CT20B Wast Gate Mod Options

[yellowchinaman]

I've heard stories of people drilling out or modding the wast gate on the CT20b turbo.
As we all know it's a bit of a crap design and very restrictive.
Has anyone done this? If so, how?

[delusionz]

it doesnt give you much room to play with since its dual wastegate.

if i were to do it, i would look for something which can grind away at cast iron, do the inner sides of the wastegate (the sides closest to eachother), probably shove a vacuum cleaner with a small attachment in there while grinding

the main problem is that its a very long path and it isnt straight, its gonna be a bitch to get a grinder all the way through, i mean i can stick my finger thru those wastegate holes and not even see a finger tip through the turbine entry.


Just had another look, the port closest to the turbine exit would be easy to get a couple mms out of.

then to enlarge the exit area without getting to close to the edge of the flapper door, i would suggest grinding towards the other hole (since its an oblong shaped door, not 2 circles)

Yeah now that I'm looking at it, I think you could totally turn those 2 holes into 1 big oblong shaped wastegate, while your at it, have a look down the turbine entry, theres a whole lot of crap in there which could be ported out.

The thing is, at this stage I think the whole thing would need to be pulled apart and I believe the whole rotating assembly needs to be balanced in which case someone who builds performance CT upgrade turbos locally to you like Fensport would be best to just trade you up to one of their own upgrade packages. Just be sure to mention your issue with wastegate and inquire what they've done about it.

This post has been edited by delusionz: Apr 25, 2011 - 12:44 AM

[delusionz]

I happen to have a CT26 in my bedroom, theres oil leaking out the turbine, totally explains the smoke screen when i started my car up