Potential issues for hot upcoming track day?
 

I am wondering what things I should be careful of on my upcoming track day at California Speedway in Fontana on Aug. 10. I'm sure it will be very hot, like 100 or more. I've tracked there before, but it was much cooler. We get four 25min sessions; I have a covered garage space. I'll be running RE-11s, LTH will be installed the day before (Aug 9th), got the oil cooler, all fluids have been upgraded as well. So that gives you all some background, anything I should be weary of? Precautions I need to take?

I personally would go hard for 2-3 laps, back off to cool everything down for a lap. I know people get excited when they see traffic, but that's usually the best time to back off and cool everything down.

When you do the LTH's. Wrap some extra insulation around the clutch line. ;)

Would just installing a SS clutch line do the trick, or still wrap it? Also, I didn't get the ceramic coating on the headers. Will that come back to bite me? If so, maybe Tony can add it.

The insulation is cheap insurance. It won't hurt anything. ;)

if your oil hits 240, start cooling down. The VQ rod bearings cant be trusted past 250 under track loads, and the water likes to start getting warm at that oil temp range also

That is brutal heat and I suggest you have a way to monitor the coolant temps more accurately than just the dots. I also suggest running mostly water instead of the typical 50/50 coolant mix. Don't be too proud to back off for a lap and let some cars pass you while you let the car temps come down.

How many people lost their motor due to oil temp? I have only recall two or three posts about people losing their motor outside of oil consumption.

I don't doubt the diff may get warm pretty fast. Still running the stock unit or aftermarket?

im not specifically just talking about 370 VQ37 motors, VQ's in general from the early 35DE's, the 35HR's and the 37s have notoriously weak rod bearings when it comes to strength at high oil temps on track. 250 is like "you're about to spin a rod bearing if you keep at it" even if your oil is up to spec to survive at and past 250, the rod bearing's construction is not

from my testing, ive gotten rear diff temp to about 200 degrees give or take after 4-5 hot laps at buttonwillow raceway park in Socal during 85-90 degree weather,(300 is diff and or diff bearing kill zone) but this is also with my clutch type LSD, which can produce more heat then the stock Viscous LSD. But at the same time the stock VLSD is more prone to failure under heat at a lower temp then mechanical gear type or clutch type LSDs. general rule of thumb to keep diff from getting pissed, is keep you run session hard laps under 15 mins in 90+ degree heat, and under 20 mins in sub 80 degree weather

If you're getting LTH the day before I really hope you are having the UpRev retuned right after so you don't go super lean with all that flow and detonate like crazy. Adding a few gallons of 100 octane helps at high temps and it wouldn't hurt to have a 95 octane tune done (replace valet?) and run that mixture on track.

Definitely insulate the clutch line. Oil and diff fluid changes before and after track.

Still on stock rear diff (on wish list!), no diff cooler either.

I was wondering about this and that is why I added this info in my initial post. I'm driving up to LA from San Diego and thought I could do a couple things in one trip. That is, go to Fast Intentions and have Tony, the exhaust master, deal with the demon bolt and install the headers, then drive across town to sleep at hotel and enjoy a track day in the morning. I was planning on doing another UpRev tune back in San Diego after the track day. I know not ideal, but will that be detrimental?
As far as octane goes, Auto Club Speedway and CA is very strict with selling it. I know that at the track it can only go into full race set-up fuel systems. They wouldn't sell it to me. Would a one-time octane booster additive help? I'm usually against those silly additives tho. :shakes head:
Again, thanks guys for all your help with these questions. This online community is great! :tup:

Sebastian at SpecialtyZ does the best LA area tunes, and he's local to FI. He can pop a $35 SS clutch line in (you provide) insulate, and dyno-adjust your tune if there's enough time left in the day. There are various gas stations between the valley and the IE where you can get 100 octane. It's not leaded 110 race gas so it's not restricted. I always buy some 100 when at WSIR or BRP but haven't done ACS (I'm allergic to walls) so IDK about their policy on hi-octane unleaded..

