CM2200 Modified Turbo/Back pressure

[jfreemanak]

I am planning on modifying my HE351VE turbo soon to a larger compressor and turbine wheel (parts sourced from TurboLab of America). I am trying to think through what will need to be modified to properly use the increased airflow (both intake and exhaust). Under the airflow tab, there is the MAF Calibration, Fresh Airflow, and Charge Airflow tables, along with the Compressor Map efficiency and Comp. PRatio. Should these tables be changed to what the new compressor wheel "might" be (no compressor map), or just change the fueling table to account for the increased air mass available (also a guess)?

On the topic of the turbo, what parameters control the vane position? There are the tables to set the min and max position, but no real clue what the ECU is using to set the vanes. I know that back pressure is a variable, but there does not appear to be a place to change the allowable back pressure (there is the exhaust brake max torque table). I would like to increase the allowable back pressure, as I have 110lb valve springs, so I could potentially have a stronger exhaust brake.

Thanks for any input.

Cheers,
Jared

[sasdakota]

First off, do not go bigger than a 63mm compressor wheel.

Second, Tuning.
Use the min/max tables to drive the vanes to your desired position. Back pressure is not really a factory here, that is more for EGR or EB functions. Mass charge flow is essentially what the PCM uses to decide vane movement within the min/max tables.

[jfreemanak]

I was thinking the 67mm compressor wheel was a bit large for the turbine size. Do you have personal experience with a 63mm vs XXmm compressor wheel?

Also, on the turbine side, there is either a 70x67 or 70x64 available. Opinion on which one of those to use?

Thanks for the response.

Jared

[sasdakota]

Go 70x67 turbine.

I run a 67/67 currently, have a 63/67 set of wheels and custom cover on its way to me. Have tuned a handful of 63/65 and 67/67 also. Tater doesn't do anything bigger than 63/67 on a 351ve from the data we collected in testing.

Side note, have you logged fuel rate and torque on your sims delete tune? Are you holding full rate to say 3000+ rpm? Can PM me if you prefer.

[jfreemanak]

Thanks for the advice.

I have not logged fuel rate and torque with my tune (I actually haven't done any logging). I should probably start doing that. I just wish there was a way to not use SIMS with HP Tuners...