Quote from Woz :

If you watch a foot cam of a real racer they will jab the brakes well before each corner to test they still have brakes

I don't think that's correct. The only time racers in real life are likely to press the brake before a corner is if at the exit of the previous one they run over the rumble strip or something equally bumpy. There's a chance that this could dis-lodge the pads in the calipers slightly, meaning there's a bit of a gap between them and the pistons. So, they'll simply brush the brake pedal with their left foot, such a small amount that it has no effect on their speed / acceleration, but just enough so the pistons take up the slack between them and the pads.

I'm certainly not aware of anyone going along, "jabbing" the brakes before every corner to make sure they are still working.. if everyone did this, I'm sure there'd be quite a few pile-ups on track due to people randomly slowing down infront of someone.

Onboard footage of series like the Aussie V8's shows drivers dabbing the brakes way before a corner to ensure they still have pedal pressure. I've seen this commentated on more than once.

I only recall seeing this done on street circuits though, although I'd bet they do it on the way down the hill at Bathhurst as well.

As for my LFS setup I have it set so I never use the full travel of the brake pedal and I modulate my braking to try and achieve maximum braking at all times.

I'll subscribe to what SabersKunk is saying. I've seen it be done in Aussie V8s. To preload or test (or both) fading,

Ok fair enough, from what Moz was saying it sounded like he meant they would stamp on the brakes quite hard, which is mainly what I was disagreeing with.

Never actually seen it done on TV or elsewhere, but I believe you.

Quote from NotAnIllusion :

http://www.youtube.com/watch?v=qdWSyrqEnE4

too sexy

hell ive been searching for red sneakers for 1 month and nothing

i gave up seems to be some kind of conspiracy from the fashion looby so i cant have red pumas

hell where can i get those amazing shoes?

Quote from lerts :

hell where can i get those amazing shoes?

http://puma.subesports.com/pro ... oes/brand/PUMA/prodID/936

If you're serious - and why wouldn't you be - here's a review of those shoez
http://www.pumaracesuits.com/s ... 0820bac2d582942ba30e3cd93

yes but are they lasting?, hadnt had a godd experience with my last red pumas

i find nike more durable

but however stupid you find it ive been last 6 years wearing red snikers which i like how they combine with denim but cant find them any more red

what do you suggest me? give up and buy lame white ones as forced by the system or what

edit:

what about the size?

in spain i use a 43 and im 1,83m tall, should i get a 43 from that puma site?

edit postedit:

wow i like more and more the shoes, i also find anoying having to sock driving due to normally being with my sneakers on at home and find anoying having to take them off just to play

edit3:

ive notice the shop is usa being in dollars, can i buy from them here in spain?

Quote from Minimaxman :

I don't think that's correct. The only time racers in real life are likely to press the brake before a corner is if at the exit of the previous one they run over the rumble strip or something equally bumpy. There's a chance that this could dis-lodge the pads in the calipers slightly, meaning there's a bit of a gap between them and the pistons. So, they'll simply brush the brake pedal with their left foot, such a small amount that it has no effect on their speed / acceleration, but just enough so the pistons take up the slack between them and the pads.

How you have described it here is closest to how I understand it. Just improves the response when you first start braking if you do this. I really don't think they're testing to see if their brakes still work! A tiny tap on the brakes isn't going to give you any idea whether they will work when you really lean on them....

Yeh I'm still not completely convinced the reason they do it is to make sure they've still got brake pressure. What if they did one of these quick jabs only to realise the brakes weren't working, when they come to brake they still won't work.

This is taken from one of the comments from the video NotAnIllusion posted, and sums up what I was getting at in my first post in this thread using the correct terminology:

"My guess is pad knock back. Any lateral movement of the brake rotors can push the pads back into the caliper causing some brake pedal effort being wasted on just moving the pads back into place. In severe cases, it can cause enough knock back so a full pedal press does nothing, requiring another stomp on the pedal. The first time that happens when you're not ready for it is not fun, especially if you're at speed when it happens. Tap the brake down a straight and you reset the pads."


EDIT: When I say I don't think they are checking for brake pressure in my first sentence above, I mean actually checking to see that the brakes are slowing them down, not just tapping them to make sure all the pads are seated properly.

Quote from NotAnIllusion :

http://www.youtube.com/watch?v=qdWSyrqEnE4

Since we are talking about this, can anybody explain the shifting technique? I'm pretty much confused by it: sometimes he depresses the clutch (while keeping the throttle down), sometimes he doesn't, sometimes he lifts before changing :Eyecrazy:

Quote from NightShift :

Since we are talking about this, can anybody explain the shifting technique? I'm pretty much confused by it: sometimes he depresses the clutch (while keeping the throttle down), sometimes he doesn't, sometimes he lifts before changing :Eyecrazy:

I suspect hitting the clutch when going up and over and just a feathering when straight down...

The clutch seems to have a bit of travel before reaching the bite point as I would expect from a road car, in fact when he actually uses the clutch, the foot moves on to the pedal and the clutch is depressed just a little, before he actually gives the kick.

OTOH when he shifts without the clutch the left foot is kept on the rest, doesn't move at all then he can't be possibly feathering it, I would rather think he's revmatching but around 0:32 you can clearly see that his right foot doesn't back off one bit, he's flat out - like I would expect to see on a sequential with ignition cut.

Then again when he shifts using the clutch but without lifting (second shift from the start), you can clearly hear the engine isn't shooting up like you would expect in a car with a manual shifter.

But if the car had ignition cut, that would work only the driver was using the shift stick... or not?

Not in that car, no ignition cut. The gearboxes they use are called a dogbox (straight cut gears). I'm not exactly sure how they work, but if you put some pressure on the gearstick just before you tap the limiter in say 5th - 6th gears, when you hit the limiter, the engine cuts out for a second on the gear goes in, which is more or less like an ignition cut I suppose..
Most of the time you have to dab the clutch going from 1st - 2nd, then 2nd - 3rd, accross the gate, because it sometimes doesn't go in.. but most of the other gears you can either bang through on the limiter, or just back off the throttle a little and bang it through.

As for the flatshift, I heard the engine hit the limiter on my pc. They have electronic rev limiters, so maybe it sounds a tad different to what you expected, also, the mic in those cameras doesn't always pick up the sound.

I'm pretty sure the driver there is Neil Crompton, who commentates for V8 supercars now. Still quite a good steerer obviously

On topic (sort of): that brake dab they do, I always thought it was to get the calipers closer to the disc or something like that.. Well that's why (if) I do it anyhow. Doesn't make too much difference in the stuff I race, as the races are sprints (10 laps or so). You see V8 supercar drivers doing it more on tracks that a: you have to use the brakes at max pressure a lot, or b: endurance races. Mind you if we drove on a street track or in the enduro next year I would/will probably dab the pedal before big stops, ie before hairpins off a straight or something

Quote from [DUcK] :

As for the flatshift, I heard the engine hit the limiter on my pc.

I did listen to it better (using headphones this time) and you're pretty much right. Sorry for the little OT all

Quote from Michael Denham :

How you have described it here is closest to how I understand it. Just improves the response when you first start braking if you do this. I really don't think they're testing to see if their brakes still work! A tiny tap on the brakes isn't going to give you any idea whether they will work when you really lean on them....

That tiny tap is enough to

(1) Pump the brake system which is required as the fluid boils and gas is introduced as others have highlighted. As I said earlier you can feel this to great effect on many road car brakes. Just pump a few times and the pedal becomes firm. Over time it goes soft again.
(2) Test if you have pressure. I have watched enough V8s to hear real world V8 drivers ACTUALLY say this is why they do it on Bathurst commentary so I tend to believe that is the reason.

As I said, believe what you want but I believe the people with the balls to drive Bathurst at race pace in a V8 not people who dispute them in a forum

Quote from [DUcK] :

You see V8 supercar drivers doing it more on tracks that a: you have to use the brakes at max pressure a lot, or b: endurance races. Mind you if we drove on a street track or in the enduro next year I would/will probably dab the pedal before big stops, ie before hairpins off a straight or something

Yep. Last thing you want to do is commit everything to a corner then realise you cant actually stop. It costs you nothing in time so it is a good practice IMHO.

