Time to solve my ZL1's over heating issue on the track

[BaylorCamaro]

Originally Posted by LagunaSecaZL1

If money is no object, buy a; $1200 radiator, $550 Heat Exchanger, $30 Thermostat, Tune, $1000 Oil cooler setup(parts and labor guess) and be done with it. I report back after July 19th at Thunderhill how my 172* thermostat works with my RD Radiator at probably a 95* track day. At Laguna Seca, my temps were fine, but it was only 75* ambient.

If only money was no object... I'm curious to hear your feedback after your track event this month.

[titanfan]

Welcome to the joys of trying to track a supercharged car. The issues you're experiencing are exactly why I sold my ZL1. I recently bought a z/28 to replace it, and have yet to have any issues with heat dissipation. Good luck!

[LagunaSecaZL1]

Originally Posted by ztwentypoop

Welcome to the joys of trying to track a supercharged car. The issues you're experiencing are exactly why I sold my ZL1. I recently bought a z/28 to replace it, and have yet to have any issues with heat dissipation. Good luck!

Yep. I do 2-5 track days a year and daily drive my 2013 ZL1 as much as possible. In my case I made the right choice. I like the magnetic shocks, power and supercharger whine(RotoFab CAI). The Z/28 wasn't available when I bought mine, but a Z/28 at list is $75K and I paid $50K.

I'm considering trading in my ZL1 for 2013-2015 Viper. Just because I can. I happen to really like the ZL1, but my wife hates it.

[Todd in Vancouver]

Turned out to be a cooler cloudy day so no issues. The DIC said 270* but the gauge for my oil temp never got pinned although it did at one point go about 3-4 needle widths from pinning hot.

As far as the "dreded heat soak" I've yet to have that happen to me and I was running at 7/10's most of the day today at the Ridge. The only changes I've made are;

Bottle of Water Wetter in the cooling system
CAI
DOT 4 brake fluid flush
Hawks pads all the way around
All fluids in my car were changed before track day

Thats it and it runs hard and fast all day. Another successful track day done. My 2nd this year, and possibly 2 more to go. A number of people have told me about the issues I will have but so far none have happened. I think because I'm in the Pacific Northwest its a little easiermon the cars and I also don't run mine flat out. Imuin it for fun and have illusions of being some great race driver. Same reason I don't run mine flat out, i need my car to get me home and still work as a DD. Just my 2 cents. But I will look at additional oil cooling just for the comfort factor as I add more HP.

[LagunaSecaZL1]

Attached is my second oil change. I had my first oil change at about 1,500 miles and did not have it analyzed. The second oil change was at about 8,200 miles (6,700 miles on the oil) with two track days. I also had the TBN analysis completed and Blackstone said I can extend my oil interval to 8,000 miles. Also my aluminum are iron numbers are higher than yours and they attribute it too break in.

Originally Posted by BaylorCamaro

Looking for some advise from the track guru's (I'm looking at you X25).

*Warning a bit of a long read*


Seems like after a year of tracking and doing slight mods here and there I've finally needing to address engine cooling and radiator cooling.

A little background first, I track (road course) my 2013 Camaro ZL1 4-5 times a year. it is lightly modded: full exhaust, intake, injectors, tune, some suspension and cooling things (heat exchanger and reservoir for the blower), making just shy of 600 rwhp. I've been doing HPDE events for about a year now and have logged about 500-600 track miles. I started off with the factory oil, Mobil 1 5w-30 and made the switch fairly early on to Pennzoil Platinum under the suggestion of one of the engine builders I know. Unfortunately I didn't have access to 5w-30 or the Ultra Platinum (only Platinum) so I've been using 10w-30. I live in Houston Texas and combine that with a forced induction engine doing 20-30 minute track sessions, the heat that is generated is something that would make the devil himself sweat. From reading X25's post I've come to find the factory oil temp gauge isn't accurate past 266 F. Oil analysis shows the viscosity is still good and no signs of sheering/degrading.

Overheating Two Track Events Ago:
Two track events ago Alec Udell, pro driver of the #17 GMG Porsche GT3 Cup car in the Pirelli World Challenge did a 20-30 minute stint in my car with me ridding shotgun and unfortunately we got an engine overheat warning, the radiator coolant temp was pretty close to being maxed out on the analog gauge (can't remember what temp that is) so we did a cool down lap and brought it in to sit and cool. Later that day I was really pushing the car chasing my buddy in his Z/28 and it started to overheat again, so with that being the second time in the day (and first track event ever to overheat) I decided to call it a day. Last week I changed the radiator fluid and supercharger intercooler fluid to Engine Ice along with changing the thermostat and it seems to have brought daily driving temps down 20-25 degrees. How that will translate to the track, I'm not sure yet but I suspect that will only delay overheating and not really solve the problem.

My Historical Oil Analysis:
My most recent oil analysis (see below) shows increased aluminum and iron contents, possibly suggesting piston scuffing from what I would assume to be result of either oil thinning or slight starvation (no dry sump on this car). This past oil analysis was conducted last week, I have since changed to Pennzoil Ultra Platinum 5w-30. However I may go to a 0w-40.

