried the car with no swaybars I was in the 550/400 range. Before I understood the issues of favored speed and another characteristic called "center of suspension" (the point between the two axles where an applied vertical load compresses both ends of the car equally), I didn't understand why the rear end of the car was pitching up and down excessively.
That motion was caused by a moment arm that is the difference between the center of gravity and the center of suspension. Much like the moment arm that is the difference between the car's roll center and center of gravity, that causes the body to roll in a turn, the center of suspension moment arm levers that end of the car up and down. Effectively, the center of gravity of the rear weight bias car is closer to the rear axle than the front. The center of suspension (see above description) is closer to the front axle due to the stiffer front springs. So when the car passes over a bump, regardless of the ride frequencies the center of gravity acts at the end of the fairly long lever (moment arm) and pitches the rear end up and down in response to the motion. The rear mass literally over powers the rear springs and shocks.
Once I learned the cause, and understood the principles involved, I could adapt. I learned to adjust the rear shock valving to manage the mass and motion. This is key in making the no swaybar work effectively. Another key factor I learned with the MR2. I stared the MR2 off with very similar ride frequencies and roll ratios to the X1/9 because the X1/9 was so good. As I continued to develop the car, work with the newer generations of tires and increased levels of grip, I kept going higher on spring rates and ride frequencies. Now the MR2, which weights 300 lbs less than the X1/9 is on 800/500 F/R spring rates. The ride frequencies are much higher than the X's. In fact, my ride frequencies are in the same range as the IMSA Prototype class racecars. Yet with highly developed shock valving the car rides quite nicely. When I let other people drive the car, and tell them what the ride frequencies are, they expect a punishing ride. However, the comments I usually get after their first drives on course are "I never noticed the ride quality". The do notice the car's responsiveness and feedback.
Below are a couple of photos that, at first look may not seem that impressive, but once you understand what is happening the perspective changes:
First is a photo of my DSP X1/9. I am trail braking the car into a corner. One of the comments I get from skeptics is "That car is too stiff to work". In other words, the car can't move on its suspension and therefore can't generate weight transfer. Look closely at the amount of body roll and compression on the outside front corner. Its important to note that at static ride height this car was very close to sitting on what would have been the stock bump stops. The suspension system I had on the car added a great deal of compression travel. So note that the right front suspension is compressed well past where the stock car would have bottomed out yet still hasn't bottomed. And, most importantly, those are 750 lbs/in front springs. Now consider the amount of weight transfer to compress that spring that far.
Now look at this photo and note how little body roll the car has. It has no swaybars. The tires are Hoosier radials racing tires. The car is pulling about 1.5 lateral g in this photo. If you doubt the lateral g number, look at the tire deflection at the contact patch.
