Author Topic: bmw m50b25tu turbo torque problem  (Read 7145 times)

Offline MWfire

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bmw m50b25tu turbo torque problem
« on: April 15, 2014, 04:35:02 pm »
I'm mapping one bmw, 2.5 vanos engine(m50b25tu). Compression is around 8.5:1, turbo is gt2871 in 0.86 housing. Problem is that car doesn't make torque with 1bar of boost. Also wants very little advance(see table). Car is mapped to MBT on dyno(mapped is only in boost so far) and here is torque:

As you can see PW is stable from 3800rpm, but torque is rising with rpm. Also ign advance at 4000rpm and 5000rpm is more than 6 deg different(more advance at 4000rpm doesn't make more torque).
http://www.vems.hu/files/DamirMuha/v3.3_u008550-2014.04.14-17.39.15.vemslog

Also vanos table is strange(engine doesn't want more intake cam advance at low rpms).
Also i add ethanol to tank(30%) to boost octane rating of gasoline and no change.
What could be a problem? Could be wrong phase of intake cam because of vanos(complicated to phase)?

Offline NOTORIOUS VR

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Re: bmw m50b25tu turbo torque problem
« Reply #1 on: April 15, 2014, 06:47:48 pm »
How sure are you that the cams were installed and timed correctly?

Offline MWfire

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Re: bmw m50b25tu turbo torque problem
« Reply #2 on: April 15, 2014, 07:09:23 pm »
How sure are you that the cams were installed and timed correctly?

Not sure, i'll check that in 2 days.

Offline NOTORIOUS VR

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Re: bmw m50b25tu turbo torque problem
« Reply #3 on: April 15, 2014, 08:10:14 pm »
Not sure, i'll check that in 2 days.

 :)