TD04-13G  vs TD05-16G

Firstly we have the TD04-13G Original equipment for the 91 - 94 Lancer GSR

Simply said its far to small for serious performance.  The boost threshold is around 1800rpm, full boost is obtained by roughly 2800rpm.  A common modification is to 'high-flow' a turbo, this usually involves the turbo being rebuilt with a larger Compressor blade which can require 'machining' the compressor housing to fit the large wheel.  On the 'hot' side (exhaust)  a common practice is to have the turbine wheel 'clipped'.  A small portion is 'clipped' off each impellor blade to improve flow,  typically the boost threshold will move further up the rev-range as their is less 'blade' for the exhaust gas to turn.

Unfortunately the TD04 is not a good candidate to high flow as the housings are far to small to fit a larger compressor of useful size.

Here we have the TD05-16G fitted as OE to the Galant VR4 EVO/RS and of course the Lancer Evolution series (different trims for  various models)

What can i say ?? This is a great turbo.  Its comparable to a Garret Air Research T03.  The TD05-16G will flow 300hp all day everyday.  Any higher and you will need to look at a high flow, hybrid or even complete replacement.

The Mitsi Talon and Eclipse are American delivered cars powered by the 4G63 also feature a TD05 this time the compressor is a 14G (same as Galant VR4) .  Their is a HUGE market for turbo upgrades in the US import scene

one major player is RoardRace Engineering 

For some great turbo info check out the American DSM website.

My plan is to get hold of a TD05-14g from a JDM Galant VR4, rebuild the turbo with a 16G (or larger) compressor and a 7 degree 'clip' which will give me the top end i need oh so badly !  Whilst still performing well at lower RPM