Veloce Raptor

Rofl

Well played!

morsini

Seemingly not.

fleadh

Closer to the LMPC than to the 991 Cup. I'm still getting a feel for the 991 Cup brakes as they seem a little different than anything else.

RSR brake pedal requires about the same level of pedal pressure, but it has a much broader area "under the curve" for threshold braking to feel and control the lockup (if that makes sense). The 991 Cup brakes have a *tiny* window for maximum threshold braking (even with fresh rotors/pads) with much less feel (I'd go so far as to call them a little numb...). I'm not sure if it's more a byproduct of the tires, aero, chassis limitations, or the mechanical brake systems on each car.. but they're very different. You can really attack the RSR pedal and I have to consciously "soften" my transition from full power to attacking the brake pedal in the Cup car (worked a lot with Colin Thompson, Andrew Davis and Jeroen Bleekemolen my first weekend in the car at Sebring... if anyone else told me to ease up I'd have laughed!).

The RSR does everything you'd expect from a race car where the GT3 Cup still feels a little bit like a modified street car.

The biggest difference under deceleration is the effective length of the braking zone. Obviously the RSR will stop in a shorter distance, but in most cases, the braking zone for the RSR starts when you go to the pedal and ends when you go back to power -- it has a great platform to square corners off -- not much rolling "dwell" time while you're completely off the brake and waiting to go to power. The Cup seems to have a lot of "coasting" time as the platform isn't so good at carrying the brakes all the way to the apex and you still need to scrub speed with the front tires to get rotated before you can go back to power.

I'd say the RSR is a cross between the LMPC car and the 458 GT3 car (with GT2 pedal box).

Of course, I'm still coming up to speed in both. After a few more days in the Cup this weekend and testing at Laguna and Sonoma next week, I expect to make some improvements! :-)

edit: forgot to mention.. the 991 Cup vs 997.2 Cup braking -- 997 had a broader sweet spot, but still nothing like the RSR has. 997 also felt like it required just a *tick* more pressure on the pedal, but not much. 991 Cup brake system does seem to be more tolerant to heat cycles though... at least as far as the factory pads are concerned.

-mike

Veloce Raptor

Thanks for the explanation. Yeah, 991 Cup brakes are really different from 997...

ProCoach

Here's about a perfect brake pressure, lat g and long g trace from a guy under the track record at VIR.

Veloce Raptor

+1 !!!!!!!!!!!!!!!!!!!!!!!!!!

FFaust

Thanks Peter. Need to print that and tape is somewhere on the dash.

TXE36

Where is the downshift braking!?!?
The apex is way too late!
What's with all this complexity, I can measure stuff better by feeling it out by hand!


(I'm going to hell aren't I?)


I agree with Faust - I'm thinking center of the steering wheel would be an appropriate place for a printout of this. I've got my homework assignment for next month.

-Mike

ProCoach

Hahaha! Downshift braking...

Hahahahaha! My coffee is now on my keyboard.

It's nearly 200 degrees around this corner...

Veloce Raptor

What could possibly go wrong? Lol

electron mike

That is an excellent visual, thanks. Do you have a version with units on the axis?

I know it is car and corner specific, but as I work on my brake release technique I am trying to get a sense for the time delta between max brake pressure and zero pressure. When I have worked on it and noticed an improvement in stability from a slower brake release, I feel like it could easily be 5 tenths to a full second or more of easing off the pedal. I don't have brake pressure, but I guess I could look at long g's.

ProCoach

Yes. Will update with units and delta.

TXE36

Too much to ask for black and white for easy printing?

Thanks
-Mike

ProCoach

Let me see... I'm technologically challenged when I try go retrograde!

TXE36

No biggie. I can convert it if need be. I figure if I study it while waiting on grid and glace at it in the straights I may have a chance at actually pulling it off.

ETA: Actually pretty easy to make, see attached.


-Mike