Rote8

Make sure the thermostat has a small bypass hole like the stock one or you will not be able to get the air out of the block when filling the coolant.
Do not trust a parts house that claims "it fits". (but does it work?)

WTBRotary!

iTrader: (6)

So a quick update on my REmedy water pump and thermostat...

So I found a suction cup mount for my Cobb AP so I can keep it plugged in and watch the Live Data. While driving to a friends house 60 miles away in 77-84 degree weather @ a steady 70-80 MPH my coolant stayed right at 180 degrees and would fluctuate between 175-183. This somewhat makes me nervous because that means my thermostat is opening and closing constantly which is not the best thing. It would raise to about 180-181 then when the thermostat would open it would drop back to 175. And what scares me even more is it was ~80 degrees outside, Im curious to what my temps are going to be like when it gets around 40 degrees here...

9krpmrx8

iTrader: (46)

Mine sits at about 185F at cruise in these temps. Yesterday we did a canyon run and I got to 230F max when hitting it hard.

WTBRotary!

iTrader: (6)

I have yet to have my Cobb AP long enough to have a chance to track my temps, but i don't think mine would get that high... For some reason it seems you have a cooling problem. Every thing I've seen you do and it seems your temps never go down or get cooler... Hmm

9krpmrx8

iTrader: (46)

Why do you think I have a problem? 230F max temp in 100+F weather when flogging the car hard is good. We will see on the next statewide meet. I guarantee you will get close to or above 230F.

dannobre

iTrader: (3)

The thermostat is supposed to open and close....if it is colder outside it won't have to be open as much to cool it off ...the thermostat won't care if its 20 deg outside or 80..it opens and closes to regulate the engine temperature

The only time you have to worry is when the ambient temp is too high..then it won't cool off even if the thermostat is open all the time...But if it's that hot you will have other problems

9krpmrx8

iTrader: (46)

^ Yeah I have learned once this engine is heat soaked the only thing that will truly cool it down is to shut her down.

WTBRotary!

iTrader: (6)

I guess its not that I think you have a problem as I see you always trying to find a better way to cool your car which leads me to assume you have a problem...

We will see what my temps get at the next few cruises and at the next Texas State meet..

9krpmrx8

iTrader: (46)

I would like to see max temps in the 215F range but I'm not sure that is possible. After I get my BHR flywheel and clutch I will likely get the BHR rad (should have bought instead of the POS Koyo) and mazmart pump and thermo. If that doesn't work then oh well.

I can say though that sealing up the areas around the radiator did make 5F difference or so on my logs but there are so many factors. Many say if the cooling system is working optimally then outside ambient temps should not affect it under normal operating conditions. Adding royal purple ice didn't do ****, nor did running 80/20 distilled water/coolant.

olddragger

iTrader: (3)

just got through with Road ATlanta w/e. Ambient temps up to 95F in the evening sessions. 30 minute sessions. (These are LONG), max coolant temp on gauge and obd2 sensor.................208F.
I never go over 8K and since the sessions were so long I played with different rpm redlines. If I dropped my redline to7/ 7.5 K my coolant came down to 195 area.
After cool down lap I was at 175F
If you dont think I had a heavy load on the car just look at the vids I will post on the Pettit SC owners thread.
In conparison, a friend of mine that is kicking butt in TT with a n/a rx8 and a big old really nice Radiator (expensive too), that I will not give the name, hit 240F before he noticed. The previous evet we attending and drove he hit 230F --I was riding with him and noticed it and told him. 225+ is too hot for any lenght of time is what I have been told by several.

9krpmrx8

iTrader: (46)

So, do you think its the secondary radiator or keeping the revs low? I do know that when I spend a lot of time near red line my oil temps rise quickly. OD, are you going off of your factory tach or OBD?

p4ck37p1mp

iTrader: (1)

OD, thats odd, my water temp never got over 200 for any length of time this past weekend, and I'm slower than OMS, he should be cooling better than me. This was from my ProSport Premium gauges, electronic senders at the coupler, I didn't have the AP plugged in. Also, my oil temps with the Remedy pressure mod tend to be lower than my water temps by about 20 degrees or so on average.

olddragger

iTrader: (3)

I think its a combo of both.
Try as you may----unless you get a really good flow of air through a rad, the car is going to continue to have higher coolant temps.
There are several ways of doing this, but the simplest one to me is of course the secondary radiator set up.
The difference between 8K and 9K is huge---huge. The centrificul forces on the engine shoot straight up--the heat shoots straight up. Its ridiculus.
This engine was never properly designed for any substained 9K use--or for that matter repetitive 9K use --IMHO.
I dont understand either why dont more people drill their thermostats? Just a very small hole to balance out that bypass, primary switch-a roo flow the thermosat does? Its dont make a huge difference, but if we go to so much trouble addressing cooling issues--then this is a free and easy thing to do? I am talking about us folks in the hot climates.
Never leave out the "little things". They add up quick.
OD

olddragger

iTrader: (3)

That is odd.
To make sure I am understanding this right... you never went over 200coolant and your oil temps never went over 190F during the w/e?
Sunday ambients were cooler , but Saturday was a little warm.
OD

p4ck37p1mp

iTrader: (1)

I wasn't watching it too closely, never went to 220F as that is where it alarms. Every time I glanced water was 200-205, oil was lower, 10-20F lower. Has always been that way, assuming it was the oil pressure mod, as I didn't have gauges before we did that. Even yesterday the last two sessions I was running pretty hard and never went over 205F. Again, I wasn't logging, and was just glancing on the back straight where I had time to look. I know that compared to June I was running a lot cooler, as I hit 224F in June and had to do a lap laying off the throttle to get it to cool down. I will say Don's car cools down a hell of a lot faster than mine, he hit 230F with me in the car and it was down to 175F or so in less than half a lap. Could it be a difference in where we have our senders?

9krpmrx8

iTrader: (46)

Hmmm. OD, is there a detailed write up on drilling the bypass? Alos, OD, do you log? If so what are leanest conditions you have ever recorded?

olddragger

iTrader: (3)

yep Dons car does cool off fast--i think that his heat comes somewhat from his head on fire--driving like a bat out of hell winning all those TT events!

Leanest condition?--Explain?
I do efi dude logs when I need too.
my af's on the track are in the 12/11's mostly.
OD

9krpmrx8

iTrader: (46)

I mean do you see spike to like 20 or anything that high?

HiFlite999

iTrader: (2)

However, the OBDII water sensor is on the other side of the thermostat from the Prosport adapter. A reading there shows the temp of the radiator water being fed to the engine, but not necessarily being let in by the thermostat. In normal highway cruise, I have 165F on the Prosport with 180F on the OBDII (Stock thermostat). As thermal stress increases, the feed water temp rises until reaching ~180F, then both temps rise more-or-less together since the thermostat has opened.

p4ck37p1mp

iTrader: (1)

I see the same thing using a ProSport adapter and gauges and my UltraGauge.

PhillipM

Watch the water pump for cavitation in those last 1000rpms, that's probably where the heat is coming from, ours used to suck the coolant hose flat there there was so much vacuum being created. The oil temp shoots up there too as it starts taking up the slack from the cooling system.

Also noticed a good 3-4* difference with sustained 8-9.5k driving when we went to a richer premix ratio of 1:80 rather than the 160:1 we used to run a few years back.