Transmission Issue After Track Day

SPOHN

Yea thanks. But noise/ chatter doesn't bother me none. I'm one of those guys. Lol.

__________________

VQStryker

I wasnt sure about it so I went with the ACT and will probably swap it out for the clutchmasters and go from there.

Do what he told me, go with the performance. Of course do the research and look at reviews first.

ValidusVentus

Well my rear diff is shot. Which im not upset about. A good excuse to get a better one. What im upset about is finding out for sure that i did warp my brand new rotors and it wasnt uneven glazing like I had hoped (aparently they are beyond repair/ machining ) Ididnt park with the brakes on or E brake went slowish on the cooldown laps...wtf, these werent cheap. DBA 5000 2 piece rotors. In a bad mood right now.

__________________
Mods: Dedicated caged track car, lots of things. ||| Valkyrie Autosport |||

SPOHN

That sucks man. Rep to yea. My Z1 rotors held up great. can't wait to get my Stillen J hooks on.

__________________

roy'sz

^I had same problems with baer rotors drilled/slotted.

Red__Zed

Do you know what actually failed on the diff?


For brakes, try and get some air on the. The calipers trap a lot of heat, and running lighter rotors is just going to encourage problems being generated as a result of that heat.

ValidusVentus

I asked the mechanic the same question while I demonstrated the problem to him (they couldn't reproduce it on their own, but with my own confident right foot I had little trouble). He mumbled something about the friction surfaces probably being worn away, which would seem to make sense. The oil level apparently was ok, didnt check it myself but thatd be a hard thing to measure wrong.

So rotors can get warped JUST from getting too hot? I thought it was only when not cooled down properly after sessions. And afaik these rotors are only a couple of pounds lighter as a result of their lighter center hats. So no real loss of heat absorbing mass.

I'm at a loss with the brake issue. As far as I know those rotors were () pretty damn good... so what now? I buy a more expensive pair and kill them too? I cant afford that. Why is this such a big issue, I know for a fact there were plenty of cars out there with no brake ducting that were braking harder than me with no probs. I did deposit a not insignificant amount of brake pad onto the rotors in a somewhat uneven fashion i believe... could that have led to less cooling on the more covered parts of the rotors and hence a better pad would solve the problem? Was running Endless MX72 pads.

They quoted me about 500 bucks for the install on a new diff. Looking at the Quaife, maybe Carbonetics, couldnt care less about a clunk when it locks and takes only about 10 mins of work and 15 mins of waiting to swap out the fluid , cars are big mechanical beasts and make mechanical sounds, I like variety, tranny/diff whine (when not indicating a problem), SC whine, all great. But itl be a few weeks before I really have the money to get it ordered and installed if i go that route. By the way my car musta got hungry on the track because it ate a whole quart of its 5w30 Redline oil, which based on Redlines good NOACK rating really suprises me.


Any progress with your issue SPOHN?

__________________
Mods: Dedicated caged track car, lots of things. ||| Valkyrie Autosport |||

Red__Zed

sounds like they are just guessing. I'd love to see what actually failed. Perhaps post results of the failure analysis after you put the new diff on.
Yes, but I'm not sure you warped them...it is likely just bad wear patterns, even if your mechanic says otherwise. Did you bed your pads properly? And what street pads do you run?

Warping comes from uneven heat distribution. Keeping the brakes on while parked is one way to do it....but if there is a lot of heat in the caliper, it has the same effect. Luckily the beefy rotors on the Z are relatively difficult to warp.

ValidusVentus

I did bed the pads in on the way to the track the 1st morning... probably pissed off a few locals but the roads were empty at 530 am lol. Although I just did it by going from 60-10 about 7 times rapidly, not the reccommended 80-20 decel for 6 or so times.

Do you mean just the proximity of the hot caliper to the rotor when the car is stopped can do this, even without the brakes engaged?

Edit: yeah I'll prolly ask to take the old diff home so i can open it up to look and take pics before I toss it in the dumpster, if I do i can certainly post em.

...just keeping this thread warm for yah SPOHN, im no thread terrorist

Edit 2: If the rotors are suffering from uneven wear, is there a way i can tell this apart from warping without using a dial indicator setup? Will they get better or worse with time? The bedin/pad deposites seems to be pretty evenly spead out at this point, very little if any improvement in braking feel, car actually noticeably hesitates momentarily a couple times when braking just before coming to a stop from the uneven grabbing. MX72s are the only pads i own at this point and were reputedly a trackable street pad, tho im pretty sure I was using them harder than intended.

__________________
Mods: Dedicated caged track car, lots of things. ||| Valkyrie Autosport |||

cossie1600

Rotors usually don't warp unless you absolutely murdered it. The vibration you feel is probably deposit. I think you didnt bed in the brakes properly. I didn't do it right on my XP8, I had to run the some XP10 and and XP12 to wear them off the rotor to get rid of the deposits.

1 quart a track day? Yikes...

SPOHN

Yea I want to put my money on saying you have deposits on the rotors.

Don't worry about the getting off topic. Good info here. I wish I can get to my issue. I've been working so much this week and haven't even looked at my car. But I'm not worried. Plenty of time.

__________________

Mike

I would get deposits on my rotors all the time before I switched to the stoptechs. Cooling ducts probably are the only real answer. That and buy cheap rotors and replace every track weekend.

__________________
NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z
Porsche: 93 968 / 23 Macan GTS / 93 968

cossie1600

my corvette was faster and had smaller brakes, doubt the z runs any warmer than that. just get a set of stock blanks and cryo treat them, works as well as the 400 dollars fancy rotor

SPOHN

^ that's my plan. I have a account at O'Railly's so I get great prices on items such as these.

__________________

cossie1600

cryo treatment really helps, it eliminated all the stress crack i used to get.

i got about about 10 track days and 350 + autox runs, still on stock rotor!