Originally Posted by mark kibort (Post 11573873)

agree, going to the largrer diameter rotor in front, with no bias change will lengthen stopping distances, because less pedal pressure will use less of the rear brakes. But, the main reason i went to a larger diameter rotor, was to get more bite when the brakes start to fade, which requires more pedal pressure

Originally Posted by mark kibort (Post 11574077)

I think i know the car pretty well by now. :)

Originally Posted by RKD in OKC (Post 11574163)

When the pedal goes thump against the firewall and continues to when you pump it, there are NO BRAKES. Not fade, no brakes.

And yes i did know the limit of my car to begin with. At that time me in my 944 Turbo was the car to beat. In fact, at the local autocross the ONLY car to get within 4 seconds of my 60 second lap times was ME in my 90 GT.

I've learned that despite the rule of thumb of sliding is slower i.e., drift more than 10-15 degree slip angle, that there are some circumstances and situations where putting the car out of control and catching it, while dangerous and very risky, is faster.

Originally Posted by Speedtoys (Post 11574255)

With pop rivets holding your brake rotors together, you wouldn't make it that far. :)

Originally Posted by RKD in OKC (Post 11574163)

When the pedal goes thump against the firewall and continues to when you pump it, there are NO BRAKES. Not fade, no brakes.

And yes i did know the limit of my car to begin with. At that time me in my 944 Turbo was the car to beat. In fact, at the local autocross the ONLY car to get within 4 seconds of my 60 second lap times was ME in my 90 GT.

I've learned that despite the rule of thumb of sliding is slower i.e., drift more than 10-15 degree slip angle, that there are some circumstances and situations where putting the car out of control and catching it, while dangerous and very risky, is faster.

Originally Posted by Speedtoys (Post 11574264)

No, it's because you think 'big' is the solution to screwing up your F/R brake balance by pooching the advice given you on brake pad upgrades, then naysaying the whole planet about it.

Originally Posted by Speedtoys (Post 11574264)

No, it's because you think 'big' is the solution to screwing up your F/R brake balance by pooching the advice given you on brake pad upgrades, then naysaying the whole planet about it.

Originally Posted by mark kibort (Post 11574077)

they are not locking up.... i mispoke.

EDIT... i didnt mispeak.. i re-read it.... it skates off into the turn... not lock up, but the braking force is so much less, its like you hit ice or are locked up, but we are not locked up. in otherwords, ABS is good for rain and snow, not on the track when talking about 928 ABS. I can prove this at any time, very easily.
20 years of racing here Greg, more experience in a 928 racing than anyone here now. I think i know the car pretty well by now. :)

what are you talking about. i engage ABS and its way sllower than theshold braking. what can i say. do you think ABS should work better? again, i drive many other cars and do this test the 20 year old ABS doesnt work near as good as threshold braking.. in fact, if i race you and you use it on a 928, ill fly by so fast it will make your head spin.

Originally Posted by RKD in OKC (Post 11574066)

At the First OCIC in Wichita KS they did a DE track day at the track in Hallett OK. I was planning to take the 90GT I had just purchased from Jarrod Wise when the local 944 tuner shop offered to pay me and my expenses for the day if I took my white 88 944 Turbo S. They bought some dyno time for some intercooler testing using my 944 Turbo on the mobile Dynojet that was available for the event.

My personal goal for the track that day in the 944 Turbo was practicing my late braking/trail braking on corner entry. However, I had put on new pads the day before and not taken the time to bed them in before the first session. Towards the end of the first session I experienced the worst boiled the fluid brake fade one could possibly have.

Hallett's second turn is the tightest turn on the track, a left hander entering from the end of the fastest straight. The turn is named the stop sign and if you continued straight you don't just go off the track in about 50 ft, down hill, you go into a grove of trees. Late in the first session I was headed into the stop sign, glanced down and was accelerating past 140mph. Moved to the outside and started watching the markers leading into the corner. My brake point came up and I hit it. To my surprise the pedal just went thump against the floor, No Brakes!!

