[PMW0801]

What is the stock boost PSI and how much boost does the JB4 add on Map 2? Thanks

[Info@mad-us.com]

Originally Posted by PMW0801

What is the stock boost PSI and how much boost does the JB4 add on Map 2? Thanks

Is it a comp?

[PMW0801]

Originally Posted by Info@mad-us.com

Is it a comp?

Yes 2022 M4 competition xDrive

[Limegrntaln]

I think its 24.7 for the Competition, and the Manual is 18.9.

[Info@mad-us.com]

Originally Posted by Limegrntaln

I think its 24.7 for the Competition, and the Manual is 18.9.

Thats what car and driver stated but I’ve seen seen logs of around 22 psi in the upper gears. It all depends on the temp and altitude . Lower temps and sea level will run less boost.

[PMW0801]

Wow I'm running JB4 and I'm not even close to those numbers. I just had gauge installed and haven't given it a real good pull yet but i think im around 18 psi. I actually just check one of the logs on my JB4 and highest boost was 24.9. Looks like the average from the 3 pulls I did is around 22-23 psi. I see ECU__PSI column and boost column. For turbo boost its the boost column correct?

[Hendo741]

Like MAD said, its dependent on many factors. These cars don't have static boost tables anymore, they use volumetric efficiency and fill tables based on requested torque.

Originally Posted by PMW0801

What is the stock boost PSI and how much boost does the JB4 add on Map 2? Thanks

Map 2 is +5 psi to whatever the ECU is requesting. Personally I like the absolute maps on the JB4 compared to the additive. Map 2 has a tendency to overboost and cause throttle closures at mid rpm wot.

[Limegrntaln]

Originally Posted by Info@mad-us.com

Thats what car and driver stated but I’ve seen seen logs of around 22 psi in the upper gears. It all depends on the temp and altitude . Lower temps and sea level will run less boost.

I haven’t looked any boost tables for these motors. Have you noticed any spike and drop off? Or can the turbos hold the same or full boost, until the car stops making power? And the 24.9 seemed high to me. I remember back in the day, even trying to get 21 out of a car, would start pulling the timing on pump gas.

[mike@x-ph.com]

I have a competition, and my boost was 19-25

For piggyback users, including the JB4, note that piggybacks trick the ECU its making stock boost, so if you are checking the gauges, the power and boost will look identical to stock.

To measure the real boost, datalog and you have a column that says boost, which is your actual boost, and another column that says stock boost, which is what the car stock would be targeting if it was not tuned.

[PMW0801]

Originally Posted by mike@x-ph.com

I have a competition, and my boost was 19-25

For piggyback users, including the JB4, note that piggybacks trick the ECU its making stock boost, so if you are checking the gauges, the power and boost will look identical to stock.

To measure the real boost, datalog and you have a column that says boost, which is your actual boost, and another column that says stock boost, which is what the car stock would be targeting if it was not tuned.

Wow that’s interesting. Thanks for clarifying that. So the one log that I did with the JB4 the boost cloumn was reading between 23-24 max boost on wide open throttle.

[mike@x-ph.com]

Originally Posted by PMW0801

Wow that’s interesting. Thanks for clarifying that. So the one log that I did with the JB4 the boost cloumn was reading between 23-24 max boost on wide open throttle.

Which map were you on?

[PMW0801]

Originally Posted by mike@x-ph.com

Which map were you on?

Map 2

[mike@x-ph.com]

Originally Posted by PMW0801

Map 2

Thats +4 so your stock boost is 18-19, similar to what my stock boost was

[PMW0801]

Ok cool. Thanks for the information Mike ��