this is from 2002 edition of the service manual



a lower thermostat (like nismo) should help a lot.

 

Very interesting. While not the most civil of discussions, I sure didn't know that was there... Like I said though, I do see significant oil pressure drop after a session, indicating the oil has gotten hottER and is thinning out. I'm sure glad the OEM one is there, but am still considering adding an oil-air cooler (in addition to the OEM oil-water). While I'm sure the OEM helps, my personal opinion (and that's all it is, since I don't have oil temp data to support it) is that for track duty, particularly in hotter weather, the OEM doesn't do enough, even with a stock motor. Since I'm going FI, that will only exacerbate the (perceived?) problem.

Anyone have actual oil temp data during DE or race sessions?

ahm

 

I used that technique in my old truck while driving up steep inclines, and it works. My water temperature actually drops, but I suffer miserably for the 5 minutes that scorching hot air fills the cabin. The air gets so hot that I sometimes cannot pick up the stainless steel mug located next to the vent.

 

BTW there are some good oils that have 0% sheer loss and no viscosity drop at any temperatures, even with moderate fuel dilution...

One of these is the Motul 300v double ester racing oil.


Hehe, true. But on most tracks you are required to lap with one(or both) windows down... so it's not as unbearable. I guess it's a trick for amateurs lapping days if you can't have the fancy stuff

full heater in 100f temp, with closed windows... would get dangerously hot.

 

I did one day without an added oil cooler when we went forced induction. My oil temps were over 300 degrees. It took two coolers added on to bring the temps down to 240 as a high on a 97 degree day, and that was with a lot of air flow management. Read about it here:
http://uucurl.com/x.php?p=1184

 

Well, I went through the Pegasus Auto Racing Supplies catalog, and priced the material cost of putting together a oil cooler with thermostat, swivel hose ends, ss braided hoses, and it came out to $360 w/o tax, shipping, and handling. I would still have to fashion mounting brackets, and figure out how to assemble it properly, along with devoting precious time inherent in putting together such a component.

Suddently $575 doesn't seem so bad. I might be ordering an unit from Ntech in the near future since their unit is the only one that comes with a thermostat (a $94 component from Pegasus). I guess that's the drawback of using a daily driver on the track. There are just so many compromises, as I don't really want to run 20w50 in a daily driver that sees a lot of easy freeway miles. Royal Purple 41 (10w40) + oil cooler w/thermostat may be the most liveable compromise. There goes my Nismo exhaust fund... :-)

 

You did a lot of reasearch.

Why not change to a higher grade oil before each event? I change my oil each time anyways (oil only, same filter). It might be simplier?

 

Or get something like a perma cool kit, and replace the sandwich plate with one that has a thermostat built in. Like so:

$155 http://www.jegs.com/cgi-bin/ncommerc...14&prmenbr=361

$80 http://www.racerpartswholesale.com/mocal.htm (the one at the bottom)

ahm

 

I think I see what you're describing. But, the way I see it, the sandwich plate with thermostat regulates the flow of coolant, not the oil itself. Therefore, the jegs tube-type oil cooler would still function full-time. Also, the radiator-type oil coolers are supposedly more efficient than the tube-type unit, but that's assuming their about the same size.

That technique works for you since have had success using 5w30 on both street and track. Although I haven't tried a full synthetic yet, and based on the posts in this thread, I'm assuming 20w50 is what I need for these 100 degree days. If I change to 20w50 before the event, I would think I should change it back to 5w30 or 10w30 after the event for daily driving. So that basically means two oil changes per event. It seems to me that the cost and inconvenience of replacing oil so frequently would justify the oil cooler + synthetic 10w40 for both daily driving and track events.

 

I would try some mobile1 ($26 from costco) before doing anything drastic. I think we all agree that perhaps castrol oil is not the best for a tracked VQ. I have been running 5w30 and have never had any issues (that I know of). I just changed mine out with 3 track days and 3k miles and it came out very clean.

I'll keep a closer eye on it this weekend at infineon now that you have brought it to my attention though.

 

I think there is a little confusion here. The Jegs unit isn't an oil-water intercooler, its an oil-air unit - like your radiator or a turbo intercooler, and unlike the factory oil-water jobbie. So there is no coolant lines plumbed into this solution (other than the existing OEM lines for the OEM cooler, which stays in place unmolested).

The thermostat in the sandwich plate prevents oil from flowing through the radiator/oil-air cooler until the oil temp is 180F. The big issue I see with the '450 hp' jegs unit is that the cooler is 21" long. I'm going to have to find a way to mount that, or get a deeper (thicker) cooler that is not as long.

ahm

 

I was intially mistaken about the function of the sandwich plate...now I get it... We're on the same page on the jegs unit though...

I believe the JDM nismo unit utilizes a sandwich plate too. I found a photo showing the fittings located at the oil filter.

What if you went with an aluminum oil cooler instead of the jegs tube-type cooler?
http://www.pegasusautoracing.com/Pro...p?Product=1210

 

As a reference point, we use two 19 row coolers from Mocal, 235 matrix (thicker cores).

 

I think that's the link I've posted before I was originally planning on building my own kit using own of those coolers and the sandwich plate I linked to earlier. I'll probably just have the local hydraulic place make up the lines - they shouldn't be too expensive. Then I saw the jegs link somewhere and thought it looked OK. I think the pegasus-sourced coolers are probably significantly better units. Unfortunately, even someone as reputable as mocal i don't believe publish much in the way of flow, pressure drop, or efficiency numbers, so it is difficult to gauge their effectiveness.

Either way (jegs or home rolled using the pegasus cooler / sandwich plate), so long as its flow is thermostatically controlled, it should be fine on a daily driver, and give your oil some respite in hot track conditions.

2 19 row coolers? Yikes. How long are your races?

ahm

 

Remember, we are running over 400 WHP with twin turbos, almost always at very high rpm, and also at full throttle a lot. The oil temp was going up right away, and even with very good air flow, one was not enough. We went over this with their engineers, and they told us not to expect more than about a 30 degree drop with the cooler properly placed at our power level, and as it turned out, we dropped a total of about 65 degrees with the two coolers.
During this ordeal, we also were monitoring oil properties, and this is when we found that Mobil 1 was not doing as well as Royal Purple is...

 

Nick, did you notice any oil pressure drop with two cores? I'm assuming you still have the stock oil pump.

BTW, your car looks the part! Nice driving with the GT3.

 

Saw a very minor (insignificant) drop at idle. Thanks!

 

Well, I just bought some Mobil 1 5w30 at Costco to see if it helps out. I had contacted the folks at Royal Purple, and they stated that 5w30 is recommended, even for 20-30 minute track sessions in 100F+ ambient temperature. I can't seem to find Royal Purple anywhere here in Sacramento, so I went w/Mobile 1.

I also re-read one of the older issues of the Sport Z Magazine, the one where they interviewed Unitech Racing's Stewart Jackson. He seemed to indicate that the Z has poor fuel delivery capabilities when pressed hard under duration. Do you think the loss of power I experience is somewhat related? I guess I'll find out soon enough on the next outing.

I spoke to another friend who is using dino oil, and he experienced similar loss in power as temperatures rose. I've considered installing an oil and water temperature guage, but it looks like a royal pain in the **** to install. I'm not keen on dismantling my dash (yet).