How much boost can I run with no tuner

[Kramer73]

Hi there
I have a 04 (Aussie) F250 7.3L. Recently I upgraded to 38R with a turbomaster wastegate controller, 6637, straight piped the exhaust, bellowed up pipes and regulated return. However I am still running with no tuner.

My question is, due to having an adjustable wastegate, how much boost can or should I run?
I understand that gas engines need a perfect fuel/air ratio, and that diesels can run abit leaner.
Currently being stock, I have it set at 17lb boost. Would it make much difference to run maybe 20 or slightly higher?
Has anyone tried increasing boost while still running stock?

Also I understand about too much boost giving an engine light. I have a boost fooler but have not installed it yet as still running stock.

Thanks

[Turbostang500]

Wont really help at all. It will help lower egt's but if you are on a stock tune that should be good too.

Diesels make power with added fuel. You blow air in the give the fuel some oxygen which helps complete combustion and run cooler exhaust temps. At a certain point of adding fuel, you will need more air from a better turbo which you already have. To make that turbo worthwhile you need bigger sticks!

[JSchuricht]

With the stock sticks you can tighten the waste gate down, you won't be able to max that turbo out. Without a tuner, you probably won't get much over the 17psi you are seeing now regardless of where you set the waste gate.

[Kramer73]

Thanks guys, looks like my next investment will be a tuner.
And I guess one day some stage 1's.

Thanks for your help