Coolant additives to decrease engine temperatures

[Tracked Emira]

It has been very frustrating to think my car is going into limp mode because it is overheating when the outside temperature is over 90 degrees.
Obviously Lotus knows this is an issue, otherwise they wouldn't have recently upgraded the cooling system. I will eventually install JUBU's coolant system unless we can purchase the new system from Lotus.
I can't understand why I never see the temperature reading climb above 200 degrees on a hot day when tracking the car. Please explain because it is impossible for temps to never go above 200 degrees especially when you run more than 8 hard track laps with temps over 90 degrees???
I have been researching different additives and have come down to using either VP cool down and Royal Purple ice coolant to try to reduce engine temperatures.
Anyone try these and have any recommendations?

 

[MapleOreo]

I put in a bottle of water wetter as soon as I got the car.
On "normal" days, it sits at 85 degrees. On super hot days, the highest I've seen it is 89 degrees.

 

[Kaz]

If you have access to an OBD2 reader that gives you live readings you will see the actual temp is different than reported temp on the dash...on mine the OBD2 reading is usually lower for a while, then catches up but remains a little under the dash temp...will keep looking when I get my car back from tuning

 

[Kaz]

Was in the canyons all morning driving hard and OBD2 water temps never went above 170 and was mostly at 165 with ambient temp at 81, the dash was showing a range from 185-198. The car shows 185 fairly quickly even when the OBD2 value is still warming up to 150-ish. The dash is clearly showing a number that "looks" right probably to avoid worrying the driver and causing lots of dealer requests. No idea if the OBD2 reading is accurate vs the dash, but the OBD2 readings are real time and change based on throttle input so i would think just like the artificial power readings that never go above 400hp the dash water temp is same way. Will probably show just a value above 200 when the car is actually very hot (like 220+).

 

[MapleOreo]

185-198 is exactly the range my i4 runs in.

 

[Read T]

Agree that live temp monitoring through the OBD port shows a few degrees cooler. So far, mine has stayed 185-195 in hot humid NC Summer. My Mini cooper from the factory runs at 221-226 which always freaks me out. Additives like water wetter may help, but work best with straight distilled water (but then may provide less corrosion or freezing resistance)

 

[jp129]

Would you detail how you're getting limp mode? I'm curious to understand what's causing your issues.

I track my v6 Emira frequently in Texas where the ambient temps have been 98-105F, doing min 10 hot laps at my local track (MSR Houston) with no heat issues.

The only things I'm doing is running without the engine covers and I let the car idle for about 5 mins after coming into the pits.

I'm a fast advance driver (I race w2w in NASA TX region) so the car gets pushed to a fast pace on 200TW tires and race pads (1:46 ish lap times).

 

[jp129]

In terms of the dash temp reading, it's a dummy gauge. It'll only show 200F until it hits the next temperature node (which is likely when it is overheating), but it seems like it is reading slightly higher when UNDER 200F. It was showing 194F when OBD was showing 188F

When my OBD is reading 212F, dash still shows 200F. 212F is the highest I've noticed with my use.

 

[Tracked Emira]

Since I changed to Milltek Version 2 and changed O2 sensor all my fault codes have cleared. When I track New york safety track on 9/16 I hope not to overheat which may trigger a limp mode.

 

[OppositeLock]

I have a V6 Emira and I've tracked it in very hot weather, approaching 100F, and I pushed it quite hard. It never overheated. The temperature gauge is indeed an idiot gauge that always reads 200F, however, OBD-II logging on my AIM showed the actual temperature, which approached 220F.

Something's wrong with your cooling system or a sensor.

 

[Tracked Emira]

I have a V6 Emira and I've tracked it in very hot weather, approaching 100F, and I pushed it quite hard. It never overheated. The temperature gauge is indeed an idiot gauge that always reads 200F, however, OBD-II logging on my AIM showed the actual temperature, which approached 220F.

Something's wrong with your cooling system or a sensor.

