Mythbuster: continuing project thread of my 1303 '75

[Wally]

Ah! No, those temps are both measured with a thermocouple and the ecu doesn't have the ability to register those. Unless you have an expensive adapter box...

Today was a dyno day, but on the way there, I had almost no boost anymore. Engine runs very well, but no boost
I checked and even removed parts of the intake and downpipe (turbo spins fine, no play), but couldn't find a leak or anything, so I returned home. Still no clue as what the cause is.

[volkdent]

I wondered about the machining on the turbine space, the gap around the wheel. Is it possible that one of the faces needs to be machined more to tighten up the seal around the wheel?

I am not a turbo guy per se, but it looked like you just added a larger housing to your existing piece, and I wondered if maybe they needed to be matched somehow?

Lame question, but I think you might understand what I'm thinking. It's not like you to do something wrong, and the engine still runs so it's not like you left a rag in there or something, but low boost could be that the air is not being channeled well around the turbine wheel to create boost? Just a thought.

Jason

[Wally]

I understand your question and its a very valid one. This extra turbine house is however meant for a small series of same-size frames.
Most turbo's can be ordered with a variety of turbine A/R's so they all have the same 'form' so to speak.

After some wrenching today it turned out I had an exhaust leak from the complex part where I made the twin exits into one for the wastegate.
I have welded most of it shut now (saw some black traces) and had full boost again Not the same respons I had on my trip with this housing to germany last week, but close enough. Maybe I missed a spot, will have to look lateron some more into it.
Pfft..

[Wally]

Specially for Sandeep, my compensation for removing one side of the Cupstrebe as it was in the way of the turbo (inlet):

[70Turbobug]

Glad to hear it wasn't a problem with your turbo. It's strange that you had no boost though, sounds like that leak was not that small?

[Wally]

Luck and badluck all in one...

This was the perpertrader that made he resonance and had the turbo spool 250 rpm later then before: A piece of the divertor wall I had welded in there broken off and got loose:


Turbo wheel looks fine and not hit ops: