Post Track Day Q's: Rotor Wear, Gearbox Oil, Ps Pump, Manifold Nuts

[Dose Pipe Sutututu]

Hope it isn't combustion gases in your coolant system.

I have that with my car when I'm on the track with loads of boost for over taking cars lol. 

Pull over into the pits and you'll notice some black floaty bits in your overflow.

 

Hope it's just air pockets or a dodgy cap. Tridon do a 300ZX cap in the 16psi flavour for our cars which is about $15 from super it's something CB16110 (double check first b4 buying).

[niZmO_Man]

I had a small crack on the bottom rad hose (under the clamped area, engine side), for like 2 years. Always ran hot when thrashing and overflow would get full. It finally started leaking enough for me to notice it last year, changed the hose and voila! Cooling has been fine (for the standard setup anyway) ever since.

[V28VX37]

Hope it isn't combustion gases in your coolant system.
I have that with my car when I'm on the track with loads of boost for over taking cars lol. 
Pull over into the pits and you'll notice some black floaty bits in your overflow.
 
Hope it's just air pockets or a dodgy cap. Tridon do a 300ZX cap in the 16psi flavour for our cars which is about $15 from super it's something CB16110 (double check first b4 buying).

Thanks Johnny - the tee kay test came back negative so no combustion gases in coolant, head and gasket are fine. I'll keep an eye out for the floaties though! I'll have a look at the rad cap too.

[admS15]

I've got a spare cap, rad hoses and various bits and pieces I will bring along on Saturday. If you have any dramas, I'm willing to lend a hand to get you back on track[emoji106]. With a bit of luck, hopefully all goes well and you can just concentrate on driving.

[V28VX37]

I've got a spare cap, rad hoses and various bits and pieces I will bring along on Saturday. If you have any dramas, I'm willing to lend a hand to get you back on track[emoji106]. With a bit of luck, hopefully all goes well and you can just concentrate on driving.

Brilliant thanks man! Here's to hoping that I won't need to take you up on the offer but very much appreciated

[Kinkstaah]

I had that problem (lets not be scary) but there were no combustion gases in the coolant because E85. (nto enough to register)

The head WAS lifting under boost and ended up being wrong head studs was the culprit, and a blasted bottom end and all sorts of nightmare scenarios.
If I drove casually, would never bubble. If I gave it a hammering it would bubble in overflow. If the problem is linked to boost then it could very well be that.

I'd wager you would find out pretty quick on Saturday in either scenario..

[V28VX37]

I had that problem (lets not be scary) but there were no combustion gases in the coolant because E85. (nto enough to register)

The head WAS lifting under boost and ended up being wrong head studs was the culprit, and a blasted bottom end and all sorts of nightmare scenarios.

If I drove casually, would never bubble. If I gave it a hammering it would bubble in overflow. If the problem is linked to boost then it could very well be that.

I'd wager you would find out pretty quick on Saturday in either scenario..

Thanks Greg. Was your water temp still in check when bubbling, or did it shoot up?

Edit: Also I'm running 98 not E85 so in theory it should show on the tee kay..

[Kinkstaah]

Thanks Greg. Was your water temp still in check when bubbling, or did it shoot up?

Nope, I never had that problem, was juat bubbling for me but I never abused it on the track. Was just sprited driving in the hills for me that did it

[V28VX37]

10 hours ago, Dose Pipe Sutututu said:

Tridon do a 300ZX cap in the 16psi flavour for our cars which is about $15 from super it's something CB16110 (double check first b4 buying).

Thanks for the tip! I just picked up one from Supercheap. They list two part numbers for the 300ZX: CB1390(L) for older models and CB16110(L) for newer. The R34 is listed too (2.0L-2.6L so both ER34 and BNR34) and it's the CB1390(L) one so that's what I bought. I got the non-L aka non-lever = standard non-fancy model.

I had a look at the specs and 1390 stands for 13 PSI/90 kPa whereas 16110 is 16 PSI/110 kPa. Physically the two look exactly the same so make sure you check the part number suits your car.

[admS15]

Nope, I never had that problem, was juat bubbling for me but I never abused it on the track. Was just sprited driving in the hills for me that did it

I had this issue with an sr20. Was perfect on the street and hills but would fill the overflow at the track and once enough coolant was lost would get hot. Engine was forged bottom, cometic Hg and arp studs. I pulled it down and it turned out that the black coating on the Hg in certain spots had worn away and was allowing gases into the water jackets under prolonged boost. Replaced it with a nitto and happy days again.

[V28VX37]

3 minutes ago, admS15 said:

I had this issue with an sr20. Was perfect on the street and hills but would fill the overflow at the track and once enough coolant was lost would get hot. Engine was forged bottom, cometic Hg and arp studs. I pulled it down and it turned out that the black coating on the Hg in certain spots had worn away and was allowing gases into the water jackets under prolonged boost. Replaced it with a nitto and happy days again.

