Moving the waste gate actuator pipe.

[Disco_Stu]

When doing this (I'm sure a lot of you have come across this before), you move the pipe from the turbo to the back of the plenum chamber where there is a a handy unused drilling and blanking bolt. The bolt is removed and replaced with a banjo or similar fitting. What size is the drilling and therefore the bolt?

Hopefully its 1/8 BSP like everything else banjo related on Discos but a bit of clarification would be handy.

For those who dont know about this, moving the wategate actuator pipe to the back of the plenum means that actuation takes place based on the pressure at the valves rather than further around the turbocharged loop, minimising loss through pipes, mico leaks etc, hence turbo comes in earlier and with less lag. A lot of people report really good performance increases after doing this mod.

Any help appreciated, Stu.

[Disco-Ron]

Does that not act in the same way as increasing the boost though, which apparently 300's don't like.... needs to be checked with a boost gauge to keep an eye on whats going on really.....

[Disco_Stu]

Not as far as I know. From what I read its more like making everything happen more quickly rather than more forcefully. It doesn't open the wastegate further (Like the 200tdi mod you're thinking of) just sooner. I think :)

[bambamjj]

Any photo's of where you disconnect it ffrom and where you connect to? just for clarity   :?

[Disco_Stu]

Have a look at this, I havent done it yet. I like to have all the info to hand before I embark on my next disaster :)

http://forum.difflock.com/viewtopic.php?t=27368&sid=6e14e9faeaaa619ede56836ad800be5d

Stu.

[bilge rat]

i did mine and to be honest it just seemed to smoke more and not any noticable change in performance, so i altered it back .. just put  a cap over the pipe i made, so maybee put  a boost guage to it ?. not sure yet. i got the origanal plug drilled it out and soldered in a peice of copper pipe .alan....

[Disco_Stu]

Hmmm, cheers bilge rat.

I may have to give it whirl anyway. I'm like a dog with a bone when I get an idea in my head. With what you've said though I think Ill treat it as an experiment and be willing to change things back if I dont like the results. I had planned to run a boost guage from one of the outlets at some point so I may end up doing just as you've done.

Stu.

[stageonesimmo]

It made mine go faster!

I'm in the process of thinking why it would have made Bilge Rat's smoke more - its had no negative effects on mine or anyone else I've seen/heard of doing it...............

[Range Rover Blues]

Does that not act in the same way as increasing the boost though, which apparently 300's don't like.... needs to be checked with a boost gauge to keep an eye on whats going on really.....

Yes it does, the technical spec on the TDi engines is with the turbo pressure measured at the turbo output, any losses in pipework and intercooler are taken into account by engineers (who let's face it have spent more than 5 years getting qualified and millions of pounds designing this engine ;)) so by taking the waste gate "sensing" pressure from the plenum changes the boost at the back of the valves.

I can understand that it might improve pickup, waste gates exhibit "creep" as in they begin to open before the set pressure is reached and will open whilst pressure is still building up in the plenum. But a far safer option is to use a boost control valve, these will keep the waste gate shut fully until the desired pressure is reached and that pressure can be altered easily in seconds (use a boost guage though).  They work best when the set pressure of the waste gate actuator is left at the lower pressure.

Also by sensing from the turbo not the plenum the engine gets a larger charge of fuel (the black puff of smoke) when you stamp on the throttle, this should be reduced by sensing form the plenum.  Whether you want to is a different matter, on an otherwise unmodified engine you may get less fuel being delivered.

One final thought.  If you have the waste gate controlled by the plenum rather than the turbo, what happens if one of the pipes gets blocked?  the waste gate never closes and the turbo/pipework gets damaged perhaps :-k
On a standard engine, the plenum is also full of cack from the EGR and oil mist from the turbo.  This can also block the sensing pipework.

[Range Rover Blues]

i did mine and to be honest it just seemed to smoke more and not any noticable change in performance, so i altered it back .. just put  a cap over the pipe i made, so maybee put  a boost guage to it ?. not sure yet. i got the origanal plug drilled it out and soldered in a peice of copper pipe .alan....

I'd considered fiting a second boost guage there, it would give some idea of the efficiency of the intercooler upgrade.

[bilge rat]

i have tweeked the pump already . not excesive though , removed the cat and no ctr pipe . so maybee i was just over cooking it a bit . has also done 193.000 mile. when i did it i only ran the vacume off the manifold to the turbo and the one that goes to the deisel pump was ran still from the wastegate. maybee iff id have done that too but cant help but think that that would have made it over fuell even more ?. am interested to see how you get on with it ..alan....

[Range Rover Blues]

Yes that way round I'd expect it to smoke like the proverbial, if anything the fuel pump should be connected to the plenum and the waste gate to the turbo.

[bilge rat]

mm, did wonder . may try it again . when ive sorted me wheel bearing out .