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-   -   GSL-SE Rear Brake Rotors (https://www.rx7club.com/1st-generation-specific-1979-1985-18/gsl-se-rear-brake-rotors-1013731/)

elwood 10-03-12 08:25 PM

GSL-SE Rear Brake Rotors
 
It's about time for new rear brake rotors and I want the forum's advice. I use my car for track days and hard street driving. I have a vey big brake setup on the front, and the original -SE brake setup on the rear. The car has over 300 RWHP, so the rear brakes are working fairly hard.

The question is which rotors? I did a quick search and there are many options. My current rotors are OEM, and they have lasted well, but I don't want to spend that much if there isn't much of a performance difference. Here are some of the options I've come up with:

OEM at Mazdatrix $120 ea
PowerSlot at TireRack $56 ea
Beck/Arnley at RockAuto $19 ea
Centric at RockAuto $19 ea

Any past experience with these or others?

BTW -- I'm not strongly for or against slotted rotors (don't think I need them on the rear but don't think they do any harm either), while I definitely don't want drilled rotors (need all the thermal mass I can get and don't want cracking issues).

RX-7 Chris 10-04-12 10:07 AM

I have a stock car and I went with the Beck/Arnley from RockAuto. I'm very happy with them.

I would lean you that way with a set of hawk hps pads.

82transam 10-04-12 10:43 AM

Same here, I've always had pretty good luck with Beck/Arnley stuff from Rock Auto.

j9fd3s 10-04-12 11:46 AM

we've had good luck with the centric stuff. they seem to be made from a better quality iron than the really cheap stuff.

we pitted next to the CEO once, he's a nice guy, we beat them by 60 laps

rx7lives 10-09-12 12:46 PM

I bought dimpled and slotted rotors all around from Ebay cheap.
 
I bought dimpled and slotted rotors all around from Ebay cheap. I'll look for the link.

[2 Rear] POWERSPORT: *DRILLED & SLOTTED* Disc Brake Rotors | eBay

$94 each. Fit like a champ all the way around, quick shipping.

elwood 10-09-12 06:01 PM

It says those are drilled, which is a no-no for track use . . . and $94 each is on the pricey side. But, I'll follow the general idea and check eBay.

rx7lives 10-09-12 07:49 PM

Actually, mine were dimpled
 

Originally Posted by elwood (Post 11250062)
It says those are drilled, which is a no-no for track use . . . and $94 each is on the pricey side. But, I'll follow the general idea and check eBay.

Actually, mine were dimpled and slotted but only maybe 1/8" an inch deep. They said the SE bolt pattern made them nervous about drilling all the way through so I said no problem.

The price does sound high; I'm just going off on what I found on Ebay. It's been a year but I seem to recall the actual price was LESS than the stock ones.

You can't use drilled rotors for track use? Do they have to be completely stock or are there shades of interpretation of the rule?

If I find the receipt, I'll let you know what it was. Hell, brand new calipers were around the same price as rebuilds.

elwood 10-09-12 09:34 PM

Since I do track days, there aren't any rules. The concern is that the holes in drilled rotors tend to induce cracks when the rotors are subjected to very high temps. You won't generall see drilled rotors on race cars.

eBay was interesting. There were a lot of interesting options. I'm still somewhere between the Centric and Power Slot rotors. It looks like Centric, Power Slot and StopTech are all related. One potential advantage is that some of the Power Slot applications have directional vanes. Does anybody know if the GSL-SE rears come that way?

Stevan 10-09-12 09:40 PM

That eBay listing is $94. for 2 rotors.
These look nice, the price isn't listed but I imagine the price is out of your range. Fun to look anyway.
KC Raceware

Kentetsu 10-10-12 06:21 AM

Smart move on avoiding drilled rotors :)

I went with uber cheap rockauto rotors a few years ago (around $15.00 each) and threw on some Hawk pads. Still working great with zero issues. Autocross and hard daily driving. I've probably got better that 20,000 miles on both the rotors and the pads, with lots of life left in them.

Before I got the Hawk pads, I was changing them out every few months because they wore so fast. The Hawk pads obviously lost MUCH longer, but don't seem to add any additional wear to the rotors. Must be magic. lol.



