View Full Version : external wastegate on a z20let?
can you get these for this engine?
mattcoupturbo
04-01-2007, 00:00
If you get a turbo that doesn't have a built in one yes, has to be built into the manifold i believe ( could be miles off :lol:)
theblueraven
04-01-2007, 00:18
no you are completely right, an external wastegate is fitted into the manifold, and the z20let has absolutely no need for one with the std turbo.
if your going to get a massive turbo (becuse 90% of the smaller ones have internal wastegates) then yeah, you will need a manifold with and external wastegate fitting. But good luck fitting a huge turbo and external wastegate into an astra, its gonna be a ****in tight squeeze :)
Scottyboy
04-01-2007, 07:15
The picture below shos a ZLET with an external wastegate. Note the waste pipe being plumbed back into the exhaust. Some external wastegates run 'screamer' pipes where the wasted boost vents to atmosphere.
http://i71.photobucket.com/albums/i144/Scottyboy888/25072006702.jpg
This is obviously a massive turbo, and you would have a real problem fitting this into a G engine bay.
The one I've opted for is based on this design:
http://i71.photobucket.com/albums/i144/Scottyboy888/DSC00132.jpg
spanishfly
04-01-2007, 07:39
nice turbo Scotty. What the specs?
Scottyboy
04-01-2007, 07:48
nice turbo Scotty. What the specs?
Haven't quite decided on the actual turbo unit yet, the manifold will fit any GT28/30 flange though. Proabably go for a GT2871R.
theblueraven
04-01-2007, 10:49
Scotty... i respect you and what you are doing....
But that has to be the ugliest manifold i have ever seen :lol:
It had better be a damn good one! :D (and gt2871r gets my vote also)
mattcoupturbo
04-01-2007, 11:06
Thats some crazy bending on that manifold, would be a nightare to fit into a astra bay, but must go if your trying scotty. I think the turbo you mentioned was talked about on www.vauxsport.com (http://www.vauxsport.com) a while back, guy on there called chip was explaining the turbo maps stuff and i think that one was one of them, might be worth having a look.
mattcoupturbo
04-01-2007, 11:11
Not sure if one of these inlets might interest you too scotty
Inlets (http://www.vauxhallsportforum.com/phpBB2/update-on-the-inlet-manifolds-t600.html)
Here's the thread i was talking about, but i think i gotthe turbo wrong doh
Compressor maps (http://www.vauxhallsportforum.com/phpBB2/just-ordered-an-xmas-present-for-my-calibra-gt3071rs-t92,highlight,%2520+compressor+maps.html)
Scott, I'm no expert, but would the external wastegate cause problems where it's situated on that second picture?
It looks to only be connected to one cylinders 'pipe' on the manifold. I know that the pressure will equal out to some degree as the pipes will all join where they enter the turbo, but would this cause problems?
chuntnigton101
04-01-2007, 12:48
alot of the BIG bhp turbo setups like to run external gates as they allow better control of the presure. this is becasue you can get MUCH bigger gaets if you run external than internal.
Chris.