This is the next (and final) increase in power for the 4.5 Whipple. We are running the 4.0" pulley with the 10% ATI and have it working so efficiently now that we are at 1202whp with only 22/23 lbs boost at 7000 rpm.
I talked to Whipple about critical rotor speed limits and whether we could spin it faster to make more power. They did the math and said as long as we have the temps under control, the answer was.... YES. This 3.50" pulley will be the sweet spot (we hope).
The 4.5 Whipple is at the end of it's competitive life. The new 3.8 will be replacing it, but we are not going to hold our breath waiting for that to be available. Whipple told me 4 months. They also told me that the new 3.8 will be capable of supporting 2200 hp. I'm sorta holding my breath