Sebring brake failure
03-29-2016, 06:27 PM
#107
Rennlist Member
!!
In many cases it can be a good idea to help slow the car before impact or sliding into gravel, as with the Nissan at COTA. The challenge at Sebring T7 is that the brake zone is exceptionally bumpy, and has concrete walls VERY close on each side. The track isn't particularly wide there either. As Frank indicated earlier in the thread, we both witnessed 2 beautiful Cup cars totalled when they were upset by the bumps under braking and snap-spun into the walls. one rolled nearly over a wall. So imagine no brakes and just trying to use the rear tires for slowing over extreme bumps by rapidly downshifting--when there is already a MAJOR difference between road speed and engine speed. Not only would the engine spin to and beyond redline, but the tiniest rear grab or momentary lockup over the bumps is likely to cause immediate loss of control.
no Dave , it doesn work that way. it works as i did with Bell in the 350z . you blip and release the clutch .. the blip needs to be a BLIP, meaning that the RPM matches the speed, so there is no "slipping " of the rear tires, no matter how bumpy it is. its peformed often on all bumpy entrances to turns on race tracks around the country. the only time you spin out and get wildlly out of control is if you dont match the blips.
the best point was brought up recently about if you are already at redline, then what? then, you really cant just bliip and shift, but you have to pause for a second or two, because even a 1 second pause will allow for your blip to match speeds without ill effect. again, dont take my word for it.. try it on the freeway (in a V8). it works AND, this must have been lost in the message... ALL WE WANT TO DO IS HAVE THE ENGINE Brake for us!! so IF YOU ARE AT REDLINE, YOU JUST LIFT!! no need to blip. (should have been more clear there) then, you wait for the second or two, and then, blip and downshift as you slow. the key is staying in the max engine braking zone which is near max hp and redline of any engine.
so by your last statement you clearly dont understand the technique. its not a rapid downshift, its a timed , and appropriatly RPM level'ed shift . blip and shift and go down the gears as you and the engine are capable of doing. if matched, there is no mismatch (by definition), so there is no slipping and no drama. you cant compare folks that mishandled brakes and slid out and crashed as comparison. entirely different situation. we are talking this turn, turn 7 sebring, losing the brakes and how to avoid what happened to tristan.
you dont put the cliutch in.... you leave it in gear and watch the magic of the engine, and downshift as you keep the engine RPM as high as possible.
03-29-2016, 06:32 PM
#108
Rennlist Member
oh so, now you are a Doctor?
ok, DR Death!
Dave, you need to go back to school.. driving, English, reading, math , science, etc. you have 0 clue of what you are talking about. truly.
read this slowly: when you lose your brakes, you dont push the clutch in and coast. if you are not at redline, , you hard blip and select the next lower gear... after a second or two (you know the speed to downshift) you do it again. you want to be in the max hp to redline zone... you dont want to blow your engine, you dont want too upset anything, you just want a constant force on the rear tires via the engine and you will slow faster than you could ever imagine!
ok, DR Death!
Dave, you need to go back to school.. driving, English, reading, math , science, etc. you have 0 clue of what you are talking about. truly.
read this slowly: when you lose your brakes, you dont push the clutch in and coast. if you are not at redline, , you hard blip and select the next lower gear... after a second or two (you know the speed to downshift) you do it again. you want to be in the max hp to redline zone... you dont want to blow your engine, you dont want too upset anything, you just want a constant force on the rear tires via the engine and you will slow faster than you could ever imagine!
03-29-2016, 06:43 PM
#109
Rennlist Member
The only "Always" is "Keep Driving The Car" never give up... Even without brakes, you still have tools in your toolbox.. Downshifts, Swerve, Spin, glancing blow to a wall, glancing blow to a competitor, there are many ways to slow the car, use them all until the car stops moving....
edit: To Answer the direct question - If you are already redlined and don't do anything to slow the car before a downshift you are guaranteed to grenade the motor... If the motor locks up, the (rear) wheels lockup... With locked rears, the car is VERY difficult to control. Even if you don't grenade the motor, you will not be able to modulate the braking effort and risk locking (or excessively sliding) the rears... Its a tool in the toolbox, but its not the only one...
edit: To Answer the direct question - If you are already redlined and don't do anything to slow the car before a downshift you are guaranteed to grenade the motor... If the motor locks up, the (rear) wheels lockup... With locked rears, the car is VERY difficult to control. Even if you don't grenade the motor, you will not be able to modulate the braking effort and risk locking (or excessively sliding) the rears... Its a tool in the toolbox, but its not the only one...
