Which is your experinces?
Is it better than internal?
Which improvement against WG valve layout turbos?
Is it easy to modify exhaust manifold + DP?

 

You may get more luck with this sort of question over on 22b.com

 

Didn't David do this with his ??

 

Is it better than internal?
IMHO Yes..

Which improvement against WG valve layout turbos?

My choice of turbo wasnt available internally gated, Im farily sure it also allows the exhaust housing to be smaller, and supposedly allows better boost control.. you can actually apply pressure to both sides of the wastegate. Ie hold it shut until you want it to be opened.

Is it easy to modify exhaust manifold + DP?

That all depends on your choice of turbo... if its a std subaru bolt pattern then yes its fairly easy.. (they dont 'really' need to be plumbed back into the downpipe.. but mot and noise probs make it a good idea)

However the chances are whatever turbo you are considering would require a new up-pipe and downpipe anyway..

people like aps, lateral performance etc can supply these for a number of off the shelf turbos..

I think you may however be able to get something similar to the T40E with an internal wastegate if you cant be bothered..

However once you start pissing about then you may as well get an external wastegate, I use a 42mm turbonetics racegate.

David

 

Are the (all?) external wastegates loud? (I really like the WRC sound :-)

 

If you have a twin dump downpipe and you fit a splitter, you can have an externally dumping wastegate set up with a std turbo.

I've just done this to mine and it is wicked once it opens !!

You will also gain power due to the reduction in backpressure from the exhaust system.

Andy