froggy47

The Zone 8 PCA club got permission to use this track the Thursday before the annual vintage races are held this weekend. I was an invited guest. My 2nd DE.

The track is built once a year on the NAS Coronado. If you can imagine a 1.6 mile race track with a background of active/training jets, helicopters, carriers, etc. all going on whle you are getting ready to go on track that's the picture.

Link to track map.

http://www.fleetweeksandiego.org/cor...apforspeed.pdf

It was pretty fun & amazing.

There is no scale on the map, but it's about 1.6 mile I was told.

Passing (point to pass) was between 11-1, 2-3, 4-5 only, no passing under braking. About 20-25 cars per color group. 6 colors. So about 150 cars.

C5Z could get to about 108 mph if I was not blocked at 11 going into the main straight. Could have been more but you know how it is with the stock brakes being the limiting factor.

Even though it was only my 2nd DE I was in an intermediate group (due to the years of autox & being a BMWCCA instructor). Advanced group was mostly rollcage GT3 cars.

Class event, for sure. I burned up a tank of gas in 5 20 min sessions & for the last session a PCA 944 driver (won his TT class this year) gave me a couple of gallons of premium so I could get my full last session & said "pass it forward". Like I said a fine group of guys.

There were several ZR1's & C6Z there who could walk away from my C5Z & then I'd catch them under braking, new guys I guess & I was a little braver in the brake zones.

C5Z was great with new Brembo blanks, oem pads & Wilwood 570. Fresh M1 oil, P/S fluid & recent tranny/diff (Redline). No issues.

I had a square 710 setup (315 rears all around) no rubs. I ran 29 all cold which got to 35 hot. When I took comp mode off after 1st session the rear was loose at a couple of spots on track (concrete to asphalt to concrete) so I softened the rear (Pfadt) shocks all the way & dropped the rear psi 1 lb (cold) and that helped a lot.

Couple of questions.

I have not jacked up the car yet to change to street wheels & do a flush & inspect, but I could hear a sort of drag/scrape at LR (I think) when I would run close to k-rail at 10, I was maybe giving a little touch of left foot brake there or sometimes not if there was slow traffric ahead & still heard this noise (Comp mode on/off did not matter). What should I look for when I take the car down for inspection, or would a noise like that be normal considering it's a DE? The noise is gone under normal driving.

Brake pedal is pretty soft on the way home, and in a span of one week I don't buy that it's "moisture in the fluid". Is it normal to have a soft pedal after a DE? Will fresh fluid get's it back to a firm pedal (assuming all other components are in spec)? What happens to the fluid? I took some IR temps (after cool down lap & right after shut down in the pits & front rotors were about 450f outer edge to 400 inner & caliper @ about 360. So figure some UP from there while on track.

Thanks if you have some input on either of these.

One more, I have never bothered checking lug nut torque during autox, however for this DE I did check and found a couple, not LOOSE, but needing maybe 5 to 10 lbs more to get them back to spec. What would happen to make a lug nut loose torque or is it lug stretch or what?

longdaddy

inspect all your pads for material remaining and uneven wear.

Bill Dearborn

Are you sure its a soft pedal and not a long pedal? Soft pedal feels squishy from the point the pads engage the rotor while a long pedal just takes a very long stroke of the pedal and you may not hit solid brake until the pedal is close to the floor. Pad taper combined with piston knock back causes long pedal and the C5 calipers can produce some pretty wicked pad taper in a very short time.

Bill

Jason

If you heard grinding from the left on right hand turns, check your bearings. Any question, replace them.

froggy47

Thanks guys, it actually is BOTH long and a little soft. I know I need to pull & inspect, just trying to get a heads up on what to look for.

froggy47

Seemed like from the left on a left turn, I will check closly tomorrow when the car is up.

Normal sound & feel on street driving on the way home.

68sixspeed

I find the pedal a little soft after a track day, a bleed helps, but the low pedal does happen as pads taper and the pistons are sticking out more from worn pads.

It also feels funny as you get use to 'hot' brake performance and depending on the pad they may not feel as good cold.

froggy47

Clip on wheel weight vs rear arm of upper ca. I can barely make out where it hit the arm, but I could find nothing else that looked likely, will relocate the weight. I always tell my tire guy to use tape on, but he forgot on this one.

You really can't see any mark on the ca. The weight clearly rubbed many times against something.

Greywolfe

Also, dont forget to check your ball joint nut is tight!