7.3 IDI NA boost opinions?

[Macrobb]

Unplug the wastegate and take it for a test run. It's not like the boost will spiral out of control - you still only get boost when you are giving it a lot of throttle. Just gradually give it more and more throttle and see where it takes you. You can easily back off if it ends up going more than 15 at WOT.

 

[Thewespaul]

Black smoke is unburnt fuel and means you are supplying more fuel than your engine has air to burn that fuel with

 

[bblaweless]

im gonna cap the wastegate and see what happens here. do i need to actually plug it? or can i just disconnect the hose?

 

[Rossroams]

A whopping 2psi on the H1C'd 6.9 with the fuel pump turned up like 1/2 a flat... soooo thank goodness I kept that stock Garrett turbo.

 

[Thewespaul]

im gonna cap the wastegate and see what happens here. do i need to actually plug it? or can i just disconnect the hose?

Plug the hose so you don’t have a boost leak

 

[bblaweless]

Plug the hose so you don’t have a boost leak

Of course, sorry that was a dumb question. Will report back tomorrow with results!

Thanks everyone

 

[03wr250f]

Smoke doesn’t equal power, that’s unburned fuel and lost efficiency. Do you have a the pump maxed as is? If so I would look for boost leaks, a maxed pump should make at least 10 psi before you even touch the wastegate

The point of a wastegate is to relieve excess pressure, and not allow it to build over a certain point. after the wastegate opens it wont build any more pressure no matter how much fuel given.

 

[A48WillyzGuy]

I'll just throw my info in for giggles here. I had issues with my wastegate cracking open at 10psi when I just had it unhooked, so I made a rod to lock it out. Now it'll boost up to ~15 psi on ****. I have stock N/A, 270k+ mile everything except some R&D Stage 1 injectors.

I know my timing is slightly too advanced (I'm guessing it's around 9-10*... my meter was having issues when I was trying to time it), and the fueling is still set to the stock setting (assumed, I've never adjusted it anyway). My truck absolutely will NOT smoke unless I lug the crap out of it. That's not a complaint, just a reference point.

 

[bblaweless]

The point of a wastegate is to relieve excess pressure, and not allow it to build over a certain point. after the wastegate opens it wont build any more pressure no matter how much fuel given.

That's the impression I was under? I thought that the stock Wastegate setting on these idis was 7-8 therefore not allowing more boost without modification regardless of fuel supply?

 

[bblaweless]

On a seperate note- does anyone know of someone who has experience timing these engines here on Vancouver Island? I wouldn't mind doing it by the books at some point....would love to watch and learn.

 

[Thewespaul]

The point of a wastegate is to relieve excess pressure, and not allow it to build over a certain point. after the wastegate opens it wont build any more pressure no matter how much fuel given.

This simply is not true. Have you heard of boost creep? The turbine/wastegate on these trucks are very undersized for the displacement and although in normal circumstances the wastegate would cut boost pressure from building it does not happen in this application. The wastegate just adds room for more flow through the turbine and is not large enough to stop the boost from climbing. This is boost creep and in the drag racing world it is a very bad thing and means you need to upgrade to a larger external wastegate or resize your turbo. On these trucks it’s not a big deal but it shows how undersized these turbos are for the displacement.

 

[Macrobb]

Except that according to various documemtation I read, the limit is 10. The wastegate starts opening below that, and should limit it to 10 max... with stock fuel. Obvously, with more fuel burned, you'll get more boost, even against the damping effects of the wastegate.

 

[saburai]

Of course, sorry that was a dumb question. Will report back tomorrow with results!

Thanks everyone

Well? What are you getting with it disconnected and plugged?

 

[bblaweless]

Hey guys, I've got the IP open right now and the adjustment screw doesn't want to move....I'm scared to put more torque on it in fear of damaging the pump?
I don't remember these screws being to stiff?
Thoughts?

 

[Thewespaul]

If it’s stiff you’ve found the end of the adjustment. If you have a torque screw you can get more fuel from there