track driving survival (questions and info)

[Kondata]

I'm sure most, if not all, of the my information has already been covered to death on these boards, but I figured I'd chime in anyway. I've been tracking my Z3M (S52) lately for about 2 months, total of 4 track days, and wanted to share some troubling data that makes me a bit uneasy.

Oil pressure. Seems that even with a VAC oil pan baffle, the oil slosh is pretty serious under 1.2-1.4G turns. I'm seeing oil pressure stay at a steady 80psi-85psi during normal operation and on track in the straights. Most corners, pressure dips to anywhere from 30-50psi, some hard corners, I've seen as low as 17psi for 2.5 seconds. I have my engine overfilled by about 3/4qt and that did help some, but not nearly enough. Currently trying to plumb an accusump so we'll see how that helps.

Brake pedal. God awful. I'm running stock m calipers with brass bushings to prevent tapered wear with Gloc R12 compound pads. I've replaced stainless lines, new master, new booster, new front calipers, and the pedal got significantly better for street driving. 2 hot laps on the track, back to long pedal travel and mushy feel. Car stops really well, so its not an issue of fade, but rather having confidence in brake engagement that worries me. I'm running 3" brake cooling ducts to BW cooling plates (Motul 660 fluid). I see this being a common topic with e36's, so potentially something I just have to live with.

Finally, trans and diff temps. I've recorded temps of over 280 on the diff and slightly north of 250F on the trans within 15-20 minutes of track driving on an 80F day. I'm running a 6 speed with a 3.23 factory rear end and plan to integrate coolers into both at some point. But I know most people will only do diff cooling.

I have no aero on the car, mild street suspension (TC Kline single) and just basic bolt ons, nothing wild. I am running an oil cooler with a BW filter cap so that helps with oil temps (actually, oil temps are sometimes lower than my water temps).

I know theres guys on here that have years of experience tracking their cars, if you guys have any data to share, input, criticism (or even questions), perhaps this thread will help someone in the future.

I plan to to run this car next year for about 10-20 events (local tracks) my goal is to bulletproof it a bit over the winter...hence the timing.

[SunzOut]

What oil are you running ?

I have no problems with Brakes. Running stock calipers with PFC-08 front and HT-10 rear. ATE-200 fluid. I do have some cooling on the front but only 2" and small scoop on control arm. Running 2:42 at Road America.

Pedal is always solid and stops all day long....

[Kondata]

What oil are you running ?

I have no problems with Brakes. Running stock calipers with PFC-08 front and HT-10 rear. ATE-200 fluid. I do have some cooling on the front but only 2" and small scoop on control arm. Running 2:42 at Road America.

Pedal is always solid and stops all day long....

Liqui Moly 10-40. I dont really see changing oil helping all that much with starvation though. I'm definitely willing to try new pads.

[Wertles]

I never had a problem with brakes, even on 90+ degree days. I ran the brass bushings and Hawk H.P. plus pads. I did not have any brake cooling and there was more than enough stopping power for the stickiest street tire. Moving up to an R compound tire would have required a brake upgrade in pad and cooling I’m sure. Something seems off to me about your setup.

I had issues with oil heat. Nothing dangerous but more than I liked. Moving from 10-40 to 5-30 dropped my temps 10 degrees. When I wanted more, I added the S-54 oil cooler and radiator set up. I never logged oil pressure so I can’t comment on that but I can say, with the 100’s of S-52’s out there, I didn’t hear anyone complain about oil starvation in any turns. That was a discussion widely held by the LS guys.

I never checked trans or diff temps either. Just changed oil out every season with the good stuff. The only cars I saw with coolers were pure track cars that raced endurance. I don’t believe you can do much damage in a 30 minute session on stockiest tire/brake/suspension/aero setups.

[PbFut]

The diff may be old enough that excessive slip is heating things up more than normal. Even at 280, a good syn oil will hold up. Diff cooler is not normally needed unless your are enduroing.
You are for sure describing starvation. Sorry can't help you with this issue.
Brakes: Are you getting pad taper or just long travel when hot?
If pad taper, you are overworking the OEM caliper if the bass bushing is correctly working. Brass usually corrects taper.
No taper and long travel when hot. Look at hoses, lines, and fluid.
You are for sure on the right path of not throwing aftermarket BBKs at the problem. Good ducting, fluid and pads will normally hold up to even the V8 swapped cars.

[Kondata]

I was getting pad taper. Ground down the front pads and changed to brass bushings for front calipers. I suppose I could have taper in the rear, havent checked yet.

[PbFut]

Likely tapper. Have you looked into runout? Are the bearings allowing the disk to kick back the pad? Can't think of much else

[Kondata]

Likely tapper. Have you looked into runout? Are the bearings allowing the disk to kick back the pad? Can't think of much else

I'm not sure what you mean by runout

[PbFut]

If a wheel bearing is loose, it can allow the wheel and disk to wobble on the hub. If the brake disk does not stay true on its rotational plain, it will wobble and push the pad back some. Then the next time you hit the brake you have to take up that space.

[Z-Thrizzle]

I've heard that an S54 dual oil pick-up can be used on the S52. This might help with the oil starvation.

[Kondata]

I've heard that an S54 dual oil pick-up can be used on the S52. This might help with the oil starvation.

I just fitted an accusump and it seems to be doing a decent job. Oil pressure never dips below 35-40psi now. I know the dual pickup is another option, but its pretty expensive so I'm saving that until its absolutely necessary.

[19Spec3]

I don't track my Z3M but I race a non-M E36 about once per month. Assuming everything else with your brakes is in good shape, and it sounds like it is, the best way to improve pedal feel is to run new pads. For whatever reason, the pedal feel improves greatly with lots of meat on the pads.