Boosting, then not boosting, what stops spooling?

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327ire
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Post Tue Nov 25, 2008 1:21 pm

Iv been stuck in a turbo project for some time now. Its the dreaded "rear mount turbo" project. Engine problems have stunted the whole thing.

So iv got everything setup and Iv had the charge air blow my head off (from 2000rpm up) to check it before strapping it on. It seems inconsistent. One day im getting huge supplies of extra air from the charge pipe, them some days none till 6000rpm. We opened the housing to find the wastegate was open, closed it and got some boost, then none the next day.

Does the quality of air passing through the turbo matter? Iv been messing around with megasquirt during all of this so Im thinking maybe the quality of air has been varied while testing the turbo.
Turbo-Brown
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Post Tue Nov 25, 2008 1:36 pm

Take it the shaft spins freely does it?

And the filter doesn't get dragged through puddles etc.

If the wastegate is getting stuck open that would certainly cause a loss of boost though :)
325i Twin Turbo (until 10am 01/12/07 :( )

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327ire
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Post Tue Nov 25, 2008 1:45 pm

Thanks!
The shaft is fine, not much play. The car hasnt gone on the road yet but the air filter is inside the boot, right next to the bumper vent behind the wheel.

My mate is convinced its just not gonna work being rear mounted but the thing that keeps me going is that it has behaved as a turbo should, spooling a little at idle, full boost reached somewhere between 2000 - 4000rpm. Enough to blow my short hair around at least. Iv never actually red boost while strapped on.

thanks for your help!!!!
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327ire
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Post Tue Nov 25, 2008 1:46 pm

The oil feed has been inconsistent. The rear independent set up im using has failed a bit so we have been testing without the oil getting passed through the turbo sometimes
Turbo-Brown
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Post Tue Nov 25, 2008 1:50 pm

Aah, it probably won't have done the bearings in the turbo any favours if it's been run without oil for any length of time :(
325i Twin Turbo (until 10am 01/12/07 :( )

www.air-in.co.uk free M20 exhaust and inlet flange