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Rich,

Videos look great. I especially like the outside clip on the straight. I have a very similar clip on the front straight at Road America and now i want to try to find it.

Seems like you enjoyed yourself and that's the most important thing. Also seems like the track is not so harsh on the car, so that's another plus.

@babablackgoat I don't mean that there are no potential benefits from rotors, but if I had to choose between 1) high end, two piece slotted rotors paired with hawk HPS or the 5.0 pads, OR 2) cheap, single piece plain rotors (no slots or drilling) paired with high performance racing pads, I would without a doubt go with option 2.

The reason you destroyed your brake pads is not because the rotors were bad, but because the brake pads were not good enough for that particular use, on a track - they overheated and wore out rapidly. Getting higher end drilled rotors possibly allowed better cooling, lower brake temps, and prolonged the life of the pads a little because of that.

I highly recommend you install some actual racing pads next time you do a track day and you will see the difference they make - and don't worry about swapping to street pads after the track day, I've been 'daily' driving on my Hawk DTC 60 racing pads for 2+ years now and they work just as great on the street as they do on track, no need to stress out (except that they eat your rotors alive - hence why cheap plain rotors are a good option)

502488

Rotor completely worn down after 6 track days on the same racing brake pads.

502489

Brake pads at ~60-65% life and will be used again next weekend at Road America.
 

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Discussion Starter #42
Yeah, in the end I was a little too timid to really push so hard that I would start breaking things. After just barely getting it stopped in time to make turn 1 after the front straight early on, I began to appreciate the speeds I was attaining. There were a few spots I could actually get into 4th but you really roll up on those corners fast at that point! I think the brakes got better after having been heated up a few times. The rotors looked a lot smoother and cleaner after I got home. They are almost new (put them on last year) so they hadn't quite worked off all the crosshatching yet. That's all gone now though.
 

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Discussion Starter #43
Another bit of good news is that I felt my old RE-11s were past their prime even though they have tons of tread left. After a few laps I must have scrubbed the old rubber off and got down to new rubber. For a fat old car with skinny tires, it held the track pretty well.
 

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Another bit of good news is that I felt my old RE-11s were past their prime even though they have tons of tread left. After a few laps I must have scrubbed the old rubber off and got down to new rubber. For a fat old car with skinny tires, it held the track pretty well.
So is that good news or bad news?.. haha. Last year I went to NCM with pretty much brand new tires and the car felt awesome. I was able to turn in and rotate around corners better than I had ever felt on a track, easily hitting the apex and very little understeer. By the second half of the day, it was back to the way it usually is with lots of understeer and hard to get it to turn in well. Tires lose their prime pretty fast.. sadly.
 

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Discussion Starter #45
So is that good news or bad news?.. haha. Last year I went to NCM with pretty much brand new tires and the car felt awesome. I was able to turn in and rotate around corners better than I had ever felt on a track, easily hitting the apex and very little understeer. By the second half of the day, it was back to the way it usually is with lots of understeer and hard to get it to turn in well. Tires lose their prime pretty fast.. sadly.
My RE-11s are six years old..... The rubber had gotten a little hard on the outside. Must have scrubbed off that patina to new sticky rubber. I typically only put about 300-400 miles on it a year anymore so those tires hadn't really worn much since my last autocross with it about 5+ years ago.
 

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Hey @Siliev,

Thanks for the well-defined clarification. You are right in many situations. Option 2 changing to high performance pads will suffice. Replacing pads only is both easier and more cost effective as well. Upgrading to larger cross drilled or slotted rotors is not required for occasional track days. I smoked my pads in extenuating circumstances. So for many applications you are correct, and my solution of bigger cross drilled or slotted rotors might not be necessary.

The track was Texas World Speedway (now closed) near College Station, TX. Although a road course, we used one section of the high banked superspeedway where I was hitting 140 mph. In clockwise direction, we dove down into s curves after the superspeedway stretch. Please see below illustration. Apologies for my limited graphical editing skills.

For frame of reference, after smoking a new set of pads twice, including high performance pads, my upgrade is overkill for most applications:

Front:
14” cross drilled Brembo rotors
4-piston Brembo calipers
Brembo pads

Rear:
OEM diameter cross drilled Brembo rotors (for cooling)
Stock GTO calipers
Brembo pads

Stainless steel braided brake lines
DOT 5 brake fluid

I agree with you that this is definitely unnecessary dependent upon the specific track and driver. You have some valid comments. My mistake and apologies for misunderstanding any of your remarks.

