2350 excessive smoke poor mileage and poor performance

[Rawze]

Assuming up front for a moment that some idiot turbo shop, someone, etc., did not take it apart and mix matched parts on it ...

For the newer VGT 400-series turbo's seen on the CM2250's, CM2350's, and X15's, etc...

There are 2 different model 400-series VGT turbo's for the CM3250's. They are NOT interchangeable on the fly with each other ... but they do look identical on the outside.

Many people make this mistake with them and think they are all the same because they look alike on the outside, but they are not.

One is for the higher HP engines, has higher heat and HP capacity + a titanium turbine in it.

The other has a more light-weight turbine and is designed for a bit more fuel efficiency but is only for mid-tier, lighter duty applications. The lighter duty one is also a bit more responsive, but has less flow capacity restrictions on the upper HP end, heats up quicker, and is not made for heavy haul.

The only way to tell them apart without disassembling them is to measure the inner diameter at the intake port (cold side). The heavy haul (titanium turbine) version measures 36 mm, and the fuel efficient version made for lower HP measures 34 mm. This can only been checked by precision measuring the inner diameter of the intake port, and cannot be seen simply by looking at them.