I'll repeat what I said about fresh oil and fluids before and after. Seb will back me up.

Earlier VQ also weren't designed to rev to 7500RPM. Once again, how many 370's engine died from rod bearings failure?

Why would you tune for 100 octane for the track given the fuel starvation issue of the 370. You better hope you have a gas pump at the track.

the DE VQs didnt rev to 7500 stock, HR's did though, and HRs have the same rod bearing specs/size at VQ37s. the DE VQ's have a similar contruction but i believe slightly different shape. But if you dont believe me and feel 250+ oil temps is ok for your engine on track, then go right ahead. i honestly dont know, i havent gone around and counted blown from oiling issue 370z's, im just stating that it is a fact, VQ's have rod bearings on the soft side of metal compound making them eager to fail and spin at oil temps past 250.

also, he's not saying tune for 100, he's saying mix some 100 with your 91 to bring your effetive octane rating up higher then whatever octane you are tuned for, since track conditions always run harsher and hotter then any dyno can replicate. its cheap insurance against possible detonation. and your power will stay more consistant through out the day

Mine did. Yours could. More would if this place wasn't a haven for hardparkers.

[QUOTE=Why would you tune for 100 octane for the track given the fuel starvation issue of the 370. You better hope you have a gas pump at the track.[/QUOTE]

I said tune for 95. At least add some 100. There is 91 and 100 at the pump at all of our tracks. Helps a lot with these hot-running motherf*cking VQ's that we love.

my bad steve, but my input still stands.

ALWAYS run higher effective octane on track then what you are tuned for no matter the weather (unless its raining)

:tiphat:

I don't doubt you one bit that the rod bearings might be soft, but I highly doubt it is as critical as you make it sound. More people suffered from fuel starvation/clutch,ps,brake fade than rod bearings failure. I am guessing 50 cars on this forum had gone to the track more than once, the failure rate is less than 5 cars?!? I will take that odd anytime.

threeseventy, mine might fail, but it hasn't after 2000+ miles on the track and 500 autocross runs. I will keep going back at it unless something proves otherwise. I have never hit things at the track either, but it doesn't mean I won't. I hope it doesn't happen, but you don't know.

You guys with modified cars/engines have different requirements than the guys with stock cars. What's to say the failure was caused by the rod bearing and not your mods or tunes. Track conditions are rough on the engines, but most modern cars are smart enough to prevent itself from blowing up.

Just go out and have fun. Learn the car and make changes when needed. But know when to stop before anything bad happens. ;)

I snagged this from a write up my good friend Mike Kojima wrote, since he explains it better then i do regarding Nissan's engine bearings because of his race engineering backround. He used to work for Nissan and has tons of motorsports experience with Nissan platforms.

Also, mine and threeseventy's cars are no more modified then most of the people here. Simple bolt on power mods on stock motors.

"The most oil temperature susceptible parts are the engines crank and rod bearings. The engines bearings are made of soft metals, such as aluminum, tin and zinc with other trace alloying agents such as indium which refines the metals grain for better mechanical properties. The reason why soft metals are used is that they offer good embedability. If hard contaminates are present in the engines oil such as casting sand, metallic particles, hard carbon bits and dirt, a soft bearing surface will allow the particles to become embedded into the surface of the bearing where the damage to the bearing and crankshaft can be limited. The contaminating particle will be soaked up by the soft bearing instead of being ground into the hard steel journal surface of the crank with damaging effect.

Soft metals can be used as engine bearings because under normal conditions, the crankshafts journals never touch the bearings surface. Since the liquid oil layer is not compressible, the crank rides on a pressurized hydrodynamic film of oil a few thousands of an inch thick that is maintained on the bearings surface by the engines oil pump. The oil pump must maintain pressure (this varies for as low as 5 psi at hot idle to more than 60 psi at higher rpm) and continually replenish the oil because the oil leaks out at the edges of the bearing and is flung out by the centrifugal pumping action of the rotating rod journals. This circulation is necessary because the shearing action of the oil in the boundary layer between the rotating crank journal and the static bearing surface creates heat and this heat must be dissipated. Most of the heat is removed by the oil as it passes though the interface between the bearing and crank.

