These have been in the works for a while, I almost spilled the beans when everyone was talking about brake duct sizes a couple weeks back, but finally now I’m really pleased to offer 2.5” and 3” brake duct solutions to our community.
These are now in stock at Good-Win Racing and Trackspeed Engineering:
2.5" Brake Ducts @Good-Win
& 3" Brake Ducts @Good-Win
2.5" Brake Ducts @TSE
& 3" Brake Ducts @TSE
Andrew is also offering kits with hose of the appropriate size, clamps, and zip ties as an add-on.
Why 2.5” or 3” ducts?
By this point it’s well established that proper brake ducts are a key part to a track car’s braking system, and there are huge benefits to increased hose size - the airflow increases as a square of the diameter, so a ½” increase in hose size actually produces a very significant difference.
This sums up the recent discussions that have been going on regarding brake duct size, and this is essentially the type of findings that started me down the path of developing these:
Originally Posted by emilio700
We found the difference in velocity and volume from 2" to 2.5" to be huge, even with almost no bends. With a 90° bend the flow from the 2" dropped off to a bare fraction of the 2.5". The 3" was awesome even when kinked twice but just about impossible to fit in there with wide wheels. So we run 2.5" and aim it at the hub/center of rotor.
The largest difficulty that arises as hose size increases (especially with 3”) is getting the orientation just right between the wheel, spindle, sway bar, etc. since tolerances are slim - so a specialized part that locates the hose and its outlet position becomes more critical - and that is what these do for you.
But, these are not only for the extreme track crowd. It makes sense to use brake ducts on nearly ANY track-driven miata for two reasons:
Even if you aren’t at the limit of the brake pad/fluid’s operating temperature, decreasing the temps of the brakes can drastically increase their lifespan - in many cases pad life can nearly double (In other words, these pay for themselves over time)
A low-power car may be able to run track-only pads and avoid reaching the limits of the pad, but many people in the double-duty street/track category want to run a less than crazy aggressive pad. In these cases, really good brake ducting can be the key to keeping those pads within their operating temperature range and not destroying them.
3" vs. No Ducts test:
I recently ran the 3” version vs. no ducting at the track (taped over the duct inlet on one side of the car). Following a brief half-session, and after a cool down lap
which allowed temps to come down and stabilize a bit, on the non-ducted side we saw caliper temps of 585*
. For those of you keeping score, that’s just a breath away from the boiling point of the Motul RBF600.
On the ducted side of the car, the caliper was 445*
. Perfectly happy.
I had intended to do more testing with the side that was blocked off, but after seeing those temps I aborted that plan and kept both sides ducted the rest of the day. I literally would not run my car without these.
I’m running the 3” on my car and Sean has the 2.5” on his, and these are already out there on a few member's cars - Keith Tanner is running the 3” units on the V8 Targa car, Martin has recently added 3” units to Lazarus, and Curly is running the 2.5" versions. I’ll welcome them to give any of their impressions and input if they’d like.
3" On my car:
2.5" on Scooby (Sean's car):
I'm really excited to see and hear about you guys further raising the bar with your car's potential. It gives me a special kind of satisfaction to be able to have a hand in making that possible.