Track Day Brake Question

I plan on doing a few Time Trial events and want to ensure the Elantra is ready. Currently, I run Ferodo DS2500 pads up front and was thinking that I could swap in a more track-focused pad for events. There is nothing wrong with the 2500s, I really like them, but I thought perhaps I could get a bit more bite and save wear on them because I still daily drive and autocross the car.  What I am hearing, however, is that you don't want to swap pads without swapping rotors as well. Is that the case? Am I better off leaving well enough alone?  

I don't know that I've heard that, but it doesn't mean it's not true. Maybe it has something to do with embedding different braking compounds into the rotors' surface?

I have heard, however, of countless people doing exactly what you're describing doing--just swapping pads at the track. It doesn't mean they were doing the right thing either, though it does seem ambitious.

It's actually something I've never done, because the effort of pulling the nearly-molten wheels off, swapping 500 degree brake pads on the hot asphalt of the paddock, and then reinstalling the still-too-hot wheels and driving home seemed way above the amount of effort I would be willing to put forth after burning myself out all day in the heat. Instead, I just drove around with Hawk DTC-somethings and dealt with squealing brakes all the time.

Good question though. I'm here to learn what the group has to say.

I'm open to correction, but I don't swap rotors when changing pads unless the rotor is worn unevenly and has noticeable ridges. But if the rotor is flat, I swap and then re-bed. 

One thing to consider is how the pads play with the ABS system. A grabbier pad can cause the ABS to freak out, and different platforms are different. If the current pads play nicely with your ABS and aren't the limiting factor, by definition there's nothing to justify changing them. 

Changing pads isn't a problem if the compounds are compatible... generally, this would require choosing a pad from the same manufacturer.  I have been able to swap compounds with G-Loc pads on the same rotors without any issues.

I've noticed when I did bother to swap pads that they would take a few laps to come up to full grip. Probably cleaning off the old compound I imagine.

I swap pads all the time.  I have noticed that braking is far better after the first track session tho, as the pads have bedded in to the rotors at that point.

For casual trackday use you don't really "need" race pads, but they're nice to have.

What I used to do in my HPDE days was swap the street pads for race pads the day before the event and drive to the track on them. After the event I'd swap the street pads back on after I got home again. A couple of hundred miles of light street use won't harm your race pads or rotors.

In theory, you should also swap rotors, but I never bothered with that. Just change the pads and bleed the brakes before and after the event. Never had an issue.

pinchvalve (Forum Supporter) said:

What I am hearing, however, is that you don't want to swap pads without swapping rotors as well. Is that the case?

It's not always the case, but you either need to know somebody that has confirmed it, or spend the money to try it yourself.

It would be nice to be able to take a couple of thou off each side of the rotor - the new pads would bed more quickly than they will on an already glazed surface, but at a race weekend if the pads need changing you just slap them in there - they will bed in but it will take a bit longer.  

I have seen statements that grooved rotors bed pads more quickly but I haven't had occasion to test that.

Yeah you don't need separate rotors unless you're running pad compounds that are incompatible with each other, which is a pretty unusual situation.

It's not THAT unusual. I think it was Carbotech used to warn against reusing rotors that had also been used for a certain type of common pad compound. I think it meant we couldn't use Porterfields and Carbotechs on the same rotors. I forget the details, but the pad manufacturer can tell you.

If you're having trouble with overheating pads, maybe look at ducting to keep the pads in their happy zone. Doing a quick check on the DS2500, you may not need much if anything - especially if you're on street tires.

Interesting questions as I'm working on a story that discusses this right now, but here's the short answer, as I get it from multiple brake companies.

• The *best* arrangement is a set of pads and matched rotors.

• We don't live in the best of all possible worlds, though, so swapping pads with the same rotors is fairly common and not particularly harmful.

• Observing some best practices can minimize any negative impact on the swap. Mark your pads and always replace them so they present to the rotors in the same direction. Take a few minutes and hit the rotors with a stiff scotchbrite pad or some 200 grit during the swap, then re-bed the replacement pads after the swap. Re-bedding the track pads is more important than re-bedding the street pads, but doing both is best practice.

How big is the check you get for 1st place at this HPDE?

Put another way, why would you bother with all that extra work, especially when it means messing with the brake system before you go on track, at speeds around triple digits?

