KiyoKix

I've been eyeing this option for a while now and just wanted to get some feedback if anyone is using them. I see no need for larger brakes on an FC (4 piston models), but I would like to save a little weight and if possible gain a smidge of performance (not worried about the cost to performance ratio, please) to boot.

My car is 80-90% street the rest being autocross and open track days. I'm not looking for the worlds greatest brake kit as I don't need that, just looking to save a few pounds and pick up a little extra performance. I'd appreciate any meaningful feedback you guys may have on them.

Thanks,
K

Btw, I'm speaking of the 2 piece rotor setup from AWR Racing ( http://www.awrracing.com/pages/rx/rxbrakes.html )

SCCAITS

iTrader: (3)

You'll probably only find these on the higher end EP cars. For street driving, I'm not sure this small reduction in unsprung weight (2-3lbs) will do much for performance and don't forsee any improved braking. For what these cost, you can probably recieve a bigger reduction with super light wheels if not already on the car. Here is a no cost alternative... I have seen an EP driver drill holes in the rotor hat on stock replacements (Brembo vented) which effectively accomplishes the same task as two-piece : reduced unsprung weight. He drilled approx 3/4" holes every 1" or so on the side of the hat all the way around, he claims that the structural integrity was not comprised... I haven't tried it as it's not ITS legal. Two pieces rotors are definately cool though!

KiyoKix

Thanks for the reply .

On my car now are the stock FD wheels (approx 13 lbs) which are a nice drop in weight and perfect for my style of tuning to a car. I prefer everything to look as though it was designed to be there (which usually costs me more than most people spend on the other stuff). These brakes don't look wild to me and fit the stock calipers (a big thing for me) as well as offering more weight loss in the rotating assembly. I don't see me changing wheels in the future to something even lighter as they won't be factory looking (I know I'm retarded ) and possibly not exactly the size I want anyway. Overall I imagine that the drop in weight per corner with these brakes and the wheels I have now would be around 8-10 lbs per corner which is a very nice number to me while still keeping everything in the stock look I like.

I've thought about the drilling of a stock rotor but that would change the look (again...yes I'm crazy) of the car and I don't want to have to do it each time and get them balanced as well. I have seen it done before though and it's a good gain in performance as long as the driller uses moderation .

I'll see what some others say and then make a decision I suppose...maybe I'll be the ginea pig for the club as the price really is pretty low to me (think of the cost the people buying larger *cough* not needed rotors front and rear spend) especially after the initial investment. $87 per rotor isn't bad at all I'd say plus pads of course.

K

SCCAITS

iTrader: (3)

I assume the 8-10lbs is over your factory numbers with stock wheels as these rotors reduce front by 3lbs front and 2lbs rear.

Not sure if you got the whole price, rotors are $87 each but add $123 approx per hat and that's $210 per wheel + shipping and your quickly at $900 + pads. Of course you'll already need the SS lines, racing fluid, calipers in good shape. It'll be $400 + pads each time you do a change, that's why I recommended drilled stock rotors. Brembo vented rotors you can get for $160 shipped for all 4. But, yes they are cool I just can't see the cost/reward on a street/track car.

KiyoKix

Yes the difference is compared to stock wheels on the car. As for the whole price I understand the entire price for the kit (over $900) I was talking after you've already bought the whole deal once (just replacing the rotor itself). Call me crazy but I do believe you can just replace the rotor afterwards unless I'm drastically wrong.

I'm still not 100% sold on the whole deal yet, but if I do I'm willing to part with $400 per change (I'm one of those kinda guys, and no I don't mean a rich kid kinda guy). Any idea on how much the Brembo rotors weigh and how much they weigh compared to stock rotors? If I can get something that still drops the weight some then I'm willing to go with that...but I do not want to drill the rotors.

This whole deal is also a test for a later car that's life will end up being 90% track, I want some feedback on how they work in the normal world as well. If I like it then I'll keep spending the money as $400 over a year or even 6 months is a terribly small amount of money in my opinion.

