I am trying to get better all around better strip performance and never considered poly inserts for suspension how/why does it help suspension

 

By minimizing wheelp hop you have more traction available....more traction...lower 60'...lower ET.

Suspension plays a big role in your launch....minimize the weight in the rear of your car and it will minimize weight tranfer off the fronts...more traction is made available...stiffen up the rebound on the front end and minimize the amount of travel once the front end has compressed....simple tricks...better launch.

Just dont expect for a "drag" suspension to bring killer road course times