^^^ good tips.

My ET900's are on their way. Dust shield removal and cooling ducts are happening tomorrow. Next track day is next saturday. I'm looking forward to trying these things out. Hopefully they last a few more days than the last set.

 

What are you using for the ducts?

 

Home depot special

Simliar to to Spin's DIY https://www.rx8club.com/showthread.p...+cooling+ducts

I got the dust shields off and the ducts fabbed up and installed. I didn't take the dust shields off on the back for a couple of reasons. 1) because rotors are a bitch to remove and i was sick of it after the front two 2) There are a lot of rubber bushings near the rear brakes and i'm not sure if the shield protected them from heat etc. 3) My rear pads aren't wearing like my fronts were so i figured they were less of an issue.

I got my pads really quick from RB and i installed them while i had everything pulled apart. I haven't done anything besides run to Starbucks this morning so the only conclusions i've drawn is they can be driven on the street no problem. Cold bite is fine. I'll bed them in and see how well they work soon and report back.

BTW, I took my rotors to a shop to see if they would turn them. They would not because they were down to ~.89 and minimum is ~.87. Realistically how much longer should i run these? I go to the track once a month and drive ~ 1000 per month including track miles. I need tires too so i'm trying to space things out here

 

That's quite a bit of use you do.... I'd get the RB slotted 1-piece stock replacements at least....only $126 each - and well suited to the heat and extremes of race track use than cheaper PepBoy/wheever type rotors. Something that I do every now and then is take a metal straightedge and hold it across the rotor surface and shine a small light back under the ruler to see how much uneven wear there is. If it's got excessive valleys and areas of wear, I'd be more worried about causing uneven wear on the new pads you got and order up the rotors so you can pretty much start over new and keep everything in good condition longer.

My RB 2-piece got replaced this season (3ys old) as they were wearing quite a bit more in a band towards the center of the rotor where the slots weren't. The new RB ones I got have a different slot design that extends further towards the center of the rotor and cover the whole of where the pad rubs. They must have been aware and that should solve the wear issue.

 

youare lucky you didn't burn off the rubber boots on the calipers....My friend recently just did that same thing to his pads on the track and he destroyed the boots on his front calipers and severely grooved the rotors as well.

 

I think i'd sport for the 2-piece actually. I've had my eye on those for a while and it's not like you replace rotors that often so i'd rather get the ones i want and spend a little extra dough.

I dont think i'll be going to the track in July so i'm going to squeak by on these rotors for Saturday's track day and then replace them before my August track day. They'll be fine for street driving for a while but i definitely want to replace them before my next (probably august) track day.

Just wondering if you think the Racing Brake stock size 4-pot caliper upgrade would be worth it some time down the road? Or should i just get the RB BBK instead of all of these options?

I haven't looked into it that much, just curious.

 

Race teams just use the OEM calipers, apparently they're bullet proof, and I don't know of any design, no matter how expensive, that'll improve significantly upon the excellent braking we have already.

The only saving grace(s) for caliper upgrades are looks and weight savings, and of course that depends on how much $$ you're willing to spend .

Myself, with 17" RPF-01s, and 255 BFG R1s, I'm down to 38.4lbs/wheel - approx a 10lb savings, plus another 4.4lbs from the 2-piece rotors, so total ~14lbs off per corner, and I just couldn't justify the high cost for just the add'l weight saving.

 

But there Purdy

And easier to change brake pads....Oh..and did I say they are Purdy

And lighter...and aluminum...so they dump heat faster......

A lot of the race teams that use them do so because they have to as well....most stock class racing doesn't allow brake caliper changes

 

So the ET900's seem to be better than the ET800's so far. Like i said, i can drive on the street no problem with them other than an occasional squeal at low speeds when they're cold. Cold grip seems to be fine. Maybe a little less bite at cold temps than the ET800's but still a strong bite.

As for the track, they performed well. Stopping power was about the same as the ET800's. Maybe a bit better actually. I picked up a lot of speed on the 2nd straight which leads to sharpest corner on the track (25 mph). Last time i was at the top of third and this time i was in 4th for a while before braking. I'd say i picked up at least 10 mph but i'm still braking at the same point. So if anything they have a bit better grip than the ET800's. They didn't necessarily feel grippier though -- hard to explain.

They didn't seem to wear as fast as the ET800's. I haven't removed them yet but it looked like there was still quite a bit of meat left on them after 5x15 min sessions. I'm still skeptical though, i'm not convinced they're going to last me. They dont seem to dust as much as the ET800's either. That could be because i'm not wearing through the pads as quickly but dust is definitely less.

The one thing i did notice that i didn't like about these was the fact that the rear got twitchy under braking, especially trail braking. Trail braking got really sketchy unless i released perfectly. I found they were much less forgiving if you needed to pull the braking a little into the corner. My ET800 rear pads are still in pretty good shape so i might try swapping them in to see if it makes a difference.

 

Good you and your brakes survived this event at least. To help the trail braking issue one thing would be try pads of different grip/grip profile front to rear, less in the rear to give (compared to the front) less braking force therefore more lateral stick while turning and braking. Result = less oversteer, more stable trail braking. Maybe next time when you replace those ET900s w/better pads.

 

I echo what Spin9k says. Because of the load shift under high speed braking at the track a less aggressive pad at the rear helps. That's why I recommended Carbotech XP10 or XP12s up front and XP8s in the rear or Cobalt XR1 or XR2 up front and XR5 in ther rear. I feel this is particulary important if you are on a stock suspension.