I haven’t taken out on track since the sensor was changed. So I’m hoping it was the sensor and that it won’t go into limp mode again. Will post after tracking on 9/16

 

[silent cilantro]

I am pretty sure your engine is not overheating. It’s your automatic transmission overheating and putting the car in limp mode. From what I understand it happens with auto Evoras as well.

 

[mikemc]

I am pretty sure your engine is not overheating. It’s your automatic transmission putting the car in limp mode. From what I understand it happens with auto Evoras as well.

The auto has a different cooling setup that is direct oil cooling not heat exchanger (image from evora documents).

 

[mikemc]

It has been very frustrating to think my car is going into limp mode because it is overheating when the outside temperature is over 90 degrees.
Obviously Lotus knows this is an issue, otherwise they wouldn't have recently upgraded the cooling system. I will eventually install JUBU's coolant system unless we can purchase the new system from Lotus.
I can't understand why I never see the temperature reading climb above 200 degrees on a hot day when tracking the car. Please explain because it is impossible for temps to never go above 200 degrees especially when you run more than 8 hard track laps with temps over 90 degrees???
I have been researching different additives and have come down to using either VP cool down and Royal Purple ice coolant to try to reduce engine temperatures.
Anyone try these and have any recommendations?

https://www.jubu-performance.com/_data/container/container_31/Manual_en.2562/JUBU_Intercooler_hose_routing_upgrade_EmiraV6_manual.pdf

You can go to an auto store and just buy generic hose in the correct sizes and route them this way. Idk why the Emira changed the charge cooler routing from the Evora (especially since they changed it back for MY26). Lotus will 100% have the individual coolant tubes for sale as parts as well.

Use a OBD logger for true engine temp. Operating 180-215 is totally safe and is actually optimal. On track I reach up to 220ish at ~13 laps into VIR.

I saw someone else mention (SBwhatever) that they added the JUBU cooling kit and see temps in the 170s for street, this is actually below optimal. The two thermostat options JUBU offers are also have equivalent oem Toyota part numbers. The goal for these really is for track use only as it will get you a couple extra cooler laps depending on the track, the water system will start a lap or 2 sooner basically.

Track wise a lightweight water pump pulley will give you better performance at higher RPM (which you see on track) due to decreased cavitation, and worse performance at lower RPM, but you shouldn't ever hit dangerous levels in street driving anyways. NST has a lightweight water pump pulley for like $150, this likely CAN be done with the engine in the car still, but will be a pain / require really skinny arms.

 

[Porter]

It has been very frustrating to think my car is going into limp mode because it is overheating when the outside temperature is over 90 degrees.
Obviously Lotus knows this is an issue, otherwise they wouldn't have recently upgraded the cooling system. I will eventually install JUBU's coolant system unless we can purchase the new system from Lotus.
I can't understand why I never see the temperature reading climb above 200 degrees on a hot day when tracking the car. Please explain because it is impossible for temps to never go above 200 degrees especially when you run more than 8 hard track laps with temps over 90 degrees???
I have been researching different additives and have come down to using either VP cool down and Royal Purple ice coolant to try to reduce engine temperatures.
Anyone try these and have any recommendations?

The car has plenty of cooling. There are TONS of people driving these cars very hard in hot weather, including in much hotter parts of the world like Dubai.

A more likely explanation is that some part of one of your cooling loops is not operating correctly. There is an electric secondary pump I believe... and I'm not sure if it has a sensor to monitor operation.

Take it to the dealer and have them diagnose it.

 

[mikemc]

That's also a potential issue. (again pic from evora docs) You've got a bypass valve and re-circ pump that could have issues.

 

[Porter]

If I remember right the Emira has two circuits, one for the engine and the other for the charge cooler rad, and the latter has an independent electric pump. I'll have to look it up in the service manual.

 

[silent cilantro]

But he is saying his temperature gauge doesn’t go above 200 (like everyone else’s). His issue is his auto trans getting too hot. Not the engine.