Tracking again, need inexpensive brake improvements

[Kyle]

Hi guys - long time no type.

I'm taking my Z to Thunderhill for a track school day, which I've done before... this was pre-restoration, and pre-engine rebuild. With maybe 150HP, I was hitting 130 and having a scary time stopping after the first couple laps.

Well, now I've got more like 200HP, and I haven't done a thing to the brakes. Stock rotors, calipers, drums, wheel cylinders. Only mod is SS lines. Master and calipers were rebuilt about ten years ago (wow, already!), and I'm using cheapie pads. Rear brakes are in excellent original condition, and surely I must have replaced the shoes at some point in the last thirteen years of ownership.

I have a BRE spook replica on the front, with brake ducts, but they don't lead anywhere; I'm considering fabbing some ducts to the backing plates out of 4" dryer ducting. Anyone have any tips, writeups on this?

I'm also thinking some better pads would help immesurably. The car gets driven VERY rarely, and on the street when it does. So I'd like something with good cold performance, low dusting, and good (to very good) hot performance. Life is not an issue, nor is rotor abuse. I've read Hawk HPS to be good street/track pads, but am interested in your ideas.

I think pads and ducts are all I really care to invest the time and money in at this time, but I'm certainly interested in other ideas.

Time is of the essence here - track day is 7/27, leaving me two weeks of prep time.

[Arne]

Perhaps... no idea whether they work or not, but they might help?

http://cgi.ebay.com/ebaymotors/Fade-Stop-Brake-Cooler-240Z-260Z-280Z-Datsun-Brakes_W0QQcmdZViewItemQQcategoryZ42605QQihZ007QQitemZ170006667103QQrdZ1

[John Coffey]

Air ducting to solid rotors is more complex then ducting to vented rotors. With vented rotors you just get the air to the center hub area and the internal rotor vanes pull the air out through the rotor itself, cooling both friction surfaces about the same.

With solid rotors ducted air needs to be directed to both sides of the rotor to cool the friction surfaces evenly. If air is directed just to the inside friction surface the rotor will eventually cup and the brakes pads will wear unevenly, with the inner brake pad wearing out first. Plus, you'll have a lot of pulsing in the brake pedal and the car will probably pull to one side under braking.

A special can must be fabricated that takes half the air from the duct and routes it over the edge of the rotor to the ouside friction surface. In lieu of this, point the brake duct at the caliper and install one of Demers' fade stop brake coolers.

[Kyle]

Thanks guys. John, I saw your comments re: brake ducting in another thread... I sent you a PM with some questions.

As far as pads go, I've looked into Hawk HP Plus, tirerack has 'em for $70, and I think I saw other online vendors a few bucks cheaper. However, noise has been raised as a concern... so if I'm buying street/track pads that I'll hate on the street, why not just get track-only pads and change'm out when I'm done?

Axxis Ultimates sound pretty good, but I don't see them for the 240Z.

I'm having a hell of a time finding vendors that sell this stuff for the 240Z; most only have OEM replacements and maybe semi-metallic upgrades. Any love?

As far as the ducting goes, with 15" panasports and the vague cool air from the airdam, should I just leave it be? I have a welder and some fab skills, so I could make some cooling stuff if I knew what I was aiming for.

[John Coffey]

Hawk HP Plus are fine. Completely change your brake fluid to something like Motul 600, ATE Super Blue, Castrol SRF, or something similar (Ford HD is probably not good enough until you learn how to brake correctly).

Be sure to follow Hawk's instructions and bed the pads BEFORE the track event. After bedding put at least 100 miles on the brakes before going to the track event.

Adjust the rear drums so there is a slight drag as you spin the rear wheel. Plan on checking and adjusting the drums after each track session (pulling on the e-brake isn't enough.) Also plan on bleeding the brakes at least once during your track day after you've cooked them in a session. Bring bleeder bottles, 10mm brake wrench, jack, jackstands, etc.

[240ZX]

Don't forget about bleeding and freshening up your brake fluid with a good high temp fluid!

You beat me to it John!

[Kyle]

Got the HP Plus coming from Summit. Any sources for the fluid at a good price? I might be able to score something local, but ya never know.

[2003z]

Get Dr. Demers brake coolers.

[Kyle]

In spite of $150+ seeming like a ripoff for the FSBC, the results seem hard to argue with... so I'm investigating.

Drilled rotors are a no-no, is that correct?

What about removing the backing plates? Would that allow the rotors to radiate more heat, or would that lead to deformation of the rotor?

I have a feeling that good pads and fluid on good stock brakes might be all I need; I used junk fluid and pads last time out. But there's no substitute for strong reliable braking.

Thanks for any thoughts.

[jmortensen]

The Ford HD fluid is available at Ford dealers. ATE Super Blue is another good choice, available at just about any European repair place or parts store. The Super Blue is quite a bit better than the Ford fluid.

If the $150 FSBC keeps you from boiling the fluid than that's a heck of a lot cheaper than a big brake upgrade. Question is, will it do the job?

I had drilled rotors with no backing plates for years. Had vents to the inside of the rotor for a couple years also. My vents were pretty crappy though, a good vent setup might have caused problems that mine did not. Never had any of the issues that you hear of, they never cracked and they never warped, and I boiled the front fluid probably 10+ times with them installed and even punched a hole through a front brake pad with them on. Slapped a new pad on (didn't turn the rotor because I was at the track) and the damage was so minimal that I drove for a couple more years before I took them off and went for something bigger.

Here's a pic of my brake pad after the caliper went through it:

[Kyle]

The ebay seller just sent me this post on HZ:

http://forums.hybridz.org/showthread.php?p=661318#post661318

Looks like good data. With the testing, feedback here, and the "gotta do something" vibe I've got, I went ahead and bought a set. Should be here next week... pads/fluid/coolers/ducting, should be good to go. If not, I'll just slow down. Hahahah yeah right!

[Marty Rogan]

Hi Kyle,

Good to hear from you. I was wondering what had happened to you.

Just some friendly advice. Brakes are not the area you want to go cheap on. Just think of all the hard work and money that went into building that beast, then think of it as a pile of twisted metal. You don't want to go there. You have got that baby capable of 130 MPH, you gotta be able to stop it!!

The Toyota 4 piston caliper upgrade is well documented. I have used this set up for about 3 years with outstanding results. I have done 5 30 minute sessions on the car at Road America (which can be really tough on brakes) and have not had any brake fade issue.

Here's what I have on my car:

Toyota 4 piston calipers from '88 Forerunner, V6

Wheel spacers (got mine from JSK, but they aren't selling any more) I think Modern Motorsports carries them.

'84 300ZX vented rotors

Axxis Ultimate pads (Ceramic/Kevlar) good for street or track, but dust a bit

Steel braided lines (which you already have)

When you you compare the cost of this package to the cost of reapiring/replacing the car, this is pretty cheap insurance.

And if you will be going 130 MPH, make sure you have got good tires.

That being said, have a great time at the track day! They are a blast. Wish I could do it every weekend.

Marty