Brake rotors - do they make a difference for HPDE?

[mvanbuhl1]

I have a stock 2001 that I run in a couple of HPDE sessions per year. I understand the value of big brake kits, but I'm not really interested in doing big modifications. I have been running Project Mu track pads with stock rotors.

Question - should I consider investing in either slotted or cross drilled rotors? Do they make a noticeable difference on the track with only track pads and stock calipers? Any preference for slotted vs. cross drilled? I would also welcome opinions on track pads. Science of Speed has either Hawk or Carbotech.

 

[jwmelvin]

I found generic rotors good. I used some slotted ones that seemed fine. People say cross drilled are more likely to crack; o Lu a negative no benefit.

I used to use Hawk HP+ with stock calipers. I found they faded when worn down to about 1/3 remaining. On my current non-NSX track car I used Hawk DTC-60 and then switched to G-Loc R-12. I like the G-Loc much better, in terms of feel. The Hawks never faded but didn’t feel as controllable.

I take it you are looking for pads for the few track days you do, not pads for mixed street-track use?

 

[GUNDAN323]

I use Centric C-Tek blank rotors. Fronts $24; Rears $35.

https://www.rockauto.com/en/catalog/acura,2001,nsx,3.2l+v6,1370696,brake+&+wheel+hub,rotor,1896

I pair them with Winmax W5 track pads, removed the dust shields, wrap the ball joints with heat reflective tape, SS lines, Motul RBF600, and larger front brake deflectors.

Front rotors last about 5 track days before I replace them due to precaution. Rears last even longer.

 

[docjohn]

depending on your skill level and only a few events /year only requires fresh fluids and pads to start the year. SS lines carbotech pads and motul rbf 600 or whatever can't hurt but that fluid needs to be changed more often ....The better you are the more efficient you will be under braking .novice and solo first timers usually overbrake and drag brakes..increasing heat. Oem rotors are fine.

 

[mvanbuhl1]

Thanks for the responses, I appreciate the advice.

I'm driving to and from the track, but otherwise all track driving. I consider myself an intermediate driver, mostly driving in point-by groups. I'm sure I could be better with my braking technique, but just out enjoying the car, not trying to squeeze the last 1/10th out there.

I agree on the fluid changes, every track day. I appreciate the recommendations on track pads, where are you purchasing parts? In the past I was purchasing from Dali.

Also, I've got about 10 track sessions on the car with original rotors, 40,000 miles on the car. I caused some slight grooving on my right rear rotor on my last track session (rear pads should have been replaced). Should I get the rotors turned, or replaced? What are the general guidelines on replacing rotors?

 

[GUNDAN323]

I just replace rotors... probably more frequently than necessary. I rather not risk cracking a rotor during a track day. I replace rotors when the spider web cracks look pretty bad or heavy grooving.

 

[MJK]

Thanks for posting this.

I had no idea the 97+ rotors were now that cheap. For posterity, the centric P/N's are 121.40043 (front) and 121.40044 (rear) for the basic uncoated ones. 120.xxxxx for the black EDP coated centers.

Might be worth checking Amazon too, as I just got a pair of fronts for $17 shipped.

 

[christhac1978]

Thanks for posting this.

I had no idea the 97+ rotors were now that cheap. For posterity, the centric P/N's are 121.40043 (front) and 121.40044 (rear) for the basic uncoated ones. 120.xxxxx for the black EDP coated centers mouse clicker.

Might be worth checking Amazon too, as I just got a pair of fronts for $17 shipped.

I rather not risk cracking a rotor during a track day. I replace rotors when the spider web cracks look pretty bad or heavy grooving.

 

[stuntman]

Just bring an extra rotor to the track, but at that price, I guess it's not too expensive to just replace them.

You don't need to flush the fluid every event if you use a good fluid like Castrol SRF. AT MOST, just bleed the brakes ~the amount of fluid that was in the caliper (NOT MUCH) after every track event.

 

[latzke]

I found generic rotors good.

My OEM rotors took years of abuse (and developed a lot of spider cracks) before warping (and wearing) to the extent they needing replacement. Whereas generic rotors didn't even survive two days at Road America. Not sure if discrepancy is due to quality differences between the rotors, or user error (I tried to get too much life out of the pads - ran them too thin). I've never been convinced that slotted/cross-drilled are of enough benefit to matter (at least to us amateurs).

I used to use Hawk HP+ with stock calipers. I found they faded when worn down to about 1/3 remaining. On my current non-NSX track car I used Hawk DTC-60 and then switched to G-Loc R-12. I like the G-Loc much better, in terms of feel. The Hawks never faded but didn’t feel as controllable.

HP+ are what I ran too thin and had rotor issues with...but are what I use currently. Used to run DTC-60, but decided the extra performance they provided was not worth the downsides of having to swap pads for street/track or the tradeoffs using them for both street and track duty (squeak a lot in city driving, create a TON of brake dust, bite poorly unless they are up to temp which isn't always the case with street driving). I've never tried the HPS...under the assumption they're woefully insufficient for non-novice track use. One of the Carbotech SOS carries sounds unappealing to me for mixed street/track duty, and the other even less appealing (not even indicated for mixed duty - for track only, which may be what Hawk says about DTC-60 but I did it anyway because I didn't listen).

Just bring an extra rotor to the track, but at that price, I guess it's not too expensive to just replace them.

You don't need to flush the fluid every event if you use a good fluid like Castrol SRF. AT MOST, just bleed the brakes ~the amount of fluid that was in the caliper (NOT MUCH) after every track event.

Agree with Billy's "at most" upper limit on bleeding frequency/quantity here (my agreeing is kind of redundant/silly, as he has significantly more expertise in this space). Surely I wasted a lot of fluid and time before I figured out what I was doing was unnecessary. I'm too cheap for SRF (and not sure who around here would carry it). Ducati dealer near me has Motul RBF600 in stock for something like $20, so that is an easy go-to...and is "good enough."

 

[stuntman]

SRF costs twice as much. If you're bleeding 2X the amount or frequency (let alone a thorough flush), you're spending more money in the long run, wasting time, wasting good brake fluid, and contributing to the destruction of the environment.

Just run SRF.

 

[Ap2GT3]

I used to bleed too much as well. I stopped and will only bleed based on how much water has been absorbed. To check, I use a brake fluid tester. It’s cheap and good piece of mind when running expensive fluid like SRF.

Here is the tester I have:
https://www.amazon.com/BELEY-Automo...ords=Brake+fluid+tester&qid=1593267344&sr=8-5

Also, I have purchased SRF off amazon in the past.