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View Full Version : Pls explain numbers


Donald
07-09-2003, 08:56 PM
Blue is speed, yellow is intake temp and purple is coolant temp.

Seems intake temp has little no bearing on coolant temp.
Mike M
07-09-2003, 09:02 PM
Intake air temp and coolant temp should have no effect on each other.
cyclone03
07-10-2003, 07:40 AM
interesting how the car runs cooler at 78mph............
engine23ccvfd
07-10-2003, 10:17 AM
We high idle or engines (as in firetruck) in the summer to flow more water thru the system....doesnt make sense to me that running 1500RPM (high idle) instead of the normal idle keeps the engine cooler but it does......Also helps the AC compressor keep the cab cooler (bonus)
TripleTransAm
07-10-2003, 12:01 PM
Originally posted by cyclone03
interesting how the car runs cooler at 78mph............


You probably also get better air flow through the radiator at speed, not to mention a better evacuation of underhood heat.

As for coolant temp affecting intake temp, the intake temp is measured at the MAF, according to what was mentioned on this board. The coolant temp takes a measurement directly from the water jackets cooling the engine. Eventually, the underhood heat (and direct heat transfer from the interconnecting engine parts) will come to raise the intake temperature slightly, but there's no real direct relationship between the two.
LincMercLover
07-10-2003, 10:57 PM
Originally posted by engine23ccvfd
We high idle or engines (as in firetruck) in the summer to flow more water thru the system....doesnt make sense to me that running 1500RPM (high idle) instead of the normal idle keeps the engine cooler but it does......Also helps the AC compressor keep the cab cooler (bonus)

Sure that's not a diesel motor?
Bigdogjim
07-11-2003, 05:13 AM
Originally posted by engine23ccvfd
We high idle or engines (as in firetruck) in the summer to flow more water thru the system....doesnt make sense to me that running 1500RPM (high idle) instead of the normal idle keeps the engine cooler but it does......Also helps the AC compressor keep the cab cooler (bonus)

In diesel engines fast idle switch is too keep oil moving and the oil pump works better at the higher RPM than at curb idle. In the tour bus that I drove we did it because of the huge demand the blowers for heat/a/c put on the system.
yes it also helps keep the water moving.

A/C is at peak at 1500 RMP in the big coaches.