333pg333

As far as I knew, ABS was designed to allow steering input when in a dangerous situation on the roads. Obviously that has been broadened over the years and the systems have got technically superior, however I can't see that getting into the ABS on the track can be a good thing at all At the end of our main straight where we are up to around 150mph there is a long left hand corner. As you work up to more proficiency on this you go from braking and shifting down one gear to braking and staying in top, to braking deeper yet lighter and carrying more speed through there. The next corner is a double apex left hander that you come into pretty fast and there is never any need to get into the ABS. That would just wash off way too much speed.
I think your instructor is right to get you out of the electronics. It should make for a more enjoyable and involving experience too.

RedlineMan

Hey Larry;

Do it this way. Think of the onset of ABS as you locking up and flat spotting your front tires. Conjur up that acrid aroma, that sinking feeling, your fillings falling out as you attempt to ride out the event, and your credit account swooning. Without the electronics, that's what you've got uless you have the awareness to avoid it.

That instructor SHOULD have helped you see those nannies as the tools that they can be if you change your focus on them. If they activate, you did something wrong. Now, your task is trying to come up with strategies to avoid them. You are making the most of them by learning how NOT to activate them.

Trak Ratt

Could be why this thread was started.

VaSteve

I would venture to say that if your ABS comes on from the get-go, you might just have to ride out the corner and try for a better attempt next time...depending on speed etc. It's DE, if there's no body behind you, carry a little less speed down the main and brake early to see what happens.

FWIW, I will be in threshold braking and a tire will lose a little grip if the track drops away or has other non-smooth spots. Happens sometimes in the chute at SP main and the back stretch of VIR. I'd worry more if the ABS came on from the word go, since then I knew I f*ed up. (Like when the brakes weren't bedded all the way and the car was new to me. lolz)

Hey Trak Ratt, I like that avatar. You did good as my student.

tkerrmd

Larry are you still on street tires? The issue of ABS has been covered. bottom line your ABS shouldnt come on during threshold braking at least it doesnt for me.
as for PASM. once you start running R compound tires with that big heavy car and you get faster you will not be able to drive with the PASM on. it is so intrusive it makes faster driving almost impossible.

many will say not to ever turn the PASM off and you wont notice the PASM if you are smooth. But I am talking I have the exact same car as you and I know how it is on the track. when you start noticing the PASM constantly going off it isnt because you are a bad driver it is just set up for street yaw, dive and squat not track situations, at this time grasshopper it is time to turn it off.......

mrbill_fl

I was taught to think of brake pressure in a 1-10 scale. 10 being lockup, abs on,
and you want get to #9 peddle, just before lockup, but Smoothly! feet working independently, as you go down thru the gears...

the trick is knowing what peddle number you are at, and how much more you can use.

Land Jet

Guys, thanks again. This gives me exactly the info I needed and backs up what my instructor was trying to convey to me. Thanks Track Rat. I'm surprised that previous instructors never talked to me about this. This reveals the next layer of the onion to work on. Alex, see you next month.

rcc55125

One thing I haven't read in this discussion is how much time it takes to down shift for the corner you are going into. You said your entry speed was 155, so maybe 6th gear. No mention was made of what gear was needed coming out of the corner. If you need 3rd gear coming out, you will need three down shifts if your entry is in 6th. You need to complete these down shifts prior to the completion of braking. The car should be in the appropriate gear as you ease off the brake and turn in. It will take you longer to down shift than to brake to the correct entry speed. There is no reason to get into the ABS.
Remember, there are three secrets to high performance driving; smooth, smooth, smooth.

Now to stir the pot. One of my instructor manuals defines threshold breaking as maximum breaking with 15% to 20% wheel slip. How do you get 15% wheel slip in an ABS car without engaging the ABS?

FTS

Larry, please don't take this the wrong way, but I also think you are focusing on Summit's T1 braking too much. You have great discussions, no doubt, but make sure you are not missing out on maintain speed through T1, entry and throttle out of T3, T4, 5, 9, and all famous 10. There are a lot of little things about all those turns.
Our club does not do no-brakes exercises, so go to a local BMW club DE and they'll do a no-brakes session; you'll be amazed how much faster you can take those turns when you are not using your brakes

Land Jet

I have heard of the no-brakes exercise but have never attended a BMW DE.

Funny thing is I used to drive my previous sport cars on the street exactly as I am being instructed to drive my Porsche on the track. Those older cars didn't have ABS, and I always was down shifting coming into corners to be set up for exit. For some reason, my first instructor taught me that it was different for high performance driving. The brakes are cheaper than the transmission, and minimize shifting in the braking zone. Following instructors didn't really focus on changing that pattern until now. I'm going to have to relearn T1 at Summit Point. The other turns I don't have to brake hard enough to worry about ABS.

Brian P

Even turn 5?

Land Jet

T5 is only from 100 + as compared to 150 into T1. At that speed I don't engage ABS there. I remember now that I used to in green group.

Potomac-Greg

I'm wondering if you do a "no-brake" exercise even in T5. You'd need to lift at the exit of T4 to get through T5 without brakes!

Dr Strangelove

Larry,

I can't quite tell from your post...are you saying that in your older car, you down shifted coming into corners to achieve, in part, braking? I want to make sure that you understand that this is not what this thread is describing. Rather, the idea of rowing down through the gears during braking is to keep the car settled and more closely match revs. You must match revs at each downshift to keep the car settled. But the braking is still done by those cheap pads and rotors you use. I think there are many fast drivers/instructors that do not row through the gears.

-Bruce

VaSteve

Seems to me that rowing through the gears would be an added complication while trying to perfect threshhold braking. The PO of my 944 put on a short shift kit. I actually don't like it since it makes the shifting really notchy. I go from 5th to 2nd in T1 to avoid all the busywork.