Montero #482 Maf vs #399 Evo8 Maf?

[imdrax]

So I have been running with the modified 501 for about 2 weeks now and it is night and day over my MAFT setup. Its pulling very hard all the way to redline at spiking at 20psi settling at 16 by redline. With evo 560's I am adding around %30 across the board. I am running out of injector up top so I think I will bump my base FP up a couple of psi and see if I can bring the DC down some. I want to pick up some bigger injectors here fairly soon and according to the scaling numbers I have found It looks like something around 55% larger than stock would be perfect which puts me at ~690cc. Can anyone confirm that this diagram is accurate?->

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[jeffo]

They are my Excel charts, so I would have to say they are accurate.
However, those charts are actually comparing the MAS compensation maps in the code to each other, which isn't exactly the same as what fuel correction you would need. For example: if the code has to multiply the airflow Hz 55% more for a 3G MAS than a 1G, that doesn't mean you should run 55% larger injectors. In those charts I took the 3G value and divided it by the 1G value, but to calculate the effect on injector sizing I should have actually taken 1-(1G/3G), which would give you more like a 35% change in injector size needed, or about 607cc.
But, be careful with removing 35% of the airflow, as that is going to throw you way off the AFR and timing maps. When you are running 15psi the ECU only sees an airflow signal that would indicate ~4psi, so it uses maps that are way too aggressive for pumpgas. That is why a chip corrected for the 3G MAS is the only proper way to use it.

 

[imdrax]

Ok thanks for the information. However on 560's I am ADDING 30% air not removing it. I went ahead and picked up a set of 720's figuring I may need to pull a little fuel out via afc which hopefully shouldn't affect the timing curve too much. If I see to much advance I will bump down my base fp a tad. I am going to try and tune up to around 20psi on 91oct. I have a methanol kit in my garage but it will most likely be going on my turbo is300.

Btw now that I finally decided on what injectors to go with I will be getting in touch with you soon for a socket and chip.

 

[imdrax]

Sooooo I went ahead and installed some denso 720's. Reset the ecu and I still have to ADD around %25 in order to get my AFR stoich at idle. Something doesnt seem right here. I know for a fact these injectors are 720's by verifying the denso part number. I'm about to hit the streets and see how my trims and AFR look.

EDIT: Trims are way out of line, in order to get my o2 trim to hover around 100% Im adding a ton of fuel. You would think that with and Evo maf and 720's I would need to REMOVE fuel which is what I was looking for to get a little timing advance.

EDIT2: After searching around on EVOM.net I fond some latency values on these injectors. .96 @14v, and the only info on the stock 450's i can find is .648@14v. Could this small amount of added deadtime contribute to why I am having to add so much airflow?

 

[jeffo]

You can't go by the latencies on EVOM. They have MOSFET drivers in their ECU's, which are MUCH faster than the ones in your ECU. In general, you will need to add a lot more fuel.

 

[danielsl1999gsx]

Alright so i hope people still look at this thread. i Just picked up a 501 and i removed the airhorn, i also have a set of evo 9 560cc injectors. I am wondering if i just switch my 2g 609 maf and my 450cc with the 501 and 560cc will everything be working fine cherry? im really looking not to get into the tuning scene because i have no idea what to do there. i just want to able to support my 16g

 

[BeatupVR4]

I know this is a little old but a 2G 609 MAF is good for about 52lbs/min of mass flow. So unless you're running larger than an FP3052 or 50 trim, maxed out, then you are well below the limit of the MAF.