The AP 5040 system is proven to work well so no reason not to use it.
The bigger disc will always allow more leverage as long as the pad area and clamping force is able to use it.
Bear in mind that it's ultimately the pad that does the stopping part so worth spending your money wisely in that area.
If the AP has more pad area and bigger effective diameter then it's in 1st place.
The Wilwood may have more pad area due to a longer pad being pushed by the extra pistons but it will lose out on effective diameter.
No doubt there's a clever coefficient that considers all this but I've no clue what it is or where to find it!
The other consideration is whether this is a road or track only car or not and the issue of dust seals.
The 5040 doesn't have them and I don't know about the Wilwoods as it depends which one you're looking at.
I'd personally go with AP calipers but not necessarily the 5040 items.
This decision is based on Wilwoods being known to have occasional problems and AP rarely having any.
I can't imagine the differential between either is that huge.
The bigger disc will always allow more leverage as long as the pad area and clamping force is able to use it.
Bear in mind that it's ultimately the pad that does the stopping part so worth spending your money wisely in that area.
If the AP has more pad area and bigger effective diameter then it's in 1st place.
The Wilwood may have more pad area due to a longer pad being pushed by the extra pistons but it will lose out on effective diameter.
No doubt there's a clever coefficient that considers all this but I've no clue what it is or where to find it!
The other consideration is whether this is a road or track only car or not and the issue of dust seals.
The 5040 doesn't have them and I don't know about the Wilwoods as it depends which one you're looking at.
I'd personally go with AP calipers but not necessarily the 5040 items.
This decision is based on Wilwoods being known to have occasional problems and AP rarely having any.
I can't imagine the differential between either is that huge.