The main reason I haven't gone to a really heavy oil such as a 15w-50 is due to the fact that this isn't a dedicated track car. While it isn't my daily either, I still drive it on the weekends and to various car meets. I've had the car for three years (almost to the day) and I'm just about to tick 17k miles.

The oil analysis below has three different samples/logs. Each with increasing mileage and number of track events. The first sample was done with only 1,000 miles on the sample and 1 track event this was Mobil 1 5w-30 and obviously it came back completely fine. The second sample was with 2,730 miles on the oil and two track events plus one autocross event. Oil still appeared to be OK. Third (most recent) sample is with 5,029 miles on the oil, 4 track events plus two autocross events. Both the second and third sample were with Pennzoil Platinum 10w-30.



The Solution:
Now I realize that the oil weight isn't the primary issue here. The lack of cooling capacity is what I need to address. From all of the research I've been doing and the great information that has been posted by both Orange Crush 1LE and X25 I will be installing an aftermarket oil cooler. Orange Crush 1LE (and maybe X25) no longer use the radiator coolant to "cool" the engine oil. I think by doing this the benefit of the radiator coolant not having to do double duty is the real benefit.

I will need to do some research on the oil cooler selection, unlike both Orange Crush 1LE and X25, I've got a ZL1 and I need to look at fitment and where I'm going to be mounting things. I think the mounting location of Orange Crush 1LE (to the side of the radiator and in my case intercooler) will be the preferred location as opposed to X25's centralized location in front of the radiator. However this is getting into uncharted territory for me as to what I'm going to need and if I'm over looking something for this build.

I haven't really found a good thread for a ZL1 address cooling for a road course application, people are too busy drag racing them I suppose. Had I known I was going to get so involved with HPDE events I would have just bought a 1LE or Z/28

[AITI]

Have you logged it when running to see what is happening with your timing when it overheats. Seeing the corvette C7's are pulling timing due to detonation from the oil ingestion, and they are seeing timing pulled to the point it is causing the overheating. Post up some logs if you have HP Tuners for us to see.

[X25]

I can't believe I missed this post; I must have ignored it seeing ZL1 in title : )) I honestly did not have too big of an issue on cooling the SS, but I've had huge issues with cooling my supercharged Miata, which taught me a lot, and yes, I fixed it! We always need to think of cooling as the whole system.

Air flow:

• Do we have enough air flow to the radiators (water, oil etc.)? If not, can it be improved? Doing a bit of ducting work to make sure all radiators get enough air flow can do wonders.
• Also, if the radiators will have to share the air flow, the best performance is attained by stacking the radiators closely. If you have GM's giant license plate holder or other obstructing things in front of the air inlet, you should relocate or remove them.

Thermostat / Coolant:

• A well designed racing thermostat not only opens up earlier, it also does so faster (but not too fast to shock the system), and most importantly, it allows more flow!
• If you don't have enough flow, the coolant in your engine might be running at 240 degrees F while the coolant inside the radiator might be running at 210 degrees F (since it's not replaced with hotter coolant quickly enough), greatly reducing the efficiency of cooling.
• I did not change thermostat for the 1LE, but I actually completely removed it for the Miata (to test it out), and the increase in cooling capacity was nothing but dramatic.
• I checked what the coolest temp ever recorded was in my area, and set my coolant ratio taking that into consideration. You need at least 20% coolant (or you might face corrosion). I set mine to 30/70, and will leave it like that.
• On the top of that, you can add a coolant booster (like water wetter). I first used Redline's water wetter, and it gunked up, burned when my coolant temps hit 240 degrees. I switched to Amsoil's coolant booster, and no issues. Even if the booster drops the temps by, say, degrees, it's well worth it.
• Based on all these above, a high flow water pump can also do wonders, but you'll need to test it out. I see people also upgrading the supercharger's own cooling system's pump, which makes sense, too.

Oil grade:

• The lower weight oil will be thinner, and will flow much faster, aiding in cooling, reducing friction, and reducing back pressure.
• The higher grade oil provides a tiny tiny bit more protection at high temps, but it also greatly increases the back pressure, thereby reducing the flow. You know what happens to the exhaust flow if you add a few more cats to the exhaust? The same thing is happening here. The modern engines have small oil lines surrounding the engine, pistons, etc., and if you run thicker oil (than spec'ed), you end up actually reducing the flow. I learned from another thread that our oil pump actually opens up bypass valve at 50 PSI. In other words, any pressure more than 50 PSI means not all the oil going through the pump is flowing back to the engine, but rather some portion is going back to the sump.
• If I were you, I would stick to the 5W-30 oil. Don't run 40 weight oil unless you need to do so (which you can determine by doing Bob the oil guy's test, but I'm almost sure you don't need to). 50 weight? I would run away! 50 weight can easily add 20 degrees to your oil temps compared to 30 weight. There is one important point here: 0W-40 is NOT THINNER than 5W-30. For synthetics, you should judge them first and foremost by their warm weight. In other words, the difference between 10W-30 and 5W-30 synthetic oils is much less than the difference between these oils and 0W-40. 15W-50 lives on another planet.

