Rochester

iTrader: (8)

I'd like some current opinions from current members on the topic of 2-piece rotors. It's something I've always been looking at as the next-step when it's time to work on brakes. The OEM Akebono set-up on my car right now has 35k miles on it, so I don't know when that will be. I'm feeling like I've got plenty of time, like years.

I want the two-piece design for two reasons:

1. They're gorgeous.
2. There's an often-read claim about the much lighter rotors having a positive impact on how the car responds. In other words, it's a performance mod. Or maybe it just is on paper, and the street-driven butt-dyno is irrelevant.

So there's no denying they're attractive, and damn expensive, too. The rotors I've in mind are from Z1 Motorsports. Specifically, the cross-slotted non-drilled model. The rears alone are $648 for the pair. Ouch.

https://www.z1motorsports.com/brakes...rs-p-7374.html

Here's an internal threads from ApeFactory on the topic: https://www.myg37.com/forums/brakes-...ismo-pads.html

Looking for opinions from G-owners, and irrespective of stopping power, how does a lightweight rotor affect the car?

And here's a crazy question If you were going to upgrade in stages by doing either the fronts or rears first... which one would you prioritize?

blnewt

iTrader: (13)

Strictly by priority, the fronts for sure as they do the bulk of the braking duty and folks pay more attention to the fronts when checking out your balla G!

Rochester

iTrader: (8)

Irrespective of stopping power, Mr. B.

And although the fronts have the large calipers, the rotor diameter is virtually identical (12.8" rears vs. 13.0" fronts), and the rear calipers are nicely polished to match the fronts... so with the deep-dish, 10-spoke design, 10" wide rims actually make the rear wheel more impressive to eyeball than the 8.5" fronts.

I've given this a lot of thought, Brad. Specifically, 10 minutes about a half hour ago, staring at the car in my pajamas with a cup of coffee.

Crazyirish

Front 2pc rotors are a larger weight savings. I also question the rear hats ability to handle being a drum for the parking brake. I haven't heard of any failures, but it doesn't seem like a good application for aluminum.

Rochester

iTrader: (8)

As an E-brake, it would give me pause. As a P-brake, nah.

antirice

iTrader: (2)

It's a no brainer, you upgrade the front first and then the rear if you have extra $$ to spend. But to me the rears are no really worth it.

The weight saving in the front is much more significant, and is about $150 cheaper than the rear rotors.

When I need to replace my rotors my plan is to get Z1 2 piece in the front, and some cheapo stoptech or equivalent in the rear.

Baadnewsburr

iTrader: (3)

i second this...i have the same plan too

PNW_IPL

iTrader: (5)

Same. Accept im thinking ebc yellowstuff pads

ZahyMatar

iTrader: (4)

I'd get rid of those heavy Vossens before I got 2-piece rotors.

But seriously, I've considered getting Z1 2-piece rotors as well, sometime in 2018 most likely, unless there's a great deal on Black Friday. I'm leaning towards just the fronts, because I can't justify the ~$700 for 2 rear rotors.

Rochester

iTrader: (8)

I would consider doing it in two stages, because it's not inexpensive, and there's no harm in splitting up the mod. As a braking & handling consideration, yes the fronts first. But from a visual consideration on wide deep dish rims which are also the drive wheels... I'm thinking the rears.

IDK. Just talking about it and seeing what comes.

Get rid of my CVT's? Never!!! LOL

PNW_IPL

iTrader: (5)

Wheels.
Not Rims.
Cmon. Bro.

ezbme

I thought about getting them. 498 for a pair isn't bad, I got some slotted rotors for 129, but they are the same weight as factory. It would be almost impossible to lose 20 lbs from wheels unless you go carbon. I bought some Hawk rotors through a retailer on Amazon, I can't just tell them, oops.

PNW_IPL

iTrader: (5)

Cant tell who what?

Rochester

iTrader: (8)

Most pet peeves aren't worth the effort. Give it up, man.

Rim, rim, rim...

JustROLLIN

iTrader: (1)

So I just watched a nice video last night about unsprung weight and just how impactful it can be to remove as much as possible. The video was in relation to wheels, but seeing as rotors are also unsprung, the same principles apply.

The bottom line is all about rotational inertia. The car takes more power to accelerate or decelerate that unsprung weight. Additionally, the lower the unsprung weight, the better traction and in turn handling the car will have. The example given was a wheel going over a bump, and as the force applied to the wheel pushes it upward, the impact to the suspension and chassis is greater with more weight. The greater weight is typically corrected with greater spring pressure acting down on it, but that begins to impact handling as well. So, with a lesser weight moving upward, the car can correct that upward movement more quickly and put the wheel back in contact with the road more quickly and with less disturbance, giving you better traction and in turn, better handling. So yes, definitely a performance mod.

Here is the link to the vid:
There are actually some examples of dyno pulls online where someone did them before and after lightweight rotors and were able to net significant gains, just from the reduction in rotational inertia.