Factory Brakes - Am I asking too much?

[su_root]

I track the E92 M3 with a factory caliper/rotor/lines setup and upgraded pads. Fluid is next on my list to do before this weekends event at SIR and I have an appt tomorrow for a brake flush. That said I've picked up 2L of Castrol SRF for the flush.

Now- what I'm after is a really tight/firm pedal feel(low compressibility) at engagement. I want the pedal to feel how it feels in my F82 w/CCBs where I can feel the brakes bite very soon after I depress the pedal and the pedal feels tight/firm. It gives so much confidence. The E92 pedal just pushes in so much and the stopping effect comes in so deep into that pedal travel that it doesn't make you feel very confident. I believe that means it's compressing too much?

And I'm not saying I expect the E92 to last as long and handle as much heat as the F82; what I'm after is that tight, firm and much shorter pedal travel that the F82 has even during normal slow daily driving.

I apologize if my terminology is incorrect. Thanks in advance

[SYT_Shadow]

A flush should help with feel, although it will not necessarily feel like your F82.

As far as the bite, different pads can help with that. In the PFC world which is what I prefer, some people like the PFC01/11 pads because they bite quickly and very hard. I prefer a more linear pad like the PFC08/12.
In the end, the braking performance of both different types of pads in my example is the same, but how they accomplish it is different.
That said, the fastest M3 driver I've seen at WGI was on PFC08 pads

[dparm]

Originally Posted by su_root

I track the E92 M3 with a factory caliper/rotor/lines setup and upgraded pads. Fluid is next on my list to do before this weekends event at SIR and I have an appt tomorrow for a brake flush. That said I've picked up 2L of Castrol SRF for the flush.

Now- what I'm after is a really tight/firm pedal feel(low compressibility) at engagement. I want the pedal to feel how it feels in my F82 w/CCBs where I can feel the brakes bite very soon after I depress the pedal and the pedal feels tight/firm. It gives so much confidence. The E92 pedal just pushes in so much and the stopping effect comes in so deep into that pedal travel that it doesn't make you feel very confident. I believe that means it's compressing too much?

And I'm not saying I expect the E92 to last as long and handle as much heat as the F82; what I'm after is that tight, firm and much shorter pedal travel that the F82 has even during normal slow daily driving.

I apologize if my terminology is incorrect. Thanks in advance

If anything, I want the opposite of what you are describing at the track. The quick initial bite from the stock brakes makes it tricky to be smooth and progressive with braking and making quick adjustments with a touch of the brakes becomes risky.

My StopTech kit, by comparison, has more pedal travel but is much more linear.


BTW, you won't need 2L of fluid. A single 1L bottle of SRF is enough.

[SYT_Shadow]

Originally Posted by dparm

If anything, I want the opposite of what you are describing at the track. The quick initial bite from the stock brakes makes it tricky to be smooth and progressive with braking and making quick adjustments with a touch of the brakes becomes risky.

My StopTech kit, by comparison, has more pedal travel but is much more linear.

dparm is correct. More linear brakes and pads allow you to modulate brakes better

That said, many prefer the extremely grabby style of pads. I do not.

[su_root]

Originally Posted by dparm

If anything, I want the opposite of what you are describing at the track. The quick initial bite from the stock brakes makes it tricky to be smooth and progressive with braking and making quick adjustments with a touch of the brakes becomes risky.

My StopTech kit, by comparison, has more pedal travel but is much more linear.


BTW, you won't need 2L of fluid. A single 1L bottle of SRF is enough.

Good info, thanks. that gives me a lot to think about.

The flush is overdue on the E92 and its on factory fluid at the moment- I'm hoping that the fluid change in itself will improve the feel.

[su_root]

Oh and you're right. ETK lists the capacity as 1L- I was initially thinking to flush the system myself with a Motive power bleeder unit so I bought extra for any issues that undoubtedly always come up the first time you DIY.

Thankfully my local SA allowed me to supply my own fluid.

[dparm]

Originally Posted by su_root

Good info, thanks. that gives me a lot to think about.

The flush is overdue on the E92 and its on factory fluid at the moment- I'm hoping that the fluid change in itself will improve the feel.

Yes, I think it will. The reason people use SRF is that the wet boiling point is so high -- that means they don't have to keep flushing the fluid after every track event to ensure optimal performance.

If you are content to change the fluid every weekend, then go ahead and just use something like RBF 600 or whatever. I don't know about you, but I have better things to do than bleed my StopTech calipers (more involved than stock) every weekend.

[ban25]

Moving to Stainless Steel lines will stiffen up the pedal feel a bit. The next step would be to get a brace for the master cylinder. If you still want more, a BBK may be in order.

[MSteve5036]

Fluid will surely help the feel...I think the hard bite is nice on the street but like some have said...it isn't as nice on the track

I have used ATE and Motul, but find it necessary to bleed before every event or two...I plan to try out the SRF

[///Mobbin]

I would absolutely do the fluid flush but it sounds like you're already on that. Then I would suggest Pagid RS-29's or RS-19's for the pedal feel you are talking about. Good initial bite. I actually prefer the feel of those Pagid's vs the PFC08's, at least in terms of initial bite. I also keep switching back and forth between Pagid and PFC for various reasons so take this with a grain of salt.

[admranger]

Pads have a lot to do with pedal feel, as has been discussed. What "upgraded" pads are you putting in your car?

I've tried a ton including virtually every Mintex compound they made back in the 90's (I could get them cheap). They all were very 'squishy' compared to Hawk HT14s (10s are crap) and PFC 01's.

Since I have no more room for HPDE World Championship trophies in my trophy room, I just use PFC08's all around with SRF fluid (finally came to see the value of this too!). No need to screw around anymore. I don't need the last tenth on my lap times. If I did I'd put the fork down sooner.

[Z K]

Try a different brake fluid... SRF is good for not having to flush often but it is highly compressible which makes it feel spongy after it heats up.

Try Endless RF-650 or the new Torque brake fluid. Both have very low Compressibility. Also, get some more track oriented brake pads. They'll have more braking torque and a harder brake pedal.

[SYT_Shadow]

Originally Posted by ///Mobbin

I would absolutely do the fluid flush but it sounds like you're already on that. Then I would suggest Pagid RS-29's or RS-19's for the pedal feel you are talking about. Good initial bite. I actually prefer the feel of those Pagid's vs the PFC08's, at least in terms of initial bite. I also keep switching back and forth between Pagid and PFC for various reasons so take this with a grain of salt.

Heretic!

[admranger]

Originally Posted by SYT_Shadow

Heretic!

Burn him!

[dparm]

Originally Posted by Z K

Try a different brake fluid... SRF is good for not having to flush often but it is highly compressible which makes it feel spongy after it heats up.

Try Endless RF-650 or the new Torque brake fluid. Both have very low Compressibility. Also, get some more track oriented brake pads. They'll have more braking torque and a harder brake pedal.

I have experienced zero change in pedal feel with SRF, even after 6 track days (two of which had 30 minute sessions in 90+ degree heat).

I did run Torque/Prospeed and found it had a nice pedal feel, but I ended up boiling it after two track days...and switched to SRF at that time.

[Move Over]

+1 for SRF. I had RBF600 before this and cooked it. Annoying to have to bleed out every weekend.