The bearings, although soft still have to bear a heavy load because the incompressible liquid oil film transfers the forces acting upon the engines reciprocating parts to the bearings, thus the bearings have to withstand thousands of pounds of force even though direct contact does not happen. The best engine bearing have high embedability with a high load bearing capacity.

Usually everything works fine until a couple of things happen. In the case of modern late model engines, the green movement is to blame for part of the problem. In the last few years, Nissan has worked hard to make their cars green and more recyclable. In an engine traditionally one of the most toxic areas was the bearings. A few years ago, many Nissan bearings were made of trimetal construction using layers of lead, zinc and tin alloys of different percentages. This tri metal construction has been a mainstay of heavy duty bearing construction and composition for decades. The old Nissan bearings were very strong, heat resistant and durable. It’s a little known secret that old L-Series Nissan bearings are so strong and durable that many race engine builders use them, adapting them to other engines. The Infiniti IRL engine used in Indy cars used off the shelf L-Series bearings for this reason.
Sometime in the last few years, in an effort to be greener, Nissan discontinued the use of lead in all engine bearings. We know of this through discussions of sources deep within Nissan which will have to remain unnamed. At this time the engineers at Nissan noticed that warranty claims for bearing failure in the RB26 GT-R engine, another Nissan engine noted for running high oil temps, spiked. Nissan launched an intensive study on the reasons of this bearing failure and discovered that the new environmentally friendly bearings started to loose their load bearing capacity at temperatures as low as 260 degrees. Although there was plenty of reserve strength for normal passenger cars, the turbo high output RB motor pushed many sets of bearings to the failure point. Although you think of lead as a very soft metal with a low melting point, it was still a major contributor to the bearings mechanical properties and resistance to heat.

So as the oil temperatures climb, the bearings soften and loose their load bearing capacity, if the temperature climbs past 300 degrees and the engine is being pushed hard the bearing material can start to flake and spall. This disrupts the hydrodynamic film allowing metal to metal contact, resulting in catastrophic failure of the bearings, the crank, rods and even the entire engine often within seconds. Oil also begins to deteriorate quickly at temperatures above 260 degrees. It starts to oxidize and thicken, loosing its lubricity while forming sludge and varnish. This further compounds the problem, generating more drag and heat in the bearing/crank interface area.

Once again, I don't disagree with what you said for the most part except the 260F figure is not as concrete as you make it. For one, there just aren't that many bearing failures to support your claim. Two, a good full synthetic is good enough to support 260F without breaking down immediately. Will you be able to go 10K miles at 260F, of course not. Yet for a few hundred miles, I don't see any problems. I have hit 270F many times and I had my oil analysis done at 3000 miles, car had no abnormal materials in the oil.

I can attest to Seb over at Specialty Z doing great work. One of the very few shops that I trust. I use 0W-40 synthetic synthetic oil in my car. I change before and right after the track. Also, I could probably get away changing the diff fluid every other time at the track, may be a little OCD but i Dont want to take any chances. I change the diff fluid too.

If this is your first time at Fontana, I suggest paying the extra 20 dollars a day and getting a garage. You will be very happy sitting in a garage out of the heat and an actual place to make adjustments if need be.

After the heat, turn the car off, leave the parking brake off, pop the hood sit back and relax.

Like i said, if you are comfortable with operating your 370 at such temps, then that is your decision. Ive given my opinion on the topic, and so have you. Th OP and whoever else reads this thread can make up their own mind whether to follow my advice, or yours. I just tried to put some info out there for people who may not know as well about whats happening while spinning their motors on track. Yes you are correct that there are alot of good quality synthetics out there that can handle 260+ temps, im just of the opinion the VQ shouldnt be operating at that temp under track loads. Call me paranoid.

Very comfortable because I have been doing it for three years, motor is still original amazingly. I don't think I have used anything other than 93 octane either, so weird.

what's 93 octane :P

im sure your tone is tongue and cheek, at least im assuming so. :tiphat:

Alot of people dont run more octane then tuned for on track and depend on the Knock sensor and ECU to pull timing in the case of detonation, im just of the belief why even get to that point, hence i run more effective octane then what im tuned for.

Same with the Oil temps, yes ive hit 260 pre oil cooler, and yes 3 years later my motor is still kicking, but id much rather not be operating at over 240 degrees on track.

Another thing, depending on driving ability and chassis setup, the amount of wide open throttle and load on the engine per lap varies from owner to owner, less experience guys may not hit 250 oil temp till 8 laps in, more experience guys may hit the same temps 3-4 laps in. So there are more variables then what can be discussed on a forum. I guess if you're having fun and not getting towed home by AAA, you're ok:tup:

very paranoid....if you prepare for the heat I'm sure your car will hold up OP...

Have you ever monitor the difference in power output on the first lap of a session vs. the last lap with telemetry? I don't know about your car, but the difference in my car is marginal at best. I can easily match my top speed on lap 1 and the last lap even after accounting for how I come off the previous corner. I am not sure how much timing the ECU is pulling from the engine exactly. I am sure it pulled some due to the higher intake temp, but the actual difference in power is marginal at best. No way I buy into the whole knock sensor is sucking power out of the car BS, especially on a stock vehicle and the 370 especially. Racing gas is $6 or 7 bucks a gallon, I can spend the money on another track day.

I would be more worried about crashing than mechanical failures

i never said i can "feel" the difference in power, nor have a monitored the difference with telemetry. I dont bring it up as a performance advantage, its just a little extra insurance by raising the detonation threshold a bit.

Also, i didnt say fill up your tank on race fuel, i said mix in some so your over all effective octane is higher. I do about a 1/4 tank of 100 mixed with the 3/4 of 91 ill already have in the tank (since all be have out here in socal is primarily 91 octane and that is what my car was tuned on)

a few gallons of race fuel is not alot of money, and its a nice bit of extra safety. Ive done it with all my cars in the past, both my street cars that see track duty, and my past competition time attack car and because of this ie never ran into detonation related problems or failures

I can tell you this, definitive proof or not, if my oil gets north of 240 degrees, I'm backing way off until it drops back down, or parking it all together. If there's even a chance that the bearings might last longer by not exposing them to those kinds of temps, I'll err on the side of caution.

I have a massive oil cooler and have never seen temps over 220, but that's probably because I'm a terrible driver. ;)

I am not saying there is anything wrong with what you are doing. I am just saying it's an overkill and god knows if it really helps. I guess placebo effect is a powerful thing. From my personal experience, the 370 had no notable drop in power from oil temp alone. I didn't get any notable drop in power, knock sensor sucking timing out of the car and other funny business that some of you guys were getting. Once again, my car is slow. It isn't fast enough to have half the problems that you guys are having.

Got any datalogs of a session? I'd love to look at them. Ones with RPM/Coolant Temp/Oil Temp/Ignition Advance/Intake Temp would give me enough data to really understand what's going on.

Just curious, that's all.

if we both did data logs on track and compared them, it would tell the whole story, but i doubt you're willing to do that to prove you point that im just a paranoid weenie :tiphat:

I do have the logs, but not in the details that you are looking for as I don't log engine parameters. I care more about lap times than what the engine is doing. Even though I don't have engine parameters, what I do have is vehicle speed and track positioning. This is how I came to my conclusion. Let's pick a track like VIR as an example. Coming out of Oaktree, there is a 4000 ft backstretch where you basically go from 50mph to 130mph. I take my acceleration curve in that particular section on my outlap/lap 1 where my engine is "cold", I then overlay the same curve from laps later in the sessions (I did this to multiple sessions, not just one). If your theory is true about noticeable drop in power under high temps, I should see a significant drop in my acceleration curve in the laps near the end of the session. Yet in many sessions i have looked at, I just didn't see any big change. Oh yeah, before you say how you come off the previous corner can effect the speed. While that might be true, but the acceleration curve should still remain the same as you are accelerating from 50mph to 130mph. By looking at a general curve, you see an overall trend.

