Holy crap, I didn't know it was going to turn out this way . It took a while to complete, but this little five-cylinder is packing some punch with the new Holset. In short, I ditched the stock Garrett GT25C for a Holset HE221W, together with some other goodies.
Some before photos:
Right, so where to start. Initially I thought I was very clever by designing a very compact flange adapter for the Holset to mount to my exhaust manifold. My eyeball measurements indicated that the Holset wasn't much wider than the stock Garrett, so I thought there would be enough clearance for the Holset to mount where the Garrett was. The Holset fitted, but it was jammed against the steering box and there was no free space for the waste gate actuator to move.
I had to resort to a similar solution to Charlie using 50 mm diameter short-radius buttweld fittings. Furthermore, I designed my own turbine cover by scanning the turbine housing to my PC and tracing it to scale in AutoCAD. I then had it laser cut and machined. After test fitting the turbo to the flange adapter, I trial fitted a downpipe to tie in with my existing exhaust's downpipe flange. I didn't have to cut any part of my stock exhaust system. I also used 50 mm diameter buttweld fittings for the downpipe. I realised only after having the turbine cover and downpipe fabricated that the downpipe may be too narrow. However, so far it doesn't appear to be too restrictive.
This is the scanned image of the turbine housing I used for the turbine cover . I'm not kidding when I say that my laser cut housing has less than a millimeter of deviation to the turbine housing.
I ported the manifold's standard 40 mm-odd opening to 50 mm using my (slightly overused) Dremel tool. I also had the EGR opening welded shut.
Exhaust manifold and flange adapter fitted:
Oil return drain pipe fitted:
Oil feed line fitted with P-clamps to hold it in place:
Some before photos:
Right, so where to start. Initially I thought I was very clever by designing a very compact flange adapter for the Holset to mount to my exhaust manifold. My eyeball measurements indicated that the Holset wasn't much wider than the stock Garrett, so I thought there would be enough clearance for the Holset to mount where the Garrett was. The Holset fitted, but it was jammed against the steering box and there was no free space for the waste gate actuator to move.
I had to resort to a similar solution to Charlie using 50 mm diameter short-radius buttweld fittings. Furthermore, I designed my own turbine cover by scanning the turbine housing to my PC and tracing it to scale in AutoCAD. I then had it laser cut and machined. After test fitting the turbo to the flange adapter, I trial fitted a downpipe to tie in with my existing exhaust's downpipe flange. I didn't have to cut any part of my stock exhaust system. I also used 50 mm diameter buttweld fittings for the downpipe. I realised only after having the turbine cover and downpipe fabricated that the downpipe may be too narrow. However, so far it doesn't appear to be too restrictive.
This is the scanned image of the turbine housing I used for the turbine cover . I'm not kidding when I say that my laser cut housing has less than a millimeter of deviation to the turbine housing.
I ported the manifold's standard 40 mm-odd opening to 50 mm using my (slightly overused) Dremel tool. I also had the EGR opening welded shut.
Exhaust manifold and flange adapter fitted:
Oil return drain pipe fitted:
Oil feed line fitted with P-clamps to hold it in place: