There is a guy local that is just starting a new business in Suspension tuning. Its a niche that hasn't been tapped into here. He's the only one around that specializes in four corner tuning of drag cars.
He's an old friend, and had him come over to look at my car. We set it up on the scales. It weighs just under 3300lbs empty with 57% front bias. On the front, lateral (side to side) bias was within 15lbs with me in the car. In the back it was a little more dramatic. Somewhere around 55lbs with me in it.
He also calculated center of gravity and the instant center of my car. The instant center is point on the car that weight transfers on. its the "pivot point" when the front end lifts on a launch. Mine was a little low, which meant that it would hit the tires softly. After some more calculations, we found that with a 28" tall drag slick my instant center would be just about perfect for my car. Also, moving the battery to the back would even out the rear lateral bias almost perfectly.
We also measured the suspension travel of the front. I forget, but I think it was 4.5" of travel which is a little short for his liking. He likes for cars to have around 6" of travel.
One big thing we found out was when checking angles of my driveline. My motor and transmission were perfect (-4deg). However, we found that my calculated pinion angle was +3deg
:dw: We figured this was due to me cutting the springs and lowering the rear of the car. He suggested taking about 7 degress out making it a total of -4deg. I went to sears and bought a angle finder and played around with the uppers till I got it.
I went and took it for a test drive and oh my did it make a difference. The rear control arms don't chatter NEAR as much as the use to (i have solid mount uppers) going over bumps or starting from a dig. The car doesn't creek and moan and groan as much. And get this, the little bit i've driven it i have experienced NO highway speed vibrations or whining/roaring.
Also, the car freaking HOOOOOOOOKS!!!! before, from a first gear it would haze the tires up till red line and then blow them off during the 1-2 shift. Now it will squat and I can literally see the front end rising up. The car plants, still hazes the tires (but a lot less) and just plants and moves on the 1-2 shift.
That's all on a 17" Nitto Drag Radial. I can't wait to get some 28" slicks on the car with some nitrous
He's an old friend, and had him come over to look at my car. We set it up on the scales. It weighs just under 3300lbs empty with 57% front bias. On the front, lateral (side to side) bias was within 15lbs with me in the car. In the back it was a little more dramatic. Somewhere around 55lbs with me in it.
He also calculated center of gravity and the instant center of my car. The instant center is point on the car that weight transfers on. its the "pivot point" when the front end lifts on a launch. Mine was a little low, which meant that it would hit the tires softly. After some more calculations, we found that with a 28" tall drag slick my instant center would be just about perfect for my car. Also, moving the battery to the back would even out the rear lateral bias almost perfectly.
We also measured the suspension travel of the front. I forget, but I think it was 4.5" of travel which is a little short for his liking. He likes for cars to have around 6" of travel.
One big thing we found out was when checking angles of my driveline. My motor and transmission were perfect (-4deg). However, we found that my calculated pinion angle was +3deg
:dw: We figured this was due to me cutting the springs and lowering the rear of the car. He suggested taking about 7 degress out making it a total of -4deg. I went to sears and bought a angle finder and played around with the uppers till I got it.I went and took it for a test drive and oh my did it make a difference. The rear control arms don't chatter NEAR as much as the use to (i have solid mount uppers) going over bumps or starting from a dig. The car doesn't creek and moan and groan as much. And get this, the little bit i've driven it i have experienced NO highway speed vibrations or whining/roaring.
Also, the car freaking HOOOOOOOOKS!!!! before, from a first gear it would haze the tires up till red line and then blow them off during the 1-2 shift. Now it will squat and I can literally see the front end rising up. The car plants, still hazes the tires (but a lot less) and just plants and moves on the 1-2 shift.
That's all on a 17" Nitto Drag Radial. I can't wait to get some 28" slicks on the car with some nitrous
