Engine/Transmission (1998.5 - 2002) Advantage of an external wastegate?

[GOT-Torque]

Could someone explain the advantage of an external wastegate setup?



For example I see some twin kits with and some without, apparently their must be some advantage or why would you spend the extra money?



Thanks!

 

[Forrest Nearing]

you can run a smaller top turbo that'll spool up quicker without overdriving it

 

[GOT-Torque]

Why is that exactly? A wastegate is a wastegate, if the external one opened at 30 psi verses a wastegate on a turbo opening at 30 psi, wouldn't the result be the same? Or is an external wastegate capable of flowing more air than a wastegate on the turbo?

 

[RonA]

Not all wastegates are the same. Some turbos (Holset) have the gate in a poor location. In my readers rigs(RonA) there are some pictures of a wastegate mod I did to a 14cm housing on my Dodgezilla. It looks hokey, but bypasses quite a bit more exhaust than the stock wg.

Ron

 

[PC12Driver]

Or is an external wastegate capable of flowing more air than a wastegate on the turbo?

That's the ticket. If you check the twin vendors that use external W/Gs you'll find some that offer different sized 'gates to fine tune the set based on how much air you're moving. Too small and you'll overdrive the secondary and (I'm guessing) too large would have a hard time controlling the boost.

 

[DMcPherson]

ecternal gates offer better boost control and more importantly more acurate high boost levels. (over 20psi) they are generally larger and will flow much more to keep the boost levels precise. it also reduces turbulence in the exhaust that you get from internal gates, especially holsets.

 

[Jim Fulmer]

Wait till you are making real power and crack a stock wastegated housing to pieces running too much air through it. Externals will always be better but cost more to built and are more of a pain... . leaks, in the way ect.



Jim