Hello everybody. I have 2 questions.

1. Usually divided turbos are used in big turbos in order to help them spool faster. Why doesn't anybody do it with the smaller turbos, wouldn't it be able to spool even faster, say a T3/T04E?


2. Can somebody please explain to me what a divorced wastegate is? TIA

Are you talking bout some like MAYBE(BB T25 with a T3 housing) I'm I on the same page with you? If so check this webpage out! A friend showed it to me.

www.jgstools.com/turbo

Thanks,

mike

Thanks for the site. But no, that's not what i meant. What I mean is with the larger turbos (T-51) the exhaust housing is divided in to holes where the manifold connects to it. In turn the manifold is also divided like this, usually then #1 and 4 runners are connected together and the 2 and 3 runners are connected together. Like this [O] that would be the normal exhaust housing were the manifold connects to. What i mean is that the exhaust housing is like this [oo] with 2 individual ports. Then the manifold is the same way connecting to the turbo. Hope this helps.

The main reason is probably because the majority of these turbo's are small enough that spooling them is not really a problem. Now take a smaller T3 housing and jam a divider in there, you will impede flow, they would have to completely redesing the housing for this, lots of these housings have been around for a while. Although I'm sure Cadle can offer you a much better exp. I would think that it would be a waste, probably cause reversion because the housing would be even smaller with more material inside. It would probably also make the overall size of the housing larger.

A divorced waastegate, IIRC, is one that is not an integral part of the turbo itself. I think it also has to do with not routing the wastegate back into the echaust system.

Originally posted by wes
The main reason is probably because the majority of these turbo's are small enough that spooling them is not really a problem. Now take a smaller T3 housing and jam a divider in there, you will impede flow, they would have to completely redesing the housing for this, lots of these housings have been around for a while. Although I'm sure Cadle can offer you a much better exp. I would think that it would be a waste, probably cause reversion because the housing would be even smaller with more material inside. It would probably also make the overall size of the housing larger.

A divorced waastegate, IIRC, is one that is not an integral part of the turbo itself. I think it also has to do with not routing the wastegate back into the echaust system.

Divided turbine housings, when mated to a divided manifold, improve spoolup, decrease reversion. on smaller turbos, it would still help, but there aren't many made with divided housings. THe turbine divider is more than just a plate in the turbine nozzle, the divider actually runs all the way around the housing against the tip of the blades. for reversion to occur, an an exhaust pulse would have to travel all the way through the manifold, into the turbine housing, into the spinning turbine blades (!), turn 180 degrees, and head back up the other side of the divider. the clearance between the divider and blade tips is very tight.

here's some visuals:

Divided turbine housing : flange side:
http://www.monkey-r.com/divturbo.jpg

Divided manifold for above turbo (ex-paulus lee t-4 manifold):
http://www.monkey-r.com/divmanifold.jpg

external wastegates are not a part of the turbo. Divorced wastegate is an external wastegate that does not dump its exhaust back into the main exhaust tube. It either has its own little exhaust system, or just dumps out a tube.

My current setup is a long-runner manifold (divided), divorced wastegate, with a divided-housing T4/T04E. It is VERY linear. there is almost no boost onset (im only running about 7-8 lbs at the moment). It feels like a rediculously strong bolt-on car with no surge in the power curve. divided housing turbos are supposed to be smoother, but even if the turbo you run isn't divided, you can take advantage of the same principles..

Andris