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Discussion Starter #1
finally got a chance to bring the MP4 to the track today. it was a very hot day 36 -38C on a short 3.3km track - that's the best we have here in the philippines.

the car performed relatively well but i had major brake fade after 3 laps on the back straight going around 180km/h. to be honest, even from the beginning, after the first lap, the brake feel was not confidence inspiring. i had now wished i had gotten the CCB option. on the track, i feel the steel brakes of the MP4 cannot hold it's own against the PCCB of my RS 4.0. i know i may be comparing apples and oranges here (steel v. CCB) but really i was expecting a little bit more.

i am not sure about this theory, but i only had the car's handling mode in Sport, and while i could feel the brake steer bringing the car into the turn, it might have compromised the braking system the more laps i do and overheated the brakes. anyone have an opinion on this? i did some easy laps on Track mode just to get a feel for it and easily i thought i should have used this handling mode immediately as the stiffer suspension offered much better feel and control. since this was my first time on the track with the car, i wanted the safety net of driver aids but i have a feeling it might have compromised my run even more.

can anyone confirm on the latest software update that even on Track handling mode, the driver aide is still not completely turned off?

is there a better brake fluid i can use with a higher boiling temp?

also, my car only had the stock PZero tires. it just doesn't have the confidence on the track given by the Sportcups on the RS 4.0, which felt like it was really glued to the tarmac.

so what positive things did the car show:

it simply had gobs of power on tap. it's like a slingshot out of the turns. it's so fast i couldn't even go WOT. just so much power it gobbles the short track so fast. this despite the extremely hot weather.

car felt very very light and agile. the chassis is super capable. turn in was excellent. i was expecting the water temp and oil temp to move up considering the track temps, but it held steady.

car has so much potential and perhaps i can exploit it more the next time around. as it sits, i'm still 4 sec. slower on a 1:49 sec track in the Mac compared to my RS 4.0.
 

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finally got a chance to bring the MP4 to the track today. it was a very hot day 36 -38C on a short 3.3km track - that's the best we have here in the philippines.

the car performed relatively well but i had major brake fade after 3 laps on the back straight going around 180km/h. to be honest, even from the beginning, after the first lap, the brake feel was not confidence inspiring. i had now wished i had gotten the CCB option. on the track, i feel the steel brakes of the MP4 cannot hold it's own against the PCCB of my RS 4.0. i know i may be comparing apples and oranges here (steel v. CCB) but really i was expecting a little bit more.

i am not sure about this theory, but i only had the car's handling mode in Sport, and while i could feel the brake steer bringing the car into the turn, it might have compromised the braking system the more laps i do and overheated the brakes. anyone have an opinion on this? i did some easy laps on Track mode just to get a feel for it and easily i thought i should have used this handling mode immediately as the stiffer suspension offered much better feel and control. since this was my first time on the track with the car, i wanted the safety net of driver aids but i have a feeling it might have compromised my run even more.

can anyone confirm on the latest software update that even on Track handling mode, the driver aide is still not completely turned off?

is there a better brake fluid i can use with a higher boiling temp?

also, my car only had the stock PZero tires. it just doesn't have the confidence on the track given by the Sportcups on the RS 4.0, which felt like it was really glued to the tarmac.

so what positive things did the car show:

it simply had gobs of power on tap. it's like a slingshot out of the turns. it's so fast i couldn't even go WOT. just so much power it gobbles the short track so fast. this despite the extremely hot weather.

car felt very very light and agile. the chassis is super capable. turn in was excellent. i was expecting the water temp and oil temp to move up considering the track temps, but it held steady.

car has so much potential and perhaps i can exploit it more the next time around. as it sits, i'm still 4 sec. slower on a 1:49 sec track in the Mac compared to my RS 4.0.
Sounds like you cooked the fluid very quickly. Is it the original fluid with which the car was delivered? If so, it may have deteriorated and had a high moisture content to begin with, which could be the issue.

