Akebonos vs Upgraded BBK
 

After rebuilding the sport Akebonos this past weekend, my friend and I were pretty impressed with their size, heft, and finish. Aside from 4 vs 6 pistons, in what respects do the Brembo and AP Racing BBKs 'out-do' the Akebonos? I'm curious where the improvements truly reside.

extra piston

Better heat management as well. You probably wouldn't want to run the Akebono setup in a wheel-to-wheel competitive environment.

Larger mass and larger pads make the heat hold off longer. I think the brembos would probably cook after more than 30 minutes though. Fortunately, the fuel issue limits the time on track to 30 minutes max.

The calipers are a great solid design and would be more than adequate on a similar size and weight car with proper cooling. They are more substantial than the brembos on camaros, and they don't have problems

My AP-Racing BBK really has helped me allot since going turbo! But I come from a non-sport model so I did not have the Akebonos so I cannot speak for them.

Figured it was more a paucity of cooling rather than a caliper fault after seeing how well made the calipers look when disassembled.

I am cooking pretty much every pad I put in even the AP caliper. Without improving the cooling it seems pointless to upgrade the caliper. I would attack the cooling solutions first and see how the stock brakes hold up after that.

What do you guys think of some ducting from the fangs that attaches to and stops at the wheel well liner (hole cut in liner, tubing doesn't go through it). It would funnel a butt load of fresh air into the entire wheel well, but it wouldn't be delivered directly on the rotor. It would avoid any rubbing issues with ducting inside the well. Also, some huge ducting could be used since there would be minimal clearance issues. It seems our wheel wells are totally stagnant, and perhaps it would be enough to make a considerable difference. Thoughts?

Possbly, but I think ducted to the rotors would be best. Worth a try though. The corvette factory ducts just vent into the opening, but they taper down from 4" to 1" for velocity

I definitely think directing the ducts onto the brakes themselves would be most effective. Not quite sure how well just introducing more air into the wheel well would help.

I don't think it would be too terribly hard to rig a ducting system that blows air directly onto the brakes. Doing a quick google search comes up with a lot of nice custom-fabbed setups that look fairly easy to make. The most time consuming part would just be fabbing flange mounts and making sure you've got proper clearance.

Into the wheel well isn't going to be enough, has to be close to the brake rotor as my big *** wheels seem to block any passive air flow.

Travis had a custom kit made. Stillen is supposedly working on one (they have it on their press car) but any emails to them have fell silent.

I recall looking at Travis' log but he never extrapolated on the design. I'm not holding my breath for the Stillen kit as 1) they'll make everyone buy their fascia and 2) it will require plenty of labor, cutting, and redesigning to make it fit most likely (given how their other parts usually go).

The main problem I noticed when looking at the car with the fascia off is there are three options for getting air to the rotors if piping from the fangs. You can cut through the wheel liner and hope you don't have clearance issues with ducting in the wheel well. You can cut a hole in the bulkhead to pass the ducting through but you'll never get a 3" tube through there without some serious cutting. Finally you can route the ducting under the bulkhead and then back up, but you'll have ground clearance problems and have to cut or remove the underbody cover.

I'm leaning to a NACA duct pickup right by each wheel much like Modshack posted a while back on his Audi. My goal would be a single unit that bolts on with one or two bolts and can be easily removed when not desired.

I looked at it closely when I installed the oil cooler and as I remember there were quite a few openings but unfortunately they were all on the small side and would need to be enlarged. Probably the easiest route is through the fender liner, there should be enough clearance from the wheel if you route it carefully. You could even reduce the duct size at that point if necessary.

The main thing that I'm looking for is a metal duct outlet for the wheel hub. I don't have any equipment for welding so making this part is more or less impossible for me. The rest of it I'm sure I could hobble together from off the shelf parts.

Keep in mind that all parts supplied to OE manufacturers are made to a strict budget. We can surmise that one of the reasons that Nissan went from Brembo to Akebono was cost. To make calipers and rotors at lower costs, several features that improve performance/stiffness/feel/response/etc. get cut back as they are too expensive.

Also consider that the OE's usually require a cost-down schedule. This means they typically agree to pay 'X' during year one, 'X - 2%' in year two, 'X - 4%' in year three, and so on. Those cost reductions must be found by the supplier if they are to continue making money on the program. If you have ever owned a late-run GM vehicle, you might have suffered from this "cheapening" phenomenon. Those cars are usually better in year two or three, when all the bugs are worked out. But years 4, 5 and 6 get riddled with "cost-down" parts, which we has been proven to hurt reliability. I'm not saying the Akebono bits are going to get worse over time, but there is a tremendous amount of pressure on part manufacturers to reduce costs over a several year supply contract.

AP Racing aftermarket calipers, while not nearly as expensive as the full-race hardware, incorporate several features that OE calipers typically do without. That is, if you are not talking about the AP calipers that are OE on Bugattis, Koenigsegg, Lotus, Pagani, Gumpert, Ascari and the like.

One example is caliper optimization. AP invests an ENORMOUS amount of engineering R&D time and testing into making sure that each caliper model is a stiff and responsive as it can be. For example, three changes were recently made to the CP7040 6-piston calipers (the ones in the Z & G front kits) that are hardly noticeable without pretty sophisticated measuring equipment. Why would they go to all this expense for such small changes? It turns out that some of the lessons learned from the latest Radi-Cal development (NASCAR, Formula 1, others) were directly applicable to this particular caliper. Without question, they were incorporated, tooling modified, CNC programs changed, new hardware sourced, etc. A 12% improvement in dynamic stiffness (in all 3 planes) was observed as a result.

And that's just one aspect of the caliper. There are also plenty to talk about when it comes to properly vented, 2-piece rotors that are made from much better iron than the typical OE stuff.

You just won't see that sort of attention to detail on typical (less than US$80k) OE vehicles as the budget is just not there to support it. Sure, the level of fit and finish required is high, but don't expect optimum performance. If any additional R&D is spent on the OE units, it will only be due to a quality problem such as premature leaking, noise, etc. OE budgets usually do not provide for continuing development. Lessons learned from one run get wrapped up into development of the next project.