[vrships]

Just attended my first Laguna Seca HDPE with Y25 G82 Comp. 4WD. 2500 miles street driving before this.

Stock everything. PZ4 and regular brakes and OEM fluids. DSC off + 4WD

The car is super stable and powerful. No spin concern WOT in every turn exit (except turn 11 occasionally).

Unlike many people worried, brake fade is not an issue and one can never blame not enough brake power to trigger ABS.

Only thing I am struggling with is the limit during the turn. Most of the time it feels like the entire car is sliding out in a balanced way, with no need for correction, but just cannot reach high enough cornering speed like other performance cars.

Never feel any power fade for any single lap. Water and Oil temperatures are even colder than driving on high way. And an interesting part is, the brake dust is actually much better than driving on the street! Because of this extreme heat and brake pressure, all the dust are burnt into black powder. It just lands on the rim in piles and is easily blown away completely. No more sticky and uneven brownish mud like film anywhere.

Of course the tire wear is bad on such a heavy car with only 1.5 camber. And the crach prevention system force closing the windows during extreme braking at the highest speed places, just as many have experienced.

The price I have to pay is my rear pads wear sensor triggered before my last session. And after the last session the system shows it's only 360 miles left in iDrive.



Two front pads




Two rear pads

This is a bit confusing since with DSC off, and me pushing unecessarily too much, I thought the front pads should wear faster. But looking at the picture, front seems OK with >60% thickness. The rear outside has maybe 4-6mm.

Apparently much worse than the front but I still don't believe that reached the wear sensor. And do I really only have 300 miles left? Or the pads can last certainly longer than that if only used daily.

I think I am gonna switch to RS29L for the replacement. I am very satisfied with the OEM brake pads but just cannot afford to burn a set in less than 2 track days

Questions:
1. what's the part No. of RS29L for rear pads?
2. My PZ4 now look like these. The smallest grooves on the front are almost gone. And there is a strong inclination of each patch. But the tread depth look OK. Will they still be good for one more track day? I did feel the car struggled for grip the last 2 laps of the last session but I don't know if it's the track condition or tire. I assume they are totally fine for street use for another 5k+ miles.

3. What's the reason rear pads wear so faster? I heard from someone that even with DSC off, the DME still intermittently applies brake to rear end to help the car rotate. I don't think I feel that at all but I don't know how I can prove or disprove this

[spongey]

I don't think pictures came through, can you re-try?
Awesome video, what do you use for camera & overlay SW?

[vrships]

Originally Posted by spongey

I don't think pictures came through, can you re-try?
Awesome video, what do you use for camera & overlay SW?

Some how the attachment manager is totally broken this time.

This is dragy's own laptime app and I uses my phone to record the video controled by this app. It has many more lap time analysis functions which I like very much. I heard the accuray is almost exactly the same as $1000 Garmin Catalyst.

[ibimmer954]

The rear pads are definitely toast. The fronts have some pad left but are pretty torn up. Will probably be loud for a while. But if you’re going to go Pagid then you’ll want to replace all the pads at once anyway. No sense in keeping the fronts. You don’t want different pad types on front compared to rear.

Maybe the G80 used partial electronic LSD or something. I’m running Pagid RSL29 on my F80. And even with traction control full off on that car I still go through the rears faster than the fronts.

[Gottagofast]

The rear pads are toast because of traction control. If you turned both DSC and TCS off, they would have been fine.

Granted, an inexperienced driver should not turn them off because of obvious safety issues.

[vrships]

Originally Posted by ibimmer954

The rear pads are definitely toast. The fronts have some pad left but are pretty torn up. Will probably be loud for a while. But if you’re going to go Pagid then you’ll want to replace all the pads at once anyway. No sense in keeping the fronts. You don’t want different pad types on front compared to rear.

Maybe the G80 used partial electronic LSD or something. I’m running Pagid RSL29 on my F80. And even with traction control full off on that car I still go through the rears faster than the fronts.

Yes . Certainly I ll replace the full sets. But in terms of the thickness, doesn't the front look OK and has around 8-10mm if the original thickness is 12mm? The rear look like 4-6mm left but I am assuming some layer is not usable .

Actually the brake feel did not change at all on the streets. No new squealing or noise of any kind. Only thing I had is a tiny pulsation applying the brakes above 70 mph, considering what horrifying heat cycle the rotor has gone through. But I think that's also gone today.

Talking about eLSD intervention. Do we have any evidence it's really loading the rear brakes? Maybe its just the cooling. The front has enough cooling from the duct while rear has none.

[vrships]

Originally Posted by Gottagofast

The rear pads are toast because of traction control. If you turned both DSC and TCS off, they would have been fine.

Granted, an inexperienced driver should not turn them off because of obvious safety issues.

Clearly with 4WD (or sport) and DSC off, traction control is not adjustable.

[Gottagofast]

Originally Posted by vrships

Clearly with 4WD (or sport) and DSC off, traction control is not adjustable.

That is MDM. It only works when vehicle is set to RWD mode.

To turn off all driving interventions including TCS and DSC, hold the DSC off button for 5 seconds.

Still shocks me that people are not aware of this function.

