I know if I lower my Celica the roll center goes into the floor. Which means it needed RCA's. Recently I swapped back to stock suspension for rallycross. If I raised my suspension, how do I correct the roll center for that? Also, how do correct the positive camber gained by raising the car? Mac strut front. Solid axle back.
You measure everything, and do a lot of math.
Camber plates???
How much of a raise are we talking about? How far are the LCAs from parallel to the ground? If you're raising it to the point where they're higher at the inside mounting point than the outside, that's probably not terminal. Your only real choices to correct become spindles with different geometry or lowering the inner mounts. But the real answer is as long as you aren't moving the RD above the CG you'll probably get away with it with the right spring choice. As that RC moves toward the CG the car will naturally be pretty stiff because of the lack of roll couple. Super heavy springs are probably not the ideal solution in that case.
Good info. I forgot about this thread. Sorry for the neglect. I don't know what other Mac strut suspension I could incorporate. Although I'm not lifting it by much. Maybe an inch.
I could relocate the lower arm inside mount. And then Get taller tires and cut into the fenders.... But jeeZ.
For the roll center after-lift, I'd try to figure out where it ends up and also just drive the thing and see how it feels. If it's ended up somewhere unreasonable or the thing doesn't drive right, then worry about fixing it. If it seems to work well, then leave the roll center alone.
An inch will hardly change anything to be noticed. Factories do it all the time with different models.
You may be over thinking this, not enough to worry about.
Raising the car will raise the roll center, on a strut suspension, as well as the CG.
The higher RC would be a help rather than a hindrance. Allows a bit softer stab bar for better traction while maintaining balance front to rear.
As for camber, Get out the rat-tail file or die grinder and elongate the lower strut mounting holes to allow more negative camber. Grind the lower hole towards the tire to allow the knuckle to slide out at the bottom. Grind them the same side to side so at least the start point is similar. Measure and then slide the knuckle back in to meet your alignment goals. If it is a pinch-bolt type strut, you gotta go with camber plates or slotting the lower control arm mounting points.
You'll need to log in to post.
