Mixed brake pads & rotors a bad idea?

[Ch4r1ie]

One of my rear EBC YellowStuff brake pads shattered yesterday and caused considerable damage to the EBC dimpled and slotted rotor, so I've swapped the rear rotors out for a pair of new OEM rotors and put new OEM pads on all around until I can get suitable aftermarket replacements shipped in from the US.

The trouble is I have an open track day (circuit) on Thursday and I know the aftermarket kit isn't going to arrive in time, so my questions is...

I've got a pair of HAWK HP Plus pads that I was going to run up front for the OTD, along with the EBC dimpled and slotted rotors that I still have installed there, will that work with the now OEM rotors and pads at the rear, or is it a bad idea to run such different rotors and pad compounds?

Additional info/specs:
OEM calipers
SS braided brake hose
DOT 5.1 brake fluid

 

[Sleeper_08]

It would be a shame to miss a track day so I suggest that you give it a try but take it very carefully at first. Just remember that you need to be extra careful for both your sake and the other drivers sake.

If your front calipers are stock with just rotors that are slotted and dimpled with HP+ then they will take the heat better than the stock rears but a lot of us run mismatched pads front and rear on the track. In my case it is CarboTech XP10/XP8.

Some people say that slotting and dimpling of the rotors with today's pad compounds is not necessary and has little or no effect so the main difference you are looking at is the pad compounds. Make sure that the rear pads are as new as possible as they will wear pretty fast.

The other alternative is to just run new stock pads front and rear and watch the wear.

Best of all just don't use the brakes

 

[ArizonaGT]

DO NOT run the stock pads if you are used to braking with aftermarket pads, you'll exceed their temp rating and you'll be without brakes quickly.

Using any combination of rotors + pads should be fine, just make sure to BED THEM IN prior to hard use.

 

[Ch4r1ie]

I've got the HAWK HP Plus pads that I can run up front, but I won't be able to get anything else in time for the rears other than the OEM pads. I'm pretty concerned about the difference there will be in braking and heat build up between the front and rear if I run with this setup, which I would imagine will be huge :/

 

[Ch4r1ie]

OK, I managed to get the damaged rotor skimmed today and it's great, so I'm going to run the EBC dimpled and slotted rotors all around, the HAWK HP Plus up front and the OEM pads at the back.

Everything felt OK on the short road test I did this evening, but I just hope the braking doesn't become too unbalanced once I'm out on the track on Thursday!

 

[aldoe90]

Don't run OEM pads!!! i tried that once because my order was delayed once and after 3 sessions i had no pads left on the rear and the rotors were destroyed. If you do plan on using your oem pads might as well run the oem rotors incase your pads get worn out in the middle of a session and you damage the rotors.

Besides that i run carbotech xp10 up front and right now im running hp+ out back.

 

[EdwardGT]

I'll echo the comments from the other users. I would NOT run the OEM pads at the track. If you were running the OEM fronts, I think you'd be ok. However, the rears will not last long at all. I don't what it is about the compound used for the rears; but they wear like crazy. When I had 5k miles on my car, I did an event on the roval at Texas Motor Speedway. After only 5 sessions, my rears were down to the backing plates - and this was on stock 235/50/18's. Why not order HP+'s from Tire Rack? They should get there in time.

 

[Ch4r1ie]

Don't run OEM pads!!! i tried that once because my order was delayed once and after 3 sessions i had no pads left on the rear and the rotors were destroyed. If you do plan on using your oem pads might as well run the oem rotors incase your pads get worn out in the middle of a session and you damage the rotors.

Besides that i run carbotech xp10 up front and right now im running hp+ out back.

I'll echo the comments from the other users. I would NOT run the OEM pads at the track. If you were running the OEM fronts, I think you'd be ok. However, the rears will not last long at all. I don't what it is about the compound used for the rears; but they wear like crazy. When I had 5k miles on my car, I did an event on the roval at Texas Motor Speedway. After only 5 sessions, my rears were down to the backing plates - and this was on stock 235/50/18's. Why not order HP+'s from Tire Rack? They should get there in time.

Thanks for your input guys and ordinarily I would never run OEM pads at the track but, unless I want to miss the OTD... which I definately do not as I have my sister and 9 year old nephew are over visiting from the UK and they're really looking forward to it... as am I of course, I am going to have to run with the HAWK HP Plus up front and the OEM's on the rear. I'll get an extra set of the OEM's for the rear and I'll swap them out half way through the day. That way I should be good for the entire day... hopefully!

I'm located in the Middle East, so there is no way I will get replacement aftermarket pads here in time for the OTD on Thursday. Unless someone wants to handcarry a set over for me of course?

 

[kevinatfms]

ill hand carry them over for plane fare and a place to stay?

 

[HellsBells]

Actually, what you're doing isn't all that uncommon amongst weekend racers with daily driven cars. Since some 90-95% of your braking occurs in the front, the rears really don't do too much. It's the same way why big brake kits tend to only replace the front and never the rear.

You might run into a slight imbalance compared to what you're used to but in all honesty, I doubt your aftermarket rear set up really made all that much of a difference. I've raced cars with BBKs up front and drum brakes in the rear and it wasn't noticeable that the rear was negatively affecting the braking distribution.

I agree you should take it a little easier on the first few laps but that's more for makin sure it's all installed right and that your setup is not causing a serious issue to begin with. Honestly, if it does pose problems, they will not show up until you've already been lapping the track a few times. So instead of testing it for the first two laps and resting assured, by aware that your potential brake issues (if they even show up) will be most pronounced once you're well into raceday.

 

[Rapid]

i'm confused about the rear pads wearing. I had one day at Robeling on my stock pads then did a day at CMP. I wore my rears out but I was sure it was because my Son, who drove it one 20 min session, did not disable the stability control as I had.