Yes, as far as I know, handling in Track mode still has some level of electronic safety net. Track mode is definitely the way to go, unless the circuit is extremely bumpy; only then would I experiment with Sport. The difference is night and day in the handling.

I'd be impressed if you can get near your 4.0 lap times on the stock P Zeros, especially on a small track. Sport Cups are in a different league to P Zeros.
 

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finally got a chance to bring the MP4 to the track today. it was a very hot day 36 -38C on a short 3.3km track - that's the best we have here in the philippines.

the car performed relatively well but i had major brake fade after 3 laps on the back straight going around 180km/h. to be honest, even from the beginning, after the first lap, the brake feel was not confidence inspiring. i had now wished i had gotten the CCB option. on the track, i feel the steel brakes of the MP4 cannot hold it's own against the PCCB of my RS 4.0. i know i may be comparing apples and oranges here (steel v. CCB) but really i was expecting a little bit more.

i am not sure about this theory, but i only had the car's handling mode in Sport, and while i could feel the brake steer bringing the car into the turn, it might have compromised the braking system the more laps i do and overheated the brakes. anyone have an opinion on this? i did some easy laps on Track mode just to get a feel for it and easily i thought i should have used this handling mode immediately as the stiffer suspension offered much better feel and control. since this was my first time on the track with the car, i wanted the safety net of driver aids but i have a feeling it might have compromised my run even more.

can anyone confirm on the latest software update that even on Track handling mode, the driver aide is still not completely turned off?

is there a better brake fluid i can use with a higher boiling temp?

also, my car only had the stock PZero tires. it just doesn't have the confidence on the track given by the Sportcups on the RS 4.0, which felt like it was really glued to the tarmac.

so what positive things did the car show:

it simply had gobs of power on tap. it's like a slingshot out of the turns. it's so fast i couldn't even go WOT. just so much power it gobbles the short track so fast. this despite the extremely hot weather.

car felt very very light and agile. the chassis is super capable. turn in was excellent. i was expecting the water temp and oil temp to move up considering the track temps, but it held steady.

car has so much potential and perhaps i can exploit it more the next time around. as it sits, i'm still 4 sec. slower on a 1:49 sec track in the Mac compared to my RS 4.0.
the mp4 is easier than the porsche, you're for sure pretty quick with your 4.0, but you can be as quick as the porsche even with p0 stds
 

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agree. i have steel and my brakes are incredible.no fade after 20 laps in 85 degree weather. i run track/track all the time and you still have some driver aid. the mac should run faster than the 4.0 and MUCH easier.
 

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I recently did a small-ish track/circuit day (Blyton) and felt the brakes were fading to start with :eek:
The pedal had certainly dropped and I immediately did some cooling down laps.. to say I was gutted was an understatement!!:( - this wasalso within 3-4 laps (it is a short circuit, so a fair time on the brakes)

However upon returning to the circuit later in the day I found that the new lower brake pedal position remained constant for the rest of the day? Whether it was a high spot of some sort I have no idea...:confused:
I was in sport and track modes and the car performed brilliantly throughout the rest of the day- well apart from not wanting to start when the instructor got in the car!! :eek:

I had a bit of a drag with a TurboS and was on level pegging out of the tight hairpin, however the winding section of the track and the 12C showed it's true colours :D Very, very pleased...

Obligatory track photo below :D
 

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That's a great picture. Windows down in April, things are looking up!
Good view of the under body scraping thingies too.
 

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Discussion Starter #8
still on the original brake fluid. i'll try to get it flushed with a new one.

my goal is to get it close to the RS 4.0 time while using regular pzeros. i know it can be done. but i need to have confidence in the brakes that the car will be able to stop so that i can push harder.

also, i left the tire pressures on regular street pressures and after 3 laps, the rears were over 36psi and the cluster was sending a rear tire error and to stop the car.

well, next time i'll prepare better. at lease i got a feel for what the car needs.
 

