Adjusting turbo boost, 200tdi

TomE said:

So ive shortened the wastegate shaft by 4 turns, its has actually made a noticable difference to acceleration and hill climbing! Not by a lot, but its there!
I might pop down to the local Halfrauds a buy a boost gauge when i can be arsed.

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Good job!
First / next, fit the gauge at the MANIFOLD, and not just a Tee-Piece at the turbo end. This will show you the real boost at the engine.

I suggest you don't adjust again till the gauge is fitted, just in case it over boosts, though I don't think it will.

I predict that making the rod shorter by any more will not increase the boost much more, if at all. The turbo is set up (turbine and impeller sizes etc) to match the engine reasonably well across the range, and I think you will be lucky to get to 1.3 BAR 20 psi. But you will feel the difference from the original maybe 0.8 BAR going up to maybe 1.2 BAR. #

Good luck if you do!

CharlesY

Hi Guys,
Anyone got any photos of where to fit the gauge T peice at the manifold on a 200tdi?
I have the small 2" long pipe running from the turbo to the wastegate actuator, and then a long plastic tube running across the engine to the other side - is this where i should be inserting the gauge T off, near where this longer pipe enters the fuel inlet assy?
Cheers

CharlesY said:

Good job!
First / next, fit the gauge at the MANIFOLD, and not just a Tee-Piece at the turbo end. This will show you the real boost at the engine.

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This is exactly what I've always done with any turbo boost gauges.
At the rear of the TD5 inlet manifold is a bog standard steel core plug. This is the ideal place to fit your take off tapping as it is completely protected and fully reversible just by fitting a new core plug. No drilling of manifold required.

Knock the core plug INTO the manifold. If you try to knock it out it will bite into the soft alloy manifold and bugger it. You need to stop the core plug dropping into one of the manifold inlet tracts so this is a lot easier with the manifold off the engine. However I did mine by sliding a long cardboard tube into the manifold via the inlet opening to catch the core plug and then withdrew the cardboard tube with the core plug safely inside.
Another method is to glue a strong magnet to a wooden dowel and withdraw the core plug that way.

I drilled the core plug to fit the boost gauge brass tapping (which should come with the gauge) and brazed it in place.

Clean up the manifold orifice and then lightly smear the core plug with some Hermetite blue before gently tapping it back into place. Wipe off any excess sealant and connect up the gauge - Job done.

If you want to go even further you could feed the turbo wastgate from here rather than from the compressor housing but I never got round to this. This would make the turbo slightly more efficient as it will be using actual manifold pressure to regulate the boost. Its what they do on race cars as standard.

I'm not sure about the 200/300 tdi manifolds but the principle is the same.

Why don't I have a wastegate on my 1995 300 tdi ?

To get my turbo up to 1 bar I had to cut 20mm off the end of the actuator rod, wind it right the way in and add a spring over it to increase the preload even more.

It is putting 1 bar out now and it made a big difference to performance and stopped it smoking on start up which was a pleasant surprise!

Hi Gents, anyone thinking of increasing the fuelling at full boost would be advised to fit an Exhaust Gas Temperature guage cos in a diesel the richer it runs the hotter the combustion temps - if it gets up to the 720 degress Centigrade mark you will bugger it up big time - the engine temp gauge won't show it either - Just adjusted the fuelling on a 300tdi a little and it added over 100 degrees to the exhaust temp.
Pulls a hell of a lot better though

Jason F said:

Why don't I have a wastegate on my 1995 300 tdi ?

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do you have a picture?

Heres one I made earlier.

Boost to 1.1 bar, US overboost valve, T off the manifold, huge intercooler etc etc.

Works well.



Ps runs pure veg oil.

Looks a good setup mate - can i ask how the over boost valve works?

Cheers
Daz