Turbo Q's

[Wozza244]

Im a Nissan owner now and i have bought a TD42, its only punching out 7-8 pound at the moment and i can hardly feel any boost, how do i up it to a more realistic boost pressure and what sort of pressures are we running fella's?
It has adjustable boost dial but i wound it all the way up and only got 1 more pound out of it which upped it to 8
It has 245,000 on clock
Well looked after
Has a front mount intercooler
Pyrometer

Cheers
Wozza

[BadMav]

More fuel will give you more boost. A quarter turn of the fuel screw out should do it. Go for a drive, load it up and keep an eye on the pyro, if it gets up near 600, back off the throttle. Wind the fuel screw back in an eighth of a turn.

[coxy321]

You may find that the wastegate is leaking exhaust gas/pressure around 8psi boost - i know mine does. The fix for this is to add an additional spring to the actuator.

Where is your boost gauge hooked up? Compressor housing/actuator/pre-intercooler/post intercooler/inlet manifold? You really need to pick it up off the inlet manifold or post intercooler as that will give a true indication of what the engine is receiving. Intercoolers do create a drop in boost pressure.

What sort of temps are you getting on the pyro? 600 degrees celcius is the upper limit if your probe is POST turbo. If it is pre-turbo, you can spike it up to 700 degrees (spike meaning not a sustained period of time).

It sounds to me like you may need to revise/improve your intake piping. What filter setup, inlet piping, pre/post intercooler piping are you using?

[BadMav]

And just to add, some diesel engines don't even have a wastegated turbo. All the boost (in that configuration) is altered by the amount of diesel going in. That's how my 75 series was and it went like a cut snake. It made 23 psi at about 4000 rpm and 550 on the pyro post turbo. You probably could disconnect the wastegate altogether but I would think this would shorten the life of the turbo somewhat. I know of guys that have done it and yeah it made a huge difference.

[Wozza244]

The hottest i have got it to was 450 and that was fair flogging it up a 2.5km hill on the tar which is about a 15% grade, fairly steep.

Its got all silicone bends in the intercooler piping and 2.5" pipe from turbo to intercooler and then 3" off intercooler to inlet manifold.

The Pyro is on the 3" zorst 3" from the turbo on the exit.

Just saw the boost controller isnt even hooked up

The boost gauge is fed from 2 spots?? it has a "Y" piece one coming from the waste gate actuator and the other coming from the intercooler pipe just before it goes into the intake manifold.

Has a pod filter, shit as i cant wait to get a snorkel but there is gonna be some modifying because the battery has been relocated and the intercooler piping is sort of in the way.

3" off the turbo and the zorst is only about a metre long, it has been cut off.

Which is the fuel screw on the pump i will give that a little tickle and see how we go.

*EDITED*

[coxy321]

So it sounds like you need to add some more fuel if you're only seeing 450 degrees post turbo. I'd change your boost gauge to pick up off one point - ideally off the intake manifold, post intercooler for reasons stated previously.

As badmav said, the reason for your turbo not producing over 7psi may be a fuelling issue (not enough).

When you play with your fuelling, go in 1/8 turn increments, and take note of where it is before you start fiddling.

There should be picks on OL4X4 of the adjusting screw, but its on the top rear part of the pump, under the return line banjo fitting.

[5inchgq]

There should be picks on OL4X4 of the adjusting screw, but its on the top rear part of the pump, under the return line banjo fitting.

Further to this if the fuel screw hasn't benn adjusted previously it should still have a cover, it's made of a tin type material and IME it has to be removed with a small amount of force, in the past I have used tin snips and screw drivers, but take care using these sorts of methods as you can damage the pump body itself.

[garth]

easy way to add the max amount of fuel the 10mm Zexel rotor can handle (about 115-130kw) is to adjust the fuel until it starts to effect the idle.
As long as everything else is in good order and you have set the boost higher to control EGT's, that's about the most you'll get out of the pump/engine with no drama.

[Wozza244]

Cant find any pics of the adjustment screw, can anyone take a pic and show me at all or find a link for me, i have searched a bit last night and now and cannot seem to find any good pics or info, cheers.

[BadMav]

Here ya go, don't take any notice of the text in the pic (although handy to know). The screw you are after is under the hose in the middle left side of the picture. In this photo the steel cap has been removed.

[Wozza244]

Top stuff, so turn by 1/8 clockwise and then test?

[garth]

1/8th is heaps, I go up in half that or as above - until the revs change.

[Bush65]

... I'd change your boost gauge to pick up off one point - ideally off the intake manifold, post intercooler for reasons stated previously.

...

I think his assumption about being fed from 2 spots may be a misunderstanding the hosework:

The boost gauge is fed from 2 spots?? it has a "Y" piece one coming from the waste gate actuator and the other coming from the intercooler pipe just before it goes into the intake manifold.

My guess from that description is that both the boost gauge and waste gate actuator are receiving the boost pressure from the same spot. That spot after the intercooler and just before the intake manifold it is pretty much as you have suggested.

This would be ok, however if my guess it is not the case, the alternative is not very sensible.

Just my 2 cents to try and clarify for the original poster, not wanting him to change that unnecessarily.

[Wozza244]

... I'd change your boost gauge to pick up off one point - ideally off the intake manifold, post intercooler for reasons stated previously.

...

I think his assumption about being fed from 2 spots may be a misunderstanding the hosework:

The boost gauge is fed from 2 spots?? it has a "Y" piece one coming from the waste gate actuator and the other coming from the intercooler pipe just before it goes into the intake manifold.

My guess from that description is that both the boost gauge and waste gate actuator are receiving the boost pressure from the same spot. That spot after the intercooler and just before the intake manifold it is pretty much as you have suggested.

Yeah thats how its working, its how its supposed to be apparently.

I wound up the fuel screw in 3 stages eventually stopped at 1/4 turn and the new found power is great! However its still only boosting around 11 pound? Maybe i might have to wind it up some more, but dont really want to be using heaps more fuel than i need.

Thanks for the help guys

This would be ok, however if my guess it is not the case, the alternative is not very sensible.

Just my 2 cents to try and clarify for the original poster, not wanting him to change that unnecessarily.