AMG GTR PRO
#26
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Thread Starter
Your brakes faded on every track you've been to and you have the ceramics? Are you sure your fluid wasn't cooked? This seems impossible. And you are on street tires?
I plan on running mine hard on the track and with true slicks which will brake the car way way harder than your street tires. I plan on running SRF (flushed daily for track) and I don't forsee the brakes fading.
I tracked my wifes E63 4800 lb wagon with steel brakes and the pads literally caught on fire after 3 laps, (I had to put them out with a fire extinguisher) but my buddy was there in his E63 sedan on CCB's (with SRF) and he had zero issues of fade and he was on Hoosier A7's. He was extremely impressed with the brakes and this is in car with more power and 1000 lbs more weight than your GTR. You should run SRF for starters, it's wet boiling point is 30% higher than the best Motul (518* vs 399*). I'll report back here after mid January which will be my first track weekend in mine. I'm supposed to get the car next week!
I plan on running mine hard on the track and with true slicks which will brake the car way way harder than your street tires. I plan on running SRF (flushed daily for track) and I don't forsee the brakes fading.
I tracked my wifes E63 4800 lb wagon with steel brakes and the pads literally caught on fire after 3 laps, (I had to put them out with a fire extinguisher) but my buddy was there in his E63 sedan on CCB's (with SRF) and he had zero issues of fade and he was on Hoosier A7's. He was extremely impressed with the brakes and this is in car with more power and 1000 lbs more weight than your GTR. You should run SRF for starters, it's wet boiling point is 30% higher than the best Motul (518* vs 399*). I'll report back here after mid January which will be my first track weekend in mine. I'm supposed to get the car next week!
Motul660 should perform better than Castrol SRF when its new so I don't see how that could make any difference, unless my fluid was particularly old which it hasn't been.
#27
Senior Member
I change the fluid every 2-3 track days. I run the car on the standard Cup2. I don't think slicks would be a very good idea as I doubt the suspension components could take the load, unless you're planning signifcant upgrades to those too?
Motul660 should perform better than Castrol SRF when its new so I don't see how that could make any difference, unless my fluid was particularly old which it hasn't been.
Motul660 should perform better than Castrol SRF when its new so I don't see how that could make any difference, unless my fluid was particularly old which it hasn't been.
Trust me on this one, SRF is way better I promise you. It may look more expensive, but in the long run you will use less so it ends up being cheaper. I have a video of 1 foot flames coming out of my brake pads on both sides, touching the fenders of my wagon, and the brake fluid was still 100% working. The pads caught on fire before SRF faded. LOL
#28
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‘24 BMW iX M60
I put slicks on everything i buy hehe. Nothing on the suspension on this car will break, the only issue with slicks could be the alignment moving. How can motul outperform SRT when SRF has a 30% higher wet boiling temp? Who cares about dry boiling temps they don't mean anything.
Trust me on this one, SRF is way better I promise you. It may look more expensive, but in the long run you will use less so it ends up being cheaper. I have a video of 1 foot flames coming out of my brake pads on both sides, touching the fenders of my wagon, and the brake fluid was still 100% working. The pads caught on fire before SRF faded. LOL
Trust me on this one, SRF is way better I promise you. It may look more expensive, but in the long run you will use less so it ends up being cheaper. I have a video of 1 foot flames coming out of my brake pads on both sides, touching the fenders of my wagon, and the brake fluid was still 100% working. The pads caught on fire before SRF faded. LOL
And you’re right about SRF; there’s nothing better.
Bish
#29
Senior Member
Thread Starter
Here you can't run slicks unless you have a cage and belts so its not something I can try in the GTR even if I wanted to!
#30
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Well Bishman I can take the GTC and do autocross with no problems I suspect the GTR convertible would be good for that too....... I realize you need a cage for many racing venues but thankfully you dont for autocross.....
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thebishman (11-23-2018)
#31
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Not sure how you come to that conclusion? You'll be putting loads through the suspension that its not designed for. I've seen loads of broken M3s that damaged their suspension by running slicks on stock setups. I suppose your only saving grace is that a Hoosier R7 isn't a true slick?
Here you can't run slicks unless you have a cage and belts so its not something I can try in the GTR even if I wanted to!
Here you can't run slicks unless you have a cage and belts so its not something I can try in the GTR even if I wanted to!
#32
Senior Member
Not sure how you come to that conclusion? You'll be putting loads through the suspension that its not designed for. I've seen loads of broken M3s that damaged their suspension by running slicks on stock setups. I suppose your only saving grace is that a Hoosier R7 isn't a true slick?