Btw, since we seem to be the life of this thread so far what are you running on your car now and how do you like it? (also does it see any street duty)

K

SCCAITS

iTrader: (3)

I'm 98% sure you can just change rotors with 2 piece, I don't think I would turn them though. I believe the Brembo and other OEM spec rotors weigh the same, or at least within ounces of each other. I run the Brembo vented rotors that are OEM spec with Hawk blues, I have to run OEM spec because of class rules (SCCA Improved Touring). Mine is a 100% race car that is towed everywhere, it never sees the street. http://img168.imageshack.us/img168/4137/pict1243jw1.jpg

The more I think about those, if you like spending money and can, get the 2 piece. A 2-3 lb reduction on unsprung weight can only help. Of course, you can always get those 13lb wheels down some more with something different. If you are all about performance (as is this case with 2 piece rotors), forget about trying to keep a stock look wheel, go for something lighter while you are at it. Then you need Hoosiers as well, don't skimp on tires. Don't forget the HUB needs machine work as stated on AWR site.

I'm strongly considering changing directions with my car and building to NASA Performance Touring rules which allow (no point hit) for non OEM rotors...which means I can go 2 piece. Hmm.....

Get those rotors and try them out!

DarkKnightFC

How much weight would you loose by changing to a wheel with the correct offset and loosing those spacers that you're probably running? Maybe none but who knows?

RX-Heven

iTrader: (1)

You will need to machine down both the hub and the id of the rotor hat. Then you will need to trim some material off each and every brake pad for the front to avoid contact with the rotor hat or you can also turn down the od of the rotor hats. This is only for the front. Except for grinding down each pad, this all needs to be done at a machine shop.

On the rears, you will need to grind down the flanges of the hub to clear the id of the rotor hats. This is easily done with a grinding wheel or whatever.

The rotors are much better than standard replacement btw and reducing unsprung weight is the holy grail of suspension.

KiyoKix

As for the wheels being changed, it truly is not an option in my book as I like my cars to retain a stock appearance (to include no names out in the open, yes I'm strict which seems dumb to some people but that's what makes people great...differences ). I can't remember the weight of the spacers off the top of my head but it's a very small amount on each end of the car and can be offset with any number of things.

Btw, SCCAITS I'm not "all about performance" else I'd either have a PP or turbo car and no interior etc. I'm about a very acute measured amount of performance, kinda like an OEM style tuning company (way more Honda type R, Audi S Line, and BMW M Division minded than say APR, Scoot, or Panspeed). There will be no slicks or anything like that, no 400# springs though there will be coilovers, etc.

It's a hard thing to describe to anyone especially when most people never even recognize that the companies I mentioned (the 'OEM' style guys) are really just doing the same thing we're doing to a stock car. Most people look for very large jumps in performance but I just like to fine tune things...if this car in the end hits 1.01g, 0-60 in 4 secs, or 180mph then I will consider it a complete failure.

K

Yea...I know my style is 'weird'

KiyoKix

Btw...I agree on the reduction of unsprung weight being a holy grail in suspension tuning (by F-A-R my favorite thing about tuning cars). RX-Heven have you used these rotors before...any results/thoughts?

K

SCCAITS

iTrader: (3)

And this question is for? If me, the answer is ounces and I. But, what you suggest can't be done. Those are +35 15 x7 with aluminum 1/2" spacers and ARP studs, the only reason it has spacers is Team Dynamics who made the wheels for me couldn't go lower than +30. This setup gives approx 3/8" clearance between the spring seat and a 225/50/15 tire.

KiyoKix

I think he may have been talking to me as I'm using FD wheels (of the 13# uber stock looking variety ) and in order to run them truly perfectly I'm using spacers. I did think about running with vert wheels (11#) and the same tire setup you have, but it's a tad shorter overall than I want it to be.

Again of course that was all done for a specific reason (not just the weight) so that is not an option to be changed unless you know of another Mazda wheel that will fit the same bill w/less weight and no spacers (including the 8" width).

K

KiyoKix

Okay I'm off to sleep for now but I'd love to talk more about this tomorrow (seems more like a chat room than a thread which is good).

K

Black91n/a

The OP could save 2lbs off the FD wheels and spacers by going this route, but that's not exactly stock looking.

https://www.rx7club.com/showthread.php?t=648016

R32 Skyline GTR wheels are the same size (16x8), but are the right offset (30mm), so no spacers are needed, but they're probably not the easiest wheels to get ahold of and I don't know that you'd save any weight.

KiyoKix

As much as I LOOOOOOOOOVE the RPF1's (always have) they're just too obviously not stock for what I want...even though they weigh 11# (2 less than my FD wheels) if I remember correctly. I don't mind the spacers at all as they do make things look very very nice with the almost perfectly flush look which I LOVE.

