D40 Turbo Exciting new concepts in boost control

[Jardsoooo]

Having had a squiz at variable vane turbo's on Google it seems pretty clear that the rise in vacuum pressure acts to restrict airflow over the turbine ergo if one was to remove the vacuum hose - perhaps block it then the variable vanes would'nt activate so you should end up with a lot of boost.

To finess this then if you were to fit a variable valve onto the vacuum hose yuo should be able to control boost.

If that variable valve was remote operated you should be able to dial up whatever boost you desire as you drive.

Sound so damn simple. Can somebody pls tell me what is wrong with this proposal.

 

[Old.Tony]

I'm willing to bet that without some modification to the ECU programming you'll end up with a CEL on and maybe even a full-on limp mode.

The ECU varies fuel rail pressure and turbocharger output (that's why the actuator moves like it does) and monitors the resulting oxygen levels in the exhaust. It expects to see a pattern in the oxygen levels that is similar to the pattern being input by the ECU's control. If there's something wrong, the ECU will assume there's a problem with either the fuel system or the air system and either one will trigger a full limp mode. You'll be restricted to about 2,000rpm max with a top speed of 80km/h.

All that said, I guess you could try it. An ECU reset might clear the CEL if it comes on as long as you return the system back to normal afterwards.

 

[jjohn]

Or use a chip that controls boost.....

 

[Dion]

The vanes aren't variable to control boost exactly. They're variable to combine the function of a small turbo (no lag) with the function of a big turbo (big boost). Mess with the settings and you'll just get the same peak boost, with more lag

 

[Jardsoooo]

As it turns out pulling the vac hose off and blocking it decreases performance. I dont think the Turbo was working at all. Case closed.

 

[tweak'e]

its called a dawes valve. check out patrol4x4 forum as lots of them use it. it allows manual control of the turbo instead of the ecu.

 

[qqc d22]

Variable vein or not puta boost t in the vac lines of the internal waste gate and you will have control of boost just like any other turbo. That said its like any car add more boost and if the ecu cant allow for it or keep up it will go into limp mode or worse be running a very lean air fuel mixture which will result ultimatly in engine failure in one way shape or form

 

[tweak'e]

Variable vein or not puta boost t in the vac lines of the internal waste gate and you will have control of boost just like any other turbo. That said its like any car add more boost and if the ecu cant allow for it or keep up it will go into limp mode or worse be running a very lean air fuel mixture which will result ultimatly in engine failure in one way shape or form

they do not have waste gates and running lean is normal for a diesel and engine will be fine. go back to school.

 

[jjohn]

Chip it, chip it good.

 

[qqc d22]

they do not have waste gates and running lean is normal for a diesel and engine will be fine. go back to school.

Diesels do run lean doesnt mean you should just just keep adding boost so it leans out more.i was simply trying to say that so he doesnt go and destroy a motor if he wasnt aware of it. Thanks for your kind comments

 

[joe2006]

Chip it, chip it good.

Oh John, you are a Devo

 

[jjohn]

And here's me thinking I was a little too obscure.
Crack that whip.......

 

[tweak'e]

Diesels do run lean doesnt mean you should just just keep adding boost so it leans out more.i was simply trying to say that so he doesnt go and destroy a motor if he wasnt aware of it. Thanks for your kind comments

you missed the buss entirely.
you can't make it to lean. you have to burn fuel to make boost.
stock turbo will run horribly inefficient well before it even starts to run super lean.
some guys are running 40lb boost on these motors (with different turbo of course).
lean simply means lack of power, which is what it does at cruise.
you only have to watch out for running to rich, ie pouring to much fuel in.

 

[180degrees]

Pretty sure Diesels can run up to 100:1 AF ratio in some motors, you have **** all power but it will still run.

 

[tweak'e]

just a quick google throws up a few figures of 40:1 up to 140:1 at part throttle.
think about the instant you get off the throttle. the intake still has boost in it, your injecting the amount of fuel you would use at idle (sweet stuff all), so the AF will be massively lean till the boost drops.