What a track weekend/Rotor question

[VBNSX]

So.. how was everyone's easter?

At the track I cooked my rotors.. (powerslot slotted) I cracked the rear and now I'm opening up my options. I had powerslot rotors but i'm rather viscious on the brakes.. I thought I was doing good buying the good chit... Next thing I'm gonna do is add on some brake ducting for the rears.. hopefully that'll fix some things.

Question: Has anyone here ever purchased Autozone's 'Duralast' brake rotors? They come with a 2 year warranty and I'm rather confident I'm going to use that warranty (considering these only lasted about 7 months.. I track alot though)... But my main question is: Have I set myself up for failure here by buying cheapy rotors? I mean will I be using my warranty after two track events?

All opinions would be GREATLY appreciated..

BTW... at the event.. I was the lowest hp car there... kinda crazy.. but.. I did pass some people! Had troubles w/ the GT3 and the RX-7 w/ a license plate that said 'VIPRKILR'... it was cool watchin him though.. whenever he left off the gas, flames shot out.. =P

x

 

[NSXLuvr]

Be very careful using any Autozone products. Sure the warranty will cover it. However, the products are known to not last. Do you really want to risk rotor failure at the track. I have tried their brake pads, rotors and got tired of the frequent failures. I finally just went with OEM.

 

[VBNSX]

Yeah.. that where my question is stemming from.. I'm assuming you got the rotors for the nsx? I think I'm gonna fold and buy some Brembo blanks...

Might be the best situation...

btw.. here are a few pics:

x

 

[NSX-Racer]

As the rear brakes of the NSX are usualy stressed much less than the fronts I'm really astonished about your experience - even stock brakes don't suffer much - not even with BBK at the front (I had that for a long time, now I use BBK at all four wheels).

 

[VBNSX]

Yeah.. I thought it was rather weird...

here's what I added in hopes of some sort of cooling... used an idea from Dan O

x

 

[MarkB]

...now I use BBK at all four wheels....

Wolfgang, what wheels and brakes do you use?

 

[NSX-Racer]

I'm pretty sure this solution will not improve too much. First: Usualy heat is not the main problem at the rear brakes - they stay much cooler than the fronts.
2nd: Air should be lead directly to the calipers and rotors - so you may construct short ducts from the side scoops to the brakes.

 

[NSX-Racer]

Wolfgang, what wheels and brakes do you use?

Mark, I'm absolutely puzzled that you didn't already read all the infos here :biggrin:
I use 16/17" stock wheels with 22 mm spacers (adapters) and Brembo brakes (Mov'it front, custom adapted rear with additional Brembo parking brake).
Works amazingly good and long on the track- especialy with race slicks.

 

[MarkB]

Mark, I'm absolutely puzzled that you didn't already read all the infos here :biggrin: ...

Es tut mir leid. Himpups(?).

 

[VBNSX]

I'm pretty sure this solution will not improve too much. First: Usualy heat is not the main problem at the rear brakes - they stay much cooler than the fronts.
2nd: Air should be lead directly to the calipers and rotors - so you may construct short ducts from the side scoops to the brakes.

I would like to agree with you but this 'concept' came from Dan O who last I checked noted his temperatures and did see some differences in rotor temps.. well.. I'll find out this weekend.. (doing VIR Grand and Full course)

I'll let everyone know in a bit..

x

 

[evof575gtc]

if you do get brembo, i suggest the pillar vented rotors VS straight or curved vain. theyre supposed to be stronger.

what kind of pads are you using?
cermamic?

 

[VBNSX]

if you do get brembo, i suggest the pillar vented rotors VS straight or curved vain. theyre supposed to be stronger.

what kind of pads are you using?
cermamic?

Carbotech Panther Plus pads.

Thanks for the suggestion.. I'll look a lil more into them..

x

 

[NSXT]

Just an observation, but what is the thickness of you cracked rotors in your photo? It could be the angle of the photo, but it looks to me like they have quite a bit of wear on them, and, if they are thin, that could explain the cracking.

 

[Hrant]

I'm pretty sure this solution will not improve too much. First: Usualy heat is not the main problem at the rear brakes - they stay much cooler than the fronts.
2nd: Air should be lead directly to the calipers and rotors - so you may construct short ducts from the side scoops to the brakes.

This may be true for OEM setup but has not been my experience with the DaliRacing 2 piece floating rotors. I have taken temps on my rotors (both OEM and the 2 piece floating) for some time now, and there is a definite differnece. I have the dust shield removed on the fronts, but the rears still have them.

Using the Panther Plus pads, the OEM used to run about 500F to 600F depending on ambient temp (often after a moderate cool down lap into the paddock), both front and rear. When I went to the 2 piece floating rotors, the fronts are running about 125-150F cooler than the rears. With more braking torque with the new rotors, my temps hot from the track (no cool down) read about 600F fronts and 720F rears at Laguna Seca. YMMV.

 

[docjohn]

My rear rotors also run at least 100 deg more than my fronts,but I have stock rears with no extra ventilation,and my fronts are ducted with brembo 12.4 rotors and Indy callipers.The above is with the ducts closed with them open the temp difference can be as high as 200 deg.