Here you can't run slicks unless you have a cage and belts so its not something I can try in the GTR even if I wanted to!
Here you can't run slicks unless you have a cage and belts so its not something I can try in the GTR even if I wanted to!
A pro driver at the Nurbrugring probably puts more stress on the suspension on street tires than a good amateur driver will with slicks. I've got 4000 track miles on my bone stock ACR on Michelin slicks, never broke anything. And 3000 track miles on my 740whp 9 liter Viper on Michelin slick, never broke anything and I run at least 9/10ths all the time.
Everyone that runs GT3's around here on Pirelli slicks don't break suspension parts either.
#33
Senior Member
You’d be placing more ‘stress’ through the suspension components running the R7, although I doubt anything would break. Certainly everything would need to be checked often, and as Porsche mentions in the GT cars, after a certain number of track miles, replacement of certain components would be wise. The R7 is for all intents and purposes a ‘slick’, as it’s not a tyre recommended by Hoosier to ever drive on the street with.
BTW A7's are much much faster than R7's , even faster than Michelin or Pirelli slicks until the very end of a session will the slicks pull ahead. I only run the Michelins because they last 3 times as long as the A7's on the front of my Viper. I've got 8 Nasa track records currently, 7 on A7's, one on the Michelins, I've tried many times to break my records on A7's with the Michelin's, but it's not gonna happen.
#34
Senior Member
And yeah on the SRF, Motul lures people in with their wet boiling temps. Motul is great, it's just not SRF.
#35
Senior Member
Thread Starter
I'll be running MIchelin S8L's, not Hoosiers. What organization wont let you run slicks without a full cage? You should try NasaProRacing.com they only require a full cage in race group. They are nationwide, and a great group with a great Time Trial program.
A pro driver at the Nurbrugring probably puts more stress on the suspension on street tires than a good amateur driver will with slicks. I've got 4000 track miles on my bone stock ACR on Michelin slicks, never broke anything. And 3000 track miles on my 740whp 9 liter Viper on Michelin slick, never broke anything and I run at least 9/10ths all the time.
Everyone that runs GT3's around here on Pirelli slicks don't break suspension parts either.
A pro driver at the Nurbrugring probably puts more stress on the suspension on street tires than a good amateur driver will with slicks. I've got 4000 track miles on my bone stock ACR on Michelin slicks, never broke anything. And 3000 track miles on my 740whp 9 liter Viper on Michelin slick, never broke anything and I run at least 9/10ths all the time.
Everyone that runs GT3's around here on Pirelli slicks don't break suspension parts either.
An ACR is a very different car to the GTR, friend of mine recently had a 9L conversion done on his as it happens. I wouldn't voice any concerns about that option.
996/997 GT3 is fine with slicks, Porsche themselves even ok it. Not so 991GT3 , I know one person who ran slicks on his for a day and got all sorts of RWS issues so never bothered again. Both ACR and 996/997 GT3s are close relations to their racing brethren so its logical that they're more suited to slick IMO.
Anyway, let us know how you get on! My comments are speculation because obviously I've never run slicks on this car.
#36
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‘24 BMW iX M60
I only plan on tracking the car twice a year at a track that has a sound limit that my Viper's won't pass so I can still get my points in my class. I'm not going to tear this car up.
BTW A7's are much much faster than R7's , even faster than Michelin or Pirelli slicks until the very end of a session will the slicks pull ahead. I only run the Michelins because they last 3 times as long as the A7's on the front of my Viper. I've got 8 Nasa track records currently, 7 on A7's, one on the Michelins, I've tried many times to break my records on A7's with the Michelin's, but it's not gonna happen.
BTW A7's are much much faster than R7's , even faster than Michelin or Pirelli slicks until the very end of a session will the slicks pull ahead. I only run the Michelins because they last 3 times as long as the A7's on the front of my Viper. I've got 8 Nasa track records currently, 7 on A7's, one on the Michelins, I've tried many times to break my records on A7's with the Michelin's, but it's not gonna happen.
The A7 is known to be ‘quicker’ than the R7, but it wears much quicker, yes?
#37
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John Gaydos at Autoquest mentioned to me iirc that the RSC1 is the compound many use on the Porsche PCCBs, so I was going to buy a set. However, until my son started driving the car with me at the last track weekend, the wear rate on the OEM pads was excellent so I just purchased a second set of OEMs to have as a back-up. An excellent price btw of about $600 for both front and rear OEM pads. I have always driven the car with ESP totally ‘Off’, hence there was no increased rear brake pad wear, but with my son driving I make him keep the ESP set to ‘Sport’, so now the rears have worn down to approximately 33% of pad left. I’m having them replaced next Spring. I’m also old enough now that I’m a firm be.iever in ‘smooth equals fast’, so I’m fairly easy on my brakes.
