Brake recommendations, please!

[sopwith21]

Got issues with my 260Z racecar.

Currently the car has stock brakes with Porterfield's best race pads, fabricated vents on the front end, and Motul 600 fluid in the system. This combination is barely sufficient for short sprint races of 30 miles or less. Near the end of the race I have to pump the brakes 5-7 times before I get any stopping power... not a good thing since we're hitting 120 mph on the straights. Eek.

I am getting ready to switch to stock endurance racing, which places new demands on the brakes and also limits my ability to use aftermarket upgrades.

I know that AZ Z Car has a nice Wilwood setup, but that's clearly not stock and would result in a penalty. Is there another system available? Does another Datsun/Nissan car have a 4-wheel disc system with bigger brakes that would bolt up? There is a bit of leeway on the rules for using other stock parts from another vehicle, but I hate to try and get a new Wilwood system through tech.

Any ideas you might have would be appreciated. Thanks!

[jmortensen]

Vintage cars use the Toyota 4x4 vented front setup and the 79-81 rear disk setup. I think you'll need dual masters to get that balanced as the fronts have a lot more power than the rears. Back in the day there was a FIA brake system from Nissan Comp which had a vented system very similar to the Toy setup and I believe the 79-81 rear disk is exactly the same as the FIA rear disk system that was sold. Not sure what class you're in, so it's tough to say how it will go in tech.

[John Coffey]

Hawk Blue pads up front, Porterfield R4S in back. Change the fluid often (before every race weekend in some cases) and keep adjusting the rear brakes between sessions.

I've done a 6 hour Enduro with an ITS 240Z and we (3 drivers, 3 crew) kept the brakes alive with 1 front pad change, 4 rear brake adjustments, and 1 fluid partial change (front only). Luckily we were required to make two 10 minute and two 5 minute pits stops during the enduro so we were able to time the front pad changes, rear brake adjustments, and fluid change. We were first in our group.

You don't know hot until you do a pad change on the front of a 240Z after three hours of racing.

EDIT: Getting huge amounts of air to the front brakes is critical. We ran two 3" ducts to each front. One to a sheetmetal can that routed air to both side of the solid rotor and another that blew directly on the caliper.

Edited September 9, 2010 by John Coffey

[rxsleeper]

FWIW, I use Hawk HT-10 in front and Carbotech Green shoes. If you can change to discs all around, you should. Aluminum drums are unobtanium these days.

Get as much air as you can to the fronts Here are a couple of pictures of my "shrouds" for the front.

Ignore the ducting the previous owner was responsible for the dryer duct.

As it looks today:

Also ventilate the rear drum backing plates.

What John said is critical. Flush and change fluid after every race weekend. Adjust the rears as needed, usually before practice each day, and then use the handbrake for in race adjustments.

YMMV

Paul

Edited September 9, 2010 by rxsleeper

[sopwith21]

I've done a 6 hour Enduro with an ITS 240Z and we (3 drivers, 3 crew) kept the brakes alive with 1 front pad change, 4 rear brake adjustments, and 1 fluid partial change (front only).

Wow. Really helpful stuff everyone. Many thanks.

Regarding the above - was that with stock brakes?

[John Coffey]

Yes, stock brakes. One other trick is to toss the factory stainless shims that go between the caliper piston and the pad and make shims out of .032" Titanium that are the same shape as the pad backing plate with two little tabs on top to hold them in place.

One ITS competitor I know made caliper pistons out of Titanium. Very expensive and difficult to make due to the heat expansion differences between Ti and steel.

[mlc240z]

Just in case you want to keep rears stock, RockAuto shows a composite aluminum/Steel drum for 1974 260Z available again. Believe these are aluminum body with steel contact lining.

CENTRIC Part # 12242002.

<$30 +shipping.

[sopwith21]

Any recommendations on brake fluid? FRE or Motul 600 is what we've used in the past. What think ye? Thanks.

[sopwith21]

Just a note to say that you guys are AWESOME. We just placed third in our latest race, and if the second place guy hadn't rear-ended me while passing for the lead, we would have won both events going away. We set fast lap in our class for the day, too. BE SURE TO WATCH THIS SUPER SHORT VIDEO IN HD - IT'S GOT GREAT COLOR AND QUALITY AND TURNED OUT REALLY WELL.

We don't run many club races, but with a new set of tires (the ones we had last weekend were 5 yrs old and showing cord) I think we'll smoke the field next time.

We did everything you guys suggested in this thread. We took a computer out to the shop and blew up the photos from RXSLEEPER so we could see them better. Then we used the headlight openings and the lower valance fog light openings to run two air ducts to each front wheel.

We tried to shorten the distance and use as little hose as possible so as not to slow down the air flow. We also went with aluminum hose for heat resistance and durability.

We then turned the steering wheel until a tire crimped the aluminum. Then we would adjust the hose to a safe place and repeat the test until no hoses were touching the tires or steering system when full lock was applied.

Then we converted the front to Hawk Blue pads and kept the Porterfield drums on the rear. Then, with some help from our racing pals at the track (I can drive like a bat out of Hades but I'm a horrible mechanic), we flushed and bled the entire system just an hour before the race.

PRESTO! We had the best brakes on this car in the last five seasons! No fade whatsoever until the last lap in a 25-minute event. I'd still like for them to be a bit better, but we had full pedal until the very last lap when the brakes started to fade just a bit. So I'm super happy.

Many thanks to everyone who responded to this thread. We read every post here 30 times or more and studied every photo thoroughly.

Just wanted you all to know that your time and effort to respond wasn't wasted, and your knowledge is appreciated.

[EuroDat]

FWIW, I use Hawk HT-10 in front and Carbotech Green shoes. If you can change to discs all around, you should. Aluminum drums are unobtanium these days.

There is a thread on the aluminium brake drums. They are still available, but they are getting hard to find.

http://www.classiczcars.com/forums/wheels-tires-brakes-s30/48550-new-source-s30-aluminum-brake-drums.html

Datsunparts.com Partnumber 2550 Datsun Z Car 70 - 78 & 510 68 - 73 Rear Aluminun Finned Brake Drum

Chas

[sopwith21]

Other than weight savings, is there any other advantage?

Also, Rxsleeper suggested that we ventilate the rear drum backing plates. Where's the best place to get air to do that? The front is easy... just steal air through the headlights and fog lamp openings. Is there a tried and true way to get air to the rear drums, or should we just experiment?

[sopwith21]

test test