The Joshua Tree

I just want to see what peoples opinions and thoughts are of going mafless and switching to speed density, going mafless has been recommended to me due to a problem which apparently newage cars suffer from where you get hesitation/stuttering, i had it explained to me why it does it on newage cars.

Danjo

Speed density is often used when the airflow starts to exceed the working range of a MAF sensor. The advantages are that it removes any restriction from the turbo intake, as you are no longer limited by the size of the MAF housing, and it also removes a potential failure point (the MAF). Speed density is also better at adjusting to changes, you can fit different intakes and intercoolers as the ECU is calculating the air flow at the inlet manifold. A MAF setup would require map adjustments to cope.

MAF’s are generally the better option when kept within their working range, so for more mildly modified car a MAF sensor is often preferred as it gives an actual mass air reading, rather than a calculation, so is better at adapting to temperature and barometric pressure changes.

ALi-B

iTrader: (1)

As said MAF is accurate, so in sorts keeps the air/fuel correct. Caveat is assuming it is accurate which of course can be affected by leaks and exceeding its working range . A wide band OS sensor should help keep that in check to monitor any deviation and correct it. Larger diameter MAF housings do exist if it's seen as a restriction but obviously calibration needs to be checked, especially if transferring existing sensor into new a housing.

Hesitation/stuttering should be checked out graphing oxygen sensor output, map, maf, pedal position and rpm to see what's going on. Hooking up a Fuel pressure gauge at the same time would also be beneficial on ruling out any dynamic changes of pressure whilst driving.

Bit of an anecdote on this, but on some Renault diesel vans running Bosch EDC15, which is a MAF based ECU but actually had no MAF fitted and instead calculated MAF value via the MAP sensor m, intake temp and EGR position. What made it so bonkers is the ECU behaved like it had a MAF sensor, so when it had a boost leak or sticky EGR it'd log a P0101 MAF code despite no MAF ever being fitted No help here but just shows it's possible to use software to simulate/calculate MAF and manufacturers like Renault/Bosch do it, so it is acceptable even if it's not the usual way of doing things.