JG Pasterjak said:

• Observing some best practices can minimize any negative impact on the swap. Mark your pads and always replace them so they present to the rotors in the same direction. Take a few minutes and hit the rotors with a stiff scotchbrite pad or some 200 grit during the swap, then re-bed the replacement pads after the swap. Re-bedding the track pads is more important than re-bedding the street pads, but doing both is best practice.

 

I want to double click on the one point...  on the c5/c6 setup its pretty common practice to flip pads driver side to passenger side to fight pad taper...  it sounds like based making sure they present in the same direction flys in the face of the taper problem, is that not true?

racerfink said:

How big is the check you get for 1st place at this HPDE?

Put another way, why would you bother with all that extra work, especially when it means messing with the brake system before you go on track, at speeds around triple digits?

Scraping the car off the wall after the brake pads melt and don't stop the car costs the same whether it's a competitive event or not.

dps214 said:

racerfink said:

How big is the check you get for 1st place at this HPDE?

Put another way, why would you bother with all that extra work, especially when it means messing with the brake system before you go on track, at speeds around triple digits?

Scraping the car off the wall after the brake pads melt and don't stop the car costs the same whether it's a competitive event or not.

If the Ferodo pads are doing the job now, there is no point in swapping the pads unless one is really annoyed with the feel of said Ferodo pads.

I'm in the camp of don't fix what isn't broken.

dps214 said:

racerfink said:

How big is the check you get for 1st place at this HPDE?

Put another way, why would you bother with all that extra work, especially when it means messing with the brake system before you go on track, at speeds around triple digits?

Scraping the car off the wall after the brake pads melt and don't stop the car costs the same whether it's a competitive event or not.

I learned something quite a few years ago with some guys I ran endurance races with.  The owner had to replace pads and rotors on his two rental cars every race.  His house car, with a couple of SCCA Pro champions on the list of drivers, could go two races before it needed pads.  He replaced the rotors because it was cheap insurance for endurance racing.  The biggest reason is the renters would hammer the brakes hard in initial application, and then use them longer and over-slow for the corner, generating much more heat.

I've done three track days with my V6 Camaro (not a 1LE) on the stock pads and fluid.  I've made at least 20 passes at the drag strip where I hit the trap at 100mph.  My car is 9 years old now, and 106k miles, all on the original pads and rotors.

In reply to racerfink :

You should really consider changing out that fluid. 

Drag racing is a single stop, so heat management isn't that big a deal. Multiple track days on the stock pads is impressive. 

ClearWaterMS said:

JG Pasterjak said:

• Observing some best practices can minimize any negative impact on the swap. Mark your pads and always replace them so they present to the rotors in the same direction. Take a few minutes and hit the rotors with a stiff scotchbrite pad or some 200 grit during the swap, then re-bed the replacement pads after the swap. Re-bedding the track pads is more important than re-bedding the street pads, but doing both is best practice.

 

I want to double click on the one point...  on the c5/c6 setup its pretty common practice to flip pads driver side to passenger side to fight pad taper...  it sounds like based making sure they present in the same direction flys in the face of the taper problem, is that not true?

Something something maintaining grain alignment something something. I'm asking around about it more, but I've heard from multiple sources that they believe that flipping can accelerate wear such that it outpaces potential taper wear. I'm not sure I believe that for all brands and compounds, though, so I'm bugging more people about it.

What kind of Elantra? The current one? A "N" model? What is your experience level? What tires will you be using?

I'm not familiar with the Ferodo 2500, although a quick google search shows that they appear to be a track-focused pad. 

I run G-Loc GS1s on the street, slap to R16/R12 for DEs as I'm putting my track tires on (R8s on our track Sienna), then slap back to GS1s after the track event.

Same rotor, about 40min total,

I'd think 1.11s or DSUNOs would play well with the 2500 street pads.

In reply to RacerBoy75 :

DS2500 is a mixed use pad. 
----

RE swapping pads, I'll be swapping this year for track events. I'm starting my 2nd year in HPDE. OEM pads and rotors weren't cutting it by the end of my last year. I swapped to Girodosc rotors and Pagid RSL29 pads. The pagids are really too loud for me on the street (the car is also my daily) so I got some Endless MX72 for the street. Happy so far, but haven't tried the pagid on track yet since it was after my last event last year that I changed the brakes.