 

The ET900s WILL NOT last you at the track. I just finished a two-day event with the Schattenbaum Porsche Club. The ET900 pads were installed on the 16th and the track days were the 17-18th at New Jersey Motorsports Park. After four -20 min sessions on Thursday at Thunderbolt, the ET900 fronts were on their last leg. I ended up doing one run on them Friday morning at Lightning before the pads were completely gone and I had to pull into the paddock running on the backing plates in the front. The pads just don't have the proper wear characteristics for a track pad. I will now be using Carbotechs or Hawk DTC compounds. Hopefully I get better wear out of these pads.

 

Great, sounds like i wasted my $154.

Maybe they should change their name to Lightly Driving Brake instead of Racing Brake. This is getting ridiculous.

 

Yea that does suck, and I'm suprised as I think highly of RB rotors. Didn't realize their pads were crapola. It bears saying again that there's nothing better - and in the long run nothing cheaper - than the best stuff you can get.

Example - here are my Cobalt XR2/XR5's taken out of service this spring after 9 months and maybe 20 intermediate and advanced track hrs - NJMP Thunderbolt and Lightning, Tremblant, NHMS, Watkins Glen. Definitely some use left. Just saying....

 

PPF's or Carbotech are both good stuff.

 

I usually get about 4 3-hour track days (12 hours track time) out of the front Cobalts or front Carbotechs in my RX8 (the rears last a lot longer). And that's not down to the rivets, just getting close enough so that I buy a new set for the next event. Slightly different vehicle but our FWD Mitsubishi 3000 GT Lemons racer got through the first 9.5 hour race day of a 2-day race and looked like it could have done 2 more hours on the Carbotechs up front but we replaced them that night so we wouldn't need to change pads on the second day during the race. That's consistent with my track day experience.

It might be worth stating, and this goes for all pads, that the wear rate is not linear. When you have half of a pad thickness left you have less than half of the pad life left. The further they wear down the faster the wear rate is. Also check for rivets, most track pads have rivets and they stick up about 1/8 inch from the backing plate so when you have 1/8 left you are down to the rivet head and done.

 

^ interesting you should mention the wear rate and rivets in pads. Those in the pic I posted earlier were just starting to open up the holes showing that some of the rivets were about to be exposed. That's why I took them out of service, but anyway.... after getting the new ones I called Cobalt and asked about what wear, and how long I could reasonably expect to use the pads. I mentioned the rivets appearing thu the pad material and all.

What they said.... the pads were ok until there was 4mm material left. They said the rivets they used were a special alloy that would NOT scar or wear rotor surface and so they were useable until the 4mm, regardless of the rivets being there and exposed and wearing down. This was news to me and I though quite interesting that they had considered even such a thing as that in their development and engineering of their race pads.

Additionally, beyond that they said, and their web site lists specs for their race pads with a "Pad Wear Rate-of-Change from New-to-End of Life". For their pads they are <10% for XR1/2 and <5% for XR3/4/5. These low percentages are exemplary and of course mean you get more real use from what you pay for.

 

That's good to know about the Cobalts. I should probably ask Danny at Carbotech about their rivets and wear rate.

 

bump

ET900's wear just as bad as the ET800's i have less than half a pad left after one track day. Looks like i have to buy more pads and now i'm just stuck with some squeaky street pads Not that i was expecting any less... anyways moving on.

My car is getting the whole shi-bang before the next track day in August. New pads, rotors and some stainless steel lines. I'm debating between the DBA 4000 rotors or the Racing Brake one piece (decided on keeping things economical with one-piece rotors). I'm pretty sure the Racing Brake rotors will provide provide better cooling but i've heard the DBA are super durable. I'm just not convinced the "Kangaroo Paw" ventilation is even close to being as effective as curved vane.

Another factor in choosing the right rotor is what pads i can run with them. I know it may sound strange but i've read about people having issues with some compounds on RB rotors (pad deposits etc). RB even has a disclaimer that you should only use Hawk pads with their rotors. But unfortunately i haven't researched Hawk compounds that much so it's back to the drawing board on that front.

If i did get RB rotors i'd stick with Hawk just because i'm sick of brake pad issues and dont want to chance it. What do you all think the longest lasting Hawk pad would be? I know the Hawk Blue is an old compound but i have a buddy who drives an E36 M3 hard and fast on RE01R's and they've lasted him all season -- they dont even dust that much! Should i run HT-10's all around or maybe DTC60/HT-10? DTC-60 all around? I dont know. I feel cursed when it comes to brake pads now. Someone else make my decision for me

To throw a wrench in everything i picked up a set of 17x9.5 wheels with 255/40/17 BFG R1. I needed tires, wanted to downsize and it was a friggen steal. But now i have to take my new super grippy tires into consideration while shopping for brakes. HALP!

 

Blues are super old, and not even that good compared to the DTC series.

 

I know.

I'm seriously leaning towards Cobalt XR2/XR5's now. Seems like a lot of people are having good pad life with them.

 

DON'T BUY THE ET900s!!! I have posted in another thread about my experience with Racing Brake pads. I was at the same Shenandoah event as Striker-7. I managed to use up the front pads in just four sessions that day. I'm a lot heavier on the brakes than an experienced driver but I still found the pad wear to be unacceptable. I then talked to RB and they gave me a 40% discount on the ET900s. I caved and bought them. My next event was on June 17th-18th at New Jersey Motorsports park. The ET900s managed to last the first track day at Thunderbolt and then the following morning they were finished. I had extreme wear from both series of pads. They don't have the heat range required for repetitive track use. I have below some pictures of my ET800 pads after one track day at Shenandoah. You be the judge. The one pad was completely gone and the damage you see is from driving home on that pad. They were too hot at the track to change and I had obligations that night forcing me to drive home on them. I'll let you guys be the judge. This wear was after approximetly 110 track miles and 170 street driven miles on the pads.

 

That's just pathetic

 

Wow.

 

Caliper is the problem there, bad bad bad. Have them both rebuilt to save yeself some more trouble.