Hi, have you a pitch range or a min max limit ?
here is a example of my code i use:
Code:

---

	...
	my.car_topSpeed = clamp(my.car_topSpeed,0.1,pmax_topspeed[0]);

	temp = 0;
	if (my.car_topSpeed > 0.1)
		{
		temp = (rpm_range / pmax_topspeed[0]) - rpm_work;
		temp = my.car_topSpeed * temp;
		temp = clamp(temp,0,rpm_range);
	}
	else
	{
		my.carEngineTorque = 0;
	}

	...
	rpm_range = veh_daten[19] - veh_daten[18];

	eng_pitch = veh_daten[18] + temp;

	eng_pitch = clamp(eng_pitch,veh_daten[18],veh_daten[19]);	// min, max SND_TUNE
	snd_tune (enghandle1, null, eng_pitch, null);
	...

---

mfg