TECHNICAL PAGE
I get lots of questions about rebuilding and upgrading Mitsubishi turbos so I have added this technical page. I hope this may help people understand what's involved. I will be expanding on this information when I get time!

 There are two basic type of Mitsubishi TD05/06 turbochargers a TC and a TD.

 

  This picture shows the difference between a TC and TD type turbo. The TD is the later style design and features two bearings. In this design the bearings take no end thrust. With the TC design the main single piece main bearing is also the thrust bearing as well.

The TD design offers lower friction and is just basically a better arrangement.

 

 TC centre bearing housing shown

 TD centre bearing housing shown. Note clips which retain the bearings.

BALANCING
Because turbo chargers spin at very high RPM (100,000+ !) they must be accurately balanced. Of course this is done in the factory however if you are upgrading or just rebuilding a turbo it is essential to maintain the correct balance
When upgrading the turbo by fitting a bigger compressor wheel you must re-balance the rotating assembly on a special turbo balancing machine. Unfortunately these machines cost many thousands of dollars and are not for the home workshop!
 

  To balance a turbo you must assemble the rotating parts

 

This assembly is then placed on a special turbo balancer and is spun up. Material is removed as required.

This operation may be repeated a number of times before the turbo is balanced correctly. Once balanced the assembly is fitted into the centre bearing housing with whatever seals and o'rings are required and the turbine and compressor housings are fitted. The balancer shown is an older Heins (USA) machine we use a Schenck (Germany) balancer.

 
 Another sort of machine is a VSR balancer. This machine spins up the assembled centre bearing housing (the turbo without turbine or compressor housings fitted) and can rotate it at high speed. We use a MRB1000 VSR.

Turbocharger Testing
Testing turbochargers is an interesting subject. Also there are many challenging aspects to turbocharger design including thermodynamics and material science. From an engineering point of view getting things to live at 850°C+ is not easy! Obviously turbocharger testing is done on actual engines but there is also a thing called a turbocharger dyno. Ever wondered how they got those compressor maps you see published? A turbocharger dyno is a very specialized piece of equipment it allows the turbocharger to be operated throughout the complete turbine RPM range and compressor airflow of the turbocharger. The turbo is operated exactly as it would be on the engine with the same temperatures, pressures and airflows. Turbochargers can also be endurance cycle tested for many hours on such equipment. Turbine RPM, in and out temperatures/pressures and air flows are monitored by computer.

 

 Here is our GTPS01 turbo undergoing "torture" testing note glowing red turbine housing!

The turbochargers we supply are engineered to make the numbers!

 

Turbo dyno control room

 There are many different types of compressor wheels the picture below shows just a few

 

 There are many different types of turbine wheels the picture below shows just a few