Thread: TDI VNT Turbo Upgrade +++

Dump pipe cut, bend welded on. Should be enough to get me to the exhaust shop for a full fit.

The bonnet stay slots nicely into the old scissor retainer on the bonnet, so I didnt fit the P slot I purchased. Maybe some other day.

No idea where I put the heater vent cover for the left wing, or where the left over bag of bolts and screws are meant to go.

Still, could take it for a wee spin tomorrow

First test run around the block was rubbish, no boost. One of the clamps had not been tightened 🤦. After that it was OK but I could only run it up to 60kph

Not sure what I should expect for PSI @ RPMs with this turbo.

Not much boost action until 2000rpm then it quickly rises to 16psi. Hard to notice anything other than exhaust roar and turbo spool with the open dump pipe. Disengage the clutch plate under load and that turbo sings!

Once the exhaust is done I'll have a tweak, its not pleasant checking under the bonnet when the engine is pumping out smoke. Hope to get peak boost up to 20psi and find a little more at 1800rpm

I dont know what that turbo is capable of, but with any VNT you should be able to get plenty at 1800 rpm

Exhaust done.

2.25" on first bend from turbo opening up to 2.5" for second bend, then straight through to the factory TD5 rear section with resonator, also 2.5". Will be sending the dump pipe for ceramic coat.

Getting pretty much the same response as the open 2" dump pipe. Sound levels are close to the old exhaust set up with center muffler. Hint of drone at idle.

Happy with it, only concern is there is not much flex the way it is mounted, compared to how it was before, so it might need a flexi cut in to relieve some stress. Or more flexible rubber mounts.

Took it between exits on the M3. Put the foot all the way down and saw boost between 9 - 12psi at 1800rpm. Can rise to 19psi anywhere above 2000rpm, although more likely to see a steady 17psi. I can feel a much stronger change in acceleration booting it in 5th now! Need to take it out the city for a proper test, but feels promising.

Less smoke at idle with this new turbo, so the old one must have been adding some oil or the restrictive intake was pulling some out the crankcase breather. That old smoke issue moved me to turn down the fuel pre boost by winding back the smoke screw. So if I go back and re-adjust the IP at the boost pin I might find some more boost off the line.


















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Good to hear.

Either way, DIY or pro tune, it sounds like there is more to be found - hows EGT?

Flexi cant hurt. Might cut down on the noise coming back into the cab too.

Egt peaked at 510c when foot was down accelerating in 5th, but that was a cool night on the flat. I've run this motor from Melbourne up to Seymour many times, so a benchmark has been set. Eager to see how it compares. Old set up could only maintain 110 in 4th on that long hill after broadford (just after the weighbridge) , EGT around 600. If I get similar EGTs or lower on this new set up I will consider turning up the max fuel slightly.

Would love to hear the results.
A friends 200Tdi is getting tired (suspect the stock turbo has had it) and we were a bit put off by the price of VNT kits.

Originally Posted by SSmith

Would love to hear the results.
A friends 200Tdi is getting tired (suspect the stock turbo has had it) and we were a bit put off by the price of VNT kits.

Maybe get it compression tested before trying to juice it up. If compression is OK, check EGT and boost to see where its at. They go alright on a stock turbo if you tweak the pump a little.