In many cases it can be a good idea to help slow the car before impact or sliding into gravel, as with the Nissan at COTA. The challenge at Sebring T7 is that the brake zone is exceptionally bumpy, and has concrete walls VERY close on each side.
snip....(major blahablahaha )
So imagine no brakes and just trying to use the rear tires for slowing over extreme bumps by rapidly downshifting--when there is already a MAJOR difference between road speed and engine speed. Not only would the engine spin to and beyond redline, but the tiniest rear grab or momentary lockup over the bumps is likely to cause immediate loss of control.
snip....(major blahablahaha )
So imagine no brakes and just trying to use the rear tires for slowing over extreme bumps by rapidly downshifting--when there is already a MAJOR difference between road speed and engine speed. Not only would the engine spin to and beyond redline, but the tiniest rear grab or momentary lockup over the bumps is likely to cause immediate loss of control.
again, the downshifts are blip downsifts (meaning rev matching downshifts) and that allwos for the car to slow down without being upset or having any "lockups"... .............. but if you want to lock up, you can do that by just grabbing a gear , poping the clutch and then twisting the wheel!
03-29-2016, 06:54 PM
#110
Rennlist Member
OK, Mark, I won't get in the way of your endless personal insults against Peter and myself. You are only smearing yourself. Again. As you have countless times before on this forum.
Carry on!
Carry on!
03-29-2016, 07:07 PM
#111
Rennlist Member
Okay, so this has been super amusing to follow. To add some clarity, I've actually had a brake failure going into T7 at Sebring. It's not a great moment. In my case, it happened in my E class 944 S2, and I frankly don't remember how fast I was going (my guess would be 120-ish under the bridge toward the brake zone in that car). A brake line popped in the right front caliper; when I initiated hard braking there was a brief moment when the car started to slow and then nothing. Trust me, there's not a lot of time to figure out what to do. In my case, I pumped the crap out of the pedal, which may have helped a tiny bit, side to side scrubbed,concentrated on driving the car, managed to make the right turn onto the old straight, and scrub speed and get it stopped. Never occurred to me to downshift, don't know if that's right or wrong. I was super lucky, and it worked out okay. But look at the track map below- that car was going way faster than I was, and the bend to the left is softer than trying to make the right, so I'm sure that looked like a great call until the fence showed up!. I actually got flat- bedded out that gate, and as you can see from the video, it's not pretty there, but better than trying to go right, ending up in the berm and maybe rolling it. Plus, you can't see the gate until you're on it. Having gone through what this guy did, albeit at a lower speed, I think what he did was genius. Unless you've been there, pretty hard to second guess this one. I have been there, and I think he did well. Just sayin'.
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03-29-2016, 07:16 PM
#113
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Trust me, there's not a lot of time to figure out what to do.
In my case, I pumped the crap out of the pedal, which may have helped a tiny bit, side to side scrubbed, concentrated on driving the car, managed to make the right turn onto the old straight, scrub speed and get it stopped. Never occurred to me to downshift, don't know if that's right or wrong.
I was super lucky, and it worked out okay. But look at the track map below- that car was going way faster than I was, and the bend to the left is softer than trying to make the right, so I'm sure that looked like a great call until the fence showed up!.
Having gone through what this guy did, albeit at a lower speed, I think what he did was genius. Unless you've been there, pretty hard to second guess this one. I have been there, and I think he did well. Just sayin'.
In my case, I pumped the crap out of the pedal, which may have helped a tiny bit, side to side scrubbed, concentrated on driving the car, managed to make the right turn onto the old straight, scrub speed and get it stopped. Never occurred to me to downshift, don't know if that's right or wrong.
I was super lucky, and it worked out okay. But look at the track map below- that car was going way faster than I was, and the bend to the left is softer than trying to make the right, so I'm sure that looked like a great call until the fence showed up!.
Having gone through what this guy did, albeit at a lower speed, I think what he did was genius. Unless you've been there, pretty hard to second guess this one. I have been there, and I think he did well. Just sayin'.
