something ive been thinking about. if you were to remove the internal gate and run an external what issues would you run into? would flow in the exhaust housing be extremely disrupted? would there even be a disruption if the flapper was removed?

 

You'd need to weld the flap shut or permanently block the wastegate port some other way.

There should be no issues at all. Flow through the back of the turbo will actually be improved because there's no wastegate flow to cause turbulence at the turbine outlet.

 

thanks for the info.

 

Added complexity...added cost...
If you're going to go through all that trouble, you might as well go full turbo upgrade...


-Ted

 

An external wastegate is complex?

 

to build it into a project with a stock turbo then yes...

do you have a tubular manifold that you can adapt the new wastegate to? Are you using a stock, cast iron, manifold? that's where you're going to encounter problems. why fabricate a custom exhaust manifold for a stock turbo just to eliminate the wastegate?

you'd be better off doing all of that for an upgraded turbo and fuel system.

Ray

 

Pfft, its not *that* difficult.

Mine kicked *** and cost less then a quality T4 flanged tubular manifold (if your purchased one already built that is)

Plus, you can now run a hybrid turbo (see, cheap and most popular turbo upgrade used on these cars) without having to port the internal gate within an inch of its life and even after that, still having to deal with adding springs to the actuator to prevent pre-mature opening.

Its easy, its cheap. I'd do it over porting the wastegate if I had the choice (IMO that is)

EDIT: I dunno why the pics are being gay - I've posted these same ones before. They're only 113kb's

 

yea i picked up a tubular manifold for $60 with a s4 footprint already on it. i figure weld on a external,do a compressor upgrade and ill be good for what i want to do with out a full turbo upgrade.

 

My S4 TO4B hybrid W/ External gate

 

I can't believe you would go through this much trouble only to be choked by a stock hotside. you could get a used, real garrett T04B/E/S for $500 or less and an HKS manifold for probably 200 or 300. I paid $900 for a brand new manifold (HKS log) and turbo (real garrett T04S), plus an hks knockoff wastegate.

 

couldn't you technically, just take an S4 manifold, remove the twin scroll, drill a hole in it and have another pipe welded on?

I imagine, the cost of that, the wastegate(off brand) and the pipe from the waste gate couldnt be much more than, $200?

 

How is that more complex? Complex means "consisting of many different and connected parts" or "not easy to analyze or understand; complicated or intricate". This is none of those things.

Actually it can be done and has been posted about numerous times. Welding to the cast iron is tricky, but can be done by a welder who who's what they're doing. But since he's not using a stocker...

You're talking about a massive difference in cost. The man obviously just wants good boost control.

Why do it? Probably for the same reasons as all the other people running hybrid turbos...

Chuck in the cost of all new oil and water lines, plus a new custom DP, and it's laughable to compare the two approaches.

 

Found these pics on rx7club once before. I want to do a similar thing as I want to run external gate for better boost control on the track.

http://www.pbase.com/meanrex/externa...ybrid_s4_turbo