Got a track related question? I'll try to answer.

[ddeflyer]

Originally Posted by jvincent

Sorry for the slight off topic here.

I've been struggling with the validity of data from a UOA for the track. As I understand the process, they measure for wear metals and the current viscosity. I don't believe they address viscosity at high temps. So, while a really bad number can be a sign of wear, it's probably too late at that point and a "good" wear report may not be indicative of degraded high-temp viscosity, which is what we care about.

Personally I'd rather change the oil more frequently, a change only costs me ~$60, for the peace of mind.

They test the viscosity at a standardized temperature. In my case I am running the JR oil cooler so I am not seeing as high of temperatures. I am also running 300V 0w20 which is probably going to be a bit more stable than other 0w20s against abusive conditions. It is also thick oil in the 0w20 spectrum.

Also, changing oil really frequently (like if you were doing it once a month) carries its own set of risks. Every time you change oil you are changing the specific nature of what is running through the engine. A fresh load of oil is going to be undergoing a set of initial changes, among them is some initial shear and some chemical changes. These variations are not the easiest thing on the motor compared to a steady state healthy oil (not that it is actually that hard on the engine, but still...). Beyond the fact that you are exposing your car to more chances of a loose drain plug or what not,

In the end though, you have to decide what is best for you, your car and your wallet. Just be aware that while the manual calls for energy conserving oil, that oil is at the very thin end of the 0w20 spectrum.

[Apex_BRZ]

In the end though, you have to decide what is best for you, your car and your wallet.

Right, that's the whole point. How? If the oil testing is under scrutiny about how effective it is at determining if the oil is ok for track usage and temps, how in the world does anyone decide when to change the oil exactly?

[ddeflyer]

Originally Posted by Apex_BRZ

Right, that's the whole point. How? If the oil testing is under scrutiny about how effective it is at determining if the oil is ok for track usage and temps, how in the world does anyone decide when to change the oil exactly?

As I said, they heat the oil to a standard temperature for the viscosity tests. That temperature (100C and 210F) aren't actually that far off what my oil temps are with my oil cooler.

Remember that UOAs were designed more for airplane and over the road trucker use than for track days. The standards that they require for those fields is pretty astonishing. A used oil analysis can tell you both if you have problematic wear in your engine AND the health of the oil. It doesn't cover EVERY possible scenario, but it does give you a whole bunch of very useful information.

[Apex_BRZ]

How is everyone dealing with the trans and diff temps? Anyone using a cooler?

Any experience with something like this?

http://www.evasivemotorsports.com/mm...S-TRANSMISSION

[ATL BRZ]

Originally Posted by Apex_BRZ

How is everyone dealing with the trans and diff temps? Anyone using a cooler?

Any experience with something like this?

http://www.evasivemotorsports.com/mm...S-TRANSMISSION

I haven't had the need for a cooler yet with lots of track abuse but I am using a premium gear oil that's designed for track abuse: Millers Motorsport CRX 75W90 NT

DESCRIPTION:
Competition full synthetic transmission oil. A blend of full synthetic base oils incorporating new "Nano Technology" additive chemistry to significantly reduce internal frictional and power losses.

APPLICATION:
Use as received for the lubrication of competition transmissions and differentials which require API GL4 or GL5 performance. Suitable for use in synchromesh and sequential transmissions. Recommended for modern transmissions where full synthetic oil is specified, especially for high performance road and track day applications. For use in all dedicated track cars with synchronized transaxles, including clutch type limited slip differentials.

USER BENEFITS:
• Exceptional cold flow properties for easier gear changes.
• Fast lubrication flow to component extremes on start up.
• Very good oxidation resistance and superior thermal stability.
• Low friction/low drag formula to help reduce operating temperatures.
• High film strength for maximum component protection.
• Significantly reduces friction, temperature, wear and minimizes power loss.

I'm changing it once a year or as needed.

[Apex_BRZ]

Unfortunately, I overlooked the diff/trans oil and DID NOT change it. I've been tracking on the stock fluid for the 5 track days I've done, plus street miles. I have nearly 30k on the car and I have rear differential whining now, and I can only assume that is the cause. If I can get away with running a more race spec oil and only changing it once a year...that would be fantastic. I read here that others were changing diff/trans fluid every 2-3 or 4-5 track days.

Your thoughts? I'll need to bring the car in for warranty work, I'm guessing. I doubt changing the oil at this point will stop it.

edit: There are warnings on that page about using it on the street. My car is still a daily driver at the moment, so I need to consider that.

[CSG David]

Originally Posted by Apex_BRZ

How is everyone dealing with the trans and diff temps? Anyone using a cooler?

Any experience with something like this?

http://www.evasivemotorsports.com/mm...S-TRANSMISSION

Good for racing. Not so good for day to day life. Get the oil too cool and it won't protect properly. Get the oil too hot, it won't protect properly as well. If anything, you will want to have a thermostatic setup with the cooler.

Originally Posted by Apex_BRZ

Unfortunately, I overlooked the diff/trans oil and DID NOT change it. I've been tracking on the stock fluid for the 5 track days I've done, plus street miles. I have nearly 30k on the car and I have rear differential whining now, and I can only assume that is the cause. If I can get away with running a more race spec oil and only changing it once a year...that would be fantastic. I read here that others were changing diff/trans fluid every 2-3 or 4-5 track days.

