Bailey-86-MA

I have been having some problems with my turbo and could use the wisdom of this board. I have a Porsche 930 GT1 prepared car. We have been using the Innovative Turbo Systems (ITS) GT66 Turbo with oil feed and water cooling. The turbo has failed 3 times after maybe 10 hrs of use. It has generally been the cartridge with the bearings on the turbine housing side failing. I have heard some people recommend the Garrett GT35R. The ITS turbo is a modified Garrett I believe. Any thoughts on the right application for my car, use of a stock Garrett, modified Garrett, KKK etc. is appreciated.

Here are my engine specs:

3.5 liter long stroke (3.6 crankshaft)
CMW Motorsport billet d-port cylinder heads with enlarged valves
Twin plug cylinder heads with iridium spark plugs
Porsche 944 Turbo fuel injectors – have been flow matched
Carrera intake manifold
Andial GT 2 camshafts
Proto tech rising rate fuel pressure regulator
Mahle motorsport pistons and cylinders with Total Seal rings
Autronic engine management tuned by KTR Performance in Massachusetts
Innovative Turbo Systems GT66 Turbo (now broken)
Tri-flow exhaust with Tial wastegate
1 bar boost (it is adjustable with autronic)
Two front oil coolers in series

Car uses 110 or 112 octane leaded fuel and Castrol Syntech 5W50 motor oil

On dyno at .6 bar I believe we achieved 485 rear wheel hp and 440 foot pounds of torque. My mechanic is learning more and more about the Autronic, and we need to check the settings of the Anti-lag feature which can make it run very hot.

Thanks for thoughts/ideas,

Bailey

nathanUK '81 930 G50

I'm guessing that you need to give more details about the ALS.