Thread: Changing MAF with tunercode

When changing a maf (has tunercode). I should probably stray away from adjusting K as always via the formula to do so.

I see some forum members here use the current/base injector settings so they can bypass the "K" constant. Shall we all be going this route now???

If you switch to an N60 or E60 you can get away without touching the K value. If you switch to a Z32 maf then you will have to adjust the K value.

Treat the K value as the MAF scaler and treat the Current injector size as the injector scaler.

Problem: You installed different injectors.
Solution: Update the current injector size until your AFR's are at 14.7 cruising.

Problem: You installed a new MAF.
Solution: Update the K value until your AFR's are at 14.7 cruising. You will need to rescale your TP scales.

Problem: You installed a new MAF and different injectors.
Solution: Now you've done it, you divided by zero and the universe is ending! Stay calm we can piece it back together. Most likely you will have to modify both the K value and the Current injector size. You will have to rescale your TP scales.

I went from a DE to N60 maf Vadim and use stock injectors.

Ive always used to "K" when changing maf and had no issues besides the scalling being off some. no biggie

So do you think i should go with a modified "K" or use the injector scaler?

I just thought it made more sense to go this route because you want to keep "K" as close to stock as possible.

The idea is to keep from having to change the TP scales.

When swapping to a larger MAF, the same mass flow rate produces a lower voltage from the sensor. Depending on the differences between the VQ tables, you will generally need to increase K in order to produce the same TP scale. As long as the same mass flow rate produces the same TP (through VQ table and K value) only fine tuning of K and VQ table should be necessary.

Installing larger injectors has no effect on TP calculation, but it does effect the amount of fuel injected for a given injector pulse width (IPW). In this case, increasing the current injector size decreases the IPW proportionally, so latency should be the only other tuning change necessary.

Dave

thanks for the help.

I will just stick to adjusting K by the method of new maf/old maf*K and leave the current/base injector alone at 259cc

With 370cc injectors and E60 maf I was able to get away with using stock K value and just adjusting down the Current injector size to 250 (and stock at 259). The main reason I didn't need to touch the K value is because my TP values where on par with what they would be stock. If I increased K value for the MAF, I would be going above 100's while not even in boost .