[vrships]

Originally Posted by Gottagofast

That is MDM. It only works when vehicle is set to RWD mode.

To turn off all driving interventions including TCS and DSC, hold the DSC off button for 5 seconds.

Still shocks me that people are not aware of this function.

You shocked me when you can't read the clear letters on the screen. That says " DSC off" , not "MDM".

And it seems you do not know MDM and DSC off are exclusive. You can only choose one from 3 options" DSC on,MDM and DSC off".

And with ID8 you cannot turn DSC off even if you keep pressing it for 5000s. You must select 1 in 3 options on the screen.


How could you get most of things completely wrong and still having fun ridiculing others

[Gottagofast]

Sigh. Someone show this clown how to turn all the driving aids off so he doesn't burn more pads.

[vrships]

Originally Posted by Gottagofast

Sigh. Someone show this clown how to turn all the driving aids off so he doesn't burn more pads.

Just shut up. You already humiliated yourself enough and I can't standing watching anymore.

You can't figure out just a few simple outcomes of a few easy clicks and selections and you don't have the ability or courage to spend 15s to test it out. And you kept lying.

Pathetic

[FC4]

Sub 40 in a stock car your first time at Laguna? Damn, well done. There's room for improvement in your line too.

I don't think non-locals will appreciate how quick that is.

[techwhiz1]

Originally Posted by FC4

Sub 40 in a stock car your first time at Laguna? Damn, well done. There's room for improvement in your line too.

I don't think non-locals will appreciate how quick that is.

I'm a local and I'm impressed.

[kingikra]

Not sure if true but dealer told me that front pads are ceramic unlike the back ones.

[vrships]

Originally Posted by FC4

Sub 40 in a stock car your first time at Laguna? Damn, well done. There's room for improvement in your line too.

I don't think non-locals will appreciate how quick that is.

Appreatiate it bro.

Unecessarily slower in T5, corkscrew and T10. I didn't sense the limit properly then.

T3 is probably the hardest with this line if I want to hold 60mph at apex. It always understeers and turn exit and drops to ~57 mph. Have to plan the line differently next time.

I am tempted to blame no improvment the next day due to zero clean lap but then I read the logs and realize it's almost impossible I best all sectors together and even if that happens, I could barely shave 1s off it

[vrships]

Originally Posted by kingikra

Not sure if true but dealer told me that front pads are ceramic unlike the back ones.

Yeah the composition may be different. I thought BMW configured it in the way that with street use, front and rear eventually wear out evenly.

With heavy track use, the front being streesed much harder than the rear should make it burn faster.

Either it's because of the horrible cooling in the rear, or some unknown mechanism that brakes the rear in situations I am not aware of.

[CJ421]

vrships

The tires look like they have enough tread to handle another track day. If they can be rotated side to side, that would help even the wear.

The pads are toast ...agreed on replacing the entire set.
Also get new brake fluid (high-temp, as well). That will greatly help stopping power.

You did prep the car by removing the little brake air duct shields, right?

Charles

[vrships]

Originally Posted by CJ421

vrships

The tires look like they have enough tread to handle another track day. If they can be rotated side to side, that would help even the wear.

The pads are toast ...agreed on replacing the entire set.
Also get new brake fluid (high-temp, as well). That will greatly help stopping power.

You did prep the car by removing the little brake air duct shields, right?

Charles

THanks for the suggestion to rotate the wheels to balance the wear. That didn't cross my mind while I was thinking of turning more aggresively in daily use to wear the thicker side

Took of the rear wheels to check the pads and they were like 5mm on the outerside and 4mm on the inner side. Waiting for my backup pads.

Since this is a new car, I didn't fill it with race brake fluikd like RBF600. But surprisingly there is no brake fade I can feel. Only thing is when I look at the fluid tank in the engine bay, there is a few drops of clean fluid spill near it.

Took off the brake cover just according to this video before the 1st session. Turned out it helped a lot. Front calipers were like 240C 20 minutes after the last session. Wow

[Needsdecaf]

Originally Posted by vrships

But surprisingly there is no brake fade I can feel.

You can't feel any brake fade because the car is brake by wire. All feel that you are getting through the pedal is force feedback that is being generated by the computer.

[vrships]

Originally Posted by Needsdecaf

You can't feel any brake fade because the car is brake by wire. All feel that you are getting through the pedal is force feedback that is being generated by the computer.

Yes I am aware of this. But then what is the sign of brake fade? Brake power doesn't go up beyond certain pedal travel and cannot trigger ABS?

[CJ421]

Originally Posted by vrships

Yes I am aware of this. But then what is the sign of brake fade? Brake power doesn't go up beyond certain pedal travel and cannot trigger ABS?

Brake fade will be most obvious if you are using the car's maximum braking power ...if the brakes are fading, you won't stop nearly as quickly.

You shouldn't have fade issues with high temp fluid and street performance tires like PS4S. Stickier tires will increase the load on the brakes and create more heat. But high-temp fluid + track pads will go a long way with these cars.

Charles

[NYG]

The factory pads are never going to last long if you're pushing the car.

Grab some PFCs and get rid of those PZ4s. They suck ass.

IOMG G82 LCI track crew representing.