Without taking time to think I just reacted and immediately pumped the pedal a couple of times...nothing. Without further hesitation I did a scandinavian flick sending the car sliding sideways pointed towards the inside of the turn. As I slid sideways it dawned on me that I seemed to be slowing pretty well, and maybe if I downshifted and got into the throttle I could make the corner and did just that. As i got back in the throttle i counter steered to keep the rear from coming around too much and amazingly enough the car continued it's sideways slide, but arced towards and into the apex. Keeping on the gas and counter steering I straightened it out and was exiting the turn heading down the next straight.

Did a quick glance back at the corner worker, he was standing up and giving me a thumbs up with both hands. I kind of coasted blankly through the next two turns not even going fast enough to touch the brake pedal. On the next turn I gingerly tested the brakes and sure enough, soft spongy pedal and almost not brakes. It wasn't until then I realized I had boiled my brakes. So I used the last three laps left in the session to just cruise around the track, letting everyone pass me, and NOT use my brakes so they could cool as much as possible.

Kim Crumb was riding as an instructor in the track prepared 928 directly behind through that corner. He came over to me after the session and told me he saw what I did, and wanted me to know, "You only have so many of those in you!"

So, with all this talk about brake bias, ABS, and trail braking and car setup, my fastest time through that corner was with no brakes at all!

Originally Posted by GregBBRD (Post 11574391)

I'm not going to debate this stuff with you....I found out, long ago that was futile.

I can simply tell you what I know. You can either listen and take away some of that, or totally ignore my experiences.....either way has absolutely zero impact on my life.

Originally Posted by RKD in OKC (Post 11574494)

The stop sign corner I described with no brakes was called the stop sign because it was not only the tightest slowest corner on the track it was at the end of the fastest straight. Hence the name Stop Sign, which I thought I described.

AND besides a turn tighter than the turning radius of the car, a tight chicane is another place where doing an out of control tank slapper is faster than a car "hooked up." And have an example to back that one up too. Had a course where I set fastest lap by .006 seconds against a full race prepared 914-6 that was used to setting FTD and I should not have been able to better. I was in my BMW X3 SUV. He watched my laps intently and had his pit crew timing both of us and told me I was beating him in the chicane he was quicker everywhere else on the course. I was treating the chicane like there was something in the road I was avoiding at the last minute before the chicane and throwing the car into a skid. I would then power through the tank slapping recovery from the skid. Timed right the tank slapping recovery is what carried me through the chicane without having to brake for it.

Originally Posted by mark kibort (Post 11574761)

why do your experiences out weigh mine? i just took the 928 out for a 120mph to 50mph, several sequence exercise, and got to the fade point to get temp on the rotors with the temp sensor paint.
then, i did some threashold braking stops and then a couple with just standing on the pedal. standing on the pedal was like the "car was just giving way" when the abs kicked in. then i pulled the fuse and did it again. the braking force was so much obvious, just at the edge of lockup.

I dont know, but i could video tape a 100mph to stop with feel vs ABS , and show you the difference. I dont know where you get this information , but most anyone I speak with, in the racing world, and those that own the newer cup cars, agree. the new cars you can stand on the brakes and the abs takes care of it all. the older stuff, is almost dangerous, if you rely on it for stopping as well as feel.

another example. a long time ago, going into sears point turn 11 a little hot and in a close battle, i got well on the inside and ABS engaged and at the time i wasnt skilled enough to release and feel the tires again, as i said, it was like i hit a patch of oil or ice.

Now, you can just think im imagining things , or maybe i have some experience here that is worth taking note of.

remember long ago, we were arguing about the dual disc "H" adjusters... you were just as emphatic then, and you might understand, if you do the tests ive done, that i might be right here too.

if i am not, heck, it sure would be easier to brake if i can just engage ABS on all my critical turn approaches. :)