.

elwood 10-10-12 06:52 AM

I like that setup. I was thinking about something similar last night as I looked at my car. I'll ask them about it. One advantage of a separate rotor/hat setup is the posibility of stepping up to larger diameter rotors. Larger diameter wouldn't be much more expensive -- maybe cheaper than a stock rotor. I can get an 11.75" X 0.81" rotor for $32.

I would have to do these things:
1. Buy the brake hats
2. Buy 11.75" X 0.81" rotors
3. Make new caliper brackets to space them further ourboard radially (I'm already using custom brackets that I made, since I'm using a Toyota 8" rear axle)
4. Make new, longer flex hoses to reach the calipers (These are already custom)
5. Install an adjustable prop valve in the rear circuit to correct brake bias

I already have or can get everything on the list for no added cost except the hats.

j9fd3s 10-10-12 10:33 AM

the big brake thing is a good idea, in the meantime just buy the $19 centrics

rx7lives 10-10-12 12:30 PM

I found my receipt
 

Originally Posted by elwood (Post 11250248)
Since I do track days, there aren't any rules. The concern is that the holes in drilled rotors tend to induce cracks when the rotors are subjected to very high temps. You won't generall see drilled rotors on race cars.

eBay was interesting. There were a lot of interesting options. I'm still somewhere between the Centric and Power Slot rotors. It looks like Centric, Power Slot and StopTech are all related. One potential advantage is that some of the Power Slot applications have directional vanes. Does anybody know if the GSL-SE rears come that way?

I found my receipt. I bought all four dimpled and slotted rotors for an '84 GSLSE for a grand total of $143.00 which is $35 each and the company was brakelabs.

Not a bad deal if you can live with the dimpled and slotted surface that only goes less than an 1/8" deep. Heck, the stock ones from them might be cheaper!
This was on 9/10/2011.

They all went on with perfect fit and the bearings and seals for the fronts went in easily using a brass punch.

Well worth the money, they still look new but I am using ceramic pads.

elwood 10-10-12 03:01 PM


Originally Posted by j9fd3s (Post 11250707)
the big brake thing is a good idea, in the meantime just buy the $19 centrics

I agree -- especially since I found out the Power Slots don't have directional vanes. It looks like Power Slot = Centric + Slots (and some paint) . . . and I don't need either one.

DreamInRotary 10-11-12 08:47 AM

So through Rock Auto, here's what I found you guys talking about. I'm wondering if I'm correct, since I'm getting a rear axle tonight and will need to do the brakes on it - and I figured this would help the OP :nod:

Under Economy

CENTRIC Part # 12145000 for $14.57

CENTRIC Part # 12145011 for $24.99

Under Daily Driver

RAYBESTOS Part # 9828R for $18.82 - says it's one of the most popular parts (has a heart next to it)

BECK/ARNLEY Part # 0832011 for $14.12 - states there's only one left in stock right now

I'm just wondering which ones you guys are talking about - I'm looking into the same thing as the OP.

Thanks again guys, appreciate the info.

abeomid 10-11-12 04:37 PM

Don't buy the cheap stuff if you plan to go on the track. The cheap stuff are typically lighter material and will warp on you pretty quick on the track! the OEM or the PowerSlot will be good!

j9fd3s 10-11-12 05:08 PM

we run centrics on the race car, and they have been totally fine, although we run good brake pads, not hawks

elwood 10-11-12 09:46 PM


Originally Posted by abeomid (Post 11252246)
Don't buy the cheap stuff if you plan to go on the track. The cheap stuff are typically lighter material and will warp on you pretty quick on the track! the OEM or the PowerSlot will be good!

StopTech, Power Slot, and Centric all appear to be the same company. The Power Slot rotors have slots, but otherwise, do you think there's any difference? Have you ever compared the two?

elwood 10-11-12 09:48 PM


Originally Posted by j9fd3s (Post 11252286)
we run centrics on the race car, and they have been totally fine, although we run good brake pads, not hawks

Which pads do you run?

I've been using Brake HP pads in the front on StopTech ST40 calipers and Hawk HPS in the rear.


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