mark kibort

Bob, the brakes work but they didnt work as well as i like them to work. i was in some very close battles with no chance of any issues relating to braking. the only difference was i didnt feeel confidence to brake like i normally do for getting that really fast lap time. having a little air in the system doesnt cause total brake failure, it just makes things a little less than optimal.
your right, i probalby shouldnt have gone out in qualifying, but there was enough brakes to toodle around to get a lap time with NO ONE around me.
again, you can bleed the brakes with out the inner bleeders, but if there is air in that side of the system, its tough to get out. ive taking the caliper off, turned it upside down , put a set of used pads to keep the main pads from closing, and used the cross over to bleed the bad bleeder caliper. far from optimal.
you dont need to change fluid every race, only if you get air in the system. once you race the car, the fluid changes from dry boiling point to wet boiling point. then, the good quality fluids are less Hygroscopic than superblue, which in the racing world is crap. (which means it doesnt absorb water as much as the other fluids) didnt really know this until recently. going to castrol SRF, or motul or maybe stoptech.

IcemanG17

http://www.livermoreperformance.com/...ml#Porterfield

Scroll down a little bit...your size is AP609 front and AP608 rear....I would try ST41 (most aggresive) and ST43 rear...thats what Sean & I run Not cheap, but the best.

dr bob

Mark--

Part of my amazement is that you chronically ignore simple mechanical issues. "ive always done bleeding with the 1 bleeder busted. for some reason, i couldnt get it to work." is an example. You depend on your supre driving and car-preservation skills to make up for lack of preparation. I might be able to see working around something that you discover at the track that day, like a stripped/rounded bleeder. What else on the car is band-aid and baling wired together to 'just make it through another session'? And for how long?

My background in racing is skewed to support the fact that I'm not a good driver. I lack the killer competiive go-for-it and damn the torpedo's mentailty. Instead, I made darn sure that there was only one weakest-link in the effort, me. Nothing in the car prep was left to chance, al least not on purpose. And there's the difference-- You allow weak prep to affect your program, and you do it on purpose. You revel in the fact that your driving parially makes up for poor prep. But that poor prep is always there as an excuse for not winning too.

After every session, you and your crew need to make a detailed list of every single thing that didn't work perfectly, and formulate a plan to eliminate those things before you go out again. Note what works, and do that again. What doesn't work, don't that any more. Believe it or not, there's a discipline required just like in any other competitive environment. The world is full of almost successfull, just needed a little more something, not quite as good as the real fast guys on the big teams, if only I could catch a break also-rans and backmarkers. Folks that won't fix a stripped bleeder screw.

"I don't want to sharktune my stroker cuz it will make toomuch power and brake things." "I'm OK with driving with xxxx, since it doesn't slow me down that much." If you're just out there to drive around, buy a spec Miata and drive with a group that really rewards better driving in cheap to support race cars. If you are out there to win, regardless of 928 or Schwinn, do it like you mean it. Seriously.


[/rant mode]

the flyin' scotsman

If you cant stop you shouldn't go........period. What would happen if the brakes failed and a huge accident occurred and some other racer was seriously injured or worse??

One of the major reasons I retired from pro m/cycle racing was finances for that level of competition.....perhaps consider this or the Miata solution.

mark kibort

I have no crew. im all alone in my program. I have had this broken bleeder and have worked around it. I can bleed the system in a way that you might not understand. (take the calipers off and turn them upside down and bleed through the cross over. its what I did when I changed the brake lines to SS)
I have been on a serious budget and now, this year, I can get the right stuff done and lots need to be done.... shocks are 18 years old, rear is completely blown out. tires were junk, brakes need some help with fixing that caliper. and yes, I do drive around some of the issues. Still have to get a transmission, as I have to hold the gear shifter in 2nd while driving! I also think it makes you a better driver to be able to drive around issues. yes, safety should not be compromised, I agree. you think im the first club or pro driver that has run with a spongy pedal or had brake fade or boiling brake fluid that didn't come in the pits? that's a tough call, and I think my judgment is sound (most of the time) and my race set up was perfectly safe and had NO chance of failing. it just wasn't optimal. Ill figure out a way to fix that broken off bleeder and get it working correctly and get the others to break free.

So, you think im just driving around? watch one of my races Bob. you are the typical Monday morning quarterback here, and its a bit insulting! As around what type of racer and individual I am at the track and you might get a reason I do what I do.

if you are following here, I just finished up a race at laguna, where 6 folks spun, one wrecked and I was running 5th among cup cars, transam and other very expensive hardware, and 1st in class. so make no mistake, I compete out there. its my thing!