Thanks again for the info. I hope your track day next weekend at Road America goes great. If you do not mind, perhaps you could post about track session afterwards?

502520
502521
 

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@babablackgoat , that track looks very fun, and very fast! I would also definitely share some picutres/videos that I have after my track day this weekend. I can't wait and I'm feeling excited and nervous about it at the same time.

Not trying to pick at you at all, but there is something in your set-up that concerned me, and it is appropriate for this thread, so hopefully it might be useful for others in the future as well:
You said you're using DOT 5 brake fluid. Is it DOT 5 or DOT 5.1? If it is actually DOT 5, I would be concerned about using that. It may have higher boiling points than DOT 4 fluids, but it has some very serious drawbacks as well. Please take a few minutes to read through the following overview of different brake fluid types:
What is the difference between brake fluids?

To summarize the important points of that article,
  • "DOT 3, DOT 4, and DOT 5.1 are all glycol-ether based. DOT 5 brake fluid is silicone based."
  • "The silicone based fluid is hydrophobic, meaning it will not absorb moisture. If any moisture is introduced into the system, it can collect in pockets that can either freeze or boil off. This can lead to damage to the brake system and/or brake failure. Silicone is also more compressible than glycol, which can lead to a "spongy" feeling brake pedal."
  • "Because of the way they deal with water, glycol and silicone based fluids are NOT compatible with each other. Never mix the 2 types of fluid. Only add DOT 5 silicone brake fluid to a completely dry system or a vehicle that already has DOT 5 in it. Do not add anything other than DOT 5 to a system that calls for DOT 5 brake fluid."
If my car currently had DOT 5 fluid in the brake system, I would definitely revert back to DOT 4.
I would thoroughly flush it out with lots of cheap DOT 4 brake fluid:
  1. suction out as much of the fluid as possible from the master cylinder reservoir
  2. fill reservoir to the top with new, cheap DOT 4 fluid, and repeat step 1 (do this 3 or 4 times, making sure the brake fluid in the reservoir is fully replaced with DOT 4)
  3. start bleeding brake fluid from the rear left (RL) caliper (bleed at least 1 L of brake fluid through the caliper to make sure there are no remains of the DOT 5 fluids anywhere in the lines or the caliper itself)
    • make sure to keep refilling the master cylinder reservoir and not letting it run dry
  4. repeat step 3 for the rear right (RR), front left (FL), and the front right (FR) calipers
    • the order of which to do this can be disputed, but that is how I bleed my brakes
  5. Optional step: once all of the DOT 5 fluid has been flushed out with cheap DOT 4, then flush the system with a high quality DOT 4 that you prefer (StopTech STR 600/660, Motul RBF 600/660, Brembo, whatever..)
    • might be a good idea to drive around for a hundred miles or so with the cheap brake fluid and possibly engage the ABS system a few times on purpose to make sure any trapped DOT 5 fluid that might have been in there gets released and will be flushed out on the next flush with the good quality fluid.
Again, you can still run your car however you want, I have no problems with it, I'm just trying to share some knowledge in case you or someone else who stumbles upon this might not have considered.
 

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Discussion Starter #48
Actually, I wouldn't mix 4 and 5 at all. Drain the system as best you can and flush it with alcohol if you can then fill with 4. 4 mixed with 5 can sometimes turn to a gel that you'll have a heck of a time getting out of the system.

And that all said, I use DOT 5 in all my old cars that don't get driven a lot. The pedals are firm as they should be and I've never had a problem with it, it actually works quite well in certain applications. An added bonus is that it won't damage painted surfaces should you spill a bit of it. I would never, however, use it in a high performance situation such as road racing.
 

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Any idea how long it takes to turn into this jelly substance? Is it almost instantenous or does it take some time? I've never used DOT 5 nor seen it mixed with a non silicone based fluid, but yes they shouldn't be mixed. It's not a good situation to have to switch from one to the other.
 

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Discussion Starter #50
Any idea how long it takes to turn into this jelly substance? Is it almost instantenous or does it take some time? I've never used DOT 5 nor seen it mixed with a non silicone based fluid, but yes they shouldn't be mixed. It's not a good situation to have to switch from one to the other.
No idea how long it takes.
 

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@Siliev

Thanks for correction. DOT 5.1. I misspoke.

Had the Brembo's for many years. They are excellent. The DOT 5.1 with braided brake lines is new. The braided brake line were required for the DOT 5.1.

Improves pedal feel slightly, yet not much. So sticking with Motul DOT 4 is probably better.