Your thoughts? I'll need to bring the car in for warranty work, I'm guessing. I doubt changing the oil at this point will stop it.

edit: There are warnings on that page about using it on the street. My car is still a daily driver at the moment, so I need to consider that.

If you want the transmission and differential to last a long time with an aggressive schedule, change the fluids every 2-3 track days...4 at most. If you want to keep it within reasonable changes, keep in mind that heat is what causes a lot of the issues. Yes you can have a differential fluid that can last for a year, but remember you will always have some sort of particles/shavings that accumulates over time. The magnitude is extremely small, but you always want to make sure you clean that up from time to time. The common schedule for diff and transmission changes has been around 3-4 track days or about 10k miles. The interval may sound short, but changing fluid is much less expensive than changing mechanical components.

Once you change your fluid, the differential whine should decrease. We suggest running Gear 300 LS in the differential if you are tracking.

[Apex_BRZ]

Originally Posted by CSG David

Once you change your fluid, the differential whine should decrease. We suggest running Gear 300 LS in the differential if you are tracking.

I'm concerned that the damage has already been done. Is that the case? Or is it just whining because the oil has been broken down by heat and is too thin? I'll get it changed asap.

[CSG Mike]

Originally Posted by jvincent

Sorry for the slight off topic here.

I've been struggling with the validity of data from a UOA for the track. As I understand the process, they measure for wear metals and the current viscosity. I don't believe they address viscosity at high temps. So, while a really bad number can be a sign of wear, it's probably too late at that point and a "good" wear report may not be indicative of degraded high-temp viscosity, which is what we care about.

Personally I'd rather change the oil more frequently, a change only costs me ~$60, for the peace of mind.

The gamut of tests include one for viscosity at 212F; they will let you know if your oil is degrading(shearing).

300V does not shear, period. It's also significantly more than $60 for one oil change.

[CSG Mike]

Originally Posted by Pat

That was my thought, also. My car has no power modifications. I drive it at it's limit on the track, and typically get in four 15 minute sessions each day. I don't have an oil cooler, and am concerned about getting it too hot, so I don't drive the full 20 minutes. I change the oil after ever track weekend (two days). I have never done a UOA, so I don't know if that's good or bad. It's just what I do.

Which brings up another question. How long does it take for oil to get too hot? I know this can be a gray area, but am I helping to protect the car at all by cutting my sessions a little short? I have not measured temps.

60 seconds in 3rd gear at 70mph will get it too hot during "daily driving" conditions, without an oil cooler. You can guess how it is on the track...

[CSG David]

Originally Posted by Apex_BRZ

I'm concerned that the damage has already been done. Is that the case? Or is it just whining because the oil has been broken down by heat and is too thin? I'll get it changed asap.

As long as you're not launching the car, you should be okay. All differentials whine to a certain degree. What you need to do is drain the differential, check for shavings or particles, clean that drain plug (guaranteed it has shavings), and refill your differential.

If it was a little dirty, I suggest you run a couple days on track or another 5k miles, then change the fluid again. That 2nd change will be pretty good for some time.

[Captain Snooze]

Originally Posted by CSG David

clean that drain plug (guaranteed it has shavings),

I have these drain plugs fitted to gearbox and diff housing. It was difficult to get the diff plug in because the magnet is so strong it kept on grabbing the housing. They made the oem plugs look so wimpy by comparison.

http://www.drainplugmagnets.com/

[Captain Snooze]

I am toying around with the idea of 16 inch wheels for track days but I'm not sure of the advantage when comparing RPF1 17x8 and TWS T66-F 16x7
Weight RPF1 + Hankook Z214 225x45 16.8 kg
..........T66-F+ Hankook Z214 225x50 14.8 kg
The 16 inch tyre diameter is only 2mm smaller than the 17 inch so gearing is so close there is no advantage there.
So the benefit is 2 kg of unsprung weight plus an unknown amount of angular momentum but given that the overall diameters are so close and the 16 inch tyre is actually 1 pound heavier I am thinking there wouldn't be much saving there either.
The choice of 45 series 16 inch tyres is almost non-existant.

Do the T66-F clear the Sprint Kit?
Am I missing something here?
Ta.

[CSG David]

Originally Posted by Captain Snooze

I am toying around with the idea of 16 inch wheels for track days but I'm not sure of the advantage when comparing RPF1 17x8 and TWS T66-F 16x7
Weight RPF1 + Hankook Z214 225x45 16.8 kg
..........T66-F+ Hankook Z214 225x50 14.8 kg
The 16 inch tyre diameter is only 2mm smaller than the 17 inch so gearing is so close there is no advantage there.
So the benefit is 2 kg of unsprung weight plus an unknown amount of angular momentum but given that the overall diameters are so close and the 16 inch tyre is actually 1 pound heavier I am thinking there wouldn't be much saving there either.
The choice of 45 series 16 inch tyres is almost non-existant.

Do the T66-F clear the Sprint Kit?
Am I missing something here?
Ta.

Don't worry about the weight. Worry about the rigidity. However, T66-F happens to have both compared to the RPF1. As for the 16x7 clearing the Sprint kit...I think I answered it in the past but I forgot. What's the reason with going with the 16s instead of the 17s?