Originally Posted by
Krio
More drastic in what way? What force on the chassis is being magnified by such a change in geometry? What does that mean for different circumstances on the track? I'm not arguing against you, but you are making blanket statements that are easily mis-interpreted. Technically the car is .003 inches wider with the 2.5 block, the arm becomes more trailing by half a degree, and without adjusting shims increases the wheelbase by .05 inches.
There is a difference if you do not shim hubs back to original location…
The biggest difference with the 3.0 block and 0 hub vs. the 2.5 block and .5 hub is the position of the hub in relationship to the outdrives.... The 3.0 and 0 hub setup creates more down angle drive with the driveline which pulls the rear end down under acceleration more than the 2.5 with .5 hub (Unless hub is shimmed in exact same location as 3.0/0.0 setup)
It seems like a small change but driveline angle is a huge tuning factor most don't take into consideration. With the 3.0 and 0 setup the rear hubs are moved forward a little in comparison to other setup. This is what changes the driveline angle creating a larger down pull on the chassis under acceleration.
This is the same effect you get when you in general move your hubs forward and is usually a combination of weight transfer change as well as driveline bind change. More often the driveline bind change is actually what creates the increased rear drive under acceleration more than the weight transfer change by moving hubs forward or back.