Ok, I'll put my flamethrower away because I agree with a lot of what you just said.

But having grown up and learning to drive in the era of drum brakes, I have some thoughts to add. Good drums do stop better than good discs at low speed, such as in heavy traffic. So I agree with your 'greater swept area' theory, because it gives a better low-speed 'bite'.

But having had my 4-wheel drum brakes fade completely away, causing me to leave a mile-long hill at nearly 90mph because I simply had nothing I could do about it, completely cured me of being a fan of drum brakes. It probably also cured the other 3 teenagers in my 2-ton Oldsmobile who were screaming just as loud as I was that day.

When I bought my disc/drum 240Z and discovered the brakes simply refused to fade on any of the steep Hawaiian mountainsides, I was completely sold on discs forever.

Disc/drums were introduced on American cars (the Avanti) to combat brake fade, not for increased braking power. Trains use discs exclusively, because reliable stopping power (sustained braking force over long distances) for a Bazillion tons of freight at speed was more important than panic stops at low speed in the railyard. (Also because they could be changed without removing the wheels, saving time/money).

The tiny, weightless Mini Coopers had used 4-wheel discs since about 1960, and kept getting rammed from behind by big 4-wheel drum American beasts which couldn't stop in time to avoid running over the top of them. So when weight is less of a factor, discs bite OK at low speeds, too.

I have to agree with you about drilled, slotted, vented, supercharged, finned, hyper discs having little application on street cars. They indeed were intended for racing applications (Sebring, specifically), where you're either standing on the gas or standing on the brakes. And with what I just learned in this Thread about slotted discs cracking under normal street driving conditions, I'll stick with solid discs.

I always suspected a drilled and slotted disc was an attempt to shave another ounce off unsprung weight. I recognized it would give a slight cooling advantage, but also recognized it sacrificed some small percentage of the swept braking area.

I'm not gonna flame ya at all cuz yer 100% correct. With modern pad compounds there is no need for drilling and slotting. Vented is good though.
I was gonna post a longer reply but you saved me a lot of work.

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71 on a rotisserie, two more in pieces in my shed...and a 69 1600 waiting for me to get to it

AJ iz ALIVE!!!

Thanks for the input fellaz... I'll give the drilled and slotted a shot since they are ordered and are on the way... Best Case they'll look pretty cool and might feel better, Worst case, I go back to solid. Plus a lot of what I am doing is learning how to work on these things.

I'll let you know what I think about it all when I am done.

the lame slo-mo customer

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Keith Hultmark
2009 370Z Touring - Sold (5 years owned)
1993 300ZX - Sold (5 years owned)
1976 Porsche 912E. #163 of 2200 - SOLD (3 years owned)
2018 BMW 330i GT xdrive daily driver
2004 BMW Z4 3.0i ….it is a Z

You're right Keith, they do look purty!!

_________________
Phil
1981 280zxt - Now in the care my son!
2014 370Z Sports Touring Roadster

That's the upside of steel rims w/wheel covers, you don't have to be
concerned about what your brake components look like unless you're
doing a show!

All Z Best,............................Kathy & Rick

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All Z Best,.......Kathy & Rick

1969 Z.CAR (#00013 10/69) 8/30/76
1969 ITSA.Z (#00171 11/69) 8/24/73
1970 OLD.Z (#06289 6/70) original owner
1971 510 2dr since 12/31/75
1969 1600 rdstr (our 160-Z)
1971 (#19851 1/71) sold
1975 75.Z (#01343 1/75)

1. this is on a very small percentage of disc. Internet horror stories don't equate to valid evidence.

2. This is a wear and tear item. You got to pay to play.

3. Drilled slotted are hot stuff and super JDM. Plus you have those nice shoes to show em off.



One reason among a few is,

Cost.

Reason why most commercial trucks don't come with plush leather 24 way adjustable heated / cooled massaging seats, 24" in chromed rims, and titanium frames, with carbon/kevlar cabs.

Commercial / industrial vehicles use the cheapest minimum standards to get the job done.

Among other reasons.

Plus they don't look mad JDM tyte with thse semi truck steel wheels.

1. Again, I am talking about track use not street use. The heating cycle of rotors on the track is very different than what a rotor used on a street car will see. 40 min sessions, trying to stop a 3000lb car from 125 mph+ put LOTS of stress on the rotors, pads, and brake fluid. I see first hand the crack stress that rotors can develop just after a few uses. If you think that the slots in the rotor are clean and leave no micro cracks....think again. The heating and cooling just helps expose the flaws.

2. Yes, wear and tear item but vented rotors are the way to spend the money NOT bling. Bling is fine if you do not intend to abuse it. My car sees 5-8 track days a year so no BLING here.

3. See comment above

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Clive Bogle President - New York Z Car Club - NYZCC.COM
1971 240Z - LS1/T56
1974 260Z-L30
1976 Fairlady Z

Moar Bling!

If you ever visit Japan or Okinawa, the commercial HINO "Jingle" trucks will knock your socks off! These things are dressed-up more than a Tijuana taxi cab!

Big chrome custom rims, wild paint jobs, tassels hanging in every window, decals all over them, pristine-clean, quad airhorns...they look more like an RV than a dumptruck, and cost far more than the homes the drivers live in. Now they're starting to be seen in Afghanistan. Never checked the brakes, tho.

Now that's BLING! I could never understand it, they all wear plain garments, very plain housing, but have everything else all gaudied up. Well, IMO, if not on the track, why spend money on something like that. It does look good I agree. Go fast first, then worry about braking.

I go fast enough, when I am coming off the highway at 100+ I still need to stop. Parts are paid for and in my garage they are going on this weekend. Who's to say I'll stop any better. Based on the great responses here on both sides of the spectrum and what I've read, I may or may not feel the difference being a street driver. But, I am having fun leanring and trying out some new things. Hey it's just money! You can't take it with you.

_________________
Keith Hultmark
2009 370Z Touring - Sold (5 years owned)
1993 300ZX - Sold (5 years owned)
1976 Porsche 912E. #163 of 2200 - SOLD (3 years owned)
2018 BMW 330i GT xdrive daily driver
2004 BMW Z4 3.0i ….it is a Z

Keith, if you're having problems dispensing of your money, please feel free to sponsor my Z!!

_________________
Phil
1981 280zxt - Now in the care my son!
2014 370Z Sports Touring Roadster

Nice try Phil, but I do not seem to be having a problem.....so I'm Good.

_________________
Keith Hultmark
2009 370Z Touring - Sold (5 years owned)
1993 300ZX - Sold (5 years owned)
1976 Porsche 912E. #163 of 2200 - SOLD (3 years owned)
2018 BMW 330i GT xdrive daily driver
2004 BMW Z4 3.0i ….it is a Z

If you're completely undecided, you could conduct a rolling test. Change the rotor on ONE side and leave the other alone! Tell us how it feels and which side fails first!