In my Civic hatch with a B18C GSR swap, when I autocross it or on a track day the temp is fine but when I drive it down the road at 50mph the temp falls down almost to the first line on the gauge. Could it be my thermostat?

 

It sound like you don't have a thermostat in your engine. Another thing is your temp sensor may be bad.

 

^ agreed....did you buy the car recently with the swap or did you do the swap? i had the same problem with a car i bought w/ a LS, they jammed somethin in the thermostat to make sure it would run cold i would think everything was fine...bunch of sneaky asses out there

 

Bought the engine from HMO. Did the swap myself. Guess I will have to pull the thermostat out and check it.

The temp gauge stayed right were it should through 4 20 min sessions at NHMS.