200tdi manifold on 300tdi...

[Mercguy]

The turbo on my 300tdi needs a new core, It's running slow - probably choked with carbon on the turbine - but there are a few other things that I'd like to attend to on the engine and 'reliability' wise there's probably a need to replace head at least, maybe do some block work... yes, 'those' unknowns and a strange slap/knock sound that is extremely hard to chase down.

So I am looking at 200tdi manifolds - primarily because they have a t25/28 style flange and a split (twin outlet) manifold. Much more sensible for turbo tweaking or other 'mods'. Easier to mod in other words.

But do they bolt on?

Pretty sure they would - but I'm asking the learned folk for confirmation either way.

And turbo - well

Garrett do a t25 inlet with internal wastegate and a v band outlet - a much nicer turbine housing solution than the 300tdi.

In theory I could stuff ludicrously huge compressor but obviously no point in that.

My best guesstimate based on current performance and driving, is that the turbine housing could do with a minor upsize from the 0.49 to mid 0.5's and the compressor is rather inefficient.

VNT may overcome some of the perceived limitations of small housings, but if they aren't sized correctly at the outset, they too will be poor performing. Not to mention consequences of spool etc.

But looking at the 200tdi manifold, it appears to be ripe for good performance, and possibly a little cleanup with the carbide burrs will make it a heavy breather.

Interested to know if anyone has done this or if they went the other way and machined the 300tdi turbine housing instead, or even went to the HS2.8 manifold.

[loanrangie]

Yes they bolt straight on and provide you with a flange to mount various turbos to.
You want the disco type not defender type as they have the flange facing upwards.

[Mercguy]

Thanks for confirming.

I have the correct manifold here then.

Can only think that the 300tdi setup was done for cost reasons, because they could have easily chosen t25/28/t3 flange and made life easier for everyone - especially mechanics... but then again.

At least this gives me plenty of options. Thanks.