The rules for V8s at Bathurst are such that you are required to change brake pads at least once in the race. Fail to do that and your are disqualified, that is if you managed to complete 1000Kms of a track like Bathurst on one set. The run down from the hill ends a 300Km/h straight in a tight 90deg bend. The brakes take HUGE punishment

Quote from Hallen :

Since all brakes are hydraulic, you are trying to compress a fluid, which you can't compress. At a certain point, brake travel should stop for the most part as the slack in the system is taken up....

If the pedal continues to move, you have a bad master cylinder, a leak, or air in the system.

You will lock up all four tires well before the point where the brake pedal stops moving. Go ahead and try it in your real car parked but with the engine on. Push the pedal all the way until it stops moving. That's a lot of force, and more than enough to already lock the wheels if the car was moving.

If you look at the vid above, you can see that no where does that racer run out of pedal movement.

I think sim pedals using movement is fine. It just needs to be a lot stiffer, and perhaps with the braking force not linearly proportional to pedal movement.

http://www.youtube.com/watch?v ... DVgWc&feature=related

For all those doubters, LISTEN to the commentary. To quote "Just testing he has brake pressure on the way into turn 9"

As an explination for why race car drivers tap the brakes before a corner.

As the brakes cool down from the last corner parts and fluids shrink, with anything when you heat it up it expands and when it cools it shrinks. What they are doing is removing the slack in the pads so the whole system is ready to apply force.

If they didn't do that they could have to re-pump the brakes and lose valuble time or run off the track.


As for the flatshifting, there is an ignition cut , I can't remember for sure, but I think its actualy a button on the shifter. I heard that somewhere but I can't be sure it's right. There is an ignition cut though, I know that for sure.

Edit: here it is: http://ca.youtube.com/watch?v=8TjO_hi8woQ&NR=1 micro switch on the shifter, it cuts spark.
LOL, rollbar adjustment from IN THE CAR, thats just an awsome feature I would love to have.

When he shifts without the clutch he's just letting things line up in the transmission as he doesn't need to double clutch if he doesn't clutch at all. I have driven like this before, I only use the clutch for starts and stops, everything else can be rev matched.

Back on-topic-ish: I set up the brakes in LFS so I can floor the pedal on the heaviest-braking corner (either flat or downhill) without locking up. On other sims I'm happy enough to modulate the pedal, but I think it screws up my lap times.

To be fair in a real car it's a lot easier to sit on the limit of the brakes than it is with a set of Logitech pedals.

I am actually surprised by the long pedal throw in that video. From other videos that I have seen of race prepped cars, the throw was lot shorter and it was more the pressure at the end where the modulation takes place.

But, here is another video showing quite a bit of pedal travel too.

http://video.google.com/videos ... operty-revision&cd=1#

Here is another one that uses much less pedal throw. It is a bit hard to see because the brake is partially out of the picture. This is a C6R with a sequential box and you can see it doesn't take much of a blip to match the revs.

http://www.badboyvettes.com/qtlimerock07

And of course this one in a Radical. The shifts are fast, but you can see the brake travel is fairly short.

http://video.google.com/videos ... ion&cd=1&start=30

Sorry for the long links.

Brakes are the one thing that are completely unrealistic in driving sims. Even if you do become adept at modulating your brakes to avoid lock up in LFS you're not relying on the same inputs to sense lock up as you would be in real life. In real life even relatively crap brakes give you some feedback through the pedal. In sims feedback is non existant.

I would dearly love to have a realistic braking system available used in all sim pedals, (I don't believe it would be that hard just requires a pressure sensitive rather than position sensitive type potentiometer), then we'd clearly be able to tell the users who are drivers IRL IMO.

Quote from NotAnIllusion :

http://www.youtube.com/watch?v=qdWSyrqEnE4

i dont get it, why is he using clutch in an ignition cut gearbox. and hes 'heel & Toe' is very very odd.. using 75-100% while on clutch? then releases both. even in a dockring gearbox, i never uses clutch. :o