I'm trying to confirm the proper kpa scaling for the stock USDM MAP Sensor (MDP). If someone has a JDM MAP sensor and a stock sensor, could you log it in evoscan with the key on/engine off with the formula in evoscan just set as x? Then go unplug the sensor and plug the other sensor in and see what it reads in evoscan?

I'm away from the shop but need to confirm this before my head explodes lol.

I'll owe ya one

-Jamie

 

no one?

 

JDMMAP the number was 74

OEM MDP the number was 200

 

You rock, thanks man. That's close enough to support my theory.

So the stock MDP sensors KPA scaling is the same as the stock MAF Baro:

KPA= x*0.5

JDM: 74*(4/3)=98.67kpa
USDM: 200*0.5= 100kpa

Due to rounding with the ADC input voltages, it's possible that the JDM MAP was 74.4 and the USDM MDP was 199.6 in reality. This would be much closer:

74.4*(4/3)= 99.2kpa
199.6*0.5= 99.8kpa

Close enough in my book lol.

-Jamie

 

what ya doin ???

 

Just finding a quick way to log engine VE on MAF cars for data acquisition. Sure makes it easy to build an entire 3D VE table in the 0-120KPA area before making the switch. I built an entire VE table on the most stock Evo8 I have had come through the shop in years.

Its also good to see how the VE changes before/after certain mods are installed like intake & exhaust manifolds or cams.

-Jamie

 

I thought you already had ve= ([LOAD1B]/[MAP])*100 ? Does this do something easier?

 

I just wanted to find the exact scaling for the stock MDP sensor for easier data gathering. I can log any MAF evo that comes in since they all have a stock MDP sensor. Its nice to have an average VE for idle and cruise areas on multiple part combinations so I have a database of VE tables to start with.

-Jamie

 

Oh gotcha. I had to edit that with the formula being correct as to not cause more confusion later

 

So this just correlates that the ve you logged on a stock mdp sensor can be transferred to a full on sd set up. Clicked now! Lol!

 

Yeah, same way you would with any other map sensor. The only difference is it cant read past 120kpa. Although, the resolution from 0-120kpa far exceeds any other map sensor we use. Thats why I wanted to use it originally.

-Jamie

 

So it appears the evo 8 and evo 9 stock USDM map sensors have different scaling.

JDM MAP= 76

Stock evo 8 (MD305600)= 242

Dammit.

-Jamie

 

I need to wait until an evo 9 comes in with a stock sensor but it appears the correct formula for a 2003-2004 USDM Evo 8 is

KPA= (x-7)*(3/7)
PSIa= (x-7)*0.06216
PSIg=(x-7)*0.06216-B (where B= your atmospheric pressure. sea level=14.7psi)

-Jamie

 

So if we had a completely stock 8/9 tuned exactly like stock and then used only the fuel map to retune, we would know what every part you bolt on did to VE because then you would add the percentage to the VE instead of the fuel map.

Interesting.

 

Yeah, its one reason Im trying to nail down the formulas for the evo8 and evo 9 stock sensors. It would be a great way to quickly show how mods change the VE between 0-120kpa. Adding a larger map sensor would allow VE moitoring while boosting. Great for back-pressure testing with exhaust components and turbine housing changes.

I just need to feel 100% confident on the proper formulas to log these damn sensors!

-Jamie