Roadracers help on rear brakes, brake pad combos....

[Bugeater]

Question for the roadracers -

I have the STOPTECH big brake fronts and 38MM stock rears with the
proportioning valve removed. Non ABS car.

I have been running Brakeman 3's on all four corners. To my surprise I went
through the REARS after 5 hard days on a long roadcourse (VIR) and a couple
AutoX events. What I mean by "went through" is from brand-new rear pads pre-
Viper Days July, to no pad (metal to rotor) this sunday, same track. I know
guys that roadrace and dont replace the rears but once every couple YEARS.

Can someone concur that brakewear of this rate on the rears does indeed happen,
or should I be looking into a system problem?

Also, what suggestions are there for rears while using Brakeman 3's, or what is
a good front/rear combo when the rears are being used "aggressively" along with
the fronts?

That reminds me...anyone that has old rear pads laying around I'd be happy to
buy them or pay to ship them my way...that way I wont miss future lap sessions
cuz I forgot spares for the rear

Thanks in advance for any input.

 

[Frank Parise]

Not unusual on a hard braking track. 2-3 days at Road America will turn brand new pads into toast, both front and rear. It would be very unusual for just the rears to be worn out. You should see more wear in the front than the rear.

 

[REDSLED]

I've found that the Brakeman 3's didn't last lomg at the track unless they had some good break ducting to go with them. Brake ducting for the fronts is critical for extending the life of the pad. I've used the Pagid (Blacks), Stop Tech Club Sport, as well as the Cobalt pads and have found slight differnces in all of them. I've found theClub Sport pad to wear well and still have an aggressive bite to them. The rears should last 2X's as long as the fronts. Good luck.
Jonathan

 

[Bugeater]

Frank,

I had replaced the fronts before July 17 and again before this weekend as they were near-toast. I didnt replace the rears before this weekend, so yes, the fronts did wear faster than the rears. Sorry for the confusion.

For some reason I always thought the rears would last longer...oh well. Is there a combo that works better to get longer life out of the rears? Anyone running a mix of maybe Brakeman 3's front and ??? rear?

 

[Tom F&L GoR]

The front caliper-only StopTech setup uses *smaller* than OEM pistons, to shift the balance of front-rear braking more rearward. Therefore, you will get more rear pad wear than an OEM set-up because the fronts are doing "less" work so the rears can do proportionately "more" work.

The OEM rear calipers are 36mm (unless you got 38mm from me or made your own?) With my 40mm rears, they get hot enough to melt valve stem caps if you park in the wrong rotation, and pad wear is down to 1.5X front and 1X rear using all four pads of the same compound. I've used Porterfield R4 (not R4S) and Brakeman #3. I think there's some truth to pad life and cooling being related - I've ducted hoses to the rear calipers now and that seems to help. There is a Brakeman #4 pad you could try.

 

[Bugeater]

Tom,
I knew you would reply - Thanks! I got the 38mm spec from a comment Bob Woodhouse made on another thread I searched on. He mentioned the oem rear piston for 2000 cars was 38MM vs the 36 for 1999 and earlier models.

I would say my wear is definately 1.5 to 1 front to rear.
Not bad I guess if that means my setup is more balanced now.

I do like the setup - I ran a 40 minute session this sunday and noticed no real fade.

 

[Tom F&L GoR]

Bob's been helpful to me in the past on this brake issue, but I think he got this one wrong. At least the Viper parts books show the same caliper up through 2000.

The number "38" always catches my eye because the StopTech smaller fronts with the 36mm OEM rears provide the same balance as the OEM fronts and 38mm rears. So switching to either the StopTech fronts or 38mm rears should provide equivalent balance.

I'm working up a small batch of 38mm and 40mm calipers... if anyone is interested.

 

[Supercharged Vipermad]

Sheeesh John...all you gotta do is cruise over and help yourself to any spares I have. In fact...I was cleaning out my tiny garage and found my stockers....with about 15K miles on them, and ALMOST threw them away!! I knew there was a reason I keep ANYTHING Viper-related!!

 

[Chuck 98 RT/10]

I know guys that roadrace and dont replace the rears but once every couple YEARS.

"Years?" Holy smokes, what do they run one event annually?

 

[RC Viper]

John

My rears normally last about twice as long as my fronts. The number of days is highly dependent on the conditions and how aggresive I am being.

I recently switched out my stock brakes for a Wilwood big brake kit. I have some new #3's that I was planning on putting on Ebay. Give me a call if you are interested.

 

[GTS Dean]

I can get a year out of my PFC 90s in the back. The Brakeman #3 pads have a very high wear rate - even worse than the stockers. Temperature, friction and wear are VERY much heat-related. BM3s will wear 2-3:1 f/r if the temps are around 900-1000 front/ 600 rear. If you get more heat than that up front, you need #4s which are good to ~1300F. If your rotors run that hot, you will cook the caliper seals (and ball joint boots) and should rebuild them at least annually.