Re: brake fluid. Have you ever tried Endless 650?
Bish
#38
Member
This is what I have and no issues so far;
hoosier R7
cobalt race pads
stock rotors (iron )
SRF fluid
I don’t have to manage my brakes, actually I brake super deep/late in most of the corners at COTA and some of those are downhill.
My brakes are transformed with cobalt pads.
hoosier R7
cobalt race pads
stock rotors (iron )
SRF fluid
I don’t have to manage my brakes, actually I brake super deep/late in most of the corners at COTA and some of those are downhill.
My brakes are transformed with cobalt pads.
Last edited by V8ray; 11-23-2018 at 09:06 PM.
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thebishman (11-23-2018)
#41
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http://www.pagidracing.com/en/produc...s/vehicle.html
John Gaydos at Autoquest mentioned to me iirc that the RSC1 is the compound many use on the Porsche PCCBs, so I was going to buy a set. However, until my son started driving the car with me at the last track weekend, the wear rate on the OEM pads was excellent so I just purchased a second set of OEMs to have as a back-up. An excellent price btw of about $600 for both front and rear OEM pads. I have always driven the car with ESP totally ‘Off’, hence there was no increased rear brake pad wear, but with my son driving I make him keep the ESP set to ‘Sport’, so now the rears have worn down to approximately 33% of pad left. I’m having them replaced next Spring. I’m also old enough now that I’m a firm be.iever in ‘smooth equals fast’, so I’m fairly easy on my brakes.
Re: brake fluid. Have you ever tried Endless 650?
Bish
Check out this video, these are iron brakes on my E63 wagon after two laps-
https://www.youtube.com/watch?v=7nWA...ature=youtu.be
Also, my front center caps melted and before I installed metal valve stems the first time I tracked the car.
I pulled off after two laps, parked the car and the tires exploded from the valve stems melting. Scared the hell out of me LOL. Wife was PISSED. Needless to say the wagon is retired from track duty
Here are the two cars in question-
Last edited by BenzGTR; 11-24-2018 at 02:05 PM.
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Case1906 (11-25-2018)
#42
Senior Member
#43
Senior Member
The A7, is MUCH faster than an R7 especially in the first 10 minutes. It's even faster than the Pirelli or Michelin slicks in the first 10 minutes are so of a session.
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thebishman (11-24-2018)
#44
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Bish
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#45
Senior Member
So I use a fantastic independent shop for all of the non-warranty maintenance on all of our vehicles. The guys that own/run it are ex-SCCA racers and only use top-of-the-line Hunter equipment, so I had them check the factory alignment before I took the car out on track for the first time last year. I was pleasantly surprised to find out that front camber from the factory was about -2.2 and rear was about -1.8. They were happy with caster and toe also. I’ve been really happy with tyre wear both on the street, but especially on the track, so I haven’t gone more aggressive; yet. One good thing about our cars is that they use shims to set the alignment and once it’s set, it shouldn’t move, or so I’ve been told. It does of course take longer to adjust though.
Bish
-1.8 rear is really aggressive, I'm sure we could benefit from more on the front like 2.8-3.2 or so if we could get it that high, but I don't think I'm going to mess with mine. I'm going with a 310 wide slick on a 11" wide wheel up front so I can get away with less camber than the skinnier factory tires (The 310 Michelin gets really fat on a wide wheel, more like a 330)
#48
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2021 AMG GLE 63s Coupe AMG GLC 63s Coupe
Ronac, they simply ‘destroy’ the OEM Sport Cup 2’s in the handling and traction dept. IMHO. Driving as you do in the canyons I think you’d see a major difference. Obviously as RFT’s they have less compliance on broken up highway, but the ride is still ‘OK’ even in my GT R. On crappy roads when driving to/from the track I’ll leave the car in ‘C’ mode of course. On the positive side if you get a flat you aren’t stranded as these can be driven 50 miles without air in them iirc. They will not last as long obviously and I’m not able to tell you how many street miles to expect out of them as I always use them for the track mounted on a set of Signature forged wheels, but their treadwear is listed as 180. Oh and their wet weather performance is marginal due to the decreased tread depth and compound difference:
https://www.tirerack.com/tires/tires...oModClar=Coupe
That being said you get a bigger ‘footprint’ and a stickier compound than the ‘regular’ SC2s. The above link is to the GT R option tyre (R03) which is the tyre Michelin specifically designed for the Chevy C7 Z06/7. I’m not sure of other sizes if the above won’t fit your car btw.
Bish
Thanks