I like a competitive race, and I do it like I mean it. (why don't you ask one of my competitors how I race) but keep in mind, its the love of the race and driving to the limit as what drives me to continue in this sport. Also, keep in mind that shark tuning was NOT a big deal. first of all, I cant use it, and we checked the set up to make sure it was safe, and that was most important. getting a few more HP and risk the mixture and timing to be not being safe for a myriad of conditions, worries me. so, I didn't take steps to do something off stock. Oh yeah, but you have seen me race for many many years now. I guess you think I must be pretty stupid, but who never misses a race weekend with a mechanical or blown motor???

mark kibort

thanks Brian.

On order and brake system getting opened up this weekend.

by the way, have you tried pagid blacks? RS14s are pretty good by the way. they also cost more, so its not a cost thing at all. Im giving them a shot to see. if they are not as good as the porterfields, then I think ill try the relatively new pads from pagid... Pagid Grey. RS15. 700 degree fade resistance vs 650 degree. make no mistake , they are all good racing pads. one last one ive heard great things about is the Hawks DTC 70s

Cheburator

maybe a bit too late since i see you have ordered them, but i would have given the Pagid Yellow RS29 a try. Better pedal modulation than the RS19 and longer lasting... Not cheap though.

For the ultimate stopping power, however, I would go with Carbone Lorraine RC8. Immense is the best way to describe them. However, get ready to change discs twice as often as normal. The pad compound is super aggressive and also sticks to paintwork as it is sinter metallic...

ThetaTau87

I've had good success with Carbotech pads on my 24 Hours of LeMons race car. Our 95 Probe GT is lighter than a 928 and we're running at least 7 hours of non-stop racing so our needs are different than running a 928 in a much shorter race. The XP12 front and XP8 rear pads last a full day of racing and still have plenty of meat left.

Carbotech offers many different pad choices depending on the weight of your car and how hard the braking zones are on the track you'll be running. They are also very responsive to making pads quickly if they don't have them in stock. They turned around a set for me in 1 day.

http://www.ctbrakes.com/

IcemanG17

MK
Dr Bob brings up some excellent points. You admit your shocks are blown, haven't done an alignment in years and still run stock brake lines (1986 rubber ones)....running well worn tires hurts performance too, but I do that as well..how old is your steering rack (Does it have solid bushings), how old are the tie rods? I change my tie rods every season & the rack as soon as it gets the slightest play

I think one of the reasons Casper was as fast as it was in version 1.0 was the little things. Better brake pad selection, shocks and springs specifically tuned to the car. Alignment tailored to driving style and slicks using data from tire temps and pressures to make adjustments.

The upside of your way....very limited time on track at full pace. This makes for longevity.

The downside of my way is it requires extensive testing at full pace. I rarely run less than 1 hour per day, typically put two hours on the car during a DE day. Take tire temps-pressures after every session..then make slight adjustments to find that extra .5 second... I was running 2:04, with a best of 2:03.8 until I started taking tire temps and tweaking alignment....

2:02.1 over the top with 265whp and the poor OB aero (.40 drag) with zero aero mods speaks for itself.

justaguy

I've run the Padgid yellows for years they're an endurance compound and take a while to come up to temp but don't fade during the longer races. In my opinion the ST 41s are as good or possibly better My car has what feels like Hand of God breaks but I'm running the Big Red Calipers the S4 calipers with spacers and the 13" Rotors are good but the Big Blacks just feel better.


I'm glad you're in a better position financially and you can afford to spend a few bucks on your car. Go to 1050 springs in the front 600 in the rear and have a set of Bilsteiens valve ed to match at performance shock and you will not believe how the car feels. Especially in the corners. You need to drive Casper and you'll agree with what I'm saying. I bet you'll gain a couple of seconds with a proper set up suspension.

