Steve Dallas

^ My thinking on the water thermostat is that 180F is as low as you want to go. Coolant helps heat the oil, which warms much more slowly. You also want a guaranteed operating temp of at least 180F under all conditions to evaporate moisture from the oil. In any case, the thermostat sets the floor temp of the coolant after warmup, and usually has little impact on the peak temp. To keep the peak temp under control, you need to focus on shedding heat, which means radiator, ducting and sealing, fans, glycol to water ratio, etc.

Your water pump is fine. Roll with it.

eyeguy

Thanks Steve. Maybe I'll just stick with a stock thermostat for now and see how things go. Do these series 2 cars typically do OK with stock cooling systems on track? I was looking at the rx8performance radiator but am not really excited about what I've read about fittment. Did you notice a significant improvement with the koyo, or did you fit it simply to replace a worn out stock unit? My car will likely see 4+ hours of track time each event. 20-25 minute sessions. Road atlanta in the summer is always the hottest event I typically attend.

Steve Dallas

I linked to a thread earlier in this thread that contains a lot of information on the Koyo S2 radiator, including how it is working for me. In a nutshell, it is not a vast improvement over stock, but it did bring my peak temps down around 5F, ramp up times are longer, and recovery times are faster. So, average temp is much reduced on a like-for-like basis. It is also obviously a good reliability upgrade, since there are no plastic bits to break or crack. The CSF radiator is also be well worth considering.

wannawankel

System pressure also controls peak temperatures before boiling. Any leaks/cracks or a faulty cap that relieves any pressure depresses the system-designed boiling point (at pressure).

eyeguy

Since my car is extremely low mileage I was hoping the stock reservoir would hold out for at least a few events until budget allows one of the sturdier aluminum units. I'll pull the stock reservoir out when I refresh the coolant and give it a thorough inspection.

For a normally aspirated application, do you guys think the extra money and effort to install a dual pass rx8performance radiator is worthwhile? If the koyo or csf will keep things cool enough for 30+ minutes on a hot day with moderate traffic then I'll be a happy camper.

NotAPreppie

The REmedy thermostat won't do anything for you once your coolant temps get into the low 200's (which is easy to do on the track).

I'm still running my original air separator tank from 2005. You can pressure test your cooling system with a rental tool from an autoparts store. I pumped mine up to 15 psi and it held that for over an hour so I figure I'm in pretty good shape.

Here's another thread about cooling upgrades:
https://www.rx8club.com/new-member-f...ck-car-265697/

Steve Dallas

The stock reservoir is an "ain't broke, don't fix it" item. Best not to disturb it too much, and do not try to remove its hoses. I am still running my stocker with no problems so far.

Several of us are tracking our cars with Koyo and CSF radiators with no issues. Sure, I wish my peak temps were a little lower, but I am not in the danger zone after 20 to 30 minute sessions in the Texas heat.

I don't have any experience with RX8Performance, so all I can do is post this:

https://www.google.com/search?q=site...utf-8&oe=utf-8

comebackqid

iTrader: (13)

if you plan on tracking I recommend these: 180F Oil Cooler Thermostat, RX8 | IRPerformance

Steve Dallas

Much cheaper version:

https://rotaryperformance.com/collec...ler-thermostat

eyeguy

I actually bought those yesterday!

TeamRX8

iTrader: (25)

Waste of money imo. Remove them and plug the bypass hole, then let the engine warm up before driving preferably. There are people on here without any bypass and it’s no bfd. That particular topic idea is way overplayed since it’s not a true bypass in the first place. It’s just a small bleed hole.