Right, bit of a saga here, but thought I'd share my experience of re-map then turbo swap.

Have a blob STi PPP which I got re-mapped to approx 330/330 leaving Prodrive exhaust system on. Went very well then started to hear a whistling noise which then morphed into a slight whine. Took car back to get checked out, no obvious leaks..............'sounds like turbo might be on its way out'. Anyway on more investigation it was the turbo. There was some play in shaft and could see scoring on the housing. First point mechanic made was it seemed there had been oil starvation to the turbo, caused by a blocked filter (apparently v fine mesh and easily blocked). Second point was he said Subaru UK were 'bullied' into reducing servicing intervals by motoring press etc. So I will certainly be doing more regular oil changes. Mechanic also advised me to leave this small filter out (it isn't the main one) and that in the US they actually do this on import - maybe can help save someone else's turbo

Anyway on to next bit of story; mechanic suggested a TD05 18g as replacement and as I'd searched and seen good comments, I didn't take much persuading. The good price on offer did nothing to sway me the other way. Got turbo fitted and mapped on the road (I have no RR results so will do in next weekend or so). Drove away for first time (had been at work during mapping) and thought 'OMFG what have I done', seemed to be no responsiveness whatsoever (was v happy with previous setup). Got home and had decided was to call back to get something sorted the next day. Went out for a further spin later that night, v disappointed. Then filled up with petrol, started off again. Came to roundabout by petrol station pressed the loud pedal and thought whoaa WTF is going on here, like rocket fuel and could hear it spooling up (previously didn't have much sound)!!! Now I am not suggesting the fill up had any influence but is this behaviour explainable? Turbo was brand new, I'd maybe done 30 miles. Still seems fine today though definitely spool up is a few hundred rpm behind the VF35 (isn't it amazing that on paper you think 'that's nothing' but it's a different story on the road lol). Anyway I guess I will speak to mapper to see if we can improve the spooling.

Have still retained the Prodrive exhaust, just changed the turbo. Please can someone tell me I'm not going loopy re the turbo behaviour and that there is a perfectly reasonable explanation for this . Also any comments on how close to the original characteristics I can expect to get.

Cheers,
dnc

 

IMHO.....

If it is that new, it may need a little "running-in" before it fully loosens up, I stuck an MD on mine, and initially took it really steady for a few hundred miles, just in case.

dunx

P.S. Spool VS Wallop should be a stickied thread ?

 

if its a bigger turbo than standard just might take a little more for it too get it up to speed ie spool up

 

Check your boost control pipes haven't come off.

 

As fuzz says - do you have a boost gauge?

 

Cheers for replies. Turbo actually seems fine now except slightly later spool, just that the first 30 miles or so seemed to have no low down grunt whatsoever, then suddenly went into blast off mode (ok that's a bit of an exagaration ).

Where are boost pipes BTW . Don't have a boost gauge.

Ta
dnc

 

attached to the turbo (or at least they should be) and then you can follow them to the "T" section which then runs off to the boost solenoid on the drivers wing