Internal And External Wastegates?

[novadose2009]

hi i have got a astra coupe turbo with a z20let engine fitted. im now going to run an evo6 td05 turbo and manifold on this which has a internal wastegate. As it has a internal wastegate does that mean i cannot fit an external wastegate to get the chatter sound, or have to run with a dump valve instead.

thanks simon

[cossienova]

You can't run an external wastegate if the turbo has a wastegate internally. You can run an external wastegate by welding up the wastegate washer inside the turbo and a bigger exhaust housing. You won't get chatter from an external wastegate or from a dump valve but if you remove the standard fitment dump valve u will get 'chatter'. I run an external wastegate on my Cossie and it's sounds mental but gets you in trouble with the boys in blue!

[Mieran]

Chatter sound has nothing to do with the wastegate.

I made my z20let chatter on standard turbo, just blocked the standard recirculating valve

[novadose2009]

my coupe does it now but what im asking is can i run an external wastegate on it if it already has an internal wastegate built in the turbo.

Heres what im on about.

http://www.youtube.com/watch?v=E2caXXluY1g

That is the wastegate noise.

[novadose2009]

You can't run an external wastegate if the turbo has a wastegate internally. You can run an external wastegate by welding up the wastegate washer inside the turbo and a bigger exhaust housing. You won't get chatter from an external wastegate or from a dump valve but if you remove the standard fitment dump valve u will get 'chatter'. I run an external wastegate on my Cossie and it's sounds mental but gets you in trouble with the boys in blue!

Im not worried about the police i have an agreement :)

So would there be any performace gains by running an external wastegate instead of the internal wastegate. As it seems that its going to be more hassle then its worth if it is not.

thanks mate

[Edd]

Your going to need a custom manifold to run that turbo on a Z LET for a start

Unless its a low mile engine you'll start to have problems once you up the boost going by mine and others experiences

[novadose2009]

Your going to need a custom manifold to run that turbo on a Z LET for a start

Unless its a low mile engine you'll start to have problems once you up the boost going by mine and others experiences

Ive already made a manifold out of a evo tubular manifold and weilded an zlet exhaust flange onto it biggest problem is the 4th tube which didnt line up and had to widen the pipe to fit the engine.

And this turbo wont be running high p.s.i it will be sitting about 300bhp from a courtney sport stage4 high torque remap so only 12 p.s.i i guess.

[Stuart]

well since the wastegate is to bypass the turbo and stop boost from being produced. I would imagine it matters not what type/size as to what level of performance you get lol

[Mieran]

external wastage apparently holds boost better hence why everytime you see a powerful engine 9 of 10 times its running an external wastegate

[Jack]

Theoretically there's no difference between internal and external, they both do the same job.

As for the chatter noise, just remove the DV and blank it off. lol