mark kibort

you ran some amazing slicks to run this. if you run DOTs, i woud imagine you might be just where scot and I have been with our 280hp, but 200lbs heavier weight.
now, i dont have stock brake lines. DID, but didnt change them out and they blew at laguna. (my video is posted for that ) now , SS lines all the way around
You think i dont run the car much..... funny, i run the car the full session and at fulll tilt all the way around .. this weekend, my car was in all 3 sessions ranging from 25 to 30mins each. that was over two days. usually , ill run 3 days if conditions are optimal. no short shifting , all stock engine components as far as oiling.
yes, all the suspension is stock but the bolt on shocks and springs. all bushings are stock. dont think i dont CHECK my alignment, though i havent changed it since i built the car. there might be gains with putting toe out in the rear. not sure yet as that might help with car rotation in tight turns. no looseness in the tierods or a-arms. (or wheel bearings)


yes, going to get the shocks revalved so they are not maxed out either.(no adjustment today, as from day one they were maxed out , so no adjustment)
that should help, along with some better tires and im excited to hear that the St41s are amazing pads with grip. guy from the company brian recomended talked my ear off about how his vet stops and puts his teeth in the windshield. thats what i want. so far , RS14s (pagid black) good, porterfield R4, better, and this should be more extreme. he talked about them being real hard on rotors and very grippy for poor modulation.... i dont care and not worried. im almost certain if they dont fade and grip better, ill be just fine. cant wait!

the yellows dont have the grip of the blacks, so why go backward, even if they might be fade resistant. its an endurance pad, so there is always trade offs. dont know anyone that is using them, but the porsche supercup endurance cars...... and by the way, that might not be that bad for them, because , have you seen the size of their 8 piston caliper pads??????? (along with 15" rotors?) you can get away with a lot with a bigger hammer!!!!! i still run the stock S4 pads, as did anderson, but he had the 14" rotors (2 piece)

anyway, thanks! pads on their way, new fluid on the way, and shocks are getting taken out this weekend. new rubber mounted on all 8 rims..... next race the car will be good!

I dont know that there is 2 seconds for the shocks, because if you add up all the seconds that everyone talks about, my 1:36.1, and 1:36.mid best laps, and 1:37 common laps at laguan would very unlikely go to a 1:35 with just shocks, 1:32 with slicks (2 seconds for a new slick) and then maybe 1:31 for just savinig 1-200lbs like anderson had... dont forget about all the spherical joints, wider front tires, better cage and what about the extra 200HP?? 1:29, a full 2 seconds than anderson at laguna ?? dont think that is even remotely possible. Ill show you why when we see each other at the next track day.

justaguy

Brian Gained 4 seconds after he had his suspension tuned and set up properly. Yes that's right 4 seconds at T-Hill a place he can drive blind folded. You might be very surprised, It will be a vast improvement over what you have that's for sure.

IcemanG17

is only the shocks responsible for 4 seconds, no. It was a series of mods all blended together than increased my confidence in the car allowing me to push harder.... The Doc Brown rebuilt trans and LSD helped a bunch too, Casper really jumps off the corners

In terms of tires, the used pirelli slick I use IS slower than a proper Hoosier A6 of the same size. I have sold used Pirelli slicks to friends that race GTS3 BMW's and they ran 4 seconds slower than ideal A6 (meaning 1st 6 cycles) Then the A6 drops to where the Pirelli is used. Which is why I got so many pirelli slicks, since they drop 1-2 seconds for the cup cars after 4 cycles.

Here is a decent video chasing a Vette Z07 and a stupid fast E46 M3....my times were decent mid 2:02's but I complained that the car was all over the place....didn't seem that bad watching the video...but I remember putting new tires on the rear, since both were lightly corded


This was with bad slicks (by my standards), less brakes (St43 front pads don't work as well), front suspension that bottomed out in T8 at apex (freaky) 265whp (5.0 should be 300+) All of this has been solved AND brand new super soft yokohama's 280/650-18 front and 320/650-18 rear....still no aero, that will be next!!! Aero alone is 3+ seconds, which I know you don't agree...but how did that BMW put down 1:55's with ease?? How does Tony Coliccho run 1:52.7 on the bypass in GTS3 on Hoosier A6?

Getting the car reliably running for the NASA GTS4 season is the goal. Aero mods will come next & times will continue to drop... Seans Traqmate is installed so we will have better data than my harry's lap timer, which still shows a theoretical best lap over the top of 2:01.00.

It does help having two race 928's to compare against. Once Seans is running it will be fun to compare notes-data-mods to see what works and what doesn't, which is how we got here in the 1st place.

Courtshark

I've run the PFC 08s for two track weekends, and I use BG's racing brake fluid. I think you want a more aggressive pad, though. These are made to be a bit more durable. They're more than adequate for my purposes, though.

James Bailey

so which pads did you end up ordering ?? front and rear ?