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still on the original brake fluid. i'll try to get it flushed with a new one.

my goal is to get it close to the RS 4.0 time while using regular pzeros. i know it can be done. but i need to have confidence in the brakes that the car will be able to stop so that i can push harder.

also, i left the tire pressures on regular street pressures and after 3 laps, the rears were over 36psi and the cluster was sending a rear tire error and to stop the car.

well, next time i'll prepare better. at lease i got a feel for what the car needs.
Yep you have to keep tire pressures in check, or the car will be 'all over the ice' as we say around here. You should pick up some grip, especially with handling in Track.

Definitely get the fluid flushed fully. I betcha yours is contaminated.
 

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Can we use ATE Super Blue DOT 4 Racing Brake Fluid on the MP4-12C?

I used it on the Lamborghini and never had issues on the track.

Manual says that we should use Pentosin DoT 5.1
 

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Can we use ATE Super Blue DOT 4 Racing Brake Fluid on the MP4-12C?

I used it on the Lamborghini and never had issues on the track.

Manual says that we should use Pentosin DoT 5.1
McLaren frown on not using the recommended fluid,but I can never understand why if they are proven to be an advantage,what do I know:confused:
 

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Fluids

Factory tech service stated that DOT 5.1 spec is mandated do to the low viscosity requirement of the braking system. They also stated that only the recommended Pentosin fluid be used. In the US this is available only from a dealer. No fluid manufacturers currently offer DOT 5.1 spec performance fluids that have high temperature BP's.
 

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Discussion Starter #13
cool! that was my next question, whether the car is using DOT 5 or DOT 5.1. quite lazy to look thru the manual. mclaren tech mentioned DOT 5, which really surprised me. no wonder, he is mistaken.

thanks for the info guys. i will replace the brake fluid with a racing one with higher boiling point.

you guys might want to consider this.

http://www.motul.com/ph/en/products/77?f[application]=144&f[range]=21

in the US, you can usually find it at motorcycle stores.
 

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Having looked into the brake fluid question for an hour, I come to this conclusion: The Pentosin 5.1 fluid is not silicone based, but normal glycol based, and can therefore be mixed with DOT 4. (DOT 5 is silicone based)

DOT 5.1 has its advantage especially when it is cold, so at trackdays the difference in reaction time in the system beetween DOT 4 and 5.1 should be smaller.

There are at present no 5.1 with higer dry boiling point than 280 degrees.

Having tracked cars for many years, I find you need higher than 300 degrees to avoid soft pedal, depending though on brake cooling. If no one has any good reason against it, I will suggest changing to for instance Performance Friction with a boiling point of 335 degrees, which has worked fluently on my other cars, with rock hard pedal after hours of tracking. When the market offers a 5,1 with similar boiling point I will change to that.

Ferrari has the same poblem with brand adherance, where they insist on using Shell fluid with boiling point of 280, simply not enough for hard driving.

If you are using your car in freezing condition, I guess staying with the 5,1 is better, at least for winter.

Am I missing something, or is this quite staight forward?
 

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Brake fluid DOT 4 vs 5.1

Having looked into the brake fluid question for an hour, I came to this conclusion: The Pentosin 5.1 fluid is not silicone based, but normal glycol based, and can therefore be mixed with DOT 4. (DOT 5 is silicone based)

DOT 5.1 has its advantage especially when it is cold, so at trackdays the difference in reaction time in the system beetween DOT 4 and 5.1 should be smaller.

There are at present no 5.1 with higher dry boiling point than 280 degrees.

Having tracked cars for many years, I find you need higher than 300 degrees to avoid soft pedal, depending though on brake cooling. If no one has any good reason against it, I will suggest changing to for instance Performance Friction with a boiling point of 335 degrees, which has worked fluently on my other cars, with rock hard pedal after hours of tracking. When the market offers a 5,1 with similar boiling point I will change to that.

Ferrari has the same poblem with brand adherance, where they insist on using Shell fluid with boiling point of 280, simply not enough for hard driving.

If you are using your car in freezing condition, I guess staying with the 5,1 is better, at least for winter.

Am I missing something, or is this quite straight forward?
 
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