The traditional european way of braking is the heel-toe technique, i.e.
braking with your heel as you throttle with your toe.
The traditional american way of scrubbing off speed is just to stomp the
brakes, and pick your exit gear as the speed gets low enough to do so.
As a sidenote I would think that the historical reason for this is that
the americans have always raced heavier cars, and ditto strong
transmissions, with ensuing more awkward shifting. In europe, and
britain in particular, race car drivers have used the throttle while
braking to ensure that the car brakes in a straight line without
oversteer over a wide range of racing conditions. The use of the
throttle while braking would be limited to, I'd guess, about 10-15%
engine power. We're talking a very fine addition of power to the rear
wheels. If you have to brake over a hill, you'd use additional throttle,
if you have to brake at the bottom of a hill, you'd use none.
In a non aero-downforce racing car there is no more efficient way of
braking than being as close as possible to the adhesion limit of each
tyre. If you cross the slip-angle/grip curve efficiency is impaired, as
being to far on the "safe" side would.
You can take out a racing car on a scratchpad and try and see how short
braking distance you can get by stomping the brakes while free coupling
with the clutch and compare it to doing the same thing while
downshifting and throtteling without using your clutch. You will always
find that the distance will be shorter without downshifting and throtteling.
Using the throttle while braking is only performed in order to control
the over/understeer of your car (and of course matching up the input
shaft speed with output shaft speed), never to increase the braking
efficiency. If you depend on your downshifting to control the braking
power, you'd wear out the clutch/box in 10 laps, and you'd achieve no
consistency whatsoever since it is next to impossible to change gears in
a way that would ensure constant braking.
I would think that iRacing need to have a look at more than the internal
wear to fix this, given that "this" being the case as described here. I
cannot come up with any racing class on the planet where it is efficient
using engine-braking to this extent.
--A--
>>> Next thing I notice is that you can stop more quickly by essentially
>>> pushing both pedals to the floor than you can by balancing your brake
>> Do you mean literally full throttle and brake travel? Sounds like a
>> bug and I understand your frustration, but I'm sure that iRacing is
>> working on it. Frankly I'm surprised things like this haven't been
>> ironed out yet.
> Yes. With extreme rear brake bias set just right I think you can stop
> equally as fast by pressing both pedals to the floor as you can by use
> brake pedal only with a balanced brake bias setting. If not equal
> then very close. With the slightest effort in modulating the throttle
> you can brake more quickly with 50% to 75% throttle and 45% and lower
> front brake bias.
>> Also, doesn't the very low ride height help with downforce? That
>> would shorten the braking distances too, I think.
> Low ride height will increase downforce, but you shouldn't be able to
> corner with the bottom of the chassis on the ground. The track this
> week is extremely bumpy. The car is bottoming out all over the place
> but doesn't seem to be affected. I remember the late model used to
> slide up the track at Irwindale if it bottomed out in the turns. The
> Mazda doesn't seem to be affected.
> --
> Pat Dotson