 

Interesting ... did you get the tee kay test or similar done on it before pulling the head?

[admS15]

Interesting ... did you get the tee kay test or similar done on it before pulling the head?

No I didn't because it became very evident at track days. The coolant smelled like co2. It was pushing that much coolant, I had rigged up a second overflow bottle to catch it all. LOL. In your case I wouldn't jump to any conclusions yet. If all goes well on Saturday, it will be fine.

[V28VX37]

Another track day another set of questions...

I just took the semis off the car and found a ~3x4mm piece of glass embedded in one, a big bloody chunk. Pulled it out with a screwdriver; the tyre holds air fine but is it safe (at 200 km/h)? The soft compound is a magnet for debris, there was another smaller shard in another tyre and some tiny cuts in a third, perhaps I shouldn't drive them to the track and back...

Also:

• Blown head gasket -> http://www.sau.com.au/forums/topic/467066-blown-neo-head-gasket-next-steps/
• Brake air guides -> http://www.sau.com.au/forums/topic/448613-r34-gtt-brake-improvement-without-breaking-the-bank/?do=findComment&comment=7780229

 

[V28VX37]

One more:

I'm also getting vibration through the steering wheel under braking once the brakes get properly hot. I remember this happening last time too at Sandown. You can keep driving through it but it doesn't instil full confidence. Also this seems to go away when everything cools down again - any thoughts?

I'm wondering if new rotors would help, although these one were machined earlier this year. The calipers have been rebuilt recently and I had new pads, new fluid, new brake air guides on this track day.

[WantGTR]

If its happening under braking your rotors are warped.

 

Replacements are cheap enough these days.

[V28VX37]

27 minutes ago, WantGTR said:

If its happening under braking your rotors are warped.

...

Only when hot though, they're completely fine when cool under normal braking.

These rotors have been through a quite bit though so it is possible.

[V28VX37]

Did some general maintenance over the weekend:

• Replaced & greased steering outer tie rod ends. The front right was completely shot and could perhaps have caused the vibration under heavy braking? To be tested. The steering feel is much improved now, a lot tighter.
• Measured and reset front toe, much have got it right since the car doesn't veer to either side
• Removed OEM GPS unit from dash to make some space for a wideband gauge (So Many Gauges)
• Run wideband sensor cable from engine bay to cabin
• Changed air filter
• Changed oil and filter. I've always used Ryco ones, somehow this time the old one was completely and utterly stuck. I bent a cheapo SCA oil filter wrench, gave up and did the old screwdriver-through-the-side trick (twice) and only just got it off, WTH?! After the oil change it feels like it might have a slight weep at the filter too, need to keep an eye on that..

Couple of questions:

1. Since installing the oil cooler I can only ever seem to get 4L out of the system (even after cranking with CAS disconnected) – is there a way to flush more oil out without undoing the cooler top hose?
2. With the wheels off and steering rack disconnected I noticed more 'resistance' in the LH steering knuckle i.e. you can just leave it in the middle (straight) position and it'll stay, whereas the RH knuckle moves very easily and would only rest at full left or right. My guess is that the RH steering knuckle bearing (?) might be worn, does that sound possible? Can it be replaced?
3. I also realised (doh) that the tie rod ends sit very close to the rotors, which basically glow red at the track and cop a lot of heat especially now that I've ditched the brake backing plates. The original RH rod end boot seems to have a pinhole in it and has lost some grease, leading to high wear and play – I wonder if it's taken a beating at Sandown (counterclockwise)? Anyway, is there a way to 'heat shield' the tie rod ends (only), or do you guys just replace them at regular intervals?

Cheers

[V28VX37]

On 14/11/2016 at 8:38 PM, V28VX37 said:

Couple of questions:

1. Since installing the oil cooler I can only ever seem to get 4L out of the system (even after cranking with CAS disconnected) – is there a way to flush more oil out without undoing the cooler top hose?
2. With the wheels off and steering rack disconnected I noticed more 'resistance' in the LH steering knuckle i.e. you can just leave it in the middle (straight) position and it'll stay, whereas the RH knuckle moves very easily and would only rest at full left or right. My guess is that the RH steering knuckle bearing (?) might be worn, does that sound possible? Can it be replaced?
3. I also realised (doh) that the tie rod ends sit very close to the rotors, which basically glow red at the track and cop a lot of heat especially now that I've ditched the brake backing plates. The original RH rod end boot seems to have a pinhole in it and has lost some grease, leading to high wear and play – I wonder if it's taken a beating at Sandown (counterclockwise)? Anyway, is there a way to 'heat shield' the tie rod ends (only), or do you guys just replace them at regular intervals?

Any suggestions on these?