[chiefsotos]

Hello, i just complete the docrace single turbo upgrade to my car.
It is a 2008 E93 335 MT and the kit is the docrace top mount 6466 precision ball bearing which came with two turbosmart comp 40 wastegates.
I have stock lpfp and hpfp and running shell vpower racing 100ron.

My hp goal is only for pump gas, so map 1 or 2 for daily and map 3 for once a month.

I upload the backend flash with mhd and control it with jb4 and mac 3 port solenoid.
I upload the 30/139//2 firmware version at jb4.
The turbosmart wastegates came with 2 springs of 7psi each that means 14psi springs at each wastegate.

I asked a year ago which spring should i run (14psi default) or 7psi and one member told me that turbosmart doesn't overboost like tial so i should leave it as it was.
I made some datalogs to see how it goes.
My jb4 user settings are:
Duty bias at 50
FF at 20
DWP at 75

In both map 1 and map 2 the boost reached 19psi and stayed there.
If i new that turbosmart wastegates overboost like that i would have installed only the 7psi spring.
-I checked the mac solenoid and it does make clik with map1-engine of-pressing gas petal.
-I checked the wastegates solenoids and goes from the bottom of them -to the turbo- to the mac solenoid port1 and from the top of wastegates to mac port 2.
-I tried to connect only the bottom of the wastegates to the turbo without mac solenoid interfering and again the datalog so 18+psi of boost.
-I tried to connect the top of the wastegates to the turbo (to eliminate the wrong connection) and boost reached 24+psi in 2nd gear and left of the throttle.
-The only thing i haven't tried is to connect bottom of wastegates with mac port 2 and top of wastegates to mac port 1 (to eliminate the possibility of inverted mac solenoid ports)

Any other ideas why i overboost so much (5 Psi more than springs)?

Another issue is fueling...

After 5500rpm the hpfp dropped below 9 so i know i have fuel issues.
I already have a stage 2+ bucketless lpfp sitting at home 3 years now, but haven't got time to install it, maybe in a month i will.
I also noticed that with map 2 when the rpm goes 3500 and boost climps up the hpfp drops below 8 and reaches 6 at 3900 and then climp up again.
Should upgraded lpfp solved that problems or is it hpfp problem?
Should i have a faulty low pressure fuel sensor?

Is there any setting at jb4 map2 to make boost more stable at 17psi?
(I was thinking to drop down dwp from 75 to 60.)

[what335is]

Hi, I’m running the same setup right now and I have the same issue, making ~20psi when I should be at gate pressure. I have verified functionality of the wastegates & all my plumbing is correct.

What did you do to resolve this issue?
Thank you

[konstat]

Originally Posted by chiefsotos

Hello, i just complete the docrace single turbo upgrade to my car.
It is a 2008 E93 335 MT and the kit is the docrace top mount 6466 precision ball bearing which came with two turbosmart comp 40 wastegates.
I have stock lpfp and hpfp and running shell vpower racing 100ron.

My hp goal is only for pump gas, so map 1 or 2 for daily and map 3 for once a month.

I upload the backend flash with mhd and control it with jb4 and mac 3 port solenoid.
I upload the 30/139//2 firmware version at jb4.
The turbosmart wastegates came with 2 springs of 7psi each that means 14psi springs at each wastegate.

I asked a year ago which spring should i run (14psi default) or 7psi and one member told me that turbosmart doesn't overboost like tial so i should leave it as it was.
I made some datalogs to see how it goes.
My jb4 user settings are:
Duty bias at 50
FF at 20
DWP at 75

In both map 1 and map 2 the boost reached 19psi and stayed there.
If i new that turbosmart wastegates overboost like that i would have installed only the 7psi spring.
-I checked the mac solenoid and it does make clik with map1-engine of-pressing gas petal.
-I checked the wastegates solenoids and goes from the bottom of them -to the turbo- to the mac solenoid port1 and from the top of wastegates to mac port 2.
-I tried to connect only the bottom of the wastegates to the turbo without mac solenoid interfering and again the datalog so 18+psi of boost.
-I tried to connect the top of the wastegates to the turbo (to eliminate the wrong connection) and boost reached 24+psi in 2nd gear and left of the [...]

I don’t have experience with a single turbo so I can’t help you with over boosting unfortunately but I can tell you you’re right that your fuel pressure is too low. Can you check what your Low Fuel Pressure is on a pull? Normally it’s the the LPFP that needs to be upgraded first so I would definitely start there.

You shouldn’t need port injection until above 550whp which I believe is around 24psi of boost