bit of technical advice please.

gday all,im just chasing after a bit more go out of the old 4.2tdi(2004) it was tuned before I got it, running 12psi of boost(according to my autron gauge) egt's will hit 650.c occasionally,big hill driving hard,but generally sits on 300.c on the highway,doesnt blow hardly any smoke,so my question is if I adjust the boost to say 15psi do I need to adjust the fuel pump at all or is this what the compensator does?? and will the extra 3psi make much difference,its a 2004 4.2tdi (295000 k's) 3" lift ,33"s 4.3/1 diff ratio,thanks for any advice.

It's not really ideal to push the factory turbo past about 12psi as it really just starts to become a heat pump.

Do you have a 3" exhaust?

Pumping more boost in without adding more fuel won't really do anything, you need the fuel to make power. That's not to say you could try pushing the boost up a touch and see how it goes.

There are good gains to be had by running 4" all the way from snorkel to turbo even on the factory turbo. The best way really would be to upgrade the turbo and intercooler.

As for the fuel adjustment you can do some tweaking to the compensator, this is where to start before actually adjusting the fuel screw.

Sorry mate can`t help, but 600c is a bit high
I would back off a bit and change down as I know what your hills are about especially when they stick a bend halve way up and you need to do a 3 point turn to get around .
I would think a slight adjust would only help but make sure it doesn`t over fuel.
By the way GU Camper is on the island and may try to catch up.

Quote:

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Originally Posted by nissannewby

It's not really ideal to push the factory turbo past about 12psi as it really just starts to become a heat pump.

Do you have a 3" exhaust?

Pumping more boost in without adding more fuel won't really do anything, you need the fuel to make power. That's not to say you could try pushing the boost up a touch and see how it goes.

There are good gains to be had by running 4" all the way from snorkel to turbo even on the factory turbo. The best way really would be to upgrade the turbo and intercooler.

As for the fuel adjustment you can do some tweaking to the compensator, this is where to start before actually adjusting the fuel screw.

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Yes mate sorry,3" straight through.

Quote:

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Originally Posted by pearcey

Sorry mate can`t help, but 600c is a bit high
I would back off a bit and change down as I know what your hills are about especially when they stick a bend halve way up and you need to do a 3 point turn to get around .
I would think a slight adjust would only help but make sure it doesn`t over fuel.
By the way GU Camper is on the island and may try to catch up.

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Good to hear from you old fella,if your talking to him tell him he's more than welcome to pop in.

Quote:

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Originally Posted by nissannewby

It's not really ideal to push the factory turbo past about 12psi as it really just starts to become a heat pump.

Do you have a 3" exhaust?

Pumping more boost in without adding more fuel won't really do anything, you need the fuel to make power. That's not to say you could try pushing the boost up a touch and see how it goes.

There are good gains to be had by running 4" all the way from snorkel to turbo even on the factory turbo. The best way really would be to upgrade the turbo and intercooler.

As for the fuel adjustment you can do some tweaking to the compensator, this is where to start before actually adjusting the fuel screw.

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So what does the compensator do ?

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Originally Posted by tassie wombat

So what does the compensator do ?

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Adjusts how the fuel is delivered in relation to boost.

Ok,so if I gave it a tad more boost,say 1-2 psi the compensator would adjust itself to suit? Would this drop my egt's at all ?

Quote:

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Originally Posted by tassie wombat

Ok,so if I gave it a tad more boost,say 1-2 psi the compensator would adjust itself to suit? Would this drop my egt's at all ?

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Not quite. You could try a touch more boost and see how you go, but this is will only really have an effect at full boost. Your cruising temps won't change.

Right,no worries, it will cruise all day on flatish roads on 300'c but bigger hills are when the temps rise.