 

[Sleeper_08]

i'm confused about the rear pads wearing. I had one day at Robeling on my stock pads then did a day at CMP. I wore my rears out but I was sure it was because my Son, who drove it one 20 min session, did not disable the stability control as I had.

Leaving traction control on when on the track will apparently use up rear pads really fast.

Don't ask how I know.

 

[Gray Ghost GT]

I turn off my TC when on the track. My front pads wear twice as fast as the rear pads. TC will definitely wear your pads faster! However, if you're new to HPDE, its not a bad idea since it can get you out of trouble as you learn the basics in Level 1. The S197 is a well balanced car, so once you learn the line, consistently hit the apex, and feel the weight transition under braking and acceleration, its a good idea to turn TC off so the computer doesn't jump in unexpectedly as you get faster.

 

[EdwardGT]

With my track pads, PFC01(f)/PFC97(r), I do wear the fronts at least 2x faster than the rears. However, there a lots of threads on various message boards about OEM rear pads not being up to the task of track duty. My experience at TMS was with TC disabled. I think the issue with the OEM rear pads is that they're a much softer compound for the sake of quiet operation.

And FWIW, I don't think TC has ANY place in DE environment - except maybe rain. I think any kind of TC or stability control handicaps a driver in the long run.

 

[Ch4r1ie]

ill hand carry them over for plane fare and a place to stay?

Accommodation would be no problem at all mate, but the air fare... that's a different matter!

Actually, what you're doing isn't all that uncommon amongst weekend racers with daily driven cars. Since some 90-95% of your braking occurs in the front, the rears really don't do too much. It's the same way why big brake kits tend to only replace the front and never the rear.

You might run into a slight imbalance compared to what you're used to but in all honesty, I doubt your aftermarket rear set up really made all that much of a difference. I've raced cars with BBKs up front and drum brakes in the rear and it wasn't noticeable that the rear was negatively affecting the braking distribution.

I agree you should take it a little easier on the first few laps but that's more for makin sure it's all installed right and that your setup is not causing a serious issue to begin with. Honestly, if it does pose problems, they will not show up until you've already been lapping the track a few times. So instead of testing it for the first two laps and resting assured, by aware that your potential brake issues (if they even show up) will be most pronounced once you're well into raceday.

That's all pretty much spot on what I believed to be true

i'm confused about the rear pads wearing. I had one day at Robeling on my stock pads then did a day at CMP. I wore my rears out but I was sure it was because my Son, who drove it one 20 min session, did not disable the stability control as I had.

Leaving traction control on when on the track will apparently use up rear pads really fast.

Don't ask how I know.

I turn off my TC when on the track. My front pads wear twice as fast as the rear pads. TC will definitely wear your pads faster! However, if you're new to HPDE, its not a bad idea since it can get you out of trouble as you learn the basics in Level 1. The S197 is a well balanced car, so once you learn the line, consistently hit the apex, and feel the weight transition under braking and acceleration, its a good idea to turn TC off so the computer doesn't jump in unexpectedly as you get faster.

And FWIW, I don't think TC has ANY place in DE environment - except maybe rain. I think any kind of TC or stability control handicaps a driver in the long run.

Not a problem, I never run at the track with the TCS on! Rain... what is that???

 

[Ch4r1ie]

OK, so I ended up running with the EBC dimpled and slotted rotors all round, HAWK HP Plus pads up front and OEM pads at the rear. TCS was off.

Obviously, the braking wasn't as good as normal, but it was managable and the OEM's were wearing OK. That was until I let my sister have a drive and we turned the TCS back on!

We had done a fair few laps of the circuit when, from the passenger seat, I felt the back end of the car becoming unstable under braking. I asked my sister if everything felt OK, she said it felt fine, but of course she didn't know any different and was pumped up!

I told here to take us in and it's a good thing that I did, this is what I found...

Fortunately, it was the second to last session of the day, so we didn't miss out on much and had a great day! As you can see in these threads, if you've not already...

Another open track day, more car porn... (pictures)

Mixing it up with a Lamborghini, Ferrari, Porsche, Nissan, Audi, Subaru... (video)

However, I have just ordered in a shit load of aftermarket brake pads to make sure that I never have to run with OEM's again!

 

[Gray Ghost GT]

I think you got your monies worth out of the OEM pads! LOL. Which aftermarket brake pads did you decide to go with?

 

[foolio2k4]

he bought my dtc-70s and ht-10s

Hey did you get confirmation or anything that your shippers received the package? I have pictures of the receipt and package if you need them.

 

[Ch4r1ie]

I think you got your monies worth out of the OEM pads! LOL. Which aftermarket brake pads did you decide to go with?

I really did get my monies worth out of the pads, but unfortunately it cost me a set of rotors!

I did indeed buy foolio2k4's HAWK DTC-70's & HT10's (as per below) and I've bought some more HT10's elsewhere to match up with them and have as spare.

he bought my dtc-70s and ht-10s

Hey did you get confirmation or anything that your shippers received the package? I have pictures of the receipt and package if you need them.

The shipper has received them and now I'm just waiting for some other stuff to arrive into my box, so that it can all be forwarded to be together. I'll give you a shout when they arrive here with me and I will also post an iTrader rating then too.

I meant to ask though, I couldn't find DTC-70 rears to buy anywhere. Do you know where I can find some online, or which other HAWK pads I should run with them?

 

[Gray Ghost GT]

I meant to ask though, I couldn't find DTC-70 rears to buy anywhere. Do you know when I can find some online, or which other HAWK pads I should run with them?

I recommend using the Hawk DTC-60 for the rear vs. the 70. It's part number HB485G.656 for the OEM calipers. I couldn't find a part number for the DTC-70 rear pads.