C5Lion

I have a few questions about 2 piece rotors.

I have a brand new set of DBA5000 front rotors and I am curious as to how long (track events) these might last when compared to a set of 1 pc DBA4000 or equivalent rotors?

I have been debating whether or not to sell them and just buy less expensive 1 pc rotors. I understand they are lighter and everything that goes along with this.

I can buy just about 3 sets of front rotors for what the DBA5000's are worth.

Also, when the rotors wear out on a 2 pc rotor, do you throw the entire thing away or can you buy just replacement rotors and use the original hats?

SouthernSon

I am on my first set of 2pc. and really like them. No knock back and no cracks all year. However, after first day I noticed a lot of small heat check lines. Must be normal because it hasn't progressed from that point all year. Yes, only rotor ring needs replacing, keep the hat. My AP rotors will cost 250 a pc. to replace. The front set was $1K. Well worth it since no down time at track to replace the old 1 pc every couple of events.

froggy47

Depends on how often & how hard you use them. It's a big expense for a guy who only does 2-4 events yearly & runs in the lower groups.

It's almost a must do (2 piece) for guys that do 6-12 events yearly in the red group.

C5Lion

I am not sure I follow. Are you saying that the 2 pc rotor assemblies were $1000 per set for the front and each rotor ring is 250 a pc or $500?

C5Lion

I run in the red group and do about 6 events per year. I usually get 6 or 7 events on my 1 pc rotors. Will I now get 14 to 18 events on these 2 pc rotors? I have rotors specifically for the track so they will not be used on the street.

MJM

I have never run 2 piece rotors. I stick with the stock ones because they are cheap.

I have looked into it, and the benefits I see are:

1) lighter so it reduces rotating mass
2) floating rotors, combined with proper calipers and anti-knock back valves improve brake pedal feel

If I had more money and wanted the best I would get the rotors from Hardbar. They are very elegantly designed.

Matt

Bill Dearborn

I tried two piece rotors this year. My first event with them was two days at the end of May, then 5 days in August. One of the front ones cracked during the last day and the other was just about to crack. I got 7 days from them Vs getting 5 from the stock Z06 rotors. Figure $240 ring replacement cost Vs $100 cost of new stock Z rotor delivered to my house. I was hoping to get at least 15 days from them but it doesn't look like that will happen.

Here are two different views of the crack in the rotor.


Bill

Gering

These guys have some nice 2 piece rotors.

http://shop.performanceafx.com/C6-Corvette_c11.htm

SouthernSon

AP rings are $250 apiece.

SouthernSon

These are the AP 2pc. that I have run this year. I like them.

froggy47

I don't think anyone can really predict how many events you'll get, depends on the rotor, the track, the temps (ambients)

I do 3-4 DE and approx 24 autox a year & get about a year on one piece blanks @ $200 a full (4) set.

Since I am not getting paid anything for high "finishes" at DE and the blanks are plenty for autox I decided that it's not worth the extra $$ (for me).

JRitt@essex

It's nearly impossible to gauge how long a set of rotors will last. There are so many factors that influence wear...size of disc, quality of casting, metallurgy (material composition of the actual metal), driver skill, track layout, speed/weight of car, etc...the list goes on and on.

The debate over two piece discs vs. one-piece comes down to a few factors:

1. Intended usage- If you are currently able to consistently do track days on the tracks you drive with OEM-style one-piece discs and no problems (constant cracking, brake fade (pad or fluid), constant brake bleeding), then you probably aren't at point where you'll notice all of the benefits that come with a two-piece disc.

2. Initial/replacement cost- The initial investment in two-piece discs is much higher. Replacement rings will also always be more than an Autozone replacement one-piece disc. That said, if you go with a high quality two-piece disc (like the AP Racing ones mentioned), you will likely get substantially more wear out of them vs. the cheap one-piece (I can't comment specifically on your DBA's, as I have no personal experience with them on the vette).

3. Convenience- A lot of people are willing to swap out OEM-style one piece discs after every event because they've cracked. If your brakes aren't cutting it at the track, it's a heat problem. That potentially means cracked discs, incinerated pads, boiled fluid...which means lots of pad changes, disc changes, fluid bleeding in between sessions, etc. If you value your time at the track...you are not great with a wrench, and would rather be reliving your on-track exploits with friends instead of lying on hot asphalt, then this factor really comes into play. A properly sorted brake system will allow you to do just that...relax and have fun without having to fiddle with the car constantly. It will also dramatically increase your on-track confidence and lower your lap times.

My advice would be this: Pick up a set of one-piece OEM replacement discs (if you don't already have some), and make sure you're running brake ducts, good race pads, and good racing brake fluid. Try that setup and see how it performs on the track. If it's enough for your needs, sell the DBA's and call it a day. If you have fading, cracking, accelerated pad wear, etc., then you'll need to explore further upgrade options such as two-piece discs or a complete brake system. Rule out the simple and cheap solution first though.

If you need any of these parts, we sell everything you need and are a forum sponsor. I'd be happy to help you out. Just email or call. Thanks.

95jersey

Neither will last as long as OEM basic rotors and they both cost more. It amazes me how people convince themselves (because they are more expensive, have some BS engineered vane configuration, and that they are trick looking) that 2 peice rotors do a better job than 1 piece. The only benefit is weight savings. Been there, done that, in my opinion, they are just expensive car jewlery. It is like buying a billet aluminum brake fluid cap...it looks pretty as hell, but it is still just a fluid cap and doesn't work better than the OEM plastic one.

