06-12-2011, 01:22 PM
Taking material off the hotside of the turbo means there is more of a gap between the edges of the turbine blades and the housing. Usually turbos are produced with this gap being as small as possible, to make it efficient. When the gap is made bigger (as poodle has done by grinding some material away) more hot exhaust gas (which is used to turn the turbine blades/shaft) can escape past the blades and out of the gap. So in a normal setup and application a GT15 may for example (these are guess figures, but kinda accurate) spool up at 1.5k and then run out of puff by 4k, where once it has been ground/reemed out, more gas can escape so spool time will be lengthened and maximum 'flow' at the top end extended. So Poodles turbo may now operate more in the range of 1.8k round to 4.3k.
In reality this is a fairly crude 'bodge' way of getting more top end flow (and thus more lag, also..) and how well it actually works hasnt reallly been proven by anybody. A few people have done this to T2's on XUD's, Ha11, Matthew, Max tait? But nobody has given any proper evidence it works, and like I say it quite crude really, and in theory will just replicate fitting a slightly larger less efficient turbo.
Hope that makes sense mate, if not just say and il try break it down a bit more
In reality this is a fairly crude 'bodge' way of getting more top end flow (and thus more lag, also..) and how well it actually works hasnt reallly been proven by anybody. A few people have done this to T2's on XUD's, Ha11, Matthew, Max tait? But nobody has given any proper evidence it works, and like I say it quite crude really, and in theory will just replicate fitting a slightly larger less efficient turbo.
Hope that makes sense mate, if not just say and il try break it down a bit more