Mythbuster: continuing project thread of my 1303 '75

[70Turbobug]

...that was a close call!

[Humble]

That could have ended very badly! Hopefully you can get that turned around and get it running again soon.

[Wally]

Yeah, did my best today to get it running next weekend. Used a ticker plate and had the divider wall protrude through the tube so I could weld it all the way through. Its 5 times stronger now 4sure and had now room to port the transitions inside the wastegate tubes a little as well

[volkdent]

Is there any reason to go with an external wastegate vs. an internal(turbo housing)? I'm trying to keep it simple, and I can't for the life of me figure out out if the external is necessary for my project.

Jason

[Wally]

Originally Posted by volkdent

Is there any reason to go with an external wastegate vs. an internal(turbo housing)? I'm trying to keep it simple, and I can't for the life of me figure out out if the external is necessary for my project.

Jason

Well, the really large turbo's usually don't come internal, but there are advantages if you do have a choise. Most of them are for turbo nutcases only probably, but an external gate has its own exhaust and therefore does not hinder the exit of the turbine wheel. Keeping back pressure close to zero on the downpipe (turbo exhaust side) is what this does and that is crucial to a good turbo efficiency. A little more power can be had by this.
There is also the better boost control if you have a relatively large turbo and run low-ish boost. Internal gates can be somewhat small-ish and boost creep can happen then. External gate usually flow more and don;t experience boost creep.
Thirdly you can rotate the turbine housing more freely (in all positions, 'clocking' the turbo) if you don't have the arm of the internal gate to consider, which is usually attached to the compressor housing. That makes it easier to position the turbo any way you like wrt inlet and outlet openings

[Wally]

This sunday I participated in the "Automaxx Streetpower Toyo Tires shoot-out" pfft what a name...
but it was good fun, lovely weather and good practice to get some seat time in this 1/8th mile event.
100 mile drive one way.
All went well besides terrible traction and one side of the linkage that fell off (twice...) in 2 of the 6 runs I could do. I'll deff weld the arm to the shaft now! :twisted:

First run on a cold track, cold tires and too much boost:

http://www.youtube.com/watch?v=jkntN1YTjcI

[petevw]

Nice pic!