Hey guys i just did a little experiment to find out when our temp gauge really starts moving. It is 230f and as a side note above 245 you cant reflash the car. If you have to unplug the coolant temp sensor and it will reflash.

Neat. That's using the OEM ECT, correct?

Yes

Good morning log.
What do you mean by 'reflash'?
I thought that was something only the dealer can do.

Morning Cajun. Cobb ap and mazda edit are also reflash tools. I have a cobb.

OK, thanks.

How did you get your car to overheat? IIRC the FSM states that all the way up to 243F is within spec.

Rob @ Pineapple told me that he has built a lot of dune buggies powered by the renny and older 13B's and he said they run in extreme conditions and that typically OEM coolant seals start to deteriorate if you spend any significant time around 220F.

My last engine died of a failed (well it was caught in a oil sample it didn't actually fail) coolant seal after 30,000 miles and I did often get in the 225F range (both oil and coolant) and spend some time there during our runs thru the canyons during the spring and summer. The runs are typically high RPM, low gear, fairly low speeds.

I know people have pegged their gauges and not had issues but I think overall they were just lucky.

OH and IIRC, the factory temp sensor maxes out at 248F according to the FSM.

It's not installed on the engine.

This is why I got an ultra gauge.

Oh, so he just removed it and heated it up, gotcha ;)

I just tuned it to high temp car was actually about 100f at the time.

You can tune readings from sensors!?!?

Maybe he changed the tune so the fans don't come on?

The iat and maf sensors are tunable on 04 and 05 models with cobb

So what did you actually do? I'm confused now.

:lol: I think he drunk.

Dang man its too early to be drinking.


I told the car no matter what voltage the temp sensor reported it was x tempeture. Then flashed the car. Then took a pic and reflashed it to a higher temp.

200, 225, 250.

The. It would not let me reflash and i got scared and figured it out. So i did

230, 237, and 245

Then i narrowed it down and did some of the finer incriments.

Well that's one way to do it, I guess. Thanks for sharing!

I got to the last photo at the track a couple of years ago.

The oil temp was just under 230 and I was in the heat of the battle on a hot summers day. I usually keep an eye on the oil temp and back off when it gets to 230.

The only signal I was getting from the car was hesitation as I floored the throttle on the back straight of the track. When I went around the next lap it did the same and it is then I noticed that the water temp gauge had moved I backed off for a lap and it immediately cooled down however, it returned again after a couple of laps of hard driving.

Car has been running fine after that episode.

I'm assuming this is the map you played with.... very tempting since I monitor water temp through my adaptronic that has its own ADC table.

https://cimg8.ibsrv.net/gimg/www.rx8...48a956fe41.png

so a little bit of anality here.

Sensor theoretically goes up to 284F.

To have the gauge jump sooner, rescale .620v through .224v. If you want it to jump like mad, simply set all cells from .620v on to 140. With a little bit of interpolation you could have it rise in a visible linear manner.

It's literally as simple as making the V vs T graph into a straight line from top left to bottom right.

so interpolate between the endpoints?

Like so?

https://cimg2.ibsrv.net/gimg/www.rx8...f8c0b5ff00.png