Look at the C6Z rotors, they only have 1 rotor for both left and right, so on one side, the vane actually points inward...LOL, yet they work EXCELLENT. I remember when it came out people said..."look OMG GM made a mistake"...we'll 5 years later and these rotors (even drilled) proved to work phenominal and it was no mistake.

stevensa

I get about 3 times the life vs. OEM rotors with my 2-piece. It works out to be about the same cost wise, but the PITA of having to swap rotors at the track is gone which is worth quite a bit in my book. I now crack rear rotors faster than the front.

95jersey

We'll on the C6Z you have to remove the caliper to change the pads anyway, so the rotor just slides off at that point, no extra work, but I do know the C5/6 are different.

I used several aftermarket brand rotors in my 12 years of track days and never personally found any to last long enough to make up for the cheap cost of OEM replacement. I have OEM C6Z rotors that last a season (7 days) and more. I have a rear set that is 2 full season old. I find I go through pads WAY faster than rotors. Also, it comes down to pad choice, some pads are very hard on rotors while others are not. I historically ran Carbotech, which while wore quickly are easy on rotors.

Now I have BBK up front and the caliper comes off with two 20ft. lbs allen bolts, it takes longer to jack the car than replace a rotor. Not to sound like a "know it all", but just after all these years, many TT wins, few lap records, and going through years of trial and error, I can't ignore hard raw data.

JRitt@essex

I don't agree with any of that. There are real and tangible benefits to be had with aftermarket brake components. Vane design, number of vanes, metallurgy, wall thickness, slot pattern, etc. are all contributing factors to the life, durability, and interface with a disc. That has been proven through scientific fact.

You may not be able to exceed the capability of the OEM parts on your car, but that is certainly not the case for a lot of people. Everyone has different needs and places different demands on their car. It's just that simple.

Companies like AP Racing and Brembo have a small army of engineers working continually in these areas for a reason. The fastest pro race cars also leverage these technologies for a reason. To write off real race parts and technological innovations in brakes 'jewelery' just isn't fair. They may not be of benefit or provide any value for some, but they do for many, many others.

95jersey

I respectfully disagree. Again, I point back to the OEM GM design of one rotor for both sides as an example. Aftermarket companies are in business to make money. As someone who has been around for a LONG time, I know which products are the real deal and which are BS. It is knowledge that can only be learned from experience.

Also, I don't know you and you probably don't know me, but to blanket state that I don't put an extreme demand on my highly modified C6Z is just an assumption on your part. While there are a lot of fast guys here, and even more that think they are fast, I am not some mid level HPDE guy...the last thing I care about is boasting about my accomplishments, but I have many trophies, plaques and lists of wins/records, that at the very least qualify my opinion as being valid and worth an argument. So, my point, while I am not a national champion, I am also not even close to being a novice.

Also let's be specific, you made a general comment that I imply BBK's or other aftermarket parts are jewlery...on the contrary, I am just going deeper into the subject, and are specifically calling out 2 peice rotors for the sole purpose of longevity (nothing else).

The fastest pro racers use these because they CAN, and YES there are benefits (I agreed the weight savings is a huge benefit). I would run 2 peice rotors if I could afford them for this sake alone (weight). I however would NOT run them thinking I am making out better financially (with respect to cost of consumables), and that was my sole point. The poster directly pointed toward using 2 peice because he thinks they would last longer, which ONLY coorelates to a financial savings, not performance.

I will be the fist to endorse my LG coil overs, my Wilwood BBK, my T1 bars, Carbotech Pads, DeWitts Radiators, Hoosier Tires, and other parts that I have learned do make a viable difference. It is just my personal experience that 2 peice rotors do not provide a cost benefit over 1 piece for the sole sake of saving money in either short or long term. Let me say I respect your opinion and appreciate your professional tone. We are all here to learn from eachother.

JRitt@essex

95jersey,
That certainly wasn't a personal attack on my part. My point was simply that every car/driver is different, and what works for you may not work for others. Being easy on brakes doesn't necessarily imply slow or novice. You may be blindingly quick, but easy on brakes overall.

I do believe that the right two piece discs could actually be a value proposition over the long haul, but that depends entirely on how often the discs are being cracked and swapped (particularly if you consider the labor time spent as money). As you said, that can only be determined by experience. That's why (despite my working for an aftermarket brake supplier) I suggested that the OP go out and try the OEM style rotors first, and save his pennies if he doesn't need anything further/bigger/better/more expensive.

I don't personally know you, but I've see your posts on here for years and know you're not prone to making sweeping generalizations. That's why your comments really surprised me! No offense intended.

ps You're slow, deal with it.

Just kidding.

95jersey

It's cool, some of us actually race for real rather than internet or bench race...just kidding

JRitt@essex

Ouch! I actually have my share of trophies too...although they have a lot of dust on them. I've been doing autoX, DE's, and time trials since 1999...driving Acura Integra Type R, 350Z, C5Z06, and now a lowly NA Miata. I've driven something like 14 tracks in the US, instructed for many groups, etc. I'm no Schumi, but I can find my way around a track.

That said, I have a two year old daughter and another on the way...which essentially makes the bench the only place from which I can race these days. That said, I wouldn't trade it for the world, and I'll be back in action some day when my finances and schedule allow it! For now I just have to live vicariously through all of my customers and their cool cars.