Lightweight REAR rotor options
 

I know there is the P&L lightweight rear brake upgrade as well as various lighter weight BBK kits. However, the P&L kit is hardly streetable while the BBK's are overkill IMO. I think the best compromise is installing lighter rotors for the rear. Problem is, I can't find anyone who seems to make them. I think knocking off a 2-3lbs per disc can have very noticeable effects to handling, braking, and accelerating.

Anyone wanna chime in? Some simple stock-sized, slotted rotors could do the trick. Maybe something with an aluminum hat?

Thanks in advance!

What makes the P&l not streetable?? Deletes e-brake?

OTE=JerryMichaels7;1643395]What makes the P&l not streetable?? Deletes e-brake?[/QUOTE]

Yeah for me streetable means ebrake. I know different people have different definitions of streetable, but that's where I draw the line.

I just think that a slightly lighter disc would be more than adequate and cost effective.

My guess is something like that would be so niche, the cost would be halfway to a rear BBK.

How so? There are lots of slotted or drilled rotors out there. Lots with aluminum hats. I'm just wondering if anyone makes them in the stock size. I'm not looking for ultra lightweight rotors. Just a slight and rather basic upgrade. Coupled with some SS lines and decent pads, a slightly lighter disc would make a noticeable difference in my opinion.

I don't think you'll ever find a two piece rotor with an aluminum hat that retains the stock e-brake functionality...

Why is that? The drum is still there right? Isn't this just a matter of replacing discs?

I wouldn't rule it out. They certainly exist for other applications, I've installed the Wilwood and the Stoptech setups on 350Z's in a past life. Here is an example for the Stoptech rear rotor for the 350Z. It integrates the drum inside the aluminum hat. They do state that you should absolutely not use the e-brake for anything other then parking however. Perhaps Stoptech builds one for our car since they offer it for other vehicles with a similar e-brake configuration?

http://photos.motoiq.com/MotoIQ/Tech...15_emRC3-L.jpg

The drum is part of the stock disc...

Would be interesting, but haven't seen anybody actually benefit with it. On paper and in theory, it should benefit performance, but the reality is it requires a trade-off that I'm not willing to take. Oh look, super fast acceleration from 0 to 20mph.

I am intrigued by this question as well. I haven't seen any great solutions. The one in the above picture with the aluminum hat/drum may actually work for an emergency stop, ONCE. After that you will probably need a new rotor and possible some new brake shoes and/or other parts if the aluminum has melted. Good luck trying to drive home if the shoes fuse to the drums.

The easiest example that comes to mind is Robispec. He used 4lb rear rotors. He would snap them literally almost every session. Then he used 7lb rear rotors...it would last 1 to 2 full days. Keep in mind, his car is like 400lbs lighter than all of our cars...

Aha! That explains it. Haven't actually seen the pics of the rear disc. I always thought the drum was seperated from the disc. Damn. That sucks :(

I agree with you OP. Just wasn't for sure if they did delete e brakes or not.

Non-US 86's have smaller non-vented rotors as the standard part, it looks like those come in about 1.5 lbs lighter per rotor.

WRX rear.

Aluminum hat with a working e-brake does exist for other applications (bolt in and replaceable steel liner).


I could bug him and see if he's interested in this platform...


http://i125.photobucket.com/albums/p...ps6b927f64.jpg

Racing Brake might just have it
 

Paging @RB Performance Brakes

These guys might sell you just the rear rotors. They do offer a full kit here:
https://www.racingbrake.com/ProductD...ductCode=2315K


Rotor Design:
These two-piece REAR rotors are made with the latest technology that is exclusive to RB. The rotor hats are constructed of aluminum with an iron sleeve insert. This allows significant weight savings, while still preserving the use of the stock emergency brake. This design is only available through RB!
https://www.racingbrake.com/v/vspfil...n-insert_s.jpg

https://cdn3.volusion.com/ofeb6.fdp3...jpg?1382547679

This looks great! I'm gonna reach out to them and see if there's anyway they could do a stock sized rotor. Maybe err can do a group buy if we get enough people.

Not exclusive at all :bellyroll:


Hell, those other ones I posted where developed years ago... Might have to inform him.

If taking that serious, then why need e-brake?

