Adjusting a tune with weight

[Samareye]

I found this great tune by RKM Motorsports for the Ford GT '06.

It has weight reduction stage 3, and I don't want to do that to my GT - just the de-attachable elements. How can I adjust a tune for more weight, what settings would be affected?

I appreciate anyone's help.

 

[shmogt]

Heavy cars have harder springs and pretty much everything suspension wise a little bit more so maybe just stiffen up everything. Drive it first tho to see if it even needs any changing