Turbo MX-5 20psi w 1.5hrs track time Rotella T6

[SavetheRimBrake]

Hey guys so I've been running T6 since basically the start of my rebuild which has been about 7k miles ago. I recently started attending track events (so fun) and have done 2 so far (one whole, one half day). On this particular oil change, I have 1.5 hours of solid beating on the car, which in non turbo form made less than half of the power it does now, actually probably a third. The mod list is extensive, but for the stuff that should matter for this, I am using ACL Race bearings on mains and rods, clearanced at .002. I have a Boundary Engineering oil pump with no shims (I believe its set to open around 55-65psi). Oil is Rotella T6, oil filter was a Mobil 1 #3233. I also run a Setrab oil cooler on the car, using a thermostat sandwich plate which opens at 180 or 190*. I do not have a real oil pressure gauge or oil temp gauge on the car, but at the end of a 20 minute run, my oil pressure gauge dips slightly lower than normal, then levels back up in about 5 minutes. My gauge is a moving needle with lines, but they are not numbered. It's a good reference system, just doesn't provide any concrete data, but I can see my pressure slightly drop when my massive radiator fan kicks on, so it does work in its own way

Here is a cutaway of the bearings (cant get the image to embed, sorry)
https://www.mdspares.com.au/images/1242/bearing-materials.jpg?cache=20141123210950

Lead is elevated, but copper and tin, which are both part of that fatigue layer, are right in line with universal averages. Just looking to get some feedback on how the wear is in your opinions. I was considering trying 10w-40 Castrol EDGE with Titanium next time around and doing another 1250 mile run with about 1-2 track hours to see how it compares.

 

[ryanm8]

Do you let the oil get over 180 degrees before beating on it? What kind of oil temps are you seeing on the track?

 

[A_Harman]

It looks like you are wearing the overlay, and are getting some copper from the bearing lining. You need really good oil temperature and pressure gauges if you are going to be tracking a turbocharged gasoline car. If you can datalog the oil pressure, that would be best. If your engine is suffering oil starvation in the turns, you'll not be able to see that on the oil pressure when you can check it on the straights.

I'm not a fan of running RT6 in highly boosted gasoline engines. It's formulated primarily for diesels, which have exhaust temperatures that are hundreds of degrees lower. Get an oil formulated for gasoline turbo engines that meets the Honda HTO-06 and/or the Porsche A40 spec.

 

[Pontual]

Haven't you tried race oil or some extra moly?
If you're getting temporary shearing, could also run a narrower multigrade or Ester based.

 

[Canadastang]

Originally Posted By: Cleanneon98
opinions. I was considering trying 10w-40 Castrol EDGE with Titanium next time around and doing another 1250 mile run with about 1-2 track hours to see how it compares.


I had an excellent UOA on my Mustang with Castrol Edge 5W30 on a 4000km run, including about 4 hours of track time, and a few open track nights, along with daily driving.

I'm not advocating a thinner oil for your application, but Castrol Edge worked well for me. And it's cheap.

 

[SavetheRimBrake]

So I called Blackstone and they said that for the type of driving I did, the wear is pretty normal, and its just lead thats elevated, not a lot of other things, so they are chalking it up as "normal wear". I googled and some people started having knocks in their engines with ppms in the 100s, I am still a ways away. They said if the metals start getting greater and greater with each change, then I have cause for concern, but assured me that this is not a call to rebuild my engine.

I may still try the Castrol edge, its said to withstand more pressure which might help with the wear if I am really getting my oil that hot on track. They did say that an oil pressure and temp gauges would be beneficial

 

[Olas]

Is it 20 psi boost or 20 psi manifold?

 

[Canadastang]

Originally Posted By: Cleanneon98

They did say that an oil pressure and temp gauges would be beneficial


At a minimum, grab yourself an IR temp gun and when you pull into the pits between lapping sessions (or races, you didn't specify what type of track time) and pull the dipstick and quickly get a reading of the oil on it, as well as the filter, pan, tranny, diff, yada yada.

I know it's rudimentary and not horribly accurate, but at least in the meantime until you get an oil temp gauge, you'll have a rough idea of how hot the oil is getting.

When I tried this on my car, the IR temp gun was actually within a few degrees of my OBD datalogger's oil temp. How accurate is the OBD oil temp sensor? Pretty accurate, I would hope.

Do you have a wideband O2 sensor to make sure you don't go lean? Also, consider getting a real coolant temp gauge, as the factory ones are usually 'buffered' and have to get really hot before moving above the middle.

Check out my UOA thread with Castrol Edge 5W30. I know it's a non-boosted application, but it was a hard run and yielded great results.

 

[SavetheRimBrake]

Thanks for the replies guys. 20psi is measured from the back of the intake manifold.

IR temp gun is something I need anyway, since I want to start checking my tire temps and alignments after runs. I am doing HPDE type events, so 20 minutes, on a track, then 40 minutes cool down, repeat 3 times for one day.

I do have a Wideband o2 sensor. My tune was done by arguably the best Miata tuner on the east coast, perhaps the whole country. He is a former FlyinMiata employee and has tuned well over 300 various Miatas in his lifetime. My AFR at WOT is 11.5-12, and since my engine is build to a lower than stock compression, the timing tables through Megasquirt are fairly conservative with lots of extra room for errors.

Coolant temps on track are unknown, but when I just did a log the other day on the street, I was hovering between 195 and 205* the whole time. Megasquirt is set to flash the CEL if the temp exceeds 225 I believe, and I don't get that blinking on track, so I assume coolant temps are in check. The cooling mods on this car as ridiculous (2 core crossflow radiator which is 3x thicker than stock, coolant reroute, hood louvres for heat extraction), so I'm mostly concerned with oil temps.

I'll try the IR gun on the dipstick for sure, never even thought of doing that. Engine runs healthy, oil consumption is at a minimum, and blow-by is virtually non existent. I have a dual catch can setup now, but during my last track day I only had one on the intake side which works out of boost. Basically, for my last 20 minute run on track, I had an open valve cover on the exhaust side where the "boost" catch can would be, and in 20 minutes of hard driving I only got a light mist from the port. I've heard of guys with significant blow-by filling the catch can on the exhaust side within minutes at idle, and about 1 lap on track.

 

[addyguy]

Redline is MADE for this kind of service...seriously, look into getting some, it is worth it for this application.

 

[vinu_neuro]

Generally seems like oil pressure issues caused by too big a pressure drop with your oil cooling system. It might be worth the sacrifice slightly higher oil temps with a smaller cooler to gain more stable pressure. Considering all that and the bearing wear it would behoove you to increase the viscosity to 5W/15W-50 (something with a much higher HTHS than T6). Goes without saying that proper oil temp and pressure gauges are requisite for a track car and would help for issues like this.