I might of went a little overkill chaging it all out after the boil over but, what the hell right just another 200 thrown at the Z. Even with out boiling over or expanding over that fluid is pretty damn hot though. Probably not that greT for the rack seals and such......see now you got me trying to rationalize the PS cooler:roflpuke2:

i prolly shouldnt have let it go so long, but i didnt have boil over issues even with socal heat and wide/sticky front tires. i changed it to fresh fluid last month and no change in steering feel lol. im going to do a better PS fluid cooler soon, just going to make my own so i can use a different shaped core

The only time my PS fluid has been touched since the factory really has been refilling from disconnecting the lines while installing various parts. Still on the dingy little factory cooler, too. Haven't ever boiled the fluid that I'm aware of. Then again would I even be aware of it if I did? Who knows :) My steering effort is pretty high normally just due to corner speeds, smaller steering wheel, high-caster alignment, etc.

First post on this forum! Yay me!

I'm thinking of picking up a used 370Z and I'm doing my research on the car for track/dd purposes. I'm coming from a fully built and setup 2002 WRX. I've spent some time at the drag strip but mostly on autocross and roadcourses. I was an instructor for a while at Cali Speedway, and what impressed me the most about my car was that I could run it all day on a track and not have to worry about heat, aside from the usual cool down lap, and parking it in neutral with the hood up etc. What I'm gathering is that Z's have a major heat management issue. So to address that:

- larger radiator
- oil cooler
- PS fluid (some say just fluid, others say fluid/PS cooler)
- brake ducts
- obviously pads/lines/fluid

Non heat related:
- weak LSD
- clutch master/slave cylinder
- camber/caster control arms
- various suspension setup strategies to alleviate understeer

My questions for you guys are:
- What about the transmission? Have any of you had any problems hot lapping with it?
- Ice mode on the ABS - does UpRev or anyone offer a solution to reflash the TCU? Aside from workarounds like running weaker pads, what do you do about that? Can you pull the ABS fuse and disable it altogether?
- As for air to the brakes, I read that it has to do with the front aero - has anyone run it without the front undertray to see if that helps at all? I doubt it would do that much, but it sounds like every little bit would help.
- How do the bearings and hubs hold up? Do you see excessive knockback? If people are cooking their brakes all the time, does that mean they are going through bearings like crazy?

This really is a great forum and a wonderful resource. Thanks!

They over engineer the bearings over the 350, they are not the weak point

The clutch line needs additional heat shielding and you should change to better fluid. No problems after making that switch.

No fix for this aside from race ABS or adding a bias bar and removing ABS entirely. I think it's driving style related maybe heat or wear related. Never been a problem for me.

I ran without the front undertray recently but I don't know if it made any difference.

No problems so far with bearings. I did have to replace pistons when I rebuilt the calipers though. It was a pretty cheap rebuild though really.

RadioFlyer. With your skill level. Start with a 34 row oil cooler, Stillen brake ducts, stainless brake lines, top shelf brake fluid, track pads. Then change out things as you learn the car more.

Hotchkis front swaybar, SPL upper front control arms, coilovers.

Vented hood, bigger radiator, LSD,

Never had a problem with PS fluid. Never had a problem with the MT. Thou it can be a picky an times. People have toasted the syncro's in it. Mostly 5 gear.

Thanks guys! Yes, I was planning on starting with the brakes, which is a given for any track prep. I'm just trying to wrap my head around a general cost to prevent heat management/safety related failures. Sky's the limit when it gets to handling preference. But for heat management, it sounds like $2-3K would cover it with some wiggle room budgeted in there? OP, as someone new to the platform, is this in line with what you're learning about the car?

What they said, but I'll add a few points:

Definite must-haves for serious track usage. You can't possibly overkill on oil cooling for the track, go as big as you can fit. Block things off for street usage if it overcools in "normal" conditions.

I wouldn't worry about it until/unless you have a problem

Definitely brake ducts (e.g. Stillen's kit or fab something similar). RBF600 fluid. More on pads below...

Funny thing is, while I agree the VLSD isn't all that hot.... I've been putting off upgrading for a while, and I'm starting to wonder how much it's really worth. At the end of the day the inside wheelspin isn't killing me all that much, and somehow mine hasn't completely gone open-diff yet from VLSD wear. My engine failed from track abuse and the LSD is still going ok. At this point I just think of it as a laptime upgrade but not strictly necessary.

Basically you'll want more front caster/camber, especially if you lower the car at all while putting in a better coilover system.

You can disable the ABS, but it's not as simple as pulling a fuse. If you just pull the fuse it also turns off your rear brake lights. There is a wire you can cut (or put a switch on) to just disable the ABS module but not the brake lights. I don't have the details at hand, and I don't think anyone's ever distilled the info out of whatever thread it's in and made a simple DIY page.

If you leave ABS mode on and worry about Ice Mode, the trick is to bias the car to the front with pad compound choices. Use a weak rear pad and it mostly goes away. It is very situational depending on the track, the temps, and your driving style. What seems to trigger it is if the rears lock up while the fronts are still rolling, *especially* under any kind of yawing due to trail-braking into the corner. I get hit by it a lot if I'm not careful about pad selection because I'm a fan of using that trail-braking-yaw to finish rotating the car into the apex.

Re: pad bias, keep in mind that on this car the rears don't get as hot as the fronts either, and most compounds have a torque curve that peaks then falls off as things get really hot. If you had pad torque curve printouts, you'd want a significant torque bias between the two even though the rears are running a much lower temp than the fronts. Mostly it requires experimentation. A lot of people are happy with Carbotech with XP10 or 12 in the front and XP8 in the rear.

Related: The "VDC Off" button does not shut off all traction control, and it will matter if you're really pushing the limits in the corners. You need to unplug the Bosch Yaw Sensor located underneath the cupholder area inside the center console to completely kill all forms of traction control.

I don't think it would be worth it, as it would have negative effects on other aero aspects (e.g. more engine bay airpressure pushing out the bottom, and dirtier air flowing in under the nose). No idea what it would do for brake cooling, but I think ducting is the better path to go down. You could try running the brake ducts to NACAs placed on the undertray though, might be better than the nose.

Bearings seem to last a long time without getting loose. The brake problems are just about the brakes. I never had any serious pad knockback on the stock Sport calipers.

Forgot to add one thing to my post. Wrap the clutch line down by the tranny with insulation. This help prevents the CSC problem.