There is an R32 running around here somewhere as long as he hasn't done anything too stoopid (besides lose his license), but I don't think that'd work out either...not to mention the weight. Not sure who made the stock wheels (for some reason I really wanna think Enkei though) but they're probably too heavy and not as pretty on the car either .

Okay really I'm going to sleep now...I think.

K

SCCAITS

iTrader: (3)

I actually ran the vert wheel for a bit, have 14 of them but am getting rid of some. They are all off getting refinished right now and then I'm going to sell 4 or 8. A 225/50/15 fit fine, although with it's +40 offset I did have to use spacers (.5" IIRC) because of my spring seats in front. Alot of ITS cars actually run the 225/45 tire and consider the 225/50 to tall. With stock 4.10 gears a shorter tire is going to do better on the track. I went to 5.12 gears so the 225/50 is fine, also changed 5th gear to a a lower .756 ratio.

DarkKnightFC

https://www.rx7club.com/showthread.php?t=695965

ZeroDrift

iTrader: (1)

Those are my rims. They are great rims overall, and I would keep them, but I plan to get a much lighter rim before the next autocross season. I will probably buy some Volk CE28 in either a 16x8 Front and a 16x9 Rear or possibly a 17" rim w/ the same widths. I would like to stick w/ a 16" rim due to weight and looks, but finding nice tires streetable in that size is difficult.

I will buy these 2 piece brake rotors some time this next year when I have to replace pads and work on the suspension. I plan to e-mail AWR and ask about noise and safety issues with these brake rotors for street, track and autocross use.

Helpful site: www.wheelweights.net

Flynbryn

I use these on all four corners on my track car. the unsprung weight savings is nice but a overlooked benefit is that the rotors disipate heat much better than a stock or "performance" rotor does these are true racing rotors that are made by Coleman. That said, I don't see any benefits for these in cone killing. I would think that you wouldn't want to disapate heat due to the short time you are on track, the brakes probably don't get hot enough as it is. Power slots are what you need here. Drilled rotors crack. But these are a great product for road racing. For those who are interested there are a few things that you will need to do to install them on your car:

front and rear hubs need to be clearanced on a lathe. If I remember right it is about 10/1000th that needs to come off

your front pads also need to be clearanced at the outside center so the don't hit the Hats. 1 min. on a bench grinder is all is needed here.

Also you will want to locktite, drill & safety wire the hat bolts

As with any rotor (new or not) you should get them turned after assembly


Hope this helps

RX-Heven

iTrader: (1)

Yes I do have the installed on the car.
I agree with everything the Flynbryn said except getting the rotors turned. With proper assembly, you should not need to have them turned. The clearance is easily checked and should be everytime. That said, I've never had any problems and not known anyone who has.

For your application, unless you feel like wasting money, just get some basic aftermarket rotors and stay away from anything cross-drilled.

SCCAITS

iTrader: (3)

Anyone know who makes the AWR hats and rotors? I would suspect Coleman maybe? If so, I find only 4 aluminum hats in the 5 x 4.5 bolt pattern and they are all $73.80 vs. the $123.50 each from AWR. The one's from AWR a stock item somewhere, if they were custom you wouldn't have to machine the hub.

Take out the 5/8" stud size and you have two offsets to pick from. A 12mm stud is .4728", should work just fine with the 1/2". A couple measurements of stock items and the right parts may be figured out.

www.colemanracing.com


Cast Alum.Hat,Bolt Pattern,5x4-1/2,Stud Size,1/2",Offset,2-1/2"
Cast Alum.Hat,Bolt Pattern,5x4-1/2,Stud Size,1/2",Offset,3"
Cast Alum.Hat,Bolt Pattern,5x4-1/2,Stud Size,5/8",Offset,2-1/2"
Cast Alum.Hat,Bolt Pattern,5x4-1/2,Stud Size,5/8",Offset,3"

SCCAITS

iTrader: (3)

I went ahead and bought the AWR fronts, should be here in a few days...didn't feel like doing the guessing game with Coleman.

Any reason why I can't use the AWR fronts and still keep the stock vented rears? Should be no issues, right? I may get around to doing the rears but put myself on limited race car spending for the time being.