Oil temp gauge:

• If I recall correctly, the oil temp gauge shows only up to 266 degrees even at the dash (is that right?), but you can still read it until your engine dies from OBD2 port.
• I use this Bluetooth OBD2 reader to get all the info, and watch from my phone if I need to during the track sessions: http://www.ebay.com/itm/Vgate-iCar2-...8&var=&vxp=mtr
• Well, it is calculated on the SS, so I installed my own temp gauge anyway. I don't know about ZL1's. I remember someone stating all but those with dry-sump engines (Z/28) having fake gauges. Sad.

Additional (air-to) oil cooler:
You are right, the single biggest thing you can do to drop your coolant temps is to let it free of cooling the oil. That said, cooling oil is a very hard task, and will cost you $1000 to properly do so.

My recommendation:

• Stage 1 (~$650):
  • Bigger radiator.
  • 30/70 coolant/water or so.
  • 5W-30 oil unless 40 weight is absolutely necessary.
  • Revised ducting for the radiators (if possible).
  • Lower temp / high flow thermostat.
• Stage 2 (additional ~$800+):
  • Decouple oil cooling from radiator.
  • External Oil cooler.
  • Gauges (oil temp for sure, so you know what's going on).
  • High flow water pump (highly recommended for supercharged cars)
• Stage 3 (additional ~$400+):
  • Decouple transmission cooler from radiator (you have one, right? Does it use the radiator?).
  • Additional radiator(s) (this is actually fairly easy, using go-kart radiators).
• Stage 4:
  • De-mod and sell the car

[White_SS/RS]

Lots of good info there, X25. I fully agree.

[AITI]

Originally Posted by White_SS/RS

Lots of good info there, X25. I fully agree.

I agree. All good stuff to consider and implement.

[SPCBA]

I have run in 118 ambient with the black top over 150. I am no supercharged. I run distilled water and water wetter or amsoil water boost (sorry forgot exact name). The ones with anti corrosion in it. I seperated my Trans and oil cooling off to seperate rads. It makes a word of difference. Only my brakes worry me with heat anymore x25 listed out a really good bullet point presentation... Should be a stick post!

[X25]

Thanks guys, I'm glad you guys didn't see my line of thinking ridiculous. It's a tough task, and at some point, how good your solution is will depend on how much you think it's worth investing.

[LagunaSecaZL1]

Originally Posted by BaylorCamaro

If only money was no object... I'm curious to hear your feedback after your track event this month.

Well I typed the whole response, server was busy, so I am retyping it in. A quick summary. I went to Thunderhill Raceway in Willows California. It was a typical summer day in the central valley. Started at 70* ambient and went up to 100* by about 2pm. The car is my 2013 ZL1 stock tune and pulleys. Ron Davis Radiator, heat exchanger and 174* lingenfelter thermostat with a Rotofab CAI. I used my iPhone 6 with Trackaddict and Gopoint Bluetooth OBD reader. By looking at the screen shots from the app, my first three laps were fast then the car got progressively slower. I base this on the front straightaway speed dropping from 125.9MPH to 120MPH and then about 119-118 in the later sessions of the day. Each session is about 20 minutes and did about 7-8 laps. The car always recovered to 200* coolant temp in the pits. I did use the A/C on the cool down lap and in the pits to cool the engine. I will install 160* thermostat, but doubt it will make that much of a change with regards to the powerloss. I will data log knock retard and spark advance the next time I go to the track. The Ron Davis radiator did keep the coolant temp below 230* and the oil below 260*.

[sting808]

I'm testing the lingenfelter 174 stat on the street for the last 2 days. No auto-x or hard racing yet. So far, it is a little better than OE and much better than the (2) other 180 stats, but not as cool as 160. The 160/174/180 are motorad/Murray designs. The other 180 is a Napa(worst so far) and my OE ac delco 186(3rd place). I will run it a couple more days but will probably put back the 160. With the dewitt dual core radiator and OE water pump, coolant flow based on rpm plays a huge role with the different designs and temperature openings. Ac on and off. I'll post side by side pics of the 5 stats later. Would be interesting to see the stats used with an OE radiator.

[X25]

Originally Posted by sting808

I'm testing the lingenfelter 174 stat on the street for the last 2 days. No auto-x or hard racing yet. So far, it is a little better than OE and much better than the (2) other 180 stats, but not as cool as 160. The 160/174/180 are motorad/Murray designs. The other 180 is a Napa(worst so far) and my OE ac delco 186(3rd place). I will run it a couple more days but will probably put back the 160. With the dewitt dual core radiator and OE water pump, coolant flow based on rpm plays a huge role with the different designs and temperature openings. Ac on and off. I'll post side by side pics of the 5 stats later. Would be interesting to see the stats used with an OE radiator.

Do you intend to collect data at the track, too?