Mark, I have been called a LOT of things, but never a "terrorist..." That's a new one, believe me.
__________________
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-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
03-29-2016, 07:19 PM
#114
Rennlist Member
Okay, so this has been super amusing to follow. To add some clarity, I've actually had a brake failure going into T7 at Sebring. It's not a great moment. In my case, it happened in my E class 944 S2, and I frankly don't remember how fast I was going (my guess would be 120-ish under the bridge toward the brake zone in that car). A brake line popped in the right front caliper; when I initiated hard braking there was a brief moment when the car started to slow and then nothing. Trust me, there's not a lot of time to figure out what to do. In my case, I pumped the crap out of the pedal, which may have helped a tiny bit, side to side scrubbed,concentrated on driving the car, managed to make the right turn onto the old straight, and scrub speed and get it stopped. Never occurred to me to downshift, don't know if that's right or wrong. I was super lucky, and it worked out okay. But look at the track map below- that car was going way faster than I was, and the bend to the left is softer than trying to make the right, so I'm sure that looked like a great call until the fence showed up!. I actually got flat- bedded out that gate, and as you can see from the video, it's not pretty there, but better than trying to go right, ending up in the berm and maybe rolling it. Plus, you can't see the gate until you're on it. Having gone through what this guy did, albeit at a lower speed, I think what he did was genius. Unless you've been there, pretty hard to second guess this one. I have been there, and I think he did well. Just sayin'.
+7
03-29-2016, 08:00 PM
#115
Rennlist Member
Im here to tell you , there is time and it works well. i can prove it in a bunch of different ways. there is plenty OF TIME! again, look no farther than my 130mph approach to turn 2 at laguna! worked like a champ, didnt even get dusty! why is that, o great know it all?
03-29-2016, 08:07 PM
#116
Rennlist Member
Okay, so this has been super amusing to follow. To add some clarity, I've actually had a brake failure going into T7 at Sebring. It's not a great moment. In my case, it happened in my E class 944 S2, and I frankly don't remember how fast I was going (my guess would be 120-ish under the bridge toward the brake zone in that car). A brake line popped in the right front caliper; when I initiated hard braking there was a brief moment when the car started to slow and then nothing. Trust me, there's not a lot of time to figure out what to do. In my case, I pumped the crap out of the pedal, which may have helped a tiny bit, side to side scrubbed,concentrated on driving the car, managed to make the right turn onto the old straight, and scrub speed and get it stopped. Never occurred to me to downshift, don't know if that's right or wrong. I was super lucky, and it worked out okay. But look at the track map below- that car was going way faster than I was, and the bend to the left is softer than trying to make the right, so I'm sure that looked like a great call until the fence showed up!. I actually got flat- bedded out that gate, and as you can see from the video, it's not pretty there, but better than trying to go right, ending up in the berm and maybe rolling it. Plus, you can't see the gate until you're on it. Having gone through what this guy did, albeit at a lower speed, I think what he did was genius. Unless you've been there, pretty hard to second guess this one. I have been there, and I think he did well. Just sayin'.
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you didnt think of it, because sometimes we have to rely on coaches an others to show how those things work in emergency situation. unfortunately, the two coaches here are way over their head in their own doo doo, to offer anything constructive here.
so, if it ever happens again, which im sure it wont. leave it in gear... downshift and keep those rpm levels high using the engine to slow you down. works like a champ under all circumstances. (except a high speed approach corner, (you are not driving straight, but at an angle) in pouring rain... then , i might just be lifting and not downshifting).
what tristen did was good via his intention, but the result was he could have killed someone.. no need at all to be coasting when your brakes go out. this happened exactly as it happened to you, but downhill and at 130mph into a similar speed turn. two downshifts slowed me so i never left the racing surface. its that powerful of a tool. not the VR type of tool, but the tool that actually works and makes sense!
03-29-2016, 08:10 PM
#117
Rennlist Member
Im here for racing and truth!
03-29-2016, 08:12 PM
#119
Lifetime Rennlist
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03-29-2016, 08:20 PM
#120
The Penguin King
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The amount of shoulda, coulda, woulda, bull crap that gets spewed whenever a video like this gets posted never ceases to amaze and amuse me. Sometimes I suspect that the motivation behind the comments comes from folks being in denial, and basically saying "it couldn't happen to me". The thing is, it can, and eventually it will.