Boost controller and non-wastegate turbo

[Journeydog]

What's the function of an electronic adjustable boost controller when used with a non-wastegated turbo? Does it do anything? Can it?

[britannic]

With a non-wastegated turbo it won't have a function anymore. It usually controls the wastegate to modulate boost levels.

[patrick m.]

Journeydog, dont hold back, if you have bought a non-wastegated turbo, spill-it!
I check the forum every day to see if "GMCTD" has posted about his turbo experiment, but nothing.

if you upgraded your turbo please give details :D

[Journeydog]

Hmmm...guess I'm not as dumb as I look...thanks for the confirming answer. smile.gif

Was just wondering why I was told that I might need the controller with my 95-based PCM running a new '03 engine with a non-wastegate turbo. Is it possible that the controller wants to be in there to keep the PCM from setting 78s, etc.?

I'll relay more info on this whole thingamabob when the engine gets installed and I get some feel for how it does. The turbo isn't a puzzle...why I should have a boost controller is.

[rjschoolcraft]

The function of the boost controller with a non-wastegated turbo is specifically to prevent DTC 78. However, you use it on the BARO sensor mounted on the firewall, not at the BOOST sensor mounted on the intake. In this manner, it fools the computer into thinking that the waste gate solenoid is in a high (up to 100%) duty cycle (read high elevation) so that the boost pressure needs to be higher relative to atmospheric pressure...then it won't set code 78 when it sees higher than commanded boost. At least that's the way I think it works.