Thank you very much for point out DOT 5 versus DOT 5.1. Quite useful information for readers who are using this forum for research.

502550
 

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Guys,
Thanks for the links to the brake cooling parts. I installed them yesterday and now need a track event.

My last track day was at NOLA motorsports. I am thankful that I changed the brake fluid before I went out on the track. I generally use Ate Typ200 DOT 4 fluid with good results. As for rotors, I have the DBA 4000 Series T3 rotors and Carbotech XP20 pads. Plenty of stopping power for 140mph slowdown for a turn ;)

Tires: Hankook RS4
Power Steering Oil: Flushed and filled with Amsoil ATF
Differential: Torco with type F friction modifier
Engine oil: Amsoil 10W30 with an extra 1/2 quart

Before I go to another HPDE day, I think that I need to change the stock clutch. Seems to be slipping in 3rd at WOT.
Any suggestions for a clutch? I was looking a the Monster Clutches twin Disc.

Later,
Michael
 

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@05gtoM6MBM

Hi Michael,

Welcome to the forum.

Most on this forum seem to recommend Monster. @Nothubertjfarnsworth once indicated that there are several different offerings from Monster.

I have a Mantic M921219 Twin Disc Clutch for the 04-06 Pontiac GTO and find is superb. Easy comfortable natural clutch release with no slip.

Another possible recommendation from the speed shop I work with is Centerforce DYAD.
 

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@05gtoM6MBM

Hi Michael,

Welcome to the forum.

Most on this forum seem to recommend Monster. @Nothubertjfarnsworth once indicated that there are several different offerings from Monster.

I have a Mantic M921219 Twin Disc Clutch for the 04-06 Pontiac GTO and find is superb. Easy comfortable natural clutch release with no slip.

Another possible recommendation from the speed shop I work with is Centerforce DYAD.
Thanks for the information on clutches. I really like the Mantic Twin Disc, almost too pretty to install. I will save a little more money and go for the Mantic.

Michael
 

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I put the 997 GT3 brake ducts in the intended orientation (opposite of Glynn). I don't have any objective data proving that they work but I have done two track days with them on, and have Laguna Seca next weekend which is a tough track on brakes. The front edge is a little close to the subframe but that little slot in the leading edge of the deflector kind of fit nicely where the subframe edge is. If you look under the nose of the car you can see that scoops hanging down a tad, so it has to do something. I was really happy with how they turned out from a fit standpoint. I'll snap some better pictures of them when I get home later.

I'm also running a 14" StopTech BBK up front, and recently went up to 100tw tires 265F/285R. Brakes remained solid the whole time at the last two events but I did step up from R12/R8 to R16/R10 because I think that will bite better with the wider slicks.

Both of the below videos had them on. To be honest I'm leaving a bit on the table as far as breaking zones.


 

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Before I go to another HPDE day, I think that I need to change the stock clutch. Seems to be slipping in 3rd at WOT.
Any suggestions for a clutch? I was looking a the Monster Clutches twin Disc.
I was having similar issues with track days. It was starting to slip and then would boil clutch fluid and would almost just stop grabbing altogether for a few seconds, as if the engine was in neutral. Probably caused by a combination of worn clutch and old fluid.

I ended up getting a Centerforce Dual friction clutch with the billet steel flywheel. I found both for a suspiciously low price (billet steel for the price of the regular iron, for example) so I went for it and its performed perfectly. Would recommend doing a shielded SS braided clutch line. I got the Monster one, all my clutch woes have gone out the door since doing that job. Granted, I don't do low gear clutch dumps and launches so YMMV.
 

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I was having similar issues with track days. It was starting to slip and then would boil clutch fluid and would almost just stop grabbing altogether for a few seconds, as if the engine was in neutral. Probably caused by a combination of worn clutch and old fluid.

I ended up getting a Centerforce Dual friction clutch with the billet steel flywheel. I found both for a suspiciously low price (billet steel for the price of the regular iron, for example) so I went for it and its performed perfectly. Would recommend doing a shielded SS braided clutch line. I got the Monster one, all my clutch woes have gone out the door since doing that job. Granted, I don't do low gear clutch dumps and launches so YMMV.
Clutch slipping would only be a result of a worn clutch and would not be affected by bad clutch fluid. If the fluid is bad, you would have a hard time getting the clutch to disengage, but it will have no problems staying engaged.

On the other hand, a worn out and slipping clutch would get very hot on a track day and would cause your clutch fluid to boil. So it's the slipping clutch causing the fluid to boil and not the other way around.
 
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