BTW, I understand this doesn't have F1 type of accuracy or Mythbuster type of accuracy, but it sure is more accurate than a buttdyno

I will put something together once my baby goes to bed tonight.

I have posted plenty of data and videos. You can find them on the web for sure as I post most of it. I even overlayed them on top of another if you need to see.

Yes OP the detonation caused by overlean running even without tracking causes even more heat and can cause long term damage. The power loss Clint (a sought after record-setting time attack driver and professional instructor) is debating with Cossie (Cossie) could be attributed to temperature-related less-than-optimal combustion, so you really have to retune the car right after a major modification like cat-eliminating LTH's.

Well this seems pretty evident at the dragstrip. Oil temp in the 160-200 range car runs from 12.9 to 13.1 like clockwork. Above 200 it starts to get progressively slower. Slower I ever recorded was 220 oil temp running 13.5s at a significantly reduced 104 trap. Granted boiling hot outside it was high 90s. If this is true at the strip I imagine it would be present on track to a degree but at least on track you have constant airflow. Ill have to start tracking timing as well.

It is odd though as on my two track days I havent had a decrease in performance that I could notice whereas at the strip its easy to notice. Interesting though

Sent from my GT-N8013 using Tapatalk 2

Yeah i was talking about th engine parameter logs, ive done it a few times with my car just to get water temps, but havent really recorded everything else. I could if i had to. I get what you're saying though about your track telelmetry logs. BTW what data logger are you using?

Again though, wasnt saying "run higher octane and solid cooling for optimum lap time performance". I said run it so you have that extra over head of engine safety. The potential added performance would just be a bonus. I dont run the extra octane for the speed, i run it for that extra protection against detonation/pre ignition.

I have used torque to log engine parameters via the OBDII port, but I really have no use for anything outside of RPM and maybe water temp for reference. To me it is a hassle to have a plug in between my legs, especially at the track. As I said, some of you are more into the engine/HP/tuning aspect than driving. I completely understand as I was like that 10 years ago. I just got past it and I really don't care about my engine unless it is smoking or Minis and Miatas are passing me.

I understand why you are using the high octane gas, I am simply saying it is an overkill on a stock car as the ECU SHOULD account for any possible detonation you MIGHT experience. And this is if your engine is really knocking that is. Also the effect of oil temp is greatly exaggerated in my opinion, I simply don't "feel" the same thing that you guys are doing. See what I am attaching below to support my claim. Do you guys carry 10x more in insurance coverage than your net worth too?

I have pulled the logs from my first lap and the last lap of the same session for comparison. Unless I missed something, I just don't see any HUGE drop in performance between both runs. A few horsepower maybe, but nothing so out of ordinary that would allow Miatas to pass me on the track. Even if you are right and my car is losing power from the heat, remember other cars on the track are running in the same condition too. Chances are that they will lose power if you do. BTW, I do back down every now in order to cool the engine/brakes/transmission/myself, but oil temp can climb from 220 to 260 within half a lap under full load. On a hot day, it got to nearly 280 at the end of the lap.

http://imageshack.us/a/img600/37/q3eg.th.jpg

http://imageshack.us/a/img341/3214/03bi.th.jpg

http://imageshack.us/a/img16/8787/wfdv.th.jpg

http://imageshack.us/a/img706/3216/bji7.th.jpg

http://imageshack.us/a/img845/4986/rtcm.th.jpg

I would definitely be sought after by the courts for child support if I crash my car at the track

Anyway, OP, I would avoid tracking the car before a re-tune if you put LTH on it. That said, the FI LTH are pretty conservative, so you'll probably be alright as long as you give the car time to cool down after a few laps.

cool data

well looks like you will continue to do what you're doing and ill continue to be paranoid. the OP can take the info as he pleases