Brake cooling for Nismo bumpers w/o holes - Stillen + GT3 ducts
 

Somebody asked me to post about my brake/cooling setup, so here goes.

I used the Stillen kit, but instead of cutting holes in my bumper (was never going to happen), we simply routed the hose to just below undertray, right behind and slight aft the wheel/tire, with a hard flexible mount so that it holds up to any bumps, scrapes, or off-track excursions. This inlet allows for cool fresh air. I can say, it has held up perfectly fine in all those situations, and has shown virtually no contact with anything since it's right by the wheel/tire, as it gains ground clearance nicely with any wheel movement.

Also, I have used $25 Porsche GT3 front ducts (I used them on all my track cars), as a very real and function method to increasing air-flow into the caliper and rotor areas. Both the OE and the new Z1 undertray have areas that allow air to flow directly onto the curved GT3 duct. The picture shown has the wheel turned all the way out, for better viewing, but when it's straight ahead, the duct is right behind the rotor/caliper dumping air there as well.

Finally, here's a pic of the most obvious design flaw of the Z1 rotors, compared to the Paragon race rings. The front/outer face of the rotor/hat assembly is open, meaning, any cooling that you vent into the rotor from a cooling duct, is not efficient and is turbulent. True race rotors have a solid outer face so that the air ducted INTO the cooling vanes from the back-side stay in the vanes and vent all the way through cooling the rotor. Z1's effort to "reduce" weight is on of the reasons they warp so easily, along with perhaps a lower quality metalurgy. It seems a high quality 2 piece setup isn't very common for these cars, and I wasn't sure that many people know about these guys. They will make 48-vane and 72-vane endurance rings for our cars. Until AP offers a CP5XXX kit that I don't have to cobble together from parts all over the world, I'm making the OE calipers work.

These two cooling brake mods, along with Endless RF-650 fluid, and Paragon's true floating 2-piece race brake setup offers fade free performance all session, all day. Been very happy with it. Most importantly, no hacking up my front bumper. Hope this helps for anybody with my same considerations.

Interesting. Can you show where the other end of the duct is pointed/attached?
I drive a 350z but imagine the same setup is possible with it.

that duct fits a lot better than i had suspected.
Haven't had any time to install mine yet.

There are GT3 parts that cost only $25 bucks? Whoa I would never have expected that.

Note: I just looked it up, it’s indeed that cheap, wowza

The AP Racing kit for front and rear are in the works now from Essex parts. I am waiting on a few parts to be completed, then I go for the install. They aren't cheap though. They will have AP Radical calipers.

Finally! Jeff is great to work with. Yeah, the Pro5000 calipers are pretty much their go-to, and for good reason.

I'm assuming they will be going with a 372mm x 32-34mm front ring, to ensure 18" wheel clearance?

Are the GT3 ducts only mounted to the body, and not moving with any control arms? Just wondering how the mounting worked out. I have 3 sets of them as potential add-ons to various cars, and wasn't able to figure out a good solution for them on the arms, but your setup looks much nicer.

I'll plug my Pro5000R kit which has been taking a good amount of abuse well from a few track Z's this year, myself included. I have two sets of brackets and hats still, and with the USD being so strong, the calipers are relatively cheap to pick up compared to last year. Pricing ends up being similar to Stoptech Trophy brakes as a result.
Getting away from the Akebonos means being able to use rings that support a closer to 2" pad depth, vs the roughly 2.75" depth needed with the Akebonos. This lets the rotors be much lighter and opens up a lot more choices.

Super interested in any feedback you have on Paragon's rings. They come up as very enticing alternatives to some of the AP ones, being a little bit cheaper. I'd love to hear how to wear over track days. I have a set sitting around, waiting on some more niche (much smaller) Pro5000R calipers to be in stock for my Exige.

Relevant I think, Z1 just released a full ‘kit’ with ducts at least for 2015+ Nismo’s: https://www.z1motorsports.com/z1-pro...804bcefa3cfadc

that **** is so ugly
and on the already uglier v2 bumper

I want to cut out brake cooling ducts on a v1 bumper. right where the nismo ducts go
But get paint matched magnetic covers to put in place when not at the track.

I am not sure yet. They didn't give me specific's when they were measuring my car. They did say I will not need my brake ducts anymore. LOL I guess the AP rotors move a ton of air. I did tell them the go to wheel for our cars are 18".
I am sitting here waiting on the machine shop to finish up on the brackets. It should be sometime this month. Just hang out for a little while. I can't wait to get some quality brakes.

You can always call Jeff and ask him any questions you may have.

They do. They are always 72-vane rotors. I have a Pro-5000 PC9660 kit on my M3. It's seen countless track days, and still on the same original rotors 7 years later. Crazy.

The caliper profile is much smaller than the OE caliper, so it allows them to upsize the rotor alot with the same or better clearance than OE. I'd bet on the 372, but anything will be more than adequate.

That sounds damn good. I am sure the rotors will last a long time for me. I just want to have fun and not worry about my brakes taking a dump.

One thing you will notice on here folks will piece mill the crap out of their brakes trying to get them to work properly for the track. We have never had a quality kit we can buy. The stock calipers have got to go. No way around it.

