the right braking system

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.

Dave Bilyk

Dave Bilyk
Hi H.J, Front Wilwood Superlite 4 Pot, rear, with Hispec Billet 4 all with 310mm (12.19 in) discs worked for me, no servos. I thought about 6 pots, but thought that that would definitely require servos due to the smaller total piston area. After having Servo issues I preferred to select for a servo-less system.


I think the most important factor is the diameter of the brake disc.
I would like to use this rims: 427_VintageWheels
No chance for brake discs larger than 295 m with these rims on the rear axle.

I also tend towards the AP solution.

But Mark has mentioned another point that I hear often-
How big is the problem if there is no dust protection ?

And then there is Dave's point:
Pro / Contra servo support ....
I thought most of them here are without a servo, right?
No dust protection shouldn't be a problem for a track only car. None of my race cars had that over almost 30 years. Piston seals should be replaced every season if you're really heating the brakes up.
the front calipers are usually behind the front axle line on rear engined sports cars assuming the steering rack / arm is forward of the axle line. the rear calipers are usually forward of the rear axle line.

Ian Anderson

Lifetime Supporter
Pro / Contra servo support ..
What do you think Servo yes or no....
depends on what pedal ratio you get in.
and then you have to consider two servos one for rear and one for front master cylinder Like this
or one of the hybrid servos like this
and if your engine has a big cam you may not get a good vacuum so then a vacuum pump too like this

it all adds to ££££ and weight and complexity, so if possible no servo and a decent pedal ratio