I was going to run custom rear brakes and dual caliper with hydro handbrake, but the drum hand brake is so good, do not need to change

E-brake is required to pass inspection. Dual calipers likely adds more unsprung weight. Hydro handbrake is only used for drifting, it's NEVER a replacement for parking brake as locking the system like that for extended periods will damage components and isn't reliable enough.

Leave car in gear. Same effect as handbrake

No, as even a gentle slope is enough to rotate the engine. You can rotate the engine by hand, what makes you think the entire weight of the car can't do it?

Lol.

The transmission, rear diff and something called torque multiplication?

If the engine has about 50 ft-lbs of compression/friction at the crank, that's over 700ft-lbs at the wheels. That's a 15* slope, or roughly a 30% grade...

That said, there are lots of times you'll want the engine running but the car to not go any where. Sitting in Grid, warming up the engine in the morning, in a drive through, etc.

It's a PITA to not have an ebrake but an aluminum hat could easily handle these needs.

Takes far less than that to rotate the engine, and the resistance isn't constant. If someone bumps the car and gets it over the hump of compression, the car will easily keep moving. Unlike using the parking brake which unless the cable breaks (unlikely) won't have this issue.


It's also illegal damn near everywhere to park in this manner as well.

You could always chock a wheel. I had to do that every time I got of my truck in the Air Force. I think there could be a decent market for the rb rotor setup in the rear. I wonder how much weight it would save though?

BRZ/FRS Rear Brake Kit
 

As DAEMANO mentioned,

Racingbrake rear two piece rotor aluminum hats are designed without compromising the integrity of OE's emergency brake.

How?

We integrate a iron sleeve into our rear rotor hat to allow the use of emergency brake. Do not be confused between "Emergency" and "Parking" brake.

"Emergency" brake is for you to use it during emergency when your hydraulic brake system fails, while the "Parking" brake is for you just to park the car.

If you go with an alternate rear two piece kit, that uses an all aluminum hat.
You run the risk of damaging the hat if you apply the emergency brake while driving. Which is why they will advise not to utilize your e-brake unless your only parking your car.

Being the reason why we design or rear hats with an iron sleeve,
to safety use your emergency brake the way its supposed to be. (OE)

https://www.racingbrake.com/v/vspfil...n-insert_s.jpg

https://cdn3.volusion.com/ofeb6.fdp3...jpg?1382547679


Weights

OE 1-pc (290x18mm) = 13.4 lbs
RB 2-pc (330x22mm) = 12.8 lbs
OE Calier = 6.6 lbs
RB Caliper = 6 lbs
Total weight saving per corner = 1.2 lbs

for our matching front
we use a 332mmx25 two-piece rotor and our 4 piston calipers weighing
10lbs less that OE's stock brakes at each corner.

I've got an e-brake less car and it's about a 10-15* grade before it will roll in 1st gear.

I'm not arguing it's a good idea though. I'm speaking from experience, it's a PITA on a street car. I chock my car at home because my driveway is slightly sloped. It's annoying as hell.

We have decided to offer a 15% off our front and rear bbk.
All kits are in stock and ready to ship.

Who here has the rb setup

I understand if RB gets 12 orders for two piece rotors, they will make them for us.
Chris, how about a group buy special pricing for two piece rotors?

:-)

Are we talking about stock size 2 piece rear rotors with the e-brake provision?

That is my understanding, hopefully we will receive more info from RB soon :-)

i am in for at least 2 sets of rear in stock size, personnally i don't care for the e-brake, it is for a race car that won't have it anyway.

Did this ever happen? What would the cost be?

Im guessing this never happened going to reignite the demand for a light stock size 2pc rotor. Im open to keeping or loosing the E-brake for even more weight loss. Going to be installing the lightweight Wilwood Front kit so I need something light for the rear. Car is getting close to 2450lbs so not looking for a heavy kit


I realized I went almost 2 years without my ebrake on the Vette. The handles are notorious for the teeth to break on the lever.

Did the demand for a stock size 2pc rotor ever come through. I would prefer the hat to be completely aluminum as I only ever use my ebrake for parking.


If the ultra rare situation occurred where I would have to use ebrake an emergency occurred then I wouldn't be upset to ruin a rotor if my life was saved