Ian's 99 build thread
#822
Elite Member
Thread Starter
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 5,186
Total Cats: 858
Perhaps I am to brakes what bbundy is to transmissions? I dunno.
Picked up a set of directionals from Andrew this morning.
Looking at the pattern of cracks, these are different from the usual heat/expansion/etc cracks. Those are usually radial, but these are almost tangential, it's as if the calipers are ripping the rotor ring off of the mounting tabs. Is it possible I'm getting the rotor so hot that the metal is losing strength?
--Ian
Picked up a set of directionals from Andrew this morning.
Looking at the pattern of cracks, these are different from the usual heat/expansion/etc cracks. Those are usually radial, but these are almost tangential, it's as if the calipers are ripping the rotor ring off of the mounting tabs. Is it possible I'm getting the rotor so hot that the metal is losing strength?
--Ian
#827
Elite Member
Thread Starter
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 5,186
Total Cats: 858
So this was my favorite track day club -- no run groups, track is open 9-12 and 1-5, go out when you want, come in when you want. I'd been out for 8 or 9 laps, it was running low on fuel (5 gallons left and it's starving in 6 -- a fast left). I came in for fuel, went straight back out, did 3 laps and was catching a Porsche. Smelled brake fluid, backed off, smell went away. Did another half lap and it oversteered during steady state cornering. Back at MRLS 2010, that was the first indication I had of a coolant leak, so I backed way off and brought it into the pits to check it over. Didn't find any leaks, but the saw the rotors and called it a day.
The scary thing is that if it hadn't done that oversteer thing (still not sure why -- might have been the rear tire pressures getting a tad high) I probably wouldn't have noticed for a while. That driver's side rotor is cracked a third of the way through -- how much further would it have gone before failing?
--Ian
The scary thing is that if it hadn't done that oversteer thing (still not sure why -- might have been the rear tire pressures getting a tad high) I probably wouldn't have noticed for a while. That driver's side rotor is cracked a third of the way through -- how much further would it have gone before failing?
--Ian
#830
Supporting Vendor
iTrader: (1)
Join Date: Sep 2010
Location: Lake Forest, CA
Posts: 7,991
Total Cats: 1,024
In all seriousness, when we were comparing data at MRLS a year and a half ago, his speeds on the straights were 5-10 mph faster than mine, and my cornering speeds were about the same; slightly higher through some corners. The amount of power his car makes is eye-opening.
My cornering speed through turn 6 was like 6 or 7 mph faster than his, and his peak speed up the hill through 7 was some 9 mph faster than mine. That's some serious zoom zoom. Hard on brakes.
My cornering speed through turn 6 was like 6 or 7 mph faster than his, and his peak speed up the hill through 7 was some 9 mph faster than mine. That's some serious zoom zoom. Hard on brakes.
#832
Elite Member
Thread Starter
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 5,186
Total Cats: 858
As for the fuel system, people keep saying that but that's what's going on. I've had the fuel system apart, replaced the sock with a brand-new OEM one, everything in there looks fine. Turbofan's car does the same thing, IIRC. If you go back a couple pages it's pretty clear from the data logs that the fuel pressure sags when powering out of fast left-handers. (posts 634 & 635). Maybe it's a return vs non-return fuel system thing?
--Ian
#833
Elite Member
Thread Starter
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 5,186
Total Cats: 858
Here's the driver's side rotor after taking it off the car:
Savington suggested checking to make sure that the the holes on the hat are aligned properly, because there have apparently been one or two cases where they weren't, and that would make for all kinds of weird stresses on the rotors. I haven't done that yet.
--Ian
Savington suggested checking to make sure that the the holes on the hat are aligned properly, because there have apparently been one or two cases where they weren't, and that would make for all kinds of weird stresses on the rotors. I haven't done that yet.
--Ian
#834
Perhaps I am to brakes what bbundy is to transmissions? I dunno.
Picked up a set of directionals from Andrew this morning.
Looking at the pattern of cracks, these are different from the usual heat/expansion/etc cracks. Those are usually radial, but these are almost tangential, it's as if the calipers are ripping the rotor ring off of the mounting tabs. Is it possible I'm getting the rotor so hot that the metal is losing strength?
--Ian
Picked up a set of directionals from Andrew this morning.
Looking at the pattern of cracks, these are different from the usual heat/expansion/etc cracks. Those are usually radial, but these are almost tangential, it's as if the calipers are ripping the rotor ring off of the mounting tabs. Is it possible I'm getting the rotor so hot that the metal is losing strength?
--Ian