wrighty338

iTrader: (33)

Beeen told i need an Air Temp Sensor to run on my simtek, however thought they only utilized a MAP sensor, anyone else running an ATS with their simtek?

Where do i start looking for one of these, presuming is a charge temp sensor by the way?

cars = nightmare

MartynJ

Any SimTek dealer should be able to sell you one. The MAP sensor is for load sensing only, the ATS is used for a number of things. Ignition and fuel based compensations, water spray output for those who wish to use it and an ALS fail safe.
We have never fitted a SimTek without one !

Peanuts

iTrader: (15)

but you can run without it to great effect, just without compensation.

bdog

Forgive my ignorance but IMHO cars with MAP sensors usually make use of the speed density calculations. Something like that:

(Engine Mass Airflow Rate) ≈ RPM × Volume x MAP x M / (2 x R x absolute temperature)
/from wikipedia/

Apparently the ECU needs an IAT (intake air temperature sensor) to calculate the Mass Airflow Rate.

Note: Not sure whether Simtek uses speed density.

charlesk

No IAT sensor on a MAP based ECU is bad practice.

Ideally you want the IAT sensor on the boost side to take account of the charge temp and not the ambient air temp.

Otherwise you can't compesate for hotter charge in summer/extended hard runs, nor for cooler charge during cold days and running lean...

What is the point of fitting an aftermarket ECU and not being able to tune it to do it's job properly?

tweaks

iTrader: (7)

mine was supplied and fitted with my simtek from the dealer/mapper i used

wrighty338

iTrader: (33)

right cheers lads will speak to my local mapper