 

[mikeh]

Good information in this thread, thanks folks! I've been trying to deceide what to do with my cars' brakes. On my old nsx I did the big brake upgrade before I used up all my options with the stock brakes, but they did work really well!

This time I'm much older and wiser (read: cheaper!) and I think I'll be trying to maximize the stock setup first. My only concern is a lack of shake-down time in this car before the OTC... and brake problems during the OTC are horrible because you can't really do anything about it between races (you won't be able to find parts... been there-done that with the old supra).

I think I'll just start with a new set of OEM rotors, a set of track pads + some ducting and see how long they last with the blower + hoosiers.... probably not long, but I'm a masochist.

-mike

 

[NSXLuvr]

Yeah.. that where my question is stemming from.. I'm assuming you got the rotors for the nsx?

Nope. Actually, I was going the cheap route on a 1995 Altima and a 1997 Prelude. I had such poor luck with the Autozone parts that I never used them again. I actually had a mechanic who refused to put on an Autozone pad because he felt that it is unsafe.

 

[NSXLuvr]

If the Pyro #'s show that the rears get hotter than the front, then why is it that the majority of people go with Front BBk only. I would think it would be more appropriate to get 4 wheel BBK instead. or to upgrade the rears 1st(though that doesn't quite make sense to me either).

Damnit, it was alot easier on a FF car.

 

[VBNSX]

Well for now (due to time constraint b/c event is so close) I'm going to put the Autozone rears on (feel like a guinea pig here) and just beat the heck out of them. IMO rotors are a disposable item. Warranty on a disposable item.. hrmm....

I have to remind myself to bring a IR pyrometer to hopefully get some decent readings. Doc.. for just baseline statistical sake what were your 'actual' temps? Since I never actually took the temperature stock, I'll just use your temps as a 'close' guideline to see if the ducting is doing anything.

NSXLuvr - I completely agree with you on the pads.. I mean we're paying $100 or so for 2 front pads and here are these cheapys that are $10 for both.. I mean of course there's gonna be a quality issue...

x

 

[Hrant]

Ah, trick question heh :wink:

In OEM set up, the fronts get hotter. But once you put better venting rotors, the rears catch up to the same temps. Then remove the dust shield on the fronts, you gain another +/-100F of cooler rotors on the fronts. It is a cooling issue. The rears don't have much opportunity for cooling or ducting as compared to the options (though still limited) on the fronts.

I went with the 2 piece floating rotors because that is the only option currently available for 97+ that can fit under 16 OEM wheels; the 2 piece floating rears were a bonus in terms of more cooling opportunity, and all 4 weigh less than the OEM with the rears still having more mass than the OEM. HTH.

 

[Ponyboy]

Same here though my rotor temps were always very close to each other front to back. The gauge (which may be the issue) was an infrared laser temp. reader thingie.

Higher temps on the rear make sense b/c the NSX is 60% rear weight biased and under braking the rear shoulders more responsibility than a normal FR car.

FWIH, PowerSlot is making 2 piece rotors and they may have an application for NSX rears. Either product you choose, you may want to cryo treat them to make the rotors last longer.

 

[docjohn]

Depending on the track the fronts unducted will go around 500 ducted 400.The rears get up to around 600.Of course I doubt this has much validity to your case of stock system front and rear.Just make sure you get your hot temps in the hot pits after no cool down to get a more accurate temp,my above temps can only be looked at from a relative front vs rear/ducted vs unducted ratio because I usualy take my own temps back in the garrage so the absolute temps are probably down 100 deg or so from actual as per Andy Lin.

 

[ak]

http://www.nsxsc.com/html/article9.html

here's an interesting article from NSXSC.com about 97+ brake compared to 97-. I have the NA2 brakes and they are adequate for my skill level at this point.

 

[the nsxnut]

Well, here's my 2 cents (again ) on the power of OE brakes... if you do all the possible mods (lines, fluid, pads, caliper rebuilds, remove dust shields, add ventilators), and bleed regularly, they give excellent perfomance. Yes, a $6000+ Brembo kit will give better performance, but for hobby track days, the OE stuff really gets the job done. I routinely close the gap to cars ahead on the track under braking. Remember, how you use your brakes is as important as what brakes you're using... many passengers with me or Maria have been amazed at the powerful decel.

I treat my rotors as disposable, and change them out every 8-10 track days. I have a stack of used-up, cracked rotors waiting to be taken to the recycler. I have a stack of OE take-off rotors ready to be installed. I routinely buy used rotors off of other Prime members... there is always a supply out there. My brake temps measured at the track are usually around 500-600f., front and rear nearly the same.

My experience with giving a point by on the track, it's usually a superior driver with higher horsepower, or higher cornering speeds; not really related to bigger brakes.

As always, YMMV, and my experience is applicable to hobby track days, not racing...

 

[NSX-Racer]

Higher temps on the rear make sense b/c the NSX is 60% rear weight biased and under braking the rear shoulders more responsibility than a normal FR car.

Don't forget the load transfer under braking: The rear of the car is lifted and therefor the rear tires can't do much braking. That's why you usualy experience about 3 times more brake pad and rotor eating at the front than the rear (that's what I had with the stock brakes - now with the Brembo setup it's more like 4 times). Of course this effect may be worse with FF cars and it may also be worse with the NSX if you use extremely sticky tires (race slicks in my case).