ghettosled
SYTY SUPERSTORE
Re: Downsizing turbo
the "widget" you are referring to is the factory electronic boost control selenoid. The computer alters voltage to the selenoid which in turn regulates the amount of air sent to the wastegate. If you are missing that, chances are the previous owner installed a manual knob, or just adjusted the wg rod to the desired base boost setting.
I personally believe downsizing the turbo is a step in the wrong direction, especially if talking a stock style with unmodified wastegate, etc.. These trucks suffer on the top end, and by reducing the turbo size the only thing enjoyable will be the first 60 ft. The 51 is going to require a stall converter or alky to get it to spool. You can throw a bunch of timing at it in a custom tune, but it really needs a 2700-2800 stall. The 44 works fine with the stock converter. The downside to the large turbo with a converter is sooner then later you will need a built trans.
The problem with alot of the TE series turbos (44, 51, 52, 54, 60) is they don't work well at low boost like Tooky said (ie 14-16psi) which is what we run on 91 octane 95% of the time.. So do a little homework and ask some questions on why a smaller less efficient turbo is going to be better.
Below is a compressor map of a PT51, which requires a high stall converter.
Now here for example is our RPM STG1 bolt on turbo compressor map, which you can see has a much more useable efficiency range at low boost, not to mention it spools equal to the stock turbo on the factory converter, while still improving flow, cfm and hp..
the "widget" you are referring to is the factory electronic boost control selenoid. The computer alters voltage to the selenoid which in turn regulates the amount of air sent to the wastegate. If you are missing that, chances are the previous owner installed a manual knob, or just adjusted the wg rod to the desired base boost setting.
I personally believe downsizing the turbo is a step in the wrong direction, especially if talking a stock style with unmodified wastegate, etc.. These trucks suffer on the top end, and by reducing the turbo size the only thing enjoyable will be the first 60 ft. The 51 is going to require a stall converter or alky to get it to spool. You can throw a bunch of timing at it in a custom tune, but it really needs a 2700-2800 stall. The 44 works fine with the stock converter. The downside to the large turbo with a converter is sooner then later you will need a built trans.
The problem with alot of the TE series turbos (44, 51, 52, 54, 60) is they don't work well at low boost like Tooky said (ie 14-16psi) which is what we run on 91 octane 95% of the time.. So do a little homework and ask some questions on why a smaller less efficient turbo is going to be better.
Below is a compressor map of a PT51, which requires a high stall converter.
Now here for example is our RPM STG1 bolt on turbo compressor map, which you can see has a much more useable efficiency range at low boost, not to mention it spools equal to the stock turbo on the factory converter, while still improving flow, cfm and hp..