I'll try to take some more in detail pics. They are sort of hybrid mounted on the control arm and partly on the swaybar.

So far that Paragon rings have been great, all their rings use the same motorsport quality material. The fact they can provide a 72-vane rotor for sport brakes is a great benefit. As you know, going from 48 to 72 vane is a BIG step up in thermal capacity and longevity. It's going to be good enough for most of the DE guys.

I'm a hardcore track guy, but I spread out my track miles on various cars, and until I get the ABS situation figured out, the Z will see limited track time until then, and my current setup will be adequte.

When you push this car to the limit, it's just too inconsistent with potential for a catastrophic failure by the ABS. My local tracks have too many brake zone that bend, that are exactly what this ABS system hates. It's not fun to have the baby the car into a bunch of corners to keep it from trying to kill you. If the front-only kit gives the car a bit more front bias, which this car seems to need, then I might bite, but will wait and see how things pan out.

I am tired of lifting the heads on our motors. I am turning my power down and going a different direction so I can do some track days. I won't be a serious track guy, I just want to have fun. I want to go to Road Atlanta, Daytona, and Sebring. I live 30min from Roebling road.

Hotrodz has the ABS upgrade you want. Maybe one day he will get back on here to give some details. I know they installed extra wheel speed sensors. I am not sure how they did it. WRtechnica did the install. Getting the ABS module took a while due to COVID19.

You will not be disappointed in your investment. It's the best brake system I've ever had, on any car.

It's a massive install that requires complete hub removal and machining to install the additional sensors. Car would be on a lift for 2 weeks at my shop. Not interested in going this route yet.

I am sure it can be done another way (electronically), just waiting for it to surface, or I get the time to dig into it myself. Just super busy with other stuff right now!

Yeah, they went through hell getting his to work properly.

Car went back in the shop for the test fit last week. They were supposed to start today on it. First thing on the agenda was to test fit a new street kit. The 2nd thing was to install the competition kit on my car. Essex will not sale AP Racing calipers, rotor, or top hats separate. You have to order a complete front kit or rear kit from them once they ask you a few questions to ensure a proper setup for your future needs. The competition kits will be ready to order once they do the final fitment on my car.

Im interested in the extras taken to help the ABS be more predictable.

What I guess happens is the OEM sensors especially in the front give an improper speed with the flexing of the front hub?

The factory ABS unit cannot take more that 4 speed inputs unless theyre supplementing the oem ones or upgrading them to better sensors.
Our ABS unit seems to be the same as some Subarus of the same year.
So it makes me wonder the specifics.

I was under the impression it was issues with the YAW's sensitivity more than improper wheel speed.

It's when both front speed sensors or both rear are showing different speeds under braking. Like the car is on ICE. It kicks the ABS system into thinking the car is on ice during a lockup. I am not sure how it is programmed into the ABS control module. There is a problem with the algorithm they are using from the factory.

The YAW sensor will activate the rear brakes, left or right, depending on what the sensor reads. It will activate the brakes of the inside tire to try and straighten the car out. That **** is dangerous as hell if you are on track. It happened to me on the Tail of the Dragon. I started to slide, counter steered into the slide, and the next thing I know the car snatched back the other way violently and damn near took me off a cliff.

So from my research I've noticed the ABS needs at least two sensors for our speedometer to work. It could all really be software interpretation however if they're adding extra sensors it's possible they're supplementing the ABS unit with a more finer tooth count etc

I too dislike the ABS engagement of these cars. I was under the impression ECUTEK's adjustable traction control capabilities would help it's over reaction by softening it's traction control to one a bit more decent.

I turn the traction control off. I never ever use it. It's a throttle cutting beast.
I still need to do the Yaw sensor switch to turn that crap off too. I just need to wire it up. My switch is already in place.

Here you go. New AP racing brake kits are done.

https://www.essexparts.com/my-vehicl...port%20Package

Yeah, my CP9660 kit is on the way. Went Front-only, I have the CP9660 caliper on my E92 M3, which is faster and heavier than the 370Z, and it works just beautifully. I'm still on the same rotor almost 6 years later, based on occasional DE use. The CP9668 caliper is awesome and uses the thicker pad, but the real key to this package is the 372x34mm 72-vane rotor. Can't go wrong with either kit!

So glad Spooler got his car in there!

It's a must, get that wired up.

Yup, I just got to cut a wire and splice it in. I will get it done. I hate that crap.

Just drove mine tonight. They are very good and do excellent with heat management. I really had to get after them to get them a little warm.

:tiphat: Installing mine later this week. Picked up a set of gray OE rear calipers to make things match a little nicer, since I have red calipers.

Agree! Z1 2 piece rotors are totally garbage for track days. I warped 3 sets. Two of them warped in 2 days and 1 warped just in 3 sessions.
They are OK for street driving. But stay away from Z1 2 piece rotors if you are serious about tracking.

I upgraded to AP9668 with 372mm rotors using the bracket DarkJak provided. It solve the problem completely. It handled 30+ hard track days even without ducts.

Finally, a real motorsport grade kit for this car. With cooling, these rotors are going to last a long, long time.

I added the Gray OE rear caliper to give it matching color setup, instead of the red rear caliper. Turned out great.