MAP sensor fooling?

[Matt400]

I was looking around saw Graphic man posted these MAP specs:

Boost-- Voltage

0 -- 1. 045

6 -- 1. 48

10 -- 1. 75

15 -- 2. 05

18 -- 2. 27

20. 5 -- 2. 44



Anyone ever experiment with skewing those voltages with a resister?

Just wondering if less or more fueling and or timing would result.

 

[nickleinonen]

I was looking around saw Graphic man posted these MAP specs:

Boost-- Voltage

0 -- 1. 045

6 -- 1. 48

10 -- 1. 75

15 -- 2. 05

18 -- 2. 27

20. 5 -- 2. 44



Anyone ever experiment with skewing those voltages with a resister?

Just wondering if less or more fueling and or timing would result.

if you added a resistor in the circuit, less fueling [slower fueling] would happen as the ecm closely moniters map values to determine how to fuel to minimize smoking. but at the top end of the scale, the ecm would fuel longer thinking it has more room before it's set defueling point before it has to ramp down



what you need is a smart electronic device, that above say 1. 5vdc, amplifies the voltage by 1. x amount [the higher the x over 1. 0 the more agressively the fuel will go in as the ecm will see more boost than there really is - ie, 1. 3x would more or less make the ecm think there is like 12psi boost when there is just over 6 in the manifold] and then at around 22psi signal, ramp it back down so it wouldn't show the ecm 25-27 until the actual map value would be in the mid 30's

 

[John Robinson]

I was looking around saw Graphic man posted these MAP specs:

Boost-- Voltage

0 -- 1. 045

6 -- 1. 48

10 -- 1. 75

15 -- 2. 05

18 -- 2. 27

20. 5 -- 2. 44



Anyone ever experiment with skewing those voltages with a resister?

Just wondering if less or more fueling and or timing would result.

Hook up a potenciometer with a small voltage supply.

 

[Matt400]

Interesting, I wonder what effect on timing it would have.

It doesn't sound like something you could do for power enhancement but maybe economy.

I wonder if a toggle sw. that could toggle between the resistive ckt and stock would provide better economy in the resistive mode?

 

[rbattelle]

What effect would there be on trucks with a mechanical wastegate? It might make for some very strange things if the ECM thinks boost is only 20 lb and the wastegate suddenly opens up.



-Ryan

 

[Tomeygun]

Interesting, I wonder what effect on timing it would have.

It doesn't sound like something you could do for power enhancement but maybe economy.

I wonder if a toggle sw. that could toggle between the resistive ckt and stock would provide better economy in the resistive mode?

I had heard it really makes the truck run/sound like crap if the engine sees high boost at idle,etc



BUT I know of a TDR member (I dont know if he wants people to know yet) that made a dvice to fool the TST PMCR he runs into thinks it has 40lbs of boost all the time...



He says it has quite a bit of low boost fuel now :-laf

I will pm him to see if he will mention the mod

 

[nickleinonen]

What effect would there be on trucks with a mechanical wastegate? It might make for some very strange things if the ECM thinks boost is only 20 lb and the wastegate suddenly opens up.



-Ryan

nothing really. once the gate starts to open [it does not pop open fully in an instant] the boost pressure will stablize [i am 99% sure my gate opens at 23psi, but it will make 26psi under higher rpm], and until the ecm see the pressure on the map to warrent more fuel, it will maintain the fueling as it is currently.

 

[betterthanstock]

Matt, the Edge EZ and others, already fool this sensor. All you can do is get more fuel at lower boost (more smoke, less turbo lag).

Or you can tell the ecm that you have not exceeded the maximum safe boost when you mess with the wastegate.

Will not improve mileage, will not change timing.



The other half of this sensor is the intake manifold temperature sensor. That can slightly change timing, by telling the ecm that you are running colder air (on hot days), but if overdone can set some codes.

 

[Matt400]

The other half of this sensor is the intake manifold temperature sensor.

I know there is a dual sensor MAP/IAT on the air horn, is the MAP on the intake measuring temps too?

 

[nickleinonen]

I know there is a dual sensor MAP/IAT on the air horn, is the MAP on the intake measuring temps too?

yep. the intake [pre turbo] one measures barometric pressure and in coming air temprature [ambiant temp for engine ecm] and the one in the intake manifold plate measures actual map values, and intake charge air temp. so the ecm knows how much temp increase you have between ambiant and charge air. so by fooling both sensors, you should be able to change the timing a bit [and by fooling the baro, you should be able to increase fueling [make it think you are below sea level]]

 

[lmills]

I had heard it really makes the truck run/sound like crap if the engine sees high boost at idle,etc



BUT I know of a TDR member (I dont know if he wants people to know yet) that made a dvice to fool the TST PMCR he runs into thinks it has 40lbs of boost all the time...



He says it has quite a bit of low boost fuel now :-laf

I will pm him to see if he will mention the mod

that would be very interesting.

 

[SRadke]

BUT I know of a TDR member (I dont know if he wants people to know yet) that made a dvice to fool the TST PMCR he runs into thinks it has 40lbs of boost all the time...



He says it has quite a bit of low boost fuel now :-laf

I will pm him to see if he will mention the mod

Sorry guys, I've been out of town and away fro the PC



Yes, you can get all the off boost fueling you want from a TST by simply fooling it into thinking you have boost. I've been playing around with it alot over the last month or so and my results are as of yet inconclusive.



I've tried various configuations in feeding false boost data to the ECM, TST, and my Ramifier and at this point I've had best luck with giving the ECM the real data and telling the TST I have full boost. There are some drawbacks to this setup as well but it is without a doubt the smoothest power I've ever gotten from the my TST.



-Scott

 

[lmills]

hmm Scott, we need to talk.

 

[SRadke]

hmm Scott, we need to talk.

#ad

 

[Graphic man]

Matt

i think the specs are for the 98-02 not sure if its the same for 3gen trucks





Scott

 

[Matt400]

Probably right Scott.