ALPSTA

iTrader: (3)

I have a maxidisplay gauge which has an alarm function for the sensors I am listing below.

For a 13b rotary engine what numbers would be a happy medium between the alarm annoyingly going off all the time and a blown engine?

Specs: GTX35R (15-18psi), V-mount, ID725/2000, Water/Meth inj., 3.5"dp, etc...

Boost:
Revs:
Air Fuel Ratio:
Exhaust Gas Temp:
Fuel Press:
Oil Press:
Oil Temp:
Water Temp:

cr-rex

iTrader: (114)

if your boost is set at 18psi with a good boost controller then i would set my warning at 20

you should have your revs set to 100rpm higher than the rev limit set on your ecu from the tune you have

idk about afr and egt

fuel pressure i would think you would set slightly above what your fpr is set to

idk about oil pressure and oil temp

i set my water temp warning at 100C. 110C is the absolute limit...

fuel pressure should be set to a little higher than what you have your fpr set to, i would think

arghx

iTrader: (3)

How sophisticated is the alarm functionality? Can you set conditional statements in some software or are you just turning a **** somewhere?

For example, AFR warning would only make sense if it's within a TPS voltage (heavy throttle). The same could be said for fuel and oil pressure.

EGT depends where you have the probe installed. Most turbos are rated to 900-950C before damaging them. Overrev depends a lot on the application and how you have your rev limiting setup. Rev limiters don't kick in instantly.

I'd give it 130C for oil temp and 120C for coolant temp if you want actual temperatures where problems can occur. A lot of guys like to run a lot cooler than that.

ALPSTA

iTrader: (3)

The alarm function on my gauge is not really that sophisticated. You set an X figure and it'll beep and flash when the gauge reaches that figure.

EGT probe is installed after the turbo on the downpipe.

I believe the figures you've suggested are in degrees celcius and not fahrenheit

Since oil pres, fuel pres and afr depends on other variables let me rephrase my question, I will not set an alarm for those but instead within which numbers are acceptable for them? And which numbers are start of trouble?

ALPSTA

iTrader: (3)

If I am not mistaken FD thermoswitch opens at 108C and FC thermoswitch opens at 95C, so both your numbers are within acceptable limits and not danger zone at all for a warning alarm.

arghx

iTrader: (3)

Oil pressure depends on load. IMO, either your **** works it doesn't. A warning is kind of pointless.

Fuel pressure, well I don't see how you could realistically use that in a real world scenario. The only thing it would be good for is if you are on a dyno and diagnosing a lean fuel issue.

AFR, well a basic rule of thumb is no leaner than the 11.9:1 (high 11's reading on a typical wideband AFR gauge) under full boost.

ALPSTA

iTrader: (3)

^^ Cool, thanks for the info. I just prefer an audible beep instead of watching the gauges all the time and to be honest if it wasn't for the water temp warning beep, I could've realised that water temp was too high much later. But I get what you are saying.

cr-rex

iTrader: (114)

7. Optimum Temps
65C (150F): too cold. According to service manual, EGR valve is non-operational below 150F, "to improve drivability when cold."
82C (180F): getting warm. Thermostat begins to open, circulating coolant through the radiator. Some coolant is still bypassing the radiator.
95C (203F): fully warm. Thermostat is fully open, not bypassing the radiator at all.
100C (212F): boiling point of pure water at atmospheric pressure.
105C (221F): getting hot. Stock ECU will activate fans to cool the car down. Fan speed will be low, or medium (if A/C is already on).
108C (226F): hot. Stock 93-95 coolant thermoswitch activates, changing fan speeds from low>> medium (or med>>high if A/C is already on) (switching to an FC thermoswitch will change this temp to 203F)
115C (240F): getting dangerous. OEM temp gauge begins to rise.
117C (243F): dangerous. boiling point of pure water with 13psi pressure cap.
121C (250F): too hot. OEM temp gauge will point to white line. Boiling point of pure water with 16psi pressure cap.
124C (256F): way too hot. Boiling point of pure water with 19psi pressure cap. Boiling point of 50/50 coolant mix with 13psi pressure cap.
127C (260F): way too hot. OEM temp gauge will point to red line.

from the big fat fd3s cooling thread.

personally, 110C is my limit. the highest its ever gotten on its own in stop and go traffic when it was crazy hot outside was 101C. if its running at or around 110C then there is a problem. after a hard run at the track it will get up to ~105-108C. so my personal preferance is 110C to have my warning light.

ALPSTA

iTrader: (3)

^^ thanks