Brake fluid for HPDE

[Gcole]

I am signed up for the Free NASA event at Summit Point. I used to be a NASA instructor, just haven't been on the track since 2013 (sold my track car). I don't really want to track this car but one track day should be ok. My plan is to replace the brake fluid with some Wilwood EXP 600 I had in my shop. I really don't want to replace the pads unless I need to since this is going to be a one time outing.

How do the stock pads hold up at Summit Main in this car?


Since I was a instructor they have me in group 4 which is a very fast group, I need to temper myself and not push the car too much, the red mist may get in the way however. I probably need to keep the top speed on the straight to 130 or less just to keeps the brakes in check I think.

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[gcmak]

Others have shown the factory pads and fluid to hold up fine for these NASA and other HPDE events. The only notable thing is light scoring around the rotors (seems to be the way the factory pads wear under pressure).

Since you're experienced, what keeps most of the temps in check is the tires. Assuming you're on stock PSS, it helps limit the brake temps. If you've stepped up the tires in some way, with your experience, you know the changes you need to make.

Have a blast!

 

[H2O_Doc]

I am signed up for the Free NASA event at Summit Point. I used to be a NASA instructor, just haven't been on the track since 2013 (sold my track car). I don't really want to track this car but one track day should be ok. My plan is to replace the brake fluid with some Wilwood EXP 600 I had in my shop. I really don't want to replace the pads unless I need to since this is going to be a one time outing.

How do the stock pads hold up at Summit Main in this car?


Since I was a instructor they have me in group 4 which is a very fast group, I need to temper myself and not push the car too much, the red mist may get in the way however. I probably need to keep the top speed on the straight to 130 or less just to keeps the brakes in check I think.

Which date?

 

[Rocksandblues]

If your in a fast group you are going to get soft pedal and fade on main for sure.

150 on straight and stock pads are not up to that turn one

 

[freeform911]

I am signed up for the Free NASA event at Summit Point. I used to be a NASA instructor, just haven't been on the track since 2013 (sold my track car). I don't really want to track this car but one track day should be ok. My plan is to replace the brake fluid with some Wilwood EXP 600 I had in my shop. I really don't want to replace the pads unless I need to since this is going to be a one time outing.

How do the stock pads hold up at Summit Main in this car?


Since I was a instructor they have me in group 4 which is a very fast group, I need to temper myself and not push the car too much, the red mist may get in the way however. I probably need to keep the top speed on the straight to 130 or less just to keeps the brakes in check I think.

Don't know if this helps but ..
I just ran in group 4 at Robling Road Raceway on stock pads and fluid...on the front straight I was seeing close to 150 n had no problems slowing the car for the 85ish turn 1 entry...
The one thing that was/is unsettling is the very long pedal travel...
Compared to my old 86 911 where the pedal was right there...

For a 1 day track event don't think I'd spend the money..

Car is a beast on track..have fun, be safe..

Steve

 

[nibble]

If you are not going to keep running track, it should be fine. I do instruct at NASA NE and I bought supra to track it. I've been on "full" track days entire 2020 calendar plus 3 track events (7 days) this year. stock brake system held up OK until last time. - brake pad wear sensor went off.. so I guess it's about 20+ track days.. So if you are just doing it 1 day, it should be fine. just don't get hooked into it. once you are on the track with supra, it is very addictive...

 

[dethred]

I was hitting 155-158mph on the back straight of VIR last weekend and only after the 7th or 8th lap did they start to feel a little spongy, that was braking at the 3 and entering the next turn at about 85mph still on the brakes. Front straight was hitting 135-140 on the stock fluid and pads. I'm sure you'd be fine doing some hard stops from 130.

 

[Gcole]

Thanks for the input, I am probably going to swap the fluid and bleed, just avoid boiling the fluid. I am on stock tires with 9K on them. What do people like for cold and hot pressures? I am running 35 cold on the street. Summit main really has one really hard braking zone going into one and turn 5 if you carry a lot of speed down the hill. I have instructed a lot of BMW drivers and the cars didn't have brake issues.

Years ago I could barely make a weekend at VIR on race pads in C6 VETTE

 

[Gcole]

I think I am going on the 26th, need to check NASA dates

 

[H2O_Doc]

I think I am going on the 26th, need to check NASA dates

Sounds right. That’s mine as well. Need to get curb-feelers installed ASAP.

 

[Rocksandblues]

Thanks for the input, I am probably going to swap the fluid and bleed, just avoid boiling the fluid. I am on stock tires with 9K on them. What do people like for cold and hot pressures? I am running 35 cold on the street. Summit main really has one really hard braking zone going into one and turn 5 if you carry a lot of speed down the hill. I have instructed a lot of BMW drivers and the cars didn't have brake issues.

Years ago I could barely make a weekend at VIR on race pads in C6 VETTE

vettes are really hard on pads

The trick with the Supras is you ideally want pressure below where the tps are happy. if they get too low the nannies stay on no matter what. I start around 27-29 cold

 

[Gcole]

vettes are really hard on pads

The trick with the Supras is you ideally want pressure below where the tps are happy. if they get too low the nannies stay on no matter what. I start around 27-29 cold

Thanks I will drop down some on the cold pressure.

 

[nibble]

I'd very gradually bring the pressure down. In my experience with low pressure, 33~34 psi cold, both, MSS & Federal tires shown sign of severe wear on outside of tire. so much more so on federal. I checked alignments and it did not look off. i.e. front camber was -1.5 both side and about -1.0 rear. it was so much that middle of the front tire were about 60% tread left where outside was down to the cord. inside was about 40~30%. usually, when I started on 34 psi, it will go up to 45~47 psi during session which I thought it was desired state. So this unusual behavior baffled me for sometime. I'm thinking that /w low pressure, tire is giving more pressure to outside causing the outside wear.

this weekend, I will be running brand new front tires and will be on 39 psi cold to monitor if hypothesis is correct.

So my advise is not to lower the pressure too much. it is easier to let the air out than pumping it in.

this is my thread on quest for cheaper track tires.

https://www.supramkv.com/threads/cheap-track-tires.6645/

 

[Gcole]

Too low and the tire flexes too much generating more heat and pressure, I usually loot at the side walls, this photo was after running at the Dragon in TN last week.

 

[nibble]

yep! that's a lot like what I experienced. mine on outside was down to cord. what pressure were you running?

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