If you don't know how hot your brakes are running, you can't properly tune your stopping power.

 

[Bugeater]

Dean,
I dont think my fronts are getting hotter than 1000. My brake cooling is pretty good with the autoform front w/brake box cooling, and air deflectors. The rears though, have no aftermarket cooling. I dont know whats available there. I think I might get a set of PFC 90's and test. How do they treat the rotors? The BM3's dont seem to wear them too much (I like that)...

Randy! I will most definately take what you got. You wont believe it but I was going to call you today to ask how Atlanta was. Really!

I really appreciate all the responses.

 

[99 R/T 10]

OK, here is a question from a poser. I just put on new brakes all the way around on my 99. Roto-tech rotors(drilled and slotted) and ECB greens up front and Brakeman 3s in the rear(trying to get a better balance in the braking). Should I be worried about the excesive wear on the Brakeman 3's on the street? How long can I expect them to last an the street? Will they toast my new high speed/low drag rotors?

Mike

 

[REDSLED]

Since the Brakeman 3's are a track pad you might experience excessive squeaking due to the composition of the pad. A typical track pad will squeak until it gets hot. If driven on the street the rear Brakeman 3 pad may never get hot enough to eliminate the squeak. Just a thought.

 

[Bugeater]

Mike,
FWIW, I dont get too much noise out of the rear pads. As for the wear, on the street dont worry about excessive wear due to running their compound. You dont see anywhere near the duty cycle you see on the track, let alone a larger track like I typically run. I expect you will get YEARS of usage street driving with BM3's in the rear.

 

[slaughterj]

The Brakeman #3 pads have a very high wear rate - even worse than the stockers.

So...what's the benefit of the brakeman #3 pads?

 

[Bill Pemberton Woodhouse]

One of the items you haven't mentioned, is if you are going faster? The Brakeman's may wear somewhat faster, but your rate does not sound unusual, and the advantages far outweigh the disadvantages. We have found superior pedal feel with non-ABS cars, and I honestly feel the progressive nature of the 3s is why the car has such great balance and they are very easy to trailbrake with. Do not go to 4s , as they will not get hot enough and the balance is not there. We have so many customers that call wondering why their pads are starting to wear faster and it is almost universal that they are going much faster than the month/year/etc. before. Brake ducting ( not Porsche deflectors ) will increase wear substantially, and Henry Cones's system which he copied from Bob Woodhouse's set -up and improved ( sold through the PartsRack ) is ,in my estimation, the best kit on the market. I think folks often confuse wear with a problem,when frankly if the pad wears like iron it probably is not in the efficient heat range. Speed always involves wear, so congratulate yourself for going faster, and if you enjoy the progressive feel I would stay with the Brakeman's.

 

[Chuck 98 RT/10]

Brake ducting ( not Porsche deflectors ) will increase wear substantially,

I think you meant "REDUCE wear substantially."

"The ****" is one of the fastest Vipers at Viper Days, he's just little a dyslexic.

 

[Bill Pemberton Woodhouse]

Thanks Chuckie, as the 3 hours sleep I got last night is starting to tell. Busy Monday, and hard to catch up after a little vacation. You iz correct-a-mundo and thanks for the correction.

pllib

 

[Bugeater]

Bill,
I have the Porsche deflectors, and the ducting that comes integrated in the Autoform nose when you opt for the brake box. The ducting doesnt reach as far to the caliper as Henry's system. Do you think I should extend this to simulate what ya'll have engineered? I assume you are familiar with the fascia I am talking about because I think the Autoform Daytonas you sell had them.

Also, is there cooling strategies for the rear?

For the record I wasnt concluding I had a wear issue, I know I am going faster these days but wanted to confirm that the wear sounded "typical" for someone learning to go fast.

Thanks again for all the responses!

 

[REDSLED]

I believe that your brake ducting should extend all the way to the center of the rotor for the best results. I've seen brake ducting placed directly to the calipers as well as the rotors on many Trans Am series Mustangs, Jaguars & Corvettes. The more direct air flow the better.

 

[GTS Dean]

Do not go to 4s , as they will not get hot enough and the balance is not there. Speed always involves wear, so congratulate yourself for going faster, and if you enjoy the progressive feel I would stay with the Brakeman's.

I've run both the 3 and 4 compounds in front. I've measured (with Tempilaq) stock rotor temps of 1300F, so I'm definitely in the correct range for the #4. Personal preference, but I prefer a VERY "bitey" pad with good release in the front, and a very modest torque curve rear with slow release for trailing into the